from pptx import Presentation
from pptx.util import Inches, Pt, Emu
from pptx.dml.color import RGBColor
from pptx.enum.text import PP_ALIGN, MSO_ANCHOR
from pptx.oxml.ns import qn
from pptx.oxml import parse_xml
from lxml import etree
import copy

prs = Presentation()
prs.slide_width = Inches(13.333)
prs.slide_height = Inches(7.5)

# ── COLOR PALETTE ──────────────────────────────────────────────
BG_LIGHT      = RGBColor(0xF0, 0xF7, 0xFF)   # very light blue background
HEADING_BG    = RGBColor(0xB8, 0xD8, 0xF8)   # light blue heading bar
HEADING_TEXT  = RGBColor(0x1A, 0x3A, 0x5C)   # dark navy text for headings
BODY_TEXT     = RGBColor(0x1A, 0x1A, 0x2E)   # near-black body
ACCENT        = RGBColor(0xD6, 0xEC, 0xFF)   # lighter accent for bullet rows
TITLE_BG      = RGBColor(0x4A, 0x90, 0xD9)   # medium blue for title slide
WHITE         = RGBColor(0xFF, 0xFF, 0xFF)
MEMBER_BG     = RGBColor(0xE8, 0xF4, 0xFF)   # soft blue for member box
FOOTER_COLOR  = RGBColor(0x5A, 0x8A, 0xBB)

FONT_HEADING  = "Times New Roman"
FONT_BODY     = "Times New Roman"
SIZE_HEADING  = Pt(28)
SIZE_BODY     = Pt(20)
SIZE_SMALL    = Pt(16)


def set_bg(slide, color):
    """Fill slide background with solid color."""
    background = slide.background
    fill = background.fill
    fill.solid()
    fill.fore_color.rgb = color


def add_rect(slide, x, y, w, h, fill_color, line_color=None):
    shape = slide.shapes.add_shape(
        1,  # MSO_SHAPE_TYPE.RECTANGLE
        Inches(x), Inches(y), Inches(w), Inches(h)
    )
    shape.fill.solid()
    shape.fill.fore_color.rgb = fill_color
    if line_color:
        shape.line.color.rgb = line_color
        shape.line.width = Pt(0.75)
    else:
        shape.line.fill.background()
    return shape


def add_textbox(slide, x, y, w, h, text, font_name, font_size, bold=False,
                color=BODY_TEXT, align=PP_ALIGN.LEFT, italic=False, wrap=True):
    tb = slide.shapes.add_textbox(Inches(x), Inches(y), Inches(w), Inches(h))
    tf = tb.text_frame
    tf.word_wrap = wrap
    tf.margin_left = Pt(4)
    tf.margin_right = Pt(4)
    tf.margin_top = Pt(2)
    tf.margin_bottom = Pt(2)
    p = tf.paragraphs[0]
    p.alignment = align
    run = p.add_run()
    run.text = text
    run.font.name = font_name
    run.font.size = font_size
    run.font.bold = bold
    run.font.italic = italic
    run.font.color.rgb = color
    return tb, tf


def add_heading_bar(slide, title, y=0.18):
    """Add a colored heading bar with title text."""
    add_rect(slide, 0.3, y, 12.73, 0.65, HEADING_BG)
    add_textbox(slide, 0.38, y + 0.04, 12.5, 0.58, title,
                FONT_HEADING, SIZE_HEADING, bold=True, color=HEADING_TEXT,
                align=PP_ALIGN.LEFT)


def add_bullet_block(slide, items, x, y, w, h):
    """Add a text block with bullet points."""
    tb = slide.shapes.add_textbox(Inches(x), Inches(y), Inches(w), Inches(h))
    tf = tb.text_frame
    tf.word_wrap = True
    tf.margin_left = Pt(6)
    tf.margin_right = Pt(4)
    tf.margin_top = Pt(3)
    tf.margin_bottom = Pt(3)
    first = True
    for item in items:
        if first:
            p = tf.paragraphs[0]
            first = False
        else:
            p = tf.add_paragraph()
        p.space_before = Pt(4)
        p.space_after  = Pt(3)
        run = p.add_run()
        run.text = item
        run.font.name = FONT_BODY
        run.font.size = SIZE_BODY
        run.font.color.rgb = BODY_TEXT
    return tb, tf


def add_footer(slide, member_name, slide_num):
    add_rect(slide, 0, 7.1, 13.333, 0.4, FOOTER_COLOR)
    footer_text = f"  Presenter: {member_name}   |   Pharmaceutical Surface Phenomena & Stability   |   Slide {slide_num}"
    add_textbox(slide, 0.2, 7.12, 12.9, 0.35, footer_text,
                FONT_BODY, Pt(13), bold=False, color=WHITE, align=PP_ALIGN.LEFT)


# ══════════════════════════════════════════════════════════════════
# SLIDE 1 — TITLE SLIDE
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)

# Top decorative bar
add_rect(slide, 0, 0, 13.333, 0.25, TITLE_BG)
add_rect(slide, 0, 0.25, 13.333, 0.08, HEADING_BG)

# Main title box
add_rect(slide, 0.5, 0.6, 12.33, 1.6, TITLE_BG)
add_textbox(slide, 0.6, 0.65, 12.1, 1.5,
            "Surface Phenomena and Stability of\nCalamine Lotion (Topical Suspension)",
            FONT_HEADING, Pt(30), bold=True, color=WHITE, align=PP_ALIGN.CENTER)

# Subtitle
add_textbox(slide, 1.0, 2.35, 11.33, 0.6,
            "A Pharmaceutical Analysis of a Marketed Dosage Form",
            FONT_BODY, Pt(22), bold=False, color=HEADING_TEXT, align=PP_ALIGN.CENTER)

# Subject line
add_rect(slide, 2.0, 3.05, 9.33, 0.5, ACCENT)
add_textbox(slide, 2.1, 3.08, 9.1, 0.45,
            "Subject: Physical Pharmacy  |  Topic: Surface Phenomena & Dosage Form Stability",
            FONT_BODY, Pt(17), bold=False, color=HEADING_TEXT, align=PP_ALIGN.CENTER)

# Members box
add_rect(slide, 0.5, 3.75, 12.33, 2.95, MEMBER_BG, HEADING_BG)
add_textbox(slide, 0.7, 3.82, 12.0, 0.45,
            "Group Members",
            FONT_HEADING, Pt(22), bold=True, color=HEADING_TEXT, align=PP_ALIGN.CENTER)

members = [
    ("Member 1:", "Muhammad Sulaiman"),
    ("Member 2:", "Hafza Rashid"),
    ("Member 3:", "Ume Ummarah Antique"),
    ("Member 4:", "Muhammad Afridi"),
]
col_x = [0.8, 3.9, 7.0, 10.1]
for i, (label, name) in enumerate(members):
    add_rect(slide, col_x[i], 4.35, 2.9, 1.9, WHITE, HEADING_BG)
    add_textbox(slide, col_x[i]+0.1, 4.42, 2.7, 0.45,
                label, FONT_BODY, Pt(16), bold=True, color=FOOTER_COLOR, align=PP_ALIGN.CENTER)
    add_textbox(slide, col_x[i]+0.1, 4.88, 2.7, 0.85,
                name, FONT_HEADING, Pt(18), bold=True, color=HEADING_TEXT, align=PP_ALIGN.CENTER)

# Bottom bar
add_rect(slide, 0, 7.1, 13.333, 0.4, TITLE_BG)
add_textbox(slide, 0.2, 7.12, 12.9, 0.35,
            "Pharmaceutical Surface Phenomena & Stability  |  July 2026",
            FONT_BODY, Pt(13), bold=False, color=WHITE, align=PP_ALIGN.CENTER)


# ══════════════════════════════════════════════════════════════════
# SLIDE 2 — TABLE OF CONTENTS / OUTLINE
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Presentation Outline")

add_rect(slide, 0.3, 0.95, 12.73, 0.05, HEADING_BG)

outline_data = [
    ("Muhammad Sulaiman",   "Slides 3–5",  "Introduction to Calamine Lotion — what it is, ingredients, uses, marketed form"),
    ("Hafza Rashid",        "Slides 6–8",  "Surface & Interfacial Tension + Adsorption phenomena in Calamine Lotion"),
    ("Ume Ummarah Antique", "Slides 9–11", "Wetting, Micellization & other surface phenomena in the formulation"),
    ("Muhammad Afridi",     "Slides 12–14","Stability (Physical, Chemical, Microbial) and how it is improved"),
]

row_colors = [ACCENT, WHITE, ACCENT, WHITE]
row_y = [1.1, 2.45, 3.8, 5.15]
for i, (member, slides_range, topic) in enumerate(outline_data):
    add_rect(slide, 0.3, row_y[i], 12.73, 1.2, row_colors[i], HEADING_BG)
    add_textbox(slide, 0.45, row_y[i]+0.05, 3.2, 0.45,
                member, FONT_HEADING, Pt(20), bold=True, color=HEADING_TEXT)
    add_textbox(slide, 0.45, row_y[i]+0.5, 3.2, 0.55,
                slides_range, FONT_BODY, Pt(17), bold=False, color=FOOTER_COLOR)
    add_rect(slide, 3.7, row_y[i]+0.12, 0.04, 0.95, HEADING_BG)
    add_textbox(slide, 3.9, row_y[i]+0.12, 9.0, 1.0,
                topic, FONT_BODY, SIZE_BODY, bold=False, color=BODY_TEXT)

add_footer(slide, "All Members", 2)


# ══════════════════════════════════════════════════════════════════
# SLIDE 3 — INTRODUCTION: WHAT IS CALAMINE LOTION?  (Member 1)
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Introduction to Calamine Lotion")

bullets = [
    "• Calamine Lotion is a widely used marketed topical dosage form classified as a suspension.",
    "• It is officially listed in the British Pharmacopoeia (BP) and US Pharmacopeia (USP).",
    "• The dosage form consists of finely divided solid particles (calamine and zinc oxide) dispersed in a liquid vehicle.",
    "• It is applied to the skin to relieve itching, minor skin irritations, insect bites, sunburn, and rashes (e.g., chickenpox, poison ivy).",
    "• Being a suspension, it demonstrates multiple surface phenomena that control its physical behaviour, drug release, and patient acceptability.",
    "• The product must be shaken well before use — a classic property of a suspension dosage form.",
]

add_rect(slide, 0.3, 1.0, 12.73, 5.9, WHITE, HEADING_BG)
add_bullet_block(slide, bullets, 0.45, 1.05, 12.4, 5.8)
add_footer(slide, "Muhammad Sulaiman", 3)


# ══════════════════════════════════════════════════════════════════
# SLIDE 4 — COMPOSITION & MARKETED PRODUCT  (Member 1)
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Composition and Marketed Product")

# Two-column layout
add_rect(slide, 0.3, 1.0, 6.1, 5.9, WHITE, HEADING_BG)
add_rect(slide, 6.6, 1.0, 6.43, 5.9, ACCENT, HEADING_BG)

add_textbox(slide, 0.45, 1.05, 5.8, 0.5,
            "BP Composition of Calamine Lotion", FONT_HEADING, Pt(21), bold=True, color=HEADING_TEXT)
comp = [
    "• Calamine (ZnCO₃ + Fe₂O₃)     — 15 g",
    "• Zinc Oxide (ZnO)              — 5 g",
    "• Bentonite (suspending agent)  — 3 g",
    "• Sodium Citrate                — 0.5 g",
    "• Liquefied Phenol              — 0.5 mL",
    "• Glycerin                      — 5 mL",
    "• Purified Water (vehicle)      — to 100 mL",
]
add_bullet_block(slide, comp, 0.45, 1.6, 5.8, 5.2)

add_textbox(slide, 6.75, 1.05, 6.1, 0.5,
            "Key Marketed Products", FONT_HEADING, Pt(21), bold=True, color=HEADING_TEXT)
mkt = [
    "• Lacto Calamine Lotion (Piramal Healthcare, India)",
    "• Caladryl Lotion (Parke-Davis / Pfizer)",
    "• ZnO Calamine Lotion BP (local pharmacopoeial brands)",
    "",
    "Dosage Form Classification:",
    "• Type: Aqueous suspension (external use)",
    "• Route: Topical (skin application)",
    "• Appearance: Pink, opaque, chalky liquid",
    "• pH: 6.5–8.0 (slightly alkaline)",
    "• Particle Size: 45–75 µm (sieved before use)",
]
add_bullet_block(slide, mkt, 6.75, 1.6, 6.1, 5.2)

add_footer(slide, "Muhammad Sulaiman", 4)


# ══════════════════════════════════════════════════════════════════
# SLIDE 5 — WHY A SUSPENSION? PHARMACEUTICAL SIGNIFICANCE  (Member 1)
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Why a Suspension? — Pharmaceutical Significance")

bullets = [
    "• Calamine and zinc oxide are practically insoluble in water — suspension is the only suitable liquid dosage form.",
    "• A suspension keeps the insoluble drug uniformly distributed in the vehicle, allowing accurate dosing when shaken.",
    "• The high surface area of finely divided particles improves contact with skin and enhances drug release.",
    "• Suspensions offer better patient compliance compared to solid dosage forms (ointments are greasier; suspensions feel cooler on the skin).",
    "• Surface phenomena such as interfacial tension, wetting, and adsorption directly control the physical behaviour and shelf life of this suspension.",
    "• Understanding these phenomena is essential for formulation scientists to produce a stable, effective, and elegant product.",
]

add_rect(slide, 0.3, 1.0, 12.73, 5.9, WHITE, HEADING_BG)
add_bullet_block(slide, bullets, 0.45, 1.05, 12.4, 5.8)
add_footer(slide, "Muhammad Sulaiman", 5)


# ══════════════════════════════════════════════════════════════════
# SLIDE 6 — SURFACE & INTERFACIAL TENSION  (Member 2)
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Surface & Interfacial Tension in Calamine Lotion")

bullets = [
    "• Surface tension is the force acting at the surface of a liquid that tends to minimize the surface area (cohesive forces between liquid molecules).",
    "• Interfacial tension is the force acting between two immiscible phases — in Calamine Lotion, this is the solid-liquid interface between calamine/ZnO particles and the aqueous vehicle.",
    "• High interfacial tension means particles resist being wetted by water — this would cause clumping (aggregation) of particles and poor dispersion.",
    "• Surfactants and suspending agents (bentonite, sodium citrate) are added to REDUCE interfacial tension, allowing water to surround each particle completely.",
    "• Glycerin in the formulation also lowers surface tension of the vehicle, improving flowability and spread on the skin.",
    "• Reduced interfacial tension = better particle wetting = more uniform suspension = consistent dose per application.",
    "• Measurement: Du Noüy ring method and Wilhelmy plate method are used to measure surface tension during formulation development.",
]

add_rect(slide, 0.3, 1.0, 12.73, 5.9, WHITE, HEADING_BG)
add_bullet_block(slide, bullets, 0.45, 1.05, 12.4, 5.8)
add_footer(slide, "Hafza Rashid", 6)


