• What specific topic are you studying? For example:
  • Dosage forms (tablets, capsules, suspensions, emulsions...)
  • Drug solubility & bioavailability
  • Routes of administration
  • Preformulation studies
  • Sterilization & aseptic techniques
  • Pharmacokinetics basics
• Do you need explanations, notes, practice questions, or help understanding a concept?

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📚 PHARMACEUTICS I - POWDERS

Notes for Hiba | KUHS B.Pharm First Year

Reference: R.M. Mehta - Pharmaceutics (Dispensing & General Pharmacy)

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1. DEFINITION

"Powders are intimate mixtures of dry, finely divided drugs and/or chemicals that may be intended for internal or external use."

• R.M. Mehta, Pharmaceutics

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2. ADVANTAGES OF POWDERS

1. Flexibility - doses can be easily adjusted
2. Stability - more stable than liquid dosage forms
3. Absorption - faster absorption than tablets/capsules (no disintegration needed)
4. Ease of swallowing - useful for patients who cannot swallow tablets
5. Economical - cheap to prepare
6. Bulk preparation - easy to prepare in large quantities
7. Suitable for infants and elderly who cannot swallow solid dosage forms

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3. DISADVANTAGES OF POWDERS

1. Unpleasant taste - drugs with bitter/unpleasant taste cannot be easily masked
2. Hygroscopic - may absorb moisture and deteriorate
3. Inaccurate dose - if not properly divided
4. Not suitable for: volatile, deliquescent, efflorescent, or incompatible drug combinations
5. Inconvenient to carry and administer
6. Slow onset compared to liquid preparations in some cases

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4. CLASSIFICATION OF POWDERS

A. Based on Use:

B. Based on Composition:

C. Based on Dispensing:

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5. TYPES OF POWDERS IN DETAIL

A. SIMPLE POWDER

• Contains a single ingredient
• Example: Compound Chalk Powder, Zinc Oxide Powder

B. COMPOUND POWDER

• Contains two or more medicaments mixed together
• Example: Compound Powder of Ipecacuanha

C. DIVIDED POWDERS (Chartulae)

• Individual doses wrapped in paper
• Each wrap = one dose
• Example: Aspirin divided powders
• Method: Weigh each dose, place on paper, fold properly (pharmacist's fold)

D. BULK POWDERS

• Dispensed without dividing into individual doses
• Patient measures dose using a teaspoon or 5 mL spoon
• Example: Antacid powders, laxative powders
• Disadvantage: Dose inaccuracy possible

E. DUSTING POWDERS

• Fine powders for external/topical application on skin
• Must be very finely powdered (pass through sieve #120)
• Must be sterile if applied to wounds
• Example: Zinc Dusting Powder, Talc
• Uses: Antiseptic, antifungal, absorbent, lubricant

F. INSUFFLATIONS

• Fine powders meant to be blown into body cavities (nose, throat, ear)
• Applied using an insufflator
• Must be very fine

G. DENTIFRICES (Tooth Powders)

• Powders for dental hygiene
• Example: Chalk + flavoring agents

H. SNUFF

• Powders inhaled through the nose
• Example: Medicated snuff for nasal congestion

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6. PREPARATION OF POWDERS

Steps:

1. Comminution - reducing particle size (trituration, levigation, pulverization)
2. Sifting - passing through appropriate sieve
3. Mixing - blending ingredients uniformly
4. Dividing - weighing and dividing into doses (if divided powders)
5. Packaging - in paper (divided) or wide-mouth bottle (bulk)

Methods of Mixing Powders:

Geometric Dilution is very important - used when a small quantity of a potent drug is mixed with a large amount of diluent. Equal amounts are added progressively.

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7. SPECIAL/IMPORTANT TYPES - EXAM FOCUS ⭐

A. EUTECTIC MIXTURES

• When two substances are mixed together, the mixture has a lower melting point than either substance alone
• Results in a moist/sticky/liquefied mixture - a problem!
• Examples of eutectic pairs:
  • Camphor + Menthol
  • Camphor + Thymol
  • Menthol + Phenol
  • Aspirin + Phenacetin
• How to handle eutectic mixtures in powders:
  1. Triturate each ingredient separately with an inert absorbent powder (like light magnesium carbonate, kaolin, or starch)
  2. Then mix together
  3. OR: Dispense separately in divided papers and instruct patient to mix before use

B. EFFLORESCENT POWDERS

• Substances that lose water of crystallization on exposure to air (dry atmosphere)
• Become damp/wet