1 1. Define Suppositories and pessaries, Displacement value and evaluation. Define different extraction processes like infusion, Decoction, Maceration and Percolation 2. Pharmaceutical calculations, Define Surgical dressings, absorbable gelatin sponge, sutures, Classification of Incompatibilities DPH-102: Pharmaceutics 2 1. Discuss amino acid & nucleic acid derivatives 2. Explain LFT, KFT and Electrolytes in detail Med Biochem in eASY AND SHORT EXAMINATION
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DPH-102: PHARMACEUTICS
PAPER 1 - SECTION 1
1. Suppositories and Pessaries
Definition:
Suppositories are solid dosage forms meant for insertion into body orifices other than the mouth (rectum, vagina, urethra). They melt, dissolve, or soften at body temperature to release the drug.
Types by route:
- Rectal suppositories - torpedo/bullet shaped, ~2g (adults), ~1g (children)
- Vaginal suppositories (pessaries) - ovoid/globular, ~5g
- Urethral suppositories (bougies) - pencil-shaped, ~4g
Pessaries: Solid dosage forms specifically designed for vaginal administration. Used for local action (antifungals, antibiotics, contraceptives, estrogens).
Bases used:
| Type | Example |
|---|---|
| Oleaginous (melting) | Cocoa butter (theobroma oil) |
| Water-soluble/miscible | PEG (polyethylene glycol) |
| Emulsifying | Glycerogelatin |
2. Displacement Value (DV)
Definition: The number of parts by weight of a drug that displaces one part by weight of the base (usually cocoa butter).
Why it matters: Drugs are denser than the base. Adding drug without adjustment gives a suppository heavier than intended with incorrect dose.
Formula:
DV = Weight of drug / Weight of base displaced
Calculation example:
- Mold capacity = 2g cocoa butter
- DV of zinc oxide = 4.7
- For 0.5g zinc oxide per suppository:
- Base displaced = 0.5 / 4.7 = 0.106g
- Cocoa butter required = 2 - 0.106 = 1.894g
3. Evaluation of Suppositories
| Test | Purpose |
|---|---|
| Melting/Softening point | Should melt at 36-37°C (body temp); use melting point apparatus |
| Liquefaction time | Time to liquefy in water bath at 37°C; should be < 30 min |
| Dissolution test | For water-soluble bases |
| Breaking test | Mechanical strength; should withstand handling |
| Weight variation | Not more than ±5% deviation from mean |
| Drug content uniformity | Chemical assay for active ingredient |
| Leakage test | Wrapped in foil, placed at 37°C; no leakage allowed |
4. Extraction Processes
a) Infusion
- Definition: Prepared by pouring boiling (or cold) water over crude drug and allowing to stand.
- Hot infusion: Drug + boiling water, steeped for 15 minutes, strained.
- Cold infusion: Drug soaked in cold water for several hours.
- Used for: Delicate plant parts - leaves, flowers, aromatic herbs.
- Example: Ginger infusion, chamomile tea.
- Shelf life: Short (prepared fresh daily).
b) Decoction
- Definition: Prepared by boiling crude drug with water for a definite time (usually 15-20 minutes), then straining.
- Used for: Hard, woody plant parts - bark, roots, rhizomes, seeds.
- Example: Senna decoction, cinnamon decoction.
- Difference from infusion: Heat is applied throughout (boiled, not just steeped).
c) Maceration
- Definition: Drug is soaked in solvent (menstruum) at room temperature for a specified period (usually 2-7 days) with occasional agitation, then strained and marc pressed.
- Solvent: Water, alcohol, or hydroalcoholic mixture.
- Used for: Drugs whose constituents are soluble in cold solvent; drugs damaged by heat.
- Example: Garlic maceration, belladonna tincture.
- Advantage: Simple; suitable for thermo-labile drugs.
- Disadvantage: Slow; incomplete extraction.
d) Percolation
- Definition: Solvent (menstruum) is allowed to pass slowly downward through a column of powdered drug in a cone-shaped vessel (percolator). Fresh solvent continuously contacts drug, giving complete extraction.
- Steps: Moistening drug → packing in percolator → allowing maceration → collecting percolate.
- Used for: Large-scale preparation; most tinctures and fluid extracts.
- Advantage: Complete, efficient extraction.
- Example: Nux vomica tincture.
| Method | Temperature | Time | Best For |
|---|---|---|---|
| Infusion | Hot/Cold | 15 min | Delicate parts |
| Decoction | Boiling | 15-20 min | Hard parts |
| Maceration | Room temp | 2-7 days | Thermo-labile |
| Percolation | Room temp | Hours-days | Large scale/tinctures |
PAPER 1 - SECTION 2
5. Pharmaceutical Calculations (Key Concepts)
Percentage calculations:
- % w/w = grams of solute per 100g solution
- % w/v = grams of solute per 100mL solution
- % v/v = mL of solute per 100mL solution
Dilution formula: C1V1 = C2V2
Doses:
- Child's dose (Young's formula): (Age / Age+12) × Adult dose
- Clark's formula: (Weight in lbs / 150) × Adult dose
Proof spirit: 100 proof = 50% v/v ethanol
6. Surgical Dressings
Definition: Materials used to cover, protect, and aid healing of wounds, burns, and surgical incisions.