# ══════════════════════════════════════════════════════════════════
# SLIDE 7 — ADSORPTION  (Member 2)
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Adsorption at Particle Surfaces in Calamine Lotion")

add_rect(slide, 0.3, 1.0, 6.1, 5.9, WHITE, HEADING_BG)
add_rect(slide, 6.6, 1.0, 6.43, 5.9, ACCENT, HEADING_BG)

add_textbox(slide, 0.45, 1.05, 5.8, 0.5,
            "What is Adsorption?", FONT_HEADING, Pt(21), bold=True, color=HEADING_TEXT)
ads1 = [
    "• Adsorption is the accumulation of molecules (adsorbate) onto a surface (adsorbent).",
    "• In Calamine Lotion, two types occur:",
    "  – Physical adsorption (physisorption): van der Waals forces hold surfactant molecules onto particle surfaces.",
    "  – Chemical adsorption (chemisorption): stronger bonding of stabilizers to ZnO particles.",
    "• Bentonite (a colloidal clay) adsorbs onto calamine particles, creating a protective layer that prevents particle-particle contact.",
]
add_bullet_block(slide, ads1, 0.45, 1.6, 5.8, 5.2)

add_textbox(slide, 6.75, 1.05, 6.1, 0.5,
            "Role in Formulation Stability", FONT_HEADING, Pt(21), bold=True, color=HEADING_TEXT)
ads2 = [
    "• Adsorbed molecules create steric barriers between particles, preventing aggregation and caking.",
    "• Sodium citrate adsorbs onto particle surfaces, imparting a negative charge (zeta potential), causing electrostatic repulsion between particles.",
    "• High zeta potential (> ±30 mV) = good physical stability (particles repel each other and remain dispersed).",
    "• Glycerin adsorbs at the particle surface and increases viscosity of the medium, slowing particle settling (Stokes' law).",
    "• Adsorption of phenol onto particles also contributes to antimicrobial action.",
]
add_bullet_block(slide, ads2, 6.75, 1.6, 6.1, 5.2)

add_footer(slide, "Hafza Rashid", 7)


# ══════════════════════════════════════════════════════════════════
# SLIDE 8 — ELECTRICAL DOUBLE LAYER & ZETA POTENTIAL  (Member 2)
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Electrical Double Layer and Zeta Potential")

bullets = [
    "• When calamine/ZnO particles are dispersed in water, they develop a surface charge due to ionization of surface groups and adsorption of ions.",
    "• This charge attracts counter-ions from the solution, forming an Electrical Double Layer (EDL) around each particle (Stern layer + Diffuse layer).",
    "• The Zeta Potential is the electric potential at the slipping plane of the EDL. It measures how strongly particles repel each other.",
    "• In Calamine Lotion: sodium citrate provides Na⁺ ions and citrate ions that maintain a negative zeta potential on particle surfaces.",
    "• A zeta potential more negative than −30 mV keeps particles well-dispersed and prevents flocculation (clumping).",
    "• Formulation scientists carefully control ionic strength and pH to maintain an optimal zeta potential throughout the product shelf life.",
    "• If zeta potential is too low (near zero), particles aggregate → the lotion becomes lumpy and cannot be redispersed easily.",
]

add_rect(slide, 0.3, 1.0, 12.73, 5.9, WHITE, HEADING_BG)
add_bullet_block(slide, bullets, 0.45, 1.05, 12.4, 5.8)
add_footer(slide, "Hafza Rashid", 8)


# ══════════════════════════════════════════════════════════════════
# SLIDE 9 — WETTING  (Member 3)
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Wetting Phenomena in Calamine Lotion")

add_rect(slide, 0.3, 1.0, 6.1, 5.9, WHITE, HEADING_BG)
add_rect(slide, 6.6, 1.0, 6.43, 5.9, ACCENT, HEADING_BG)

add_textbox(slide, 0.45, 1.05, 5.8, 0.5,
            "Types of Wetting", FONT_HEADING, Pt(21), bold=True, color=HEADING_TEXT)
w1 = [
    "Wetting is the ability of a liquid to spread on a solid surface. Three types are relevant:",
    "",
    "1. Adhesional Wetting: Liquid attaches to the particle surface (important during initial dispersion of ZnO powder in water).",
    "",
    "2. Spreading Wetting: Liquid spreads across particle surface replacing air — essential so no air pockets remain on particles.",
    "",
    "3. Immersional Wetting: Particle is fully submerged/covered by liquid — ensures every calamine particle is surrounded by the vehicle.",
]
add_bullet_block(slide, w1, 0.45, 1.6, 5.8, 5.2)

add_textbox(slide, 6.75, 1.05, 6.1, 0.5,
            "Wetting in the Formulation", FONT_HEADING, Pt(21), bold=True, color=HEADING_TEXT)
w2 = [
    "• ZnO and calamine are hydrophobic (water-repellent) powders — poor wettability is a major formulation challenge.",
    "• Contact angle (θ) determines wettability. θ < 90° = hydrophilic (easily wetted); θ > 90° = hydrophobic (hard to wet).",
    "• Wetting agents (sodium citrate, glycerin) are added to reduce contact angle below 90°, ensuring complete immersion of particles.",
    "• Bentonite (a hydrophilic clay) acts as a wetting and suspending agent — it swells in water and wraps around particles.",
    "• During manufacturing, the powders are triturated (ground) with glycerin first — this wet-levigation step improves wetting before adding water.",
    "• Result: uniform, smooth suspension without agglomerates or floating particles.",
]
add_bullet_block(slide, w2, 6.75, 1.6, 6.1, 5.2)

add_footer(slide, "Ume Ummarah Antique", 9)


# ══════════════════════════════════════════════════════════════════
# SLIDE 10 — MICELLIZATION  (Member 3)
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Micellization and Surfactant Action")

bullets = [
    "• Micellization is the process where surfactant molecules self-assemble into aggregates called micelles when their concentration exceeds the Critical Micelle Concentration (CMC).",
    "• Below CMC: surfactant molecules are dispersed individually and mainly lower surface/interfacial tension.",
    "• Above CMC: surfactant molecules form spherical micelles — their hydrophobic tails point inward (away from water) and hydrophilic heads face outward (toward water).",
    "• In Calamine Lotion: although the primary surfactant is sodium citrate (an anionic agent), small amounts of other surface-active impurities and excipients may form micellar structures in the vehicle.",
    "• Micelles help solubilize any slightly lipophilic components (e.g., phenol) within their hydrophobic core, keeping them uniformly distributed throughout the lotion.",
    "• Micelles also adsorb onto particle surfaces, lowering interfacial tension further and providing steric stabilization against particle aggregation.",
    "• During skin application: micelles help the lotion spread evenly and assist in drug delivery to the stratum corneum (outermost skin layer).",
]

add_rect(slide, 0.3, 1.0, 12.73, 5.9, WHITE, HEADING_BG)
add_bullet_block(slide, bullets, 0.45, 1.05, 12.4, 5.8)
add_footer(slide, "Ume Ummarah Antique", 10)


# ══════════════════════════════════════════════════════════════════
# SLIDE 11 — OTHER SURFACE PHENOMENA (Sedimentation, Rheology)  (Member 3)
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Other Surface Phenomena — Sedimentation & Rheology")

add_rect(slide, 0.3, 1.0, 6.1, 5.9, WHITE, HEADING_BG)
add_rect(slide, 6.6, 1.0, 6.43, 5.9, ACCENT, HEADING_BG)

add_textbox(slide, 0.45, 1.05, 5.8, 0.5,
            "Sedimentation (Stokes' Law)", FONT_HEADING, Pt(21), bold=True, color=HEADING_TEXT)
s1 = [
    "• Particles in a suspension settle by gravity (sedimentation) — described by Stokes' Law:",
    "   v = 2r²(ρ₁−ρ₂)g / 9η",
    "   where r = particle radius, ρ = density difference, g = gravity, η = viscosity.",
    "",
    "• To reduce sedimentation rate in Calamine Lotion:",
    "  – Reduce particle size (smaller r = slower settling)",
    "  – Increase viscosity (η) with glycerin and bentonite",
    "  – Produce controlled flocculation (loose, easily redispersible sediment)",
    "",
    "• Controlled flocculation is PREFERRED over deflocculation because flocs settle as a loose cake that can be re-dispersed with gentle shaking.",
]
add_bullet_block(slide, s1, 0.45, 1.6, 5.8, 5.2)

add_textbox(slide, 6.75, 1.05, 6.1, 0.5,
            "Rheology and Thixotropy", FONT_HEADING, Pt(21), bold=True, color=HEADING_TEXT)
s2 = [
    "• Calamine Lotion shows non-Newtonian, thixotropic flow behaviour due to bentonite.",
    "",
    "• Thixotropy: the lotion is thick/gel-like at rest (good for shelf stability — particles don't settle fast) but becomes fluid when shaken (good for pouring and application).",
    "",
    "• This behaviour is ideal for a topical suspension: stays stable in bottle but spreads easily when applied.",
    "",
    "• Bentonite forms a three-dimensional gel network at rest — this network breaks down on shaking (shear thinning) and reforms when left standing.",
]
add_bullet_block(slide, s2, 6.75, 1.6, 6.1, 5.2)

add_footer(slide, "Ume Ummarah Antique", 11)


# ══════════════════════════════════════════════════════════════════
# SLIDE 12 — PHYSICAL STABILITY  (Member 4)
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Physical Stability of Calamine Lotion")

add_rect(slide, 0.3, 1.0, 12.73, 5.9, WHITE, HEADING_BG)

# Sub-heading
add_textbox(slide, 0.45, 1.05, 12.4, 0.5,
            "Main Physical Stability Problems and Their Solutions", FONT_HEADING, Pt(22), bold=True, color=HEADING_TEXT)

data = [
    ("Problem", "Cause", "Solution"),
    ("Caking (hard sediment)", "Deflocculated particles pack tightly and form a hard cake", "Use controlled flocculation agents (bentonite) to form loose, re-dispersible sediment"),
    ("Crystal growth (Ostwald ripening)", "Small particles dissolve and recrystallize on large particles, increasing particle size", "Control particle size during milling; maintain uniform PSD; add crystal growth inhibitors"),
    ("Phase separation / creaming", "Density difference between particles and vehicle causes settling", "Adjust viscosity with glycerin; use bentonite gel structure; ensure proper particle size reduction"),
    ("Aggregation/clumping", "High interfacial tension causes particles to stick together", "Add wetting agents; maintain negative zeta potential with sodium citrate"),
]

row_y_start = 1.6
row_h = 0.88
row_colors2 = [HEADING_BG, WHITE, ACCENT, WHITE, ACCENT]
col_widths = [2.6, 3.8, 6.0]
col_x2 = [0.35, 2.97, 6.79]

for r_idx, row in enumerate(data):
    ry = row_y_start + r_idx * row_h
    for c_idx, cell_text in enumerate(row):
        add_rect(slide, col_x2[c_idx], ry, col_widths[c_idx]-0.05, row_h-0.04, row_colors2[r_idx], HEADING_BG)
        is_header = (r_idx == 0)
        add_textbox(slide, col_x2[c_idx]+0.07, ry+0.05, col_widths[c_idx]-0.18, row_h-0.1,
                    cell_text, FONT_BODY, SIZE_BODY if not is_header else Pt(20),
                    bold=is_header, color=HEADING_TEXT if is_header else BODY_TEXT)

add_footer(slide, "Muhammad Afridi", 12)


# ══════════════════════════════════════════════════════════════════
# SLIDE 13 — CHEMICAL & MICROBIAL STABILITY  (Member 4)
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Chemical and Microbial Stability")

add_rect(slide, 0.3, 1.0, 6.1, 5.9, WHITE, HEADING_BG)
add_rect(slide, 6.6, 1.0, 6.43, 5.9, ACCENT, HEADING_BG)

add_textbox(slide, 0.45, 1.05, 5.8, 0.5,
            "Chemical Stability", FONT_HEADING, Pt(21), bold=True, color=HEADING_TEXT)
chem = [
    "• Calamine (ZnCO₃ + Fe₂O₃) is chemically stable under normal conditions — inorganic salts are not prone to hydrolysis or oxidation.",
    "• Zinc Oxide (ZnO) may slowly react with CO₂ from air to form ZnCO₃ — minimized by storing in well-closed containers.",
    "• pH maintenance (6.5–8.0) is critical: acidic conditions may dissolve ZnO; alkaline conditions may cause saponification of any lipid excipients.",
    "• Sodium citrate acts as a chelating buffer — it binds trace metal ions that could catalyze oxidative degradation.",
    "• Glycerin is chemically stable but must be pharmaceutical grade (free of propylene glycol and other impurities).",
    "• Light-sensitive degradation is not a major concern but amber/opaque bottles are still preferred to protect against UV.",
]
add_bullet_block(slide, chem, 0.45, 1.6, 5.8, 5.2)

add_textbox(slide, 6.75, 1.05, 6.1, 0.5,
            "Microbial Stability", FONT_HEADING, Pt(21), bold=True, color=HEADING_TEXT)
micro = [
    "• Calamine Lotion is an aqueous system — water activity (aw) is high, making it vulnerable to microbial contamination (bacteria, yeast, moulds).",
    "• Liquefied Phenol (0.5% v/v) serves as the preservative — it is bactericidal and fungistatic.",
    "• Phenol denatures microbial proteins and disrupts cell membranes at effective concentrations.",
    "• Manufacturing is done under Good Manufacturing Practice (GMP) conditions to minimize bioburden.",
    "• BP specifies limits: Total aerobic count ≤ 10² CFU/g; absence of Staphylococcus aureus, Pseudomonas aeruginosa.",
    "• Packaging in tight, opaque containers prevents microbial ingress and secondary contamination by users.",
    "• Accelerated stability testing (40°C/75% RH for 6 months) confirms microbial stability throughout shelf life.",
]
add_bullet_block(slide, micro, 6.75, 1.6, 6.1, 5.2)

add_footer(slide, "Muhammad Afridi", 13)


# ══════════════════════════════════════════════════════════════════
# SLIDE 14 — HOW STABILITY WAS IMPROVED  (Member 4)
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "How the Stability of Calamine Lotion Was Improved")

add_rect(slide, 0.3, 1.0, 12.73, 5.9, WHITE, HEADING_BG)

improvements = [
    ("Physical Stability Improvements",
     "Controlled flocculation using bentonite prevents caking. Wet levigation with glycerin during manufacturing ensures fine particle size. Thixotropic vehicle (bentonite gel) slows settling. Sodium citrate maintains negative zeta potential preventing particle aggregation."),
    ("Chemical Stability Improvements",
     "Buffering with sodium citrate maintains pH 6.5–8.0, protecting ZnO from acid dissolution. Chelation of pro-oxidant metal ions by citrate. Tight, well-closed amber or opaque packaging prevents CO₂ and UV exposure. Storage at 15–25°C recommended."),
    ("Microbial Stability Improvements",
     "Liquefied phenol at 0.5% v/v provides adequate preservation throughout shelf life. GMP manufacturing reduces initial bioburden. Container-closure integrity testing ensures no microbial ingress. Patients are instructed to close bottle tightly after use."),
    ("Overall Formulation Strategy",
     "Modern marketed formulations (e.g., Lacto Calamine) have improved by incorporating humectants (lactic acid, aloe vera), emollient bases, and more biocompatible preservatives. Micronization of powders to < 45 µm further improves physical stability and skin feel."),
]

row_y2 = 1.1
for i, (heading, text) in enumerate(improvements):
    add_rect(slide, 0.35, row_y2, 12.6, 1.3, ACCENT if i % 2 == 0 else WHITE, HEADING_BG)
    add_textbox(slide, 0.5, row_y2+0.05, 3.5, 0.45,
                heading, FONT_HEADING, Pt(19), bold=True, color=HEADING_TEXT)
    add_textbox(slide, 0.5, row_y2+0.5, 12.2, 0.75,
                text, FONT_BODY, Pt(18), bold=False, color=BODY_TEXT)
    row_y2 += 1.35

add_footer(slide, "Muhammad Afridi", 14)


# ══════════════════════════════════════════════════════════════════
# SLIDE 15 — SUMMARY & CONCLUSION
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "Summary and Conclusion")

add_rect(slide, 0.3, 1.0, 12.73, 5.9, WHITE, HEADING_BG)

summary_bullets = [
    "• Calamine Lotion is a marketed topical suspension that serves as an excellent example of surface phenomena in pharmaceutical formulations.",
    "• Surface and interfacial tension are controlled by sodium citrate and glycerin, ensuring the hydrophobic ZnO/calamine particles are fully wetted by the aqueous vehicle.",
    "• Adsorption of bentonite and sodium citrate onto particle surfaces creates steric and electrostatic barriers that prevent aggregation and maintain physical stability.",
    "• Wetting is achieved through wet levigation with glycerin and by reducing the contact angle below 90° — a critical manufacturing step.",
    "• Micellization of surface-active excipients helps solubilize minor lipophilic components and assists in even skin coverage during application.",
    "• Thixotropic rheology (bentonite gel) provides an ideal balance between shelf stability and ease of application.",
    "• Chemical stability is maintained by pH buffering, chelation, and appropriate packaging; microbial stability relies on phenol as a preservative.",
    "• Modern improvements include micronization, humectants, and GMP practices — making Calamine Lotion a safe, effective, and stable product.",
]
add_bullet_block(slide, summary_bullets, 0.45, 1.05, 12.4, 5.8)

add_footer(slide, "All Members", 15)


# ══════════════════════════════════════════════════════════════════
# SLIDE 16 — REFERENCES
# ══════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(prs.slide_layouts[6])
set_bg(slide, BG_LIGHT)
add_heading_bar(slide, "References")

add_rect(slide, 0.3, 1.0, 12.73, 5.9, WHITE, HEADING_BG)

refs = [
    "1.  Martin, A., Bustamante, P., & Chun, A.H.C. (2011). Physical Pharmacy: Physical Chemical Principles in the Pharmaceutical Sciences (5th ed.). Lippincott Williams & Wilkins.",
    "2.  Aulton, M.E., & Taylor, K.M.G. (2018). Aulton's Pharmaceutics: The Design and Manufacture of Medicines (5th ed.). Elsevier.",
    "3.  British Pharmacopoeia (2023). Calamine Lotion BP. MHRA, London.",
    "4.  Lachman, L., Lieberman, H.A., & Kanig, J.L. (1986). The Theory and Practice of Industrial Pharmacy (3rd ed.). Lea & Febiger.",
    "5.  Florence, A.T., & Attwood, D. (2016). Physicochemical Principles of Pharmacy (6th ed.). Pharmaceutical Press.",
    "6.  USP-NF (2024). Calamine, Zinc Oxide Suspension Monograph. United States Pharmacopeial Convention.",
    "7.  Lacto Calamine — Product Monograph. Piramal Healthcare Limited, India.",
]
add_bullet_block(slide, refs, 0.45, 1.1, 12.4, 5.7)

add_footer(slide, "All Members", 16)


# ══════════════════════════════════════════════════════════════════
# SAVE
# ══════════════════════════════════════════════════════════════════
output_path = "/tmp/workspace/pharma-ppt/Calamine_Lotion_Surface_Phenomena_Stability.pptx"
prs.save(output_path)
print(f"Saved: {output_path}")
print(f"Total slides: {len(prs.slides)}")

"""
Simplify text in each slide while preserving ALL formatting (font name, size, bold, italic, color)
and ALL images/shapes. We use python-pptx to iterate paragraphs and runs, replacing text only.
"""

from pptx import Presentation
from pptx.util import Emu
import copy, shutil, os

SRC = "/tmp/workspace/attachments/cd74d21b-e1b9-4dba-82fc-6acc1dfa8096/ceutics grp 9-1.pptx"
DST = "/tmp/workspace/metro-ppt-edit/Metronidazole_Simplified.pptx"

# ── SIMPLIFIED TEXT MAP ────────────────────────────────────────────────────────
# Key = exact original paragraph text (stripped)
# Value = simplified replacement text
# (Only paragraphs that need changing are listed; others stay untouched)

SIMPLIFY = {

    # ── SLIDE 3 ──────────────────────────────────────────────────────────────
    "Biphasic system: insoluble drug particles dispersed throughout a liquid vehicle":
        "A suspension has two parts: solid drug particles mixed throughout a liquid.",

    "Used when a drug is poorly soluble, unstable in solution, or has a taste that needs masking":
        "It is used when a drug does not dissolve well in water, or needs taste masking.",

    "Suspensions are generally classified as coarse, with particles larger than about 1 micron, which distinguishes them from":
        "Suspensions contain particles larger than 1 micron — larger than colloids or solutions.",

    "Compared with true solutions, suspensions offer a practical route for drugs whose required dose exceeds their aqueous so":
        "Suspensions are practical for drugs that cannot dissolve at the dose needed.",

    "0.5–10 µm range – allows slow, uniform settling yet safe passage through dosing devices":
        "Particles of 0.5–10 µm settle slowly and pass easily through a measuring syringe.",

    "Micronization or controlled crystallization is typically used to bring bulk API powder into this target range before sus":
        "The drug powder is milled (micronized) to reach this size before making the suspension.",

    "Solid and liquid phases differ in density → thermodynamically unstable, tends to sediment":
        "Since solid and liquid have different weights, the solid slowly sinks to the bottom.",

    "Without suspending, wetting, and flocculating agents, particles aggregate, cake, and resist redispersion":
        "Without special additives, particles clump together and form a hard lump at the bottom.",

    "Left unaddressed, this instability manifests as a compact, difficult-to-redisperse sediment known as caking.":
        "This hard lump is called 'caking' and is very difficult to mix back even when shaken.",

    "Reconstitution-on-demand avoids the long-term physical and chemical instability of a ready-made liquid":
        "Keeping the product as a dry powder avoids the instability problems of a ready-made liquid.",

    "This strategy allows manufacturers to label the unreconstituted product with a much longer shelf life, often 24 to 36 mo":
        "The dry powder can last 2–3 years on the shelf. Once water is added, use within 14 days.",

    # ── SLIDE 5 ──────────────────────────────────────────────────────────────
    "Nitroimidazole antimicrobial – potent antiprotozoal and antibacterial activity":
        "Metronidazole is an antibiotic that kills parasites and harmful anaerobic bacteria.",

    "First-line therapy for numerous anaerobic and protozoal infections":
        "It is the first-choice drug for many protozoal and anaerobic bacterial infections.",

    "It is structurally related to other 5-nitroimidazoles such as tinidazole and ornidazole, which share the same nitro-redu":
        "It belongs to the same drug family as tinidazole and ornidazole.",

    "The drug is included on the WHO Model List of Essential Medicines given its broad antiprotozoal and antianaerobic utilit":
        "It is on the WHO Essential Medicines List because it treats so many common infections.",

    "Nitro group reduced by anaerobic ferredoxin-type proteins → cytotoxic free radicals → DNA strand breakage":
        "Inside bacteria/parasites, the drug is converted into toxic particles that break DNA strands.",

    "Selective toxicity: activation needs a low-redox anaerobic environment, sparing aerobic host cells":
        "It only activates in oxygen-free environments (anaerobic), so it does not harm human cells.",

    "The resulting free radicals also interact with proteins and membrane components, contributing to cell death beyond DNA d":
        "These toxic particles also damage cell proteins and membranes, leading to cell death.",

    "Resistance, though uncommon, can arise from reduced nitroreductase expression or enhanced DNA repair in the target organ":
        "Resistance is rare but can happen if the microbe reduces its ability to activate the drug.",

    "Amoebiasis, giardiasis, trichomoniasis":
        "Infections like amoebiasis, giardiasis, and trichomoniasis.",

    "Anaerobic bacterial infections (Bacteroides, Clostridium)":
        "Anaerobic bacterial infections caused by Bacteroides and Clostridium.",

    # ── SLIDE 6 ──────────────────────────────────────────────────────────────
    "Moderately lipophilic, pH-sensitive structure shapes the buffering system and degradation pathways":
        "Metronidazole is slightly fat-soluble and sensitive to pH — this guides the buffer choice.",

    "Its moderate lipophilicity permits reasonable membrane permeability while remaining compatible with an aqueous suspensio":
        "Its mild fat-solubility lets it pass through cell membranes while still mixing in water.",

    "The imidazole ring's sensitivity to both pH extremes and UV light directly shapes the buffer and packaging choices made ":
        "Since the drug breaks down in strong acid/base and UV light, an acidic buffer and opaque bottle are needed.",

    # ── SLIDE 7 ──────────────────────────────────────────────────────────────
    "7.5 mg/kg every 8 hours – weight-adjusted, not fixed-strength":
        "Dose: 7.5 mg per kg of body weight every 8 hours — adjusted to the child's weight.",

    "Calibrated oral syringe/dosing cup gives accuracy tablets cannot match":
        "A measured syringe is used to give the exact dose — more accurate than a tablet.",

    "This regimen is typically continued for seven to ten days depending on the indication being treated.":
        "Treatment usually lasts 7–10 days depending on the type of infection.",

    "Starts at reconstitution, not at manufacture":
        "The 14-day countdown starts when water is added, not from the manufacturing date.",

    "Stable only 14 days refrigerated (2–8°C); hydrolysis and microbial risk rise sharply beyond this":
        "Once mixed with water, keep in the fridge (2–8°C) and use within 14 days only.",

    "Beyond 14 days, hydrolytic degradation of the imidazole ring can reduce potency below acceptable limits.":
        "After 14 days, the drug starts to break down and may no longer work properly.",

    "Microbial contamination risk also rises as the preservative system is repeatedly challenged by cap-opening during use.":
        "Every time the bottle is opened, germs can enter — risk rises after 14 days.",

    "Maximizes pre-use shelf life and confines the vulnerable liquid-state window to two weeks":
        "Dry powder gives a long shelf life; the liquid form is kept safe for just 14 days.",

    "This approach simplifies distribution logistics, since the unreconstituted product tolerates broader temperature excursi":
        "Dry powder is also easier to store and transport as it tolerates temperature changes better.",

    # ── SLIDE 8 ──────────────────────────────────────────────────────────────
    "Micronized fine particles for uniform dosing and improved dissolution":
        "The drug is finely ground (micronized) for even mixing and faster dissolution.",

    "Micronization increases surface area, which accelerates dissolution once the suspension is administered and improves bio":
        "Smaller particles dissolve faster after swallowing, improving drug absorption in the body.",

    "High-MW anionic polysaccharide; builds a weak 3-D gel network that retards sedimentation":
        "Xanthan gum is a thick, negatively charged sugar polymer that forms a soft gel to slow settling.",

    "Its pseudoplastic, shear-thinning rheology means viscosity drops sharply when shaken or poured, easing dose administrati":
        "When shaken or poured, it becomes thinner (easier to pour). At rest, it thickens again.",

    "Non-ionic surfactant; lowers interfacial tension so water can displace air and wet particles":
        "Polysorbate 80 reduces surface tension so water can spread over and wet every particle.",

    "As a non-ionic surfactant, it is compatible with both the anionic xanthan gum and the ionic preservative system without ":
        "It is compatible with all other ingredients in the formula without causing problems.",

    "Pediatric palatability; also contributes to viscosity and osmotic character":
        "Sucrose makes the suspension sweet for children, and also adds to its thickness.",

    "Beyond taste masking, sucrose modestly raises solution viscosity, offering a secondary contribution to sedimentation ret":
        "The extra viscosity from sucrose also helps slow down particle settling.",

    "One API + suspending agent + wetting agent + sweetener; stabilizers/preservatives layered in Part 2":
        "Core formula = drug + xanthan gum + Polysorbate 80 + sucrose. More excipients are in Part 2.",

    "This core skeleton mirrors the standard four-component framework used in pediatric suspension design broadly.":
        "This four-ingredient base is the standard starting point for most pediatric suspensions.",

    # ── SLIDE 9 ──────────────────────────────────────────────────────────────
    "Most active in undissociated acid form at mildly acidic pH; penetrates microbial membranes":
        "Sodium benzoate works best in slightly acidic conditions. It enters and kills microbes.",

    "Its antimicrobial activity depends heavily on formulation pH, since only the undissociated acid form crosses microbial m":
        "Only the acid form of benzoate can pass through microbial membranes, so pH matters a lot.",

    "Holds pH 4–5; minimizes hydrolytic breakdown of the imidazole ring, supports preservative activity":
        "The citrate buffer keeps pH at 4–5, preventing drug breakdown and supporting the preservative.",

    "The buffer system also chelates trace metal ions that could otherwise catalyze oxidative degradation of the drug.":
        "The buffer also traps trace metal ions that could otherwise speed up drug degradation.",

    "Thixotropic gel at rest; breaks down on shaking and rebuilds on standing to entrap particles":
        "Aerosil forms a gel at rest to hold particles in place. Shaking breaks the gel for easy pouring.",

    "Its extremely small particle size gives it a very high surface area relative to the small amount used.":
        "Even a tiny amount of Aerosil creates a very large surface area due to its nano-sized particles.",

    "The silanol groups on its surface hydrogen-bond with water and with each other to form the reversible gel network.":
        "Its silanol (-OH) groups bond with water and each other to form a reversible gel.",

    "Strawberry flavor and carmoisine dye – organoleptic value for pediatric palatability and adherence":
        "Strawberry flavor and pink dye make the medicine more pleasant and acceptable for children.",

    "Flavor selection also considers masking any lingering bitterness from the metronidazole itself.":
        "The flavor also helps hide metronidazole's bitter taste.",

    "Colorants must be certified for pediatric use and remain stable across the product's pH and storage conditions.":
        "Only approved, child-safe dyes that stay stable at pH 4–5 are used.",

    "Every excipient maps to one of five pillars: efficacy, stability, safety, palatability, compliance":
        "Each ingredient serves one of five roles: effectiveness, stability, safety, taste, or compliance.",

    "This five-pillar framework is a useful checklist when evaluating any pediatric liquid formulation, not just this one.":
        "This five-pillar check is a useful guide for any pediatric liquid medicine.",

    # ── SLIDE 12 ─────────────────────────────────────────────────────────────
    "Net inward cohesive forces at the liquid–air interface make the surface behave like a stretched membrane":
        "Water molecules pull inward at the surface, making it act like a thin, tight film.",

    "It is quantitatively expressed in units of dyn/cm or mN/m and can be measured using methods like the du Noüy ring or Wil":
        "It is measured in mN/m using methods like the du Noüy ring or Wilhelmy plate.",

    "Same phenomenon at the boundary between the solid drug particle and the aqueous vehicle":
        "Interfacial tension acts at the boundary between the solid drug particle and the liquid.",

    "Lower interfacial tension favors spontaneous dispersion of the solid phase into the liquid vehicle.":
        "Lower interfacial tension = particles spread more easily into the liquid.",

    "Hydrophobic molecule → high interfacial tension against water → particles clump to minimize interfacial area":
        "Metronidazole repels water, so particles clump together to reduce contact with water.",

    "Shows up as poor wetting, trapped air, and clustering on reconstitution":
        "This causes poor wetting, trapped air bubbles, and clumping when water is added.",

    "Without intervention, this clumping traps air pockets within particle aggregates, further resisting wetting.":
        "Trapped air inside clumps makes it even harder for water to wet the particles.",

    "Central challenge addressed directly by the surfactant Polysorbate 80 (next)":
        "Polysorbate 80 (Tween 80) is added to solve this problem — explained on the next slide.",