Ideal properties: Sterile, non-toxic, non-irritant, absorbent, non-adherent to wound, comfortable, permeable to air.
Types:
| Type | Description |
|---|---|
| Absorbent cotton | Purified cellulose fiber; highly absorbent |
| Gauze | Loosely woven cotton fabric |
| Bandages | Roller bandages (cotton/elastic) |
| Adhesive plasters | Cotton/synthetic fabric with adhesive |
| Paraffin gauze | Gauze impregnated with soft paraffin (non-adherent) |
7. Absorbable Gelatin Sponge
- Definition: A sterile, absorbable, water-insoluble, off-white, non-elastic porous sponge made from purified gelatin solution.
- Properties: Completely absorbed by body tissues in 4-6 weeks; can absorb 40 times its weight in blood.
- Uses:
- Hemostasis during surgical procedures
- Control of capillary bleeding
- Packing dental sockets after extraction
- Neurosurgery and ENT surgery
- Mechanism: Provides scaffold for clot formation; swells and mechanically stops bleeding.
- Brand name: Gelfoam
8. Sutures
Definition: Sterile strands used to close wounds, ligate blood vessels, and approximate tissue layers.
Classification:
A. By Absorbability:
| Absorbable | Non-absorbable |
|---|---|
| Catgut (plain/chromic) | Silk |
| Polyglycolic acid (Dexon) | Nylon (Prolene) |
| Polyglactin (Vicryl) | Polypropylene |
| Polyglecaprone (Monocryl) | Steel wire |
B. By Origin:
- Natural: Catgut, silk, cotton, linen
- Synthetic: Nylon, Dacron, Vicryl, PDS
C. By Structure:
- Monofilament: Single strand (Nylon, Prolene) - less bacterial adherence
- Multifilament/Braided: Multiple strands twisted (Silk, Vicryl) - easier to handle
Needle types: Cutting (skin), Round-bodied (soft tissue), Taper-cut (tough tissue)
9. Classification of Incompatibilities
Definition: Incompatibility occurs when two or more substances in a prescription react together to produce an undesirable change in physical appearance, chemical nature, or therapeutic activity.
A. Physical Incompatibility
Physical change without chemical reaction.
- Immiscibility: Mixing of two immiscible liquids (oil + water)
- Liquefaction of solids: Eutectic mixtures (e.g., menthol + camphor)
- Insolubility/precipitation: Adding alcohol-soluble drug to water
- Color change: Physical adsorption
B. Chemical Incompatibility
New chemical compound formed.
- Oxidation-reduction: e.g., potassium permanganate + glycerin (explosion risk)
- Double decomposition/precipitation: e.g., lead acetate + sodium sulfate → lead sulfate (precipitate)
- Hydrolysis: e.g., aspirin + water → salicylic acid + acetic acid
- Complexation: Tetracycline + calcium/antacids → chelation
C. Therapeutic Incompatibility
Undesirable therapeutic outcome.
- Synergism (adverse): Two CNS depressants → excess sedation
- Antagonism: Heparin + protamine sulfate (desired antidote, but incompatible if overdosed)
- Potentiation: e.g., sulfonamides + trimethoprim potentiation (desired but can cause toxicity)
MED BIOCHEMISTRY - PAPER 2
SECTION 1: Amino Acid & Nucleic Acid Derivatives
1. Amino Acid Derivatives
Amino acids are not just building blocks of proteins; they are precursors to many biologically active molecules.
Key Derivatives:
| Amino Acid | Derivative | Function |
|---|---|---|
| Tyrosine | Dopamine, Norepinephrine, Epinephrine | Catecholamine neurotransmitters |
| Tyrosine | Thyroid hormones (T3, T4) | Metabolic regulation |
| Tyrosine | Melanin | Skin/hair pigment |
| Tryptophan | Serotonin (5-HT) | Mood, sleep, GI motility |
| Tryptophan | Melatonin | Circadian rhythm |
| Tryptophan | Niacin (Vit B3) | NAD+/NADP+ synthesis |
| Histidine | Histamine | Allergic response, gastric acid secretion |
| Glutamate | GABA | Inhibitory neurotransmitter |
| Glycine | Heme (with succinyl CoA) | Oxygen transport |
| Glycine | Creatine | Muscle energy (PCr) |
| Arginine | Nitric oxide (NO) | Vasodilation |
| Phenylalanine | Phenylethylamine; also → Tyrosine | Neuromodulator |
| Serine | Ethanolamine → Choline → Acetylcholine | Neurotransmitter |
| Cysteine | Glutathione (GSH) | Antioxidant |
2. Nucleic Acid Derivatives
Nucleotides are derivatives of purine and pyrimidine bases + sugar + phosphate.