    "Surfactants work by adsorbing at the solid–liquid interface, lowering the energy barrier to wetting.":
        "Surfactants attach to the particle surface and lower the energy needed to wet them.",

    # ── SLIDE 13 ─────────────────────────────────────────────────────────────
    "Non-ionic, HLB ≈ 15 – strongly hydrophilic, suited to O/W stabilization and particle wetting":
        "Tween 80 is non-ionic with HLB ~15 — it strongly prefers water, ideal for wetting solid particles.",

    "Polysorbate 80 is derived from ethoxylated sorbitan esterified with oleic acid, giving it a bulky, flexible hydrophilic ":
        "It is made from sorbitan and oleic acid with long water-loving chains that project into water.",

    "Its non-ionic nature makes it compatible across a wide pH range without pH-dependent charge changes.":
        "Being non-ionic, it works at any pH without losing its properties.",

    "Hydrophobic tail anchors on the drug surface; hydrophilic head groups project into water":
        "Its oily tail sticks to the drug particle; its watery head faces outward into the liquid.",

    "This orientation forms a monolayer that effectively converts the hydrophobic drug surface into a hydrophilic one.":
        "This coating makes the normally water-repellent drug surface become water-friendly.",

    "Adsorption is generally rapid, occurring within seconds of contact during reconstitution.":
        "This coating forms within seconds when water is added to the dry powder.",

    "Lowers interfacial tension → particles wet uniformly instead of floating or clumping":
        "By lowering interfacial tension, all particles get evenly wetted — no floating or clumping.",

    "Improved wetting translates directly into faster, more complete dispersion when the caregiver shakes the bottle.":
        "Better wetting means the suspension mixes quickly and completely with just a gentle shake.",

    "It also reduces trapped air within particle clusters, which would otherwise cause particles to float rather than dispers":
        "It also removes trapped air from particle clusters, preventing them from floating.",

    "Keeps particle surfaces hydrated and sterically stabilized, working alongside xanthan gum":
        "Tween 80 keeps particles coated and stable, working together with xanthan gum.",

    "The hydrated surfactant layer provides a degree of steric hindrance against particle–particle approach.":
        "The coating creates a physical barrier that stops particles from touching and sticking.",

    "Maintaining this stabilized state throughout the 14-day in-use period supports consistent dosing from first dose to last":
        "This ensures every dose in the 14-day period has the same drug concentration.",

    # ── SLIDE 14 ─────────────────────────────────────────────────────────────
    "Quantifies wetting: how a liquid displaces air from a solid surface":
        "Contact angle measures how well a liquid spreads on a solid surface.",

    "θ > 90° = poor/hydrophobic wetting; θ < 90° = good/hydrophilic wetting":
        "Angle > 90°: water-repellent (bad wetting). Angle < 90°: water-friendly (good wetting).",

    "It is measured as the angle formed between the liquid–vapor interface and the solid surface at the point of contact.":
        "It is the angle where the liquid meets the solid — smaller angle = better wetting.",

    "Shows θ > 90° against plain water – floats/clumps, traps air pockets":
        "Metronidazole has θ > 90° in plain water — it floats, clumps, and traps air bubbles.",

    "This hydrophobic tendency stems from the drug's limited aqueous solubility and moderately lipophilic structure.":
        "This happens because metronidazole does not dissolve well in water (slightly fat-soluble).",

    "Poor wettability → uneven dispersion, inaccurate dosing, gritty mouthfeel":
        "Poor wetting leads to uneven mixing, wrong doses, and a gritty feel in the mouth.",

    "Trapped air pockets within powder clumps can also promote localized microbial growth if not properly wetted.":
        "Air pockets inside clumps can also allow germs to grow if not properly wetted.",

    "Overcome via a wetting agent – the role Polysorbate 80 fulfills":
        "Polysorbate 80 is added as a wetting agent to solve this problem.",

    "Wetting agents work by lowering the contact angle below the 90° threshold, converting the surface to hydrophilic.":
        "Wetting agents reduce the contact angle below 90°, making the surface water-friendly.",

    # ── SLIDE 15 ─────────────────────────────────────────────────────────────
    "Tween 80 adsorption drops the contact angle below 90°, making the surface functionally hydrophilic":
        "When Tween 80 coats the particle, contact angle drops below 90° — particles now accept water.",

    "This shift occurs because the adsorbed surfactant layer lowers the solid–liquid interfacial energy term in Young's equat":
        "This happens because Tween 80 lowers the solid-liquid interfacial energy (Young's equation).",

    "S = γSA − γSL − γLA; a positive S means the liquid spontaneously spreads over the solid":
        "Spreading Coefficient S = γSA − γSL − γLA. If S is positive, liquid spreads naturally.",

    "Lowering γSL (interfacial tension) via surfactant shifts S toward positive":
        "Tween 80 lowers γSL (solid-liquid tension), making S positive and spreading spontaneous.",

    "A negative spreading coefficient instead indicates the liquid will bead up rather than spread across the solid.":
        "A negative S means liquid beads up instead of spreading — wetting does not occur.",

    "Complete, uniform wetting is directly tied to dosing accuracy":
        "Complete wetting ensures every particle is mixed in — this is key for accurate dosing.",

    "Ensures every 5 mL dose reliably delivers the intended 200 mg of metronidazole":
        "Every 5 mL spoonful delivers exactly 200 mg of metronidazole — no more, no less.",

    "Incomplete wetting would leave some particles undispersed, skewing drug concentration in whichever portion of the bottle":
        "If wetting is incomplete, some doses will have too much drug and others too little.",

    # ── SLIDE 16 ─────────────────────────────────────────────────────────────
    "High-MW, branched anionic polysaccharide (fermentation of Xanthomonas campestris); strongly pseudoplastic":
        "Xanthan gum is a large, branched, negatively charged sugar made by bacterial fermentation.",

    "It is produced industrially through microbial fermentation and purified before use as a pharmaceutical-grade excipient.":
        "It is made in factories by fermenting bacteria and purified for pharmaceutical use.",

    "Polymer chains adsorb onto the particle surface (Langmuir-type monolayer), coating each particle":
        "Xanthan gum chains stick to the surface of each drug particle, forming a protective coat.",

    "The polymer's long, flexible chains extend outward from the particle surface into the surrounding vehicle.":
        "The long chains stick outward into the liquid, creating a physical barrier around each particle.",

    "This adsorbed layer increases the effective hydrodynamic size of each particle, further slowing sedimentation per Stokes":
        "This coating makes each particle 'bigger' in effect, slowing its settling rate.",

    "Steric barrier + electrostatic repulsion between coated particles minimizes direct contact":
        "The physical coat + negative charge push particles away from each other.",

    "Prevents irreversible aggregation and hard cake formation":
        "This stops particles from permanently sticking together and forming a hard lump.",

    "Electrostatic repulsion arises from the polymer's anionic carboxylate groups, which are ionized at the formulation's pH.":
        "The negative charges on xanthan gum at pH 4–5 push particles apart electrostatically.",

    "Particles stay discrete within the gel network – gentle shaking redisperses evenly":
        "Particles stay separate in the gel. A gentle shake re-mixes them evenly.",

    "The surrounding weak gel network additionally restrains particle movement, slowing settling even further.":
        "The soft gel network also physically holds particles in place, further slowing settling.",

    # ── SLIDE 18 ─────────────────────────────────────────────────────────────
    "Extremely fine, high-surface-area silica; adsorbs via reactive silanol (–Si-OH) groups":
        "Aerosil is ultra-fine silica powder with a huge surface area. It adsorbs via -Si-OH groups.",

    "It is manufactured by flame hydrolysis of silicon tetrachloride, producing amorphous, non-porous nanoparticles.":
        "It is made by burning silicon tetrachloride vapor to form tiny, non-porous silica particles.",

    "Silica particles hydrogen-bond into an interconnected 3-D gel spanning the vehicle":
        "Aerosil particles link together via hydrogen bonds to form a three-dimensional gel.",

    "The resulting network behaves as a weak, elastic gel rather than a rigid solid.":
        "This network is a soft, flexible gel — not a solid. It can be broken and reformed.",

    "Network entraps drug particles, restricting movement and slowing sedimentation":
        "The gel traps drug particles inside it, preventing them from settling quickly.",

    "By physically restricting particle mobility, the network reduces the effective settling velocity predicted by Stokes' la":
        "This physical entrapment lowers the settling speed below what Stokes' law would predict.",

    "Gel-like at rest (protects against settling); breaks down on shaking; reforms on standing":
        "At rest: gel forms to protect against settling. When shaken: gel breaks so it pours easily. Then it reforms.",

    "Recovery time after shaking is typically short, restoring gel structure within seconds to minutes.":
        "The gel rebuilds within seconds to minutes after shaking stops.",

    # ── SLIDE 20 ─────────────────────────────────────────────────────────────
    "Above the CMC, surfactant molecules self-assemble: hydrophobic tails inward, hydrophilic heads outward":
        "Above CMC, surfactant molecules group together into micelles: oily tails inside, watery heads outside.",

    "Below the CMC, surfactant molecules exist predominantly as individual monomers dissolved in the vehicle.":
        "Below CMC, surfactant molecules float freely as single molecules — no micelles yet.",

    "Micelle size and shape depend on the surfactant's molecular geometry and the surrounding ionic and pH environment.":
        "Micelle size and shape depend on the surfactant structure, ions, and pH in the formula.",

    "≈0.012 mg/mL – easily exceeded by the 0.1% w/v (~1 mg/mL) formulation concentration":
        "CMC is ~0.012 mg/mL. The formula uses ~1 mg/mL — about 80× above CMC. Micelles always form.",

    "This large margin ensures micelles are consistently present throughout the product's shelf life, even accounting for min":
        "This large safety margin keeps micelles present throughout the full 14-day use period.",

    "Micellar core solubilizes trace lipophilic impurities or degradation products":
        "Micelles trap small fat-soluble impurities or degradation products inside their oily core.",

    "This solubilization capacity helps maintain a visually clear supernatant even as trace degradation products accumulate.":
        "This keeps the liquid layer clear even as tiny amounts of degradation occur.",

    "Slows dissolution/redeposition of small particles onto larger ones, keeping particle size consistent":
        "Micelles slow Ostwald ripening — preventing small particles from dissolving onto large ones.",

    "Ostwald ripening occurs because smaller particles have higher surface energy and thus greater local solubility than larg":
        "Small particles dissolve faster than large ones (higher surface energy) — micelles help prevent this.",

    # ── SLIDE 21 ─────────────────────────────────────────────────────────────
    "~1 mg/mL formulation concentration is nearly 100× the CMC (~0.012 mg/mL) – reliably stays micellized":
        "The formula concentration is ~100× above CMC — Tween 80 is always in micellar form.",

    "This large safety margin accounts for potential minor losses of surfactant to adsorption onto container surfaces or drug":
        "Even if some Tween 80 is lost to adsorption on the bottle or drug particles, plenty remains.",

    "Non-ionic surfactant, unlike ionic ones that fail to micellize below a Krafft temperature":
        "Tween 80 is non-ionic — it does not have a Krafft temperature problem like ionic surfactants.",

    "Ionic surfactants can lose their surfactant function entirely if stored below their Krafft point, forming crystals inste":
        "Ionic surfactants crystallize and stop working if stored below the Krafft temperature.",

    "Micelle formation stays consistent whether refrigerated (2–8°C) or briefly at room temperature":
        "Tween 80 forms micelles at both refrigerator and room temperature — very reliable.",

    "This reliability is especially important given that pediatric suspensions are often stored in household refrigerators wi":
        "This matters because home fridges have variable temperatures — Tween 80 works regardless.",

    "Valuable for pediatric products stored in variable home refrigerators or brief cold-chain gaps":
        "Very useful for pediatric suspensions that may face temperature changes during storage or transport.",

    "Cold-chain interruptions are common in real-world distribution, particularly in resource-limited settings where this dru":
        "In low-resource settings, temperature control is often imperfect — Tween 80 stays reliable.",

    "Dependable, robust surfactant for consistent wetting, micellization, and stabilization":
        "Tween 80 is a dependable surfactant: reliable wetting, micellization, and particle stabilization.",

    "Its combination of low CMC, no Krafft temperature, and broad pH tolerance makes it broadly applicable beyond this formul":
        "Low CMC + no Krafft temperature + works at any pH = excellent all-round surfactant.",

    # ── SLIDE 22 ─────────────────────────────────────────────────────────────
    "Total interaction energy VT = VR (electrostatic repulsion) + VA (van der Waals attraction)":
        "DLVO theory: Total energy = Repulsion (electrostatic) + Attraction (van der Waals forces).",

    "Van der Waals dominates at close range; electrostatic repulsion creates a barrier at intermediate distance":
        "At short distances, attraction dominates. A repulsion barrier at medium distance keeps particles apart.",

    "The interplay between these two forces determines whether particles remain dispersed or aggregate irreversibly.":
        "The balance of these two forces decides if particles stay separate or clump together permanently.",

    "The theory provides a quantitative framework for predicting colloidal stability from measurable physicochemical paramete":
        "DLVO theory allows scientists to predict whether a suspension will be stable based on measurable parameters.",

    "|ζ| > 30 mV generally considered sufficient to prevent irreversible aggregation":
        "A zeta potential of more than ±30 mV is enough to keep particles from sticking together.",

    "Below this magnitude, electrostatic repulsion is generally too weak to prevent particles from overcoming the energy barr":
        "Below ±30 mV, the repulsion is too weak and particles may start to aggregate.",

    "Zeta potential is measured indirectly via electrophoretic mobility using techniques like laser Doppler velocimetry.":
        "Zeta potential is measured using laser-based instruments that track how particles move in an electric field.",

    "Moderate: about −20 to −30 mV – below the strict 30 mV threshold, and intentionally so":
        "This formula has a zeta potential of about −20 to −30 mV — slightly below the strict 30 mV threshold, by design.",

    "This value falls into the range typically associated with controlled or moderate flocculation rather than full defloccul":
        "This moderate value allows controlled (loose) flocculation — particles clump gently and can be re-shaken.",

    "It reflects the combined influence of xanthan gum's anionic charge and the citrate buffer's ionic strength.":
        "This value comes from xanthan gum's negative charge and the ionic strength of the citrate buffer.",

    "Permits controlled flocculation with xanthan gum's steric stabilization – a loose, redispersible sediment":
        "This creates controlled flocculation: loose, fluffy sediment that re-mixes easily with shaking.",

    "A fully deflocculated system would instead risk forming a dense, hard-to-redisperse cake over the 14-day use period.":
        "A fully deflocculated system would form a hard, impossible-to-shake cake after 14 days.",

    # ── SLIDE 24 ─────────────────────────────────────────────────────────────
    "v = 2r²(ρs − ρl)g / 9η – terminal sedimentation velocity":
        "v = 2r²(ρs − ρl)g / 9η — this equation gives the speed at which particles settle.",

    "The equation assumes spherical, non-interacting particles settling under laminar flow conditions.":
        "The formula assumes round particles settling smoothly without touching each other.",

    "Every term in the equation represents a formulation lever that can be adjusted to slow sedimentation.":
        "Each part of the equation tells us one way to slow down settling in a formulation.",

    "Rate ∝ r² – even modest micronization gives a disproportionately large drop in settling velocity":
        "Settling speed ∝ r². Halving particle size reduces settling speed by 4× — very effective.",