Purine bases: Adenine, Guanine
Pyrimidine bases: Cytosine, Thymine (DNA), Uracil (RNA)
Important Nucleotide Derivatives:
| Derivative | Function |
|---|---|
| ATP (Adenosine triphosphate) | Universal energy currency |
| AMP/cAMP | Second messenger (protein kinase A activation) |
| cGMP | Second messenger (NO pathway) |
| NAD+/NADH | Electron carriers in cellular respiration |
| NADP+/NADPH | Reductive biosynthesis (fatty acid, steroid synthesis) |
| FAD/FADH2 | Electron carriers (Complex II of ETC) |
| CoA (Coenzyme A) | Acyl group carrier; key in Krebs cycle |
| SAM (S-Adenosylmethionine) | Universal methyl group donor |
| GTP | Energy in protein synthesis, signal transduction |
SECTION 2: LFT, KFT and Electrolytes
Liver Function Tests (LFT)
Tests used to assess hepatocellular damage, synthetic function, and biliary obstruction.
| Test | Normal Range | Significance |
|---|---|---|
| Bilirubin (Total) | 0.2-1.2 mg/dL | Elevated in jaundice |
| Direct (conjugated) bilirubin | 0-0.3 mg/dL | Elevated in obstructive/hepatic jaundice |
| Indirect (unconjugated) | 0.2-0.8 mg/dL | Elevated in hemolytic jaundice |
| AST (SGOT) | 10-40 U/L | Hepatocellular damage, MI |
| ALT (SGPT) | 7-56 U/L | More specific to liver |
| ALP (Alkaline phosphatase) | 44-147 U/L | Biliary obstruction, bone disease |
| GGT | 9-48 U/L | Alcohol liver disease, cholestasis |
| Total protein | 6-8 g/dL | Synthetic function |
| Albumin | 3.5-5 g/dL | Chronic liver disease if low |
| PT/INR | INR 0.9-1.1 | Coagulation factor synthesis |
Pattern recognition:
- Hepatocellular: AST/ALT elevated predominantly
- Cholestatic: ALP/GGT elevated predominantly
- Synthetic failure: Low albumin, prolonged PT
Kidney Function Tests (KFT)
| Test | Normal Range | Significance |
|---|---|---|
| Serum Creatinine | M: 0.7-1.3 mg/dL; F: 0.6-1.1 mg/dL | Best single marker of GFR |
| Blood Urea Nitrogen (BUN) | 7-20 mg/dL | Affected by protein intake, dehydration |
| BUN:Creatinine ratio | 10:1-20:1 | >20: prerenal; <10: renal/postrenal |
| GFR (eGFR) | >90 mL/min/1.73m² | CKD stages by GFR |
| Uric acid | M: 3.5-7.2 mg/dL; F: 2.6-6 mg/dL | Elevated in gout, renal failure |
| 24h urine creatinine | 500-2000 mg/day | Creatinine clearance |
| Urine protein | < 150 mg/day | Proteinuria indicates renal damage |
CKD Staging by eGFR:
- Stage 1: ≥90 (with kidney damage markers)
- Stage 2: 60-89
- Stage 3a: 45-59
- Stage 3b: 30-44
- Stage 4: 15-29
- Stage 5: <15 (Kidney failure)
Electrolytes
Sodium (Na+)
- Normal: 135-145 mEq/L
- Hyponatremia (<135): Confusion, seizures; causes: SIADH, heart failure, liver cirrhosis
- Hypernatremia (>145): Thirst, dehydration, altered sensorium; causes: Diabetes insipidus, excess sodium intake
Potassium (K+)
- Normal: 3.5-5.0 mEq/L
- Hypokalemia (<3.5): Muscle weakness, U-wave on ECG, arrhythmias; causes: diuretics, vomiting, diarrhea
- Hyperkalemia (>5.0): Peaked T-waves, fatal arrhythmias; causes: renal failure, ACE inhibitors, Addison's disease
Calcium (Ca2+)
- Normal: 8.5-10.5 mg/dL (total); ionized: 4.5-5.5 mg/dL
- Hypocalcemia: Tetany, Chvostek's/Trousseau's sign, prolonged QT
- Hypercalcemia: "Bones, Stones, Groans, Moans" (hyperparathyroidism, malignancy)
Bicarbonate (HCO3-)
- Normal: 22-26 mEq/L
- Low: Metabolic acidosis
- High: Metabolic alkalosis
Chloride (Cl-)
- Normal: 98-106 mEq/L
- Used in anion gap calculation: AG = Na - (Cl + HCO3); Normal = 8-12
Phosphate (PO4)
- Normal: 2.5-4.5 mg/dL
- Low in hyperparathyroidism, rickets
- High in renal failure, hypoparathyroidism
Quick Exam Tips:
- For LFT: Remember ALT is more liver-specific than AST
- For KFT: Creatinine is the best GFR marker (BUN is unreliable alone)
- Electrolytes: Always link to ECG changes for K+ and Ca2+
- Displacement value: DV = Weight of drug / Weight of base displaced
- Percolation = most efficient extraction; Infusion = quickest
- Incompatibilities: Physical = appearance change; Chemical = new compound; Therapeutic = altered drug effect
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