    "Halving particle radius, for example, reduces settling velocity to roughly one-quarter of its original value.":
        "Cutting particle size in half = 4× slower settling. Micronization is very powerful.",

    "Particle size control also indirectly benefits wetting and dissolution, compounding its formulation value.":
        "Smaller particles also wet better and dissolve faster — a bonus benefit of micronization.",

    "Rate ∝ 1/η – why xanthan gum's viscosity boost is so effective at slowing settling":
        "Settling speed ∝ 1/viscosity. More viscous liquid = slower settling. Xanthan gum provides this.",

    "Because the relationship is inverse, even moderate viscosity increases produce meaningful reductions in settling rate.":
        "Even a small increase in viscosity noticeably slows settling — xanthan gum is very efficient.",

    "Viscosity must still be balanced against ease of dosing through a syringe or measuring device.":
        "But viscosity cannot be too high, or it will be hard to draw into a syringe.",

    "Micronization minimizes r; xanthan gum maximizes η – both levers applied together":
        "Micronization reduces r; xanthan gum increases η. Both are used together for maximum stability.",

    "Applying both levers together achieves a greater stability benefit than either strategy could alone.":
        "Using both methods together is more effective than using either one alone.",

    "Slower sedimentation means longer stable, well-mixed intervals and accurate first/last doses":
        "Slower settling = the suspension stays uniform for longer = every dose is accurate.",

    "Consistent dosing from the first to the last administration is critical for maintaining therapeutic drug levels.":
        "Consistent doses throughout treatment are essential to keep drug levels therapeutic.",

    # ── SLIDE 25 ─────────────────────────────────────────────────────────────
    "Particles loosely bind into open, lattice-like flocs; settle faster but redisperse easily with gentle shaking":
        "Particles loosely join into soft clumps (flocs). They settle faster but redisperse with a gentle shake.",

    "The loose floc structure traps a relatively large volume of vehicle, giving the sediment a higher apparent volume.":
        "Loose flocs trap liquid inside, creating a large, fluffy sediment that is easy to redisperse.",

    "Because particles remain only weakly bound, minimal shaking force is needed to restore uniform dispersion.":
        "Only a gentle shake is needed to redisperse the loose sediment back into a uniform suspension.",

    "Particles stay separate, settle slowly, but pack into a dense, hard cake that resists redispersion":
        "Deflocculated particles settle slowly but pack into a hard, compact cake at the bottom.",

    "Over time, gravitational settling forces particles into progressively tighter packing, expelling vehicle from between th":
        "Gravity slowly squeezes out the liquid from between particles, making the cake harder over time.",

    "Once caked, redispersion may require vigorous or prolonged shaking, which is impractical for a caregiver at home.":
        "Once caked, even vigorous shaking may not redisperse the particles — very inconvenient for parents.",

    "Flocculated: clear supernatant, loose fluffy sediment":
        "Flocculated: the top liquid is clear; the bottom sediment is loose and fluffy.",

    "Deflocculated: turbid supernatant, compact hard sediment":
        "Deflocculated: top liquid is cloudy; bottom sediment is hard and compact.",

    "These visual cues are often used as simple, practical indicators of suspension quality during formulation screening.":
        "These visible differences are used in labs to quickly assess the quality of a suspension.",

    # ── SLIDE 26 ─────────────────────────────────────────────────────────────
    "Xanthan gum (steric barrier) and colloidal silica (electrostatic/H-bonding network) act together":
        "Xanthan gum provides steric protection; colloidal silica provides a gel network — both work together.",

    "Xanthan gum primarily governs the rheological, steric contribution, while colloidal silica contributes the electrostatic":
        "Xanthan gum mainly controls viscosity and steric protection; Aerosil adds gel structure and charge.",

    "Produces controlled, loose flocculation – sediment settles predictably yet stays soft and redispersible":
        "Together they produce a loose, predictable sediment that is easy to shake back to a uniform suspension.",

    "The resulting sediment volume is noticeably higher than a deflocculated system, reflecting the loose, open floc structur":
        "The sediment looks larger than in deflocculated systems because it is loose and open, not packed.",

    "Ensures dose uniformity after shaking; prevents hard caking across the 14-day in-use period":
        "Every dose is accurate after shaking; no hard caking occurs in the 14-day use period.",

    "It also reduces the likelihood of a patient receiving a subtherapeutic dose from settled, unredispersed drug at the bott":
        "It prevents the child from getting a too-low dose from un-redispersed drug at the bottle bottom.",

    "High physical stability – consistently delivers the correct 200 mg/5 mL dose throughout shelf life":
        "Result: excellent physical stability — always delivers exactly 200 mg/5 mL, every time.",

    "This outcome demonstrates how surface phenomena principles translate directly into a clinically meaningful, stable produ":
        "This shows how surface science principles directly create a safe, effective medicine for children.",

    # ── SLIDE 28 ─────────────────────────────────────────────────────────────
    "Imidazole ring susceptible to attack by OH⁻ under basic conditions (pH > 7) – ring-opening hydrolysis":
        "At pH > 7, OH⁻ ions attack the imidazole ring of metronidazole and break it open (hydrolysis).",

    "The rate of this reaction increases sharply as pH rises above neutral, making alkaline conditions particularly damaging.":
        "The higher the pH above 7, the faster the drug degrades — alkaline conditions are very harmful.",

    "UV light (200–400 nm) drives degradation into nitroso derivatives – reduced potency, toxicological concern":
        "UV light (200–400 nm) breaks metronidazole into harmful nitroso products, reducing drug potency.",

    "Nitroso derivatives formed by UV exposure have raised toxicological concerns in some regulatory assessments.":
        "Nitroso compounds formed by UV can be toxic — this is why opaque packaging is used.",

    "No water = no hydrolysis reactant during storage before dispensing":
        "In the dry form, there is no water — so hydrolysis simply cannot happen during storage.",

    "Without water present, the hydrolysis reaction simply cannot proceed at a meaningful rate.":
        "No water = no hydrolysis. The dry powder stays chemically stable for 2–3 years.",

    "Vulnerability begins only at reconstitution – hence the 14-day refrigerated limit":
        "Degradation risk starts when water is added — that is why the 14-day limit begins at reconstitution.",

    "Pharmacists typically add water at the point of dispensing, immediately starting the 14-day countdown.":
        "The pharmacist adds water when dispensing the medicine, and the 14-day clock begins then.",

    "Dry powder + opaque packaging address both major degradation pathways":
        "Dry powder stops hydrolysis; opaque bottle stops photodegradation — both pathways are blocked.",

    "Addressing both hydrolysis and photodegradation independently ensures neither pathway becomes a weak point in overall st":
        "Blocking both degradation pathways independently ensures no weak spots in the product's stability.",

    # ── SLIDE 30 ─────────────────────────────────────────────────────────────
    "Citric acid/sodium citrate, governed by Henderson–Hasselbalch equilibrium – holds pH 4.0–5.0":
        "Citric acid and sodium citrate (Henderson–Hasselbalch buffer) keep the pH at 4.0–5.0.",

    "Citric acid is triprotic, giving the buffer multiple overlapping pKa values that provide broad buffering capacity near t":
        "Citric acid has 3 ionizable groups, giving broad, strong buffering capacity across pH 4–5.",

    "Corresponds to the region of minimum hydrolysis rate for metronidazole":
        "pH 4–5 is where metronidazole breaks down the slowest — the stability sweet spot.",

    "Degradation rate studies for metronidazole typically show a U-shaped pH-rate profile, with a minimum near pH 4–5.":
        "Stability studies show a U-shaped curve: fastest degradation at very low or high pH, slowest at pH 4–5.",

    "Buffers against dissolved CO₂, acidic flavoring agents, and container ion leaching":
        "The buffer resists pH changes from CO₂ in air, acidic flavors, and ions leaching from the bottle.",

    "Without adequate buffering, these small pH shifts could gradually push the formulation outside its stability optimum.":
        "Without the buffer, small pH shifts would push the formulation outside its stable pH range.",

    "Maintains the optimal stability window across the full 14-day in-use period":
        "The buffer keeps pH at 4–5 throughout the entire 14-day use window.",

    "Buffer depletion is generally not a practical concern within the 14-day in-use period given the concentrations used.":
        "At the concentrations used, the buffer does not run out in 14 days.",

    "This consistency underpins the confidence placed in the labeled 14-day discard timeline.":
        "Stable pH throughout use is what makes the 14-day discard date scientifically valid.",

    "Stable pH → stable drug → stable suspension":
        "Stable pH = stable drug = stable suspension. pH control is the foundation of stability.",

    "This principle illustrates how a single excipient category can influence multiple quality attributes simultaneously.":
        "One excipient (citrate buffer) protects the drug, preservative, and taste at the same time.",

    "Everything from taste to preservative efficacy ultimately traces back to this pH foundation.":
        "pH affects taste, preservation, and drug stability — it is the foundation of this whole formulation.",

    # ── SLIDE 32 ─────────────────────────────────────────────────────────────
    "Reconstitution introduces the water activity needed for microbial growth":
        "Adding water gives microbes what they need to grow — this is why microbial control is needed.",

    "Microorganisms require free water to grow, which is essentially absent in the dry powder state.":
        "Microbes cannot grow in the dry powder — they need free water, which is absent before reconstitution.",

    "High water activity, 25% w/v sucrose (nutrient source), possible intermittent warm storage":
        "After reconstitution: high water activity + sucrose (food for microbes) + possible warm storage = high risk.",

    "Ambient room-temperature excursions during transport or storage can further accelerate microbial proliferation if they o":
        "If the bottle warms up accidentally, microbial growth can speed up rapidly.",

    "Sodium benzoate + methylparaben + propylparaben – each covers a different, overlapping spectrum":
        "Three preservatives are used: sodium benzoate + methylparaben + propylparaben. Each covers different microbes.",

    "Each preservative in this system targets a different organism class, ensuring no major microbial category is left unprot":
        "Together, they protect against bacteria, yeasts, and moulds — no microbe type is left unguarded.",

    "Combined effect exceeds any single agent alone; allows gentler, lower concentrations":
        "Using all three together is more effective than any one alone, and each can be used at a lower dose.",

    "Synergy here means the combined antimicrobial effect exceeds the simple sum of each preservative's individual effect.":
        "Synergy means: combined effect > sum of individual effects. Together, they protect better.",

    "Multi-preservative strategy is standard for aqueous pediatric oral liquids":
        "Using multiple preservatives together is the standard approach for pediatric oral suspensions.",

    "Regulatory pharmacopeias such as USP and BP require formal preservative efficacy testing against a standard panel of org":
        "USP and BP guidelines require the preservative system to be tested against standard microbes.",

    "Adopting an established, well-precedented strategy also simplifies regulatory review during product approval.":
        "Using a well-known, accepted approach also makes regulatory approval easier and faster.",

    # ── SLIDE 33 ─────────────────────────────────────────────────────────────
    "Interfacial tension, contact angle/wetting, and polymer/surfactant adsorption govern wetting, dispersion, and suspension":
        "Interfacial tension, contact angle, and adsorption of Tween 80/xanthan gum control wetting and dispersion.",

    "These principles collectively determine whether the dry powder reconstitutes into a uniform, dosable suspension.":
        "These surface principles decide whether the powder mixes into a uniform, dosable suspension.",

    "Mastery of these interfacial concepts is foundational to understanding suspension dosage form design broadly.":
        "Understanding these surface concepts is fundamental for designing any suspension dosage form.",

    "Controlled flocculation (xanthan gum + colloidal silica) – loose, redispersible sediment, not caking":
        "Xanthan gum + Aerosil together create controlled flocculation: loose sediment, no hard cake.",

    "The moderate, engineered zeta potential achieves this controlled flocculation rather than leaving it to chance.":
        "The carefully set zeta potential (−20 to −30 mV) is what makes this controlled flocculation possible.",

    "Dry-powder format (avoids hydrolysis) + citrate buffer (minimum-degradation pH)":
        "Dry powder prevents hydrolysis; citrate buffer keeps pH at 4–5 (slowest degradation rate).",

    "These two measures together protect the imidazole ring's structural integrity throughout the product's full shelf life.":
        "Together, these two strategies protect the drug from chemical breakdown throughout its shelf life.",

    "Synergistic multi-agent preservative system: sodium benzoate, methylparaben, propylparaben":
        "Three preservatives (sodium benzoate, methylparaben, propylparaben) work synergistically together.",

    "This layered preservative approach ensures broad-spectrum protection despite the introduction of water at reconstitution":
        "This layered approach gives broad protection against bacteria, yeasts, and moulds after reconstitution.",

    "Every excipient serves a specific, scientifically justified purpose – efficacious, stable, safe, palatable":
        "Every ingredient has a clear, science-based role — making the product effective, stable, safe, and pleasant.",

    "This formulation exemplifies how fundamental pharmaceutics principles translate into a safe, effective, real-world pedia":
        "This formulation is a great example of how basic pharmaceutics knowledge creates a real-world medicine for children.",

    "The result is a product that reliably delivers 200 mg of metronidazole per 5 mL across its entire labeled shelf life.":
        "The final product reliably delivers exactly 200 mg per 5 mL throughout its entire shelf life.",
}


def set_run_text(run, new_text):
    """Set text of a run without touching any font properties."""
    run.text = new_text


def process_paragraph(para):
    """If the paragraph text matches a key in SIMPLIFY, replace text while preserving all run formatting."""
    full_text = para.text.strip()
    if full_text not in SIMPLIFY:
        return False  # nothing to do

    new_text = SIMPLIFY[full_text]

    # If there is only one run, simple replacement
    runs = para.runs
    if len(runs) == 0:
        return False
    if len(runs) == 1:
        runs[0].text = new_text
        return True

    # Multiple runs: put all text in first run, clear others
    runs[0].text = new_text
    for run in runs[1:]:
        run.text = ""
    return True


# ── PROCESS ───────────────────────────────────────────────────────────────────
shutil.copy2(SRC, DST)
prs = Presentation(DST)

changed_count = 0
for slide_num, slide in enumerate(prs.slides, 1):
    for shape in slide.shapes:
        if not shape.has_text_frame:
            continue
        for para in shape.text_frame.paragraphs:
            if process_paragraph(para):
                changed_count += 1

prs.save(DST)
print(f"Done. {changed_count} paragraphs simplified.")
print(f"Saved to: {DST}")

"""
Fix the remaining paragraphs that were NOT simplified because their text was truncated
in the extraction output. We match on prefix (startswith) for these long lines.
"""

from pptx import Presentation

DST = "/tmp/workspace/metro-ppt-edit/Metronidazole_Simplified.pptx"

# (prefix_to_match, simplified_replacement)
PREFIX_FIXES = [
    # Slide 3
    ("Suspensions are generally classified as coarse, with particles larger",
     "Suspensions contain particles larger than 1 micron — larger than colloids or solutions."),
    ("Compared with true solutions, suspensions offer a practical route",
     "Suspensions are practical for drugs that cannot dissolve at the dose needed."),
    ("Micronization or controlled crystallization is typically used to bring bulk",
     "The drug powder is milled (micronized) to reach this size before making the suspension."),
    ("This strategy allows manufacturers to label the unreconstituted product",
     "The dry powder can last 2–3 years on the shelf. Once water is added, use within 14 days."),

    # Slide 5
    ("It is structurally related to other 5-nitroimidazoles such as tinidazole",
     "It belongs to the same drug family as tinidazole and ornidazole."),
    ("The drug is included on the WHO Model List of Essential Medicines",
     "It is on the WHO Essential Medicines List because it treats so many common infections."),
    ("The resulting free radicals also interact with proteins and membrane components",
     "These toxic particles also damage cell proteins and membranes, leading to cell death."),
    ("Resistance, though uncommon, can arise from reduced nitroreductase",
     "Resistance is rare but can happen if the microbe reduces its ability to activate the drug."),

    # Slide 6
    ("Its moderate lipophilicity permits reasonable membrane permeability",
     "Its mild fat-solubility lets it pass through cell membranes while still mixing in water."),
    ("The imidazole ring's sensitivity to both pH extremes and UV light",
     "Since the drug breaks down in strong acid/base and UV light, an acidic buffer and opaque bottle are needed."),

    # Slide 7
    ("This approach simplifies distribution logistics, since the unreconstituted",
     "Dry powder is also easier to store and transport as it tolerates temperature changes better."),

    # Slide 8
    ("Micronization increases surface area, which accelerates dissolution once",
     "Smaller particles dissolve faster after swallowing, improving drug absorption in the body."),
    ("Its pseudoplastic, shear-thinning rheology means viscosity drops sharply",
     "When shaken or poured, it becomes thinner (easier to pour). At rest, it thickens again."),
    ("As a non-ionic surfactant, it is compatible with both the anionic xanthan gum",
     "It is compatible with all other ingredients in the formula without causing problems."),
    ("Beyond taste masking, sucrose modestly raises solution viscosity",
     "The extra viscosity from sucrose also helps slow down particle settling."),
    ("This core skeleton mirrors the standard four-component framework",
     "This four-ingredient base is the standard starting point for most pediatric suspensions."),

    # Slide 9
    ("Its antimicrobial activity depends heavily on formulation pH",
     "Only the acid form of benzoate can pass through microbial membranes, so pH matters a lot."),
    ("The buffer system also chelates trace metal ions",
     "The buffer also traps trace metal ions that could otherwise speed up drug degradation."),
    ("Its extremely small particle size gives it a very high surface area",
     "Even a tiny amount of Aerosil creates a very large surface area due to its nano-sized particles."),
    ("The silanol groups on its surface hydrogen-bond with water",
     "Its silanol (-OH) groups bond with water and each other to form a reversible gel."),
    ("Flavor selection also considers masking any lingering bitterness",
     "The flavor also helps hide metronidazole's bitter taste."),
    ("Colorants must be certified for pediatric use",
     "Only approved, child-safe dyes that stay stable at pH 4–5 are used."),
    ("This five-pillar framework is a useful checklist",
     "This five-pillar check is a useful guide for any pediatric liquid medicine."),

    # Slide 12
    ("It is quantitatively expressed in units of dyn/cm or mN/m",
     "It is measured in mN/m using methods like the du Noüy ring or Wilhelmy plate."),
    ("Without intervention, this clumping traps air pockets within particle aggregates",
     "Trapped air inside clumps makes it even harder for water to wet the particles."),
    ("Surfactants work by adsorbing at the solid–liquid interface",
     "Surfactants attach to the particle surface and lower the energy needed to wet them."),

    # Slide 13
    ("Polysorbate 80 is derived from ethoxylated sorbitan",
     "It is made from sorbitan and oleic acid with long water-loving chains that project into water."),
    ("Adsorption is generally rapid, occurring within seconds of contact",
     "This coating forms within seconds when water is added to the dry powder."),
    ("Improved wetting translates directly into faster, more complete dispersion",
     "Better wetting means the suspension mixes quickly and completely with just a gentle shake."),
    ("It also reduces trapped air within particle clusters, which would otherwise",
     "It also removes trapped air from particle clusters, preventing them from floating."),
    ("The hydrated surfactant layer provides a degree of steric hindrance",
     "The coating creates a physical barrier that stops particles from touching and sticking."),
    ("Maintaining this stabilized state throughout the 14-day in-use period",
     "This ensures every dose in the 14-day period has the same drug concentration."),

    # Slide 14
    ("It is measured as the angle formed between the liquid–vapor interface",
     "It is the angle where the liquid meets the solid — smaller angle = better wetting."),
    ("This hydrophobic tendency stems from the drug's limited aqueous solubility",
     "This happens because metronidazole does not dissolve well in water (slightly fat-soluble)."),
    ("Trapped air pockets within powder clumps can also promote localized microbial growth",
     "Air pockets inside clumps can also allow germs to grow if not properly wetted."),
    ("Wetting agents work by lowering the contact angle below the 90° threshold",
     "Wetting agents reduce the contact angle below 90°, making the surface water-friendly."),

    # Slide 15
    ("This shift occurs because the adsorbed surfactant layer lowers the solid–liquid",
     "This happens because Tween 80 lowers the solid-liquid interfacial energy (Young's equation)."),
    ("A negative spreading coefficient instead indicates the liquid will bead up",
     "A negative S means liquid beads up instead of spreading — wetting does not occur."),
    ("Incomplete wetting would leave some particles undispersed, skewing drug concentration",
     "If wetting is incomplete, some doses will have too much drug and others too little."),

    # Slide 16
    ("It is produced industrially through microbial fermentation and purified",
     "It is made in factories by fermenting bacteria and purified for pharmaceutical use."),
    ("The polymer's long, flexible chains extend outward from the particle surface",
     "The long chains stick outward into the liquid, creating a physical barrier around each particle."),
    ("This adsorbed layer increases the effective hydrodynamic size of each particle",
     "This coating makes each particle 'bigger' in effect, slowing its settling rate."),
    ("Electrostatic repulsion arises from the polymer's anionic carboxylate groups",
     "The negative charges on xanthan gum at pH 4–5 push particles apart electrostatically."),
    ("The surrounding weak gel network additionally restrains particle movement",
     "The soft gel network also physically holds particles in place, further slowing settling."),

    # Slide 18
    ("It is manufactured by flame hydrolysis of silicon tetrachloride",
     "It is made by burning silicon tetrachloride vapor to form tiny, non-porous silica particles."),
    ("The resulting network behaves as a weak, elastic gel rather than a rigid solid.",
     "This network is a soft, flexible gel — not a solid. It can be broken and reformed."),
    ("By physically restricting particle mobility, the network reduces the effective settling velocity",
     "This physical entrapment lowers the settling speed below what Stokes' law would predict."),
    ("Recovery time after shaking is typically short, restoring gel structure within seconds",
     "The gel rebuilds within seconds to minutes after shaking stops."),

    # Slide 20
    ("Micelle size and shape depend on the surfactant's molecular geometry",
     "Micelle size and shape depend on the surfactant structure, ions, and pH in the formula."),
    ("This large margin ensures micelles are consistently present throughout the product's",
     "This large safety margin keeps micelles present throughout the full 14-day use period."),
    ("This solubilization capacity helps maintain a visually clear supernatant",
     "This keeps the liquid layer clear even as tiny amounts of degradation occur."),
    ("Ostwald ripening occurs because smaller particles have higher surface energy",
     "Small particles dissolve faster than large ones (higher surface energy) — micelles help prevent this."),

    # Slide 21
    ("This large safety margin accounts for potential minor losses of surfactant",
     "Even if some Tween 80 is lost to adsorption on the bottle or drug particles, plenty remains."),
    ("Ionic surfactants can lose their surfactant function entirely if stored below their Krafft",
     "Ionic surfactants crystallize and stop working if stored below the Krafft temperature."),
    ("This reliability is especially important given that pediatric suspensions are often stored",
     "This matters because home fridges have variable temperatures — Tween 80 works regardless."),
    ("Cold-chain interruptions are common in real-world distribution, particularly in resource-limited",
     "In low-resource settings, temperature control is often imperfect — Tween 80 stays reliable."),
    ("Its combination of low CMC, no Krafft temperature, and broad pH tolerance",
     "Low CMC + no Krafft temperature + works at any pH = excellent all-round surfactant."),

    # Slide 22
    ("The interplay between these two forces determines whether particles remain dispersed",
     "The balance of these two forces decides if particles stay separate or clump together permanently."),
    ("The theory provides a quantitative framework for predicting colloidal stability",
     "DLVO theory allows scientists to predict whether a suspension will be stable based on measurable parameters."),
    ("Below this magnitude, electrostatic repulsion is generally too weak to prevent particles",
     "Below ±30 mV, the repulsion is too weak and particles may start to aggregate."),
    ("This value falls into the range typically associated with controlled or moderate flocculation",
     "This moderate value allows controlled (loose) flocculation — particles clump gently and can be re-shaken."),
    ("It reflects the combined influence of xanthan gum's anionic charge and the citrate buffer",
     "This value comes from xanthan gum's negative charge and the ionic strength of the citrate buffer."),
    ("A fully deflocculated system would instead risk forming a dense, hard-to-redisperse cake",
     "A fully deflocculated system would form a hard, impossible-to-shake cake after 14 days."),

    # Slide 24
    ("The equation assumes spherical, non-interacting particles settling",
     "The formula assumes round particles settling smoothly without touching each other."),
    ("Every term in the equation represents a formulation lever",
     "Each part of the equation tells us one way to slow down settling in a formulation."),
    ("Halving particle radius, for example, reduces settling velocity to roughly one-quarter",
     "Cutting particle size in half = 4× slower settling. Micronization is very powerful."),
    ("Particle size control also indirectly benefits wetting and dissolution",
     "Smaller particles also wet better and dissolve faster — a bonus benefit of micronization."),
    ("Because the relationship is inverse, even moderate viscosity increases",
     "Even a small increase in viscosity noticeably slows settling — xanthan gum is very efficient."),
    ("Viscosity must still be balanced against ease of dosing",
     "But viscosity cannot be too high, or it will be hard to draw into a syringe."),
    ("Applying both levers together achieves a greater stability benefit",
     "Using both methods together is more effective than using either one alone."),
    ("Consistent dosing from the first to the last administration is critical",
     "Consistent doses throughout treatment are essential to keep drug levels therapeutic."),

    # Slide 25
    ("The loose floc structure traps a relatively large volume of vehicle",
     "Loose flocs trap liquid inside, creating a large, fluffy sediment that is easy to redisperse."),
    ("Because particles remain only weakly bound, minimal shaking force is needed",
     "Only a gentle shake is needed to redisperse the loose sediment back into a uniform suspension."),
    ("Over time, gravitational settling forces particles into progressively tighter packing",
     "Gravity slowly squeezes out the liquid from between particles, making the cake harder over time."),
    ("Once caked, redispersion may require vigorous or prolonged shaking",
     "Once caked, even vigorous shaking may not redisperse the particles — very inconvenient for parents."),
    ("These visual cues are often used as simple, practical indicators of suspension quality",
     "These visible differences are used in labs to quickly assess the quality of a suspension."),

    # Slide 26
    ("Xanthan gum primarily governs the rheological, steric contribution, while colloidal silica",
     "Xanthan gum mainly controls viscosity and steric protection; Aerosil adds gel structure and charge."),
    ("The resulting sediment volume is noticeably higher than a deflocculated system",
     "The sediment looks larger than in deflocculated systems because it is loose and open, not packed."),
    ("It also reduces the likelihood of a patient receiving a subtherapeutic dose",
     "It prevents the child from getting a too-low dose from un-redispersed drug at the bottle bottom."),
    ("This outcome demonstrates how surface phenomena principles translate directly",
     "This shows how surface science principles directly create a safe, effective medicine for children."),

    # Slide 28
    ("The rate of this reaction increases sharply as pH rises above neutral",
     "The higher the pH above 7, the faster the drug degrades — alkaline conditions are very harmful."),
    ("Nitroso derivatives formed by UV exposure have raised toxicological concerns",
     "Nitroso compounds formed by UV can be toxic — this is why opaque packaging is used."),
    ("Without water present, the hydrolysis reaction simply cannot proceed",
     "No water = no hydrolysis. The dry powder stays chemically stable for 2–3 years."),
    ("Pharmacists typically add water at the point of dispensing",
     "The pharmacist adds water when dispensing the medicine, and the 14-day clock begins then."),
    ("Addressing both hydrolysis and photodegradation independently ensures neither pathway",
     "Blocking both degradation pathways independently ensures no weak spots in the product's stability."),

    # Slide 30
    ("Citric acid is triprotic, giving the buffer multiple overlapping pKa values",
     "Citric acid has 3 ionizable groups, giving broad, strong buffering capacity across pH 4–5."),
    ("Degradation rate studies for metronidazole typically show a U-shaped pH-rate profile",
     "Stability studies show a U-shaped curve: fastest degradation at very low or high pH, slowest at pH 4–5."),
    ("Without adequate buffering, these small pH shifts could gradually push the formulation",
     "Without the buffer, small pH shifts would push the formulation outside its stable pH range."),
    ("Buffer depletion is generally not a practical concern within the 14-day in-use period",
     "At the concentrations used, the buffer does not run out in 14 days."),
    ("This consistency underpins the confidence placed in the labeled 14-day discard timeline.",
     "Stable pH throughout use is what makes the 14-day discard date scientifically valid."),
    ("This principle illustrates how a single excipient category can influence multiple quality attributes",
     "One excipient (citrate buffer) protects the drug, preservative, and taste at the same time."),
    ("Everything from taste to preservative efficacy ultimately traces back to this pH foundation.",
     "pH affects taste, preservation, and drug stability — it is the foundation of this whole formulation."),

    # Slide 32
    ("Microorganisms require free water to grow, which is essentially absent",
     "Microbes cannot grow in the dry powder — they need free water, which is absent before reconstitution."),
    ("Ambient room-temperature excursions during transport or storage can further accelerate",
     "If the bottle warms up accidentally, microbial growth can speed up rapidly."),
    ("Each preservative in this system targets a different organism class",
     "Together, they protect against bacteria, yeasts, and moulds — no microbe type is left unguarded."),
    ("Synergy here means the combined antimicrobial effect exceeds the simple sum",
     "Synergy means: combined effect > sum of individual effects. Together, they protect better."),
    ("Regulatory pharmacopeias such as USP and BP require formal preservative efficacy testing",
     "USP and BP guidelines require the preservative system to be tested against standard microbes."),
    ("Adopting an established, well-precedented strategy also simplifies regulatory review",
     "Using a well-known, accepted approach also makes regulatory approval easier and faster."),

    # Slide 33
    ("These principles collectively determine whether the dry powder reconstitutes",
     "These surface principles decide whether the powder mixes into a uniform, dosable suspension."),
    ("Mastery of these interfacial concepts is foundational to understanding suspension",
     "Understanding these surface concepts is fundamental for designing any suspension dosage form."),
    ("The moderate, engineered zeta potential achieves this controlled flocculation",
     "The carefully set zeta potential (−20 to −30 mV) is what makes this controlled flocculation possible."),
    ("These two measures together protect the imidazole ring's structural integrity",
     "Together, these two strategies protect the drug from chemical breakdown throughout its shelf life."),
    ("This layered preservative approach ensures broad-spectrum protection despite",
     "This layered approach gives broad protection against bacteria, yeasts, and moulds after reconstitution."),
    ("This formulation exemplifies how fundamental pharmaceutics principles translate into",
     "This formulation is a great example of how basic pharmaceutics knowledge creates a real-world medicine for children."),
    ("The result is a product that reliably delivers 200 mg of metronidazole per 5 mL",
     "The final product reliably delivers exactly 200 mg per 5 mL throughout its entire shelf life."),
]


def process_paragraph_prefix(para):
    full_text = para.text.strip()
    for prefix, replacement in PREFIX_FIXES:
        if full_text.startswith(prefix):
            runs = para.runs
            if len(runs) == 0:
                return False
            runs[0].text = replacement
            for run in runs[1:]:
                run.text = ""
            return True
    return False


prs = Presentation(DST)
changed = 0
for slide in prs.slides:
    for shape in slide.shapes:
        if not shape.has_text_frame:
            continue
        for para in shape.text_frame.paragraphs:
            if process_paragraph_prefix(para):
                changed += 1

prs.save(DST)
print(f"Prefix-fixed {changed} additional paragraphs.")

"""
20-slide Metronidazole Suspension PPT
- Font: Times New Roman (headings 28pt, body 20pt)
- Design: matches reference PPT style (light bg, color per member, clean layout)
- Member colors: M1=#1E3A6D(navy), M2=#2C5F2D(green), M3=#5B2A86(purple), M4=#B8460E(orange)
- BG: white/near-white, heading bars: very light tint of member color
"""

import os
os.makedirs("/tmp/workspace/metro-new", exist_ok=True)

from pptx import Presentation
from pptx.util import Inches, Pt, Emu
from pptx.dml.color import RGBColor
from pptx.enum.text import PP_ALIGN, MSO_ANCHOR

prs = Presentation()
prs.slide_width  = Inches(13.333)
prs.slide_height = Inches(7.5)

# ── COLORS ────────────────────────────────────────────────────────────────────
WHITE      = RGBColor(0xFF,0xFF,0xFF)
OFFWHITE   = RGBColor(0xF5,0xF7,0xFA)   # slide background
DARK_TEXT  = RGBColor(0x22,0x22,0x22)
GREY_TEXT  = RGBColor(0x99,0x99,0x99)
MID_TEXT   = RGBColor(0x44,0x44,0x44)

# Member accent colors (matching reference exactly)
M1_DARK  = RGBColor(0x1E,0x3A,0x6D)   # navy
M1_LIGHT = RGBColor(0xD6,0xE4,0xF7)   # light navy tint
M2_DARK  = RGBColor(0x2C,0x5F,0x2D)   # dark green
M2_LIGHT = RGBColor(0xD4,0xEC,0xD4)   # light green
M3_DARK  = RGBColor(0x5B,0x2A,0x86)   # purple
M3_LIGHT = RGBColor(0xE8,0xD8,0xF5)   # light purple
M4_DARK  = RGBColor(0xB8,0x46,0x0E)   # orange
M4_LIGHT = RGBColor(0xF9,0xE3,0xD4)   # light orange
TEAL     = RGBColor(0x02,0xC3,0x9A)   # accent (title slide)
TITLE_BG = RGBColor(0x1E,0x27,0x61)   # title slide deep blue

# font names
FH = "Times New Roman"  # heading font
FB = "Times New Roman"  # body font (Times NR for both as requested)

# ── HELPERS ───────────────────────────────────────────────────────────────────
def blank(prs):
    return prs.slides.add_slide(prs.slide_layouts[6])

def set_solid_bg(slide, color):
    fill = slide.background.fill
    fill.solid()
    fill.fore_color.rgb = color

def rect(slide, x, y, w, h, fill_color, line_color=None, line_width=Pt(0)):
    from pptx.enum.shapes import MSO_SHAPE_TYPE
    shp = slide.shapes.add_shape(1, Inches(x), Inches(y), Inches(w), Inches(h))
    shp.fill.solid()
    shp.fill.fore_color.rgb = fill_color
    if line_color:
        shp.line.color.rgb = line_color
        shp.line.width = line_width
    else:
        shp.line.fill.background()
    return shp

def tb(slide, x, y, w, h):
    """Add textbox, return text_frame."""
    box = slide.shapes.add_textbox(Inches(x), Inches(y), Inches(w), Inches(h))
    tf = box.text_frame
    tf.word_wrap = True
    tf.margin_left  = Pt(3)
    tf.margin_right = Pt(3)
    tf.margin_top   = Pt(2)
    tf.margin_bottom= Pt(2)
    return tf

def add_text(tf, text, font_name, font_size, bold=False, italic=False,
             color=DARK_TEXT, align=PP_ALIGN.LEFT, first=True, space_before=Pt(0), space_after=Pt(3)):
    if first:
        p = tf.paragraphs[0]
    else:
        p = tf.add_paragraph()
    p.alignment = align
    p.space_before = space_before
    p.space_after  = space_after
    run = p.add_run()
    run.text = text
    run.font.name  = font_name
    run.font.size  = font_size
    run.font.bold  = bold
    run.font.italic= italic
    run.font.color.rgb = color
    return p

def footer(slide, member_label, accent_color):
    """Standard footer matching reference design."""
    tf_left = tb(slide, 0.50, 7.08, 8.0, 0.30)
    add_text(tf_left, member_label, FB, Pt(11), italic=True, color=GREY_TEXT)
    tf_right = tb(slide, 8.0, 7.08, 4.80, 0.30)
    add_text(tf_right, "Metronidazole 200mg/5mL Oral Dry Suspension", FB, Pt(11), italic=True, color=GREY_TEXT, align=PP_ALIGN.RIGHT)

def heading(slide, text, accent_color, y=0.10, x=0.10, w=13.1):
    """Slide heading — colored text, no heavy bar, matching reference."""
    tf_h = tb(slide, x, y, w, 0.55)
    add_text(tf_h, text, FH, Pt(28), bold=True, color=accent_color)

def member_intro_slide(prs, member_num, member_name, section_title, section_desc, accent_dark, accent_light):
    """Divider slide for each member — matches reference layout exactly."""
    slide = blank(prs)
    set_solid_bg(slide, OFFWHITE)
    # Left white box with member label
    rect(slide, 0.70, 1.70, 3.90, 3.60, WHITE, WHITE)
    tf_m = tb(slide, 0.70, 2.55, 3.90, 0.55)
    add_text(tf_m, f"MEMBER {member_num}", FH, Pt(34), bold=True, color=accent_dark, align=PP_ALIGN.CENTER)
    tf_n = tb(slide, 0.90, 3.25, 3.50, 0.75)
    add_text(tf_n, member_name, FB, Pt(22), color=DARK_TEXT, align=PP_ALIGN.CENTER)
    # Right section title + description
    tf_st = tb(slide, 5.10, 1.90, 7.70, 1.30)
    add_text(tf_st, section_title, FH, Pt(46), bold=True, color=accent_dark)
    tf_sd = tb(slide, 5.10, 3.20, 7.70, 2.20)
    add_text(tf_sd, section_desc, FB, Pt(31), italic=True, color=MID_TEXT)
    footer(slide, f"Member {member_num}", accent_dark)

def content_slide(prs, slide_title, content_blocks, accent_dark, member_label):
    """
    content_blocks = list of (sub_heading_str, [bullet_str, ...])
    Creates a clean content slide matching reference.
    """
    slide = blank(prs)
    set_solid_bg(slide, WHITE)
    heading(slide, slide_title, accent_dark)
    # Light heading underline bar
    rect(slide, 0.10, 0.65, 13.1, 0.03, accent_dark)
    # Content area
    content_tf = tb(slide, 0.15, 0.72, 13.0, 6.20)
    first = True
    for sub_h, bullets in content_blocks:
        add_text(content_tf, sub_h, FB, Pt(20), bold=True, color=DARK_TEXT,
                 first=first, space_before=Pt(6) if not first else Pt(2), space_after=Pt(2))
        first = False
        for b in bullets:
            add_text(content_tf, b, FB, Pt(20), bold=False, color=DARK_TEXT,
                     first=False, space_before=Pt(1), space_after=Pt(2))
    footer(slide, member_label, accent_dark)


# ═══════════════════════════════════════════════════════════════════════════════
# SLIDE 1 — TITLE SLIDE
# ═══════════════════════════════════════════════════════════════════════════════
slide = blank(prs)
set_solid_bg(slide, OFFWHITE)
# Full-width deep blue background shape
rect(slide, 0, -0.14, 13.30, 7.50, TITLE_BG)
# White content panel
rect(slide, 0.92, 1.30, 11.50, 4.60, WHITE, WHITE)
# Main title text
tf_title = tb(slide, 1.30, 1.35, 10.70, 1.70)
add_text(tf_title, "Metronidazole 200mg/5mL", FH, Pt(52), bold=True, color=M1_DARK, align=PP_ALIGN.CENTER)
add_text(tf_title, "Oral Dry Suspension", FH, Pt(52), bold=True, color=M1_DARK,
         first=False, align=PP_ALIGN.CENTER)
# Subtitle
tf_sub = tb(slide, 1.30, 3.05, 10.70, 0.55)
add_text(tf_sub, "Explained on the Basis of Surface Phenomena and Stability",
         FH, Pt(26), italic=True, color=RGBColor(0x1C,0x72,0x93), align=PP_ALIGN.CENTER)
# Green badge
rect(slide, 4.85, 3.68, 3.60, 0.42, TEAL)
tf_grp = tb(slide, 4.79, 3.68, 3.60, 0.42)
add_text(tf_grp, "PRESENTED BY: GROUP 09", FB, Pt(20), bold=True, color=WHITE, align=PP_ALIGN.CENTER)
# Member names
tf_mem = tb(slide, 1.24, 4.18, 10.70, 1.75)
add_text(tf_mem, "Muhammad Sulaiman     |     Hafza Rashid     |     Ume Ummarah Antique     |     Muhammad Afridi",
         FB, Pt(20), color=MID_TEXT, align=PP_ALIGN.CENTER)
# Bottom footer bar
tf_bot = tb(slide, 0.50, 6.95, 12.30, 0.35)
add_text(tf_bot, "Department of Pharmacy  |  Pharmaceutics — Surface Phenomena & Suspension Stability",
         FB, Pt(17), italic=True, color=RGBColor(0xCA,0xDC,0xFC), align=PP_ALIGN.CENTER)


# ═══════════════════════════════════════════════════════════════════════════════
# MEMBER 1 — MUHAMMAD SULAIMAN  (Slides 2–6)
# ═══════════════════════════════════════════════════════════════════════════════
member_intro_slide(prs, 1, "MUHAMMAD SULAIMAN",
    "Introduction of\nDosage Form",
    "What is an oral suspension, Metronidazole drug profile,\nformulation composition, and why a dry powder format.",
    M1_DARK, M1_LIGHT)

# SLIDE 3 — What Is an Oral Suspension?
content_slide(prs, "What Is an Oral Suspension?", [
    ("Definition", [
        "A suspension has two parts: solid drug particles mixed (dispersed) throughout a liquid vehicle.",
        "It is used when a drug does not dissolve well in water, or when taste masking is needed.",
        "Suspension particles are larger than 1 micron — bigger than colloids or true solutions.",
    ]),
    ("Why Use a Suspension?", [
        "Useful for drugs that cannot dissolve at the required therapeutic dose in water.",
        "Gives a liquid dose form that is easy for children and elderly patients to swallow.",
        "Particle size (USP): 0.5–10 µm — small enough to pass through a dosing syringe safely.",
    ]),
    ("Physical Instability Challenge", [
        "Solid and liquid phases differ in density — the solid slowly sinks to the bottom (sedimentation).",
        "Without suspending and wetting agents, particles clump and form a hard, un-shakeable lump (caking).",
    ]),
    ("Why Dry Powder Format?", [
        "Keeping the product as a dry powder avoids instability problems of a pre-made liquid.",
        "Dry powder shelf life: 2–3 years. Once water is added by the pharmacist: use within 14 days.",
    ]),
], M1_DARK, "Member 1")

# SLIDE 4 — Drug Profile: Metronidazole
content_slide(prs, "Drug Profile: Metronidazole", [
    ("Drug Class & WHO Status", [
        "Nitroimidazole antibiotic — kills anaerobic bacteria and parasites (antiprotozoal).",
        "Related to tinidazole and ornidazole; listed on the WHO Essential Medicines List.",
        "Available as tablet, injection, topical gel, and oral suspension — the suspension is used mainly in children.",
    ]),
    ("Mechanism of Action", [
        "Inside bacteria/parasites, the drug is converted into toxic free radicals that break DNA strands.",
        "It only activates in oxygen-free (anaerobic) environments — so it does not harm normal human cells.",
        "The free radicals also damage cell membranes and proteins, causing complete cell death.",
    ]),
    ("Clinical Indications", [
        "Amoebiasis, giardiasis, trichomoniasis (parasitic infections).",
        "Anaerobic bacterial infections — caused by Bacteroides, Clostridium species.",
        "Helicobacter pylori eradication (peptic ulcer), dental infections, surgical prophylaxis.",
    ]),
], M1_DARK, "Member 1")

# SLIDE 5 — Formulation Composition (Part 1)
content_slide(prs, "Formulation Composition — Part 1", [
    ("Metronidazole 200 mg / 5 mL — Active Drug (API)", [
        "Finely ground (micronized) to increase surface area → faster dissolution and better drug absorption.",
        "Micronized particles (< 10 µm) disperse more evenly and stay suspended longer.",
    ]),
    ("Xanthan Gum 0.5% w/v — Suspending Agent", [
        "A large, negatively charged sugar polymer that forms a soft gel network to slow particle settling.",
        "Shear-thinning: becomes thinner when shaken (easy to pour/dose), thickens again at rest.",
    ]),
    ("Polysorbate 80 (Tween 80) 0.1% w/v — Wetting Agent", [
        "Non-ionic surfactant; reduces surface tension so water spreads over and wets every particle.",
        "Compatible with all other excipients; works at any pH without losing its properties.",
    ]),
    ("Sucrose 25% w/v — Sweetener / Viscosity Builder", [
        "Makes the suspension sweet and pleasant for children — improves compliance.",
        "Also adds mild viscosity, helping slow down particle settling.",
    ]),
], M1_DARK, "Member 1")

# SLIDE 6 — Formulation Composition (Part 2)
content_slide(prs, "Formulation Composition — Part 2", [
    ("Sodium Benzoate 0.1% w/v — Preservative", [
        "Works best at slightly acidic pH; the acid form penetrates and kills microbial cells.",
        "pH-dependent: only active below pH 5 — this is why the citrate buffer is essential.",
    ]),
    ("Citrate Buffer (Citric Acid + Sodium Citrate) — pH Control", [
        "Keeps pH at 4.0–5.0 throughout the 14-day use period.",
        "pH 4–5 is the stability sweet spot — metronidazole degrades slowest at this pH.",
        "Also traps (chelates) trace metal ions that could speed up oxidative drug breakdown.",
    ]),
    ("Colloidal Silicon Dioxide (Aerosil) 0.2% w/v — Structuring Agent", [
        "Ultra-fine silica that forms a thixotropic 3-D gel: holds particles at rest, flows when shaken.",
        "Silanol (–Si-OH) groups bond with water and each other to build a reversible gel network.",
    ]),
    ("Flavor, Color & Formulation Logic", [
        "Strawberry flavor and pink dye — improve palatability and acceptance in children.",
        "Every excipient serves one purpose: efficacy, stability, safety, taste, or compliance.",
    ]),
], M1_DARK, "Member 1")


# ═══════════════════════════════════════════════════════════════════════════════
# MEMBER 2 — HAFZA RASHID  (Slides 7–11)
# ═══════════════════════════════════════════════════════════════════════════════
member_intro_slide(prs, 2, "HAFZA RASHID",
    "Surface Phenomena",
    "Surface & interfacial tension, wetting behaviour,\nadsorption of Polysorbate 80, xanthan gum, and colloidal silica.",
    M2_DARK, M2_LIGHT)

# SLIDE 8 — Surface & Interfacial Tension
content_slide(prs, "Surface & Interfacial Tension", [
    ("Surface Tension", [
        "Water molecules at the surface experience a net inward pull — the surface behaves like a stretched film.",
        "Measured in mN/m using the du Noüy ring method or Wilhelmy plate method.",
        "High surface tension makes it hard for water to spread over hydrophobic (water-repelling) particles.",
    ]),
    ("Interfacial Tension", [
        "The tension acting at the boundary between two different phases — here, solid drug and liquid vehicle.",
        "High solid-liquid interfacial tension means particles resist being wet by water → they clump together.",
        "Lower interfacial tension = particles spread more easily into the liquid → uniform suspension.",
    ]),
    ("Metronidazole's Challenge", [
        "Metronidazole is slightly hydrophobic → high interfacial tension against water.",
        "Particles clump to minimize water contact → trapped air, poor wetting, uneven dispersion.",
    ]),
    ("Solution: Polysorbate 80", [
        "Tween 80 adsorbs at the solid-liquid interface and lowers interfacial tension significantly.",
        "This breaks the clumps, removes trapped air, and allows water to wet every particle.",
    ]),
], M2_DARK, "Member 2")

# SLIDE 9 — Wetting & Contact Angle
content_slide(prs, "Wetting of Drug Particles", [
    ("Contact Angle (θ) — Measure of Wettability", [
        "Contact angle is the angle where the liquid surface meets the solid — it measures how well the liquid spreads.",
        "θ < 90°: liquid spreads (hydrophilic surface — good wetting).",
        "θ > 90°: liquid beads up (hydrophobic surface — poor wetting).",
    ]),
    ("Metronidazole's Wetting Problem", [
        "Metronidazole has θ > 90° in plain water — particles float, clump, and trap air bubbles.",
        "Poor wetting → uneven mixing → inaccurate doses → gritty feeling in the mouth.",
        "Air pockets inside clumps can also allow localized microbial growth.",
    ]),
    ("Spreading Coefficient (S)", [
        "S = γSA − γSL − γLA. If S is positive, the liquid spreads spontaneously over the solid.",
        "Tween 80 lowers γSL (solid-liquid tension) → S becomes positive → liquid spreads naturally.",
        "Negative S = liquid beads up instead of spreading — wetting fails.",
    ]),
    ("Clinical Importance", [
        "Complete wetting ensures every 5 mL dose delivers exactly 200 mg of metronidazole.",
        "If some particles are not wet, drug concentration becomes inconsistent between doses.",
    ]),
], M2_DARK, "Member 2")

# SLIDE 10 — Adsorption: Polysorbate 80
content_slide(prs, "Adsorption: Role of Polysorbate 80 (Tween 80)", [
    ("Surfactant Properties", [
        "Non-ionic surfactant with HLB ≈ 15 — strongly hydrophilic, ideal for wetting solid particles in water.",
        "Made from sorbitan + oleic acid with long ethoxylated water-loving chains.",
        "Non-ionic = compatible with all excipients and stable at any pH (no charge changes).",
    ]),
    ("Adsorption Mechanism at Particle Surface", [
        "Hydrophobic (oily) tail anchors onto the drug particle surface.",
        "Hydrophilic (watery) head projects outward into the liquid vehicle.",
        "This monolayer coat converts a hydrophobic drug surface into a hydrophilic one — within seconds.",
    ]),
    ("Stabilization Effect", [
        "The adsorbed layer creates a steric barrier — stops particles from touching and sticking together.",
        "Tween 80 stays effective throughout the full 14-day use period, keeping particles stable.",
    ]),
    ("Micellization (CMC)", [
        "Tween 80 CMC ≈ 0.012 mg/mL. Formula uses ~1 mg/mL — about 80× above CMC.",
        "Micelles (oily tails inside, watery heads outside) solubilize trace fat-soluble impurities.",
        "Being non-ionic, micelles form at both fridge (2–8°C) and room temperature — very reliable.",
    ]),
], M2_DARK, "Member 2")

# SLIDE 11 — Adsorption: Xanthan Gum & Aerosil
content_slide(prs, "Adsorption: Xanthan Gum & Colloidal Silica (Aerosil)", [
    ("Xanthan Gum — Steric & Electrostatic Protection", [
        "Large, branched, negatively charged sugar polymer; chains adsorb onto particle surfaces.",
        "Polymer chains extend outward into the liquid — creating a thick steric barrier around each particle.",
        "Negative carboxylate groups push particles apart electrostatically (electrostatic repulsion).",
        "Result: particles stay separate, do not cake, and re-mix evenly with a gentle shake.",
    ]),
    ("Colloidal Silica (Aerosil) — Gel Network Formation", [
        "Ultra-fine silica particles (nano-sized) with huge surface area; adsorb via –Si-OH groups.",
        "Silanol groups hydrogen-bond with water and each other → 3-D gel network spanning the vehicle.",
        "This gel physically traps drug particles, slowing their settling below what Stokes' law predicts.",
    ]),
    ("Thixotropic Behavior — Best of Both Worlds", [
        "At rest: gel is intact → particles are held in place, minimal settling.",
        "On shaking: gel breaks down → suspension flows freely for accurate dosing.",
        "On standing: gel rebuilds within seconds → protection resumes automatically.",
    ]),
], M2_DARK, "Member 2")


# ═══════════════════════════════════════════════════════════════════════════════
# MEMBER 3 — UME UMMARAH ANTIQUE  (Slides 12–16)
# ═══════════════════════════════════════════════════════════════════════════════
member_intro_slide(prs, 3, "UME UMMARAH ANTIQUE",
    "Surface Phenomena &\nPhysical Stability",
    "Micellization, zeta potential, DLVO theory,\nsedimentation kinetics, and flocculation behaviour.",
    M3_DARK, M3_LIGHT)

# SLIDE 13 — Micellization & CMC
content_slide(prs, "Micellization & Critical Micelle Concentration (CMC)", [
    ("What Is a Micelle?", [
        "Above the CMC, surfactant molecules self-assemble: oily tails point inward, watery heads point outward.",
        "Below the CMC: individual surfactant molecules float freely — no micelles form yet.",
        "Micelle size and shape depend on the surfactant structure, pH, and ionic strength of the vehicle.",
    ]),
    ("Tween 80 in This Formulation", [
        "CMC of Tween 80 ≈ 0.012 mg/mL. Formula concentration ≈ 1 mg/mL — about 80× above CMC.",
        "This large safety margin ensures micelles are always present throughout the 14-day use period.",
        "Non-ionic → no Krafft temperature → micelles form reliably at both fridge and room temperature.",
    ]),
    ("What Micelles Do in the Formula", [
        "Micellar core (oily interior) solubilizes trace fat-soluble impurities and degradation products.",
        "This keeps the liquid layer visually clear even as small amounts of degradation occur over time.",
        "Micelles also slow Ostwald ripening — they prevent small particles from dissolving and redepositing onto larger ones.",
    ]),
], M3_DARK, "Member 3")

# SLIDE 14 — Zeta Potential & DLVO Theory
content_slide(prs, "Zeta Potential & DLVO Theory", [
    ("DLVO Theory", [
        "Predicts suspension stability: Total interaction energy = Repulsion (electrostatic) + Attraction (van der Waals).",
        "At short distances, van der Waals attraction pulls particles together.",
        "At medium distance, electrostatic repulsion creates an energy barrier that keeps particles apart.",
        "If this barrier is strong enough, particles stay dispersed; if weak, they aggregate irreversibly.",
    ]),
    ("Zeta Potential — Stability Threshold", [
        "Zeta potential measures the electric charge at the particle surface in the liquid.",
        "General rule: |ζ| > 30 mV = good stability (strong repulsion prevents aggregation).",
        "Below ±30 mV, repulsion is too weak — particles may start to aggregate and cake.",
        "Measured by laser Doppler instruments that track particle movement in an electric field.",
    ]),
    ("This Formulation's Strategy", [
        "Zeta potential ≈ −20 to −30 mV — intentionally set below the strict ±30 mV threshold.",
        "Xanthan gum's negative charge + citrate buffer ionic strength together set this value.",
        "This moderate zeta potential creates controlled flocculation — loose, re-shakeable sediment, not hard cake.",
    ]),
], M3_DARK, "Member 3")

# SLIDE 15 — Sedimentation — Stokes' Law
content_slide(prs, "Sedimentation — Stokes\u2019 Law", [
    ("Stokes' Law Formula", [
        "v = 2r²(ρs − ρl)g / 9η — gives the terminal velocity (speed) at which particles settle.",
        "r = particle radius, ρs = particle density, ρl = liquid density, g = gravity, η = viscosity.",
        "Every term in this equation is a formulation tool we can adjust to slow settling.",
    ]),
    ("Particle Size Effect (r²)", [
        "Settling speed is proportional to r² — halving particle radius reduces settling speed by 4×.",
        "Micronization (reducing r) is the single most powerful way to slow sedimentation.",
        "Smaller particles also wet better and dissolve faster after swallowing — a bonus benefit.",
    ]),
    ("Viscosity Effect (1/η)", [
        "Settling speed is inversely proportional to viscosity — xanthan gum increases η significantly.",
        "Even a small viscosity increase slows settling noticeably; but viscosity must not be too high for syringe use.",
    ]),
    ("Combined Strategy in This Formula", [
        "Micronization minimizes r; xanthan gum + sucrose maximize η — both levers used together.",
        "Using both strategies together is far more effective than either alone.",
        "Result: slower settling = suspension stays uniform longer = accurate first and last dose.",
    ]),
], M3_DARK, "Member 3")

# SLIDE 16 — Flocculated vs Deflocculated
content_slide(prs, "Flocculated vs Deflocculated Suspensions", [
    ("Flocculated Suspension", [
        "Particles loosely join into soft, open clumps (flocs) — settle faster but disperse with a gentle shake.",
        "Loose floc structure traps liquid inside, giving a large, fluffy, easy-to-redisperse sediment.",
        "Visual sign: clear supernatant above a loose, fluffy sediment layer.",
    ]),
    ("Deflocculated Suspension", [
        "Particles stay fully separate, settle very slowly — but pack into a dense, hard cake over time.",
        "Gravity slowly squeezes liquid out from between particles, making the cake progressively harder.",
        "Once caked, vigorous shaking may still not redisperse the particles — very impractical at home.",
        "Visual sign: cloudy (turbid) supernatant above a hard, compact sediment.",
    ]),
    ("Controlled Flocculation — The Best Strategy", [
        "Xanthan gum (steric) + Aerosil (gel network) together produce controlled, loose flocculation.",
        "Loose sediment settles predictably and redisperses easily after a gentle shake.",
        "Every dose delivers exactly 200 mg/5 mL throughout the full 14-day use period.",
    ]),
], M3_DARK, "Member 3")


# ═══════════════════════════════════════════════════════════════════════════════
# MEMBER 4 — MUHAMMAD AFRIDI  (Slides 17–20)
# ═══════════════════════════════════════════════════════════════════════════════
member_intro_slide(prs, 4, "MUHAMMAD AFRIDI",
    "Chemical & Microbial\nStability + Conclusion",
    "Hydrolysis, pH buffering, preservative systems,\nand overall formulation conclusion.",
    M4_DARK, M4_LIGHT)

# SLIDE 18 — Chemical Stability
content_slide(prs, "Chemical Stability", [
    ("Hydrolytic Degradation", [
        "At pH > 7, OH⁻ ions attack the imidazole ring of metronidazole and break it apart (ring-opening hydrolysis).",
        "The higher the pH above 7, the faster the drug degrades — alkaline conditions are highly damaging.",
        "In the dry powder state, there is no water → hydrolysis cannot occur → dry powder stays stable for 2–3 years.",
    ]),
    ("Photodegradation", [
        "UV light (200–400 nm) converts metronidazole into nitroso derivatives — reduced potency, possible toxicity.",
        "Solution: opaque (amber or dark) bottle packaging blocks UV light and prevents photodegradation.",
    ]),
    ("Reconstitution & Use Window", [
        "Chemical degradation risk begins only when water is added at the pharmacy.",
        "14-day refrigerated limit (2–8°C) starts from reconstitution — not from the manufacturing date.",
        "Keeping the bottle in the fridge slows hydrolysis significantly (Arrhenius principle).",
    ]),
    ("Two-Pronged Defense", [
        "Dry powder format prevents hydrolysis during storage.",
        "Opaque bottle prevents photodegradation throughout use.",
        "Citrate buffer maintains pH 4–5, the pH range of minimum degradation rate for metronidazole.",
    ]),
], M4_DARK, "Member 4")

# SLIDE 19 — pH Control & Buffering
content_slide(prs, "pH Control & Buffering", [
    ("Citrate Buffer System", [
        "Citric acid + sodium citrate: keeps pH fixed at 4.0–5.0 (Henderson–Hasselbalch equilibrium).",
        "Citric acid has 3 ionizable groups → broad, strong buffering capacity across the pH 4–5 range.",
    ]),
    ("Why pH 4–5 Is the Stability Sweet Spot", [
        "Metronidazole shows a U-shaped pH-degradation curve — slowest breakdown at pH 4–5.",
        "At higher pH (> 6), hydrolysis accelerates sharply; at very low pH (< 3), acid degradation increases.",
        "Maintaining pH 4–5 throughout 14 days is the single most important chemical stability measure.",
    ]),
    ("Resisting pH Drift", [
        "Buffer resists pH changes caused by: dissolved CO₂ from air, acidic flavoring agents, ions from bottle walls.",
        "Without the buffer, small daily pH shifts would eventually push the formulation out of its stable zone.",
    ]),
    ("Multiple Roles of pH Control", [
        "Stable pH → stable drug (minimum hydrolysis).",
        "pH 4–5 also keeps sodium benzoate in its active (undissociated acid) form for full preservative effect.",
        "pH affects taste: mildly acidic pH is well-tolerated and compatible with the strawberry flavor.",
    ]),
], M4_DARK, "Member 4")

# SLIDE 20 — Microbial Stability & Conclusion
content_slide(prs, "Microbial Stability & Conclusion", [
    ("Microbial Risk After Reconstitution", [
        "Dry powder: microbes cannot grow — no free water available. Microbial risk is essentially zero.",
        "After water is added: high water activity + 25% sucrose (microbial nutrient) + possible warmth = high risk.",
        "Three-preservative system: sodium benzoate + methylparaben + propylparaben — each covers different microbes.",
        "Synergistic: combined effect > sum of individual effects; allows lower concentrations of each.",
    ]),
    ("Summary — Surface Phenomena", [
        "Interfacial tension, contact angle, and adsorption (Tween 80, xanthan gum) control wetting and dispersion.",
        "Micellization of Tween 80 solubilizes impurities and prevents Ostwald ripening.",
        "Zeta potential (−20 to −30 mV) + DLVO theory explain why controlled flocculation is the right strategy.",
    ]),
    ("Summary — Stability", [
        "Physical: micronization + xanthan gum (Stokes' law) + controlled flocculation (xanthan gum + Aerosil).",
        "Chemical: dry powder (no hydrolysis) + citrate buffer pH 4–5 + opaque bottle (no photodegradation).",
        "Microbial: three synergistic preservatives protect against bacteria, yeasts, and moulds.",
        "Every excipient has a clear, science-based role — the formula is effective, stable, safe, and child-friendly.",
    ]),
], M4_DARK, "Member 4")


# ── SAVE ──────────────────────────────────────────────────────────────────────
out = "/tmp/workspace/metro-new/Metronidazole_Suspension_PPT_20slides.pptx"
prs.save(out)
print(f"Saved: {out}")
print(f"Total slides: {len(prs.slides)}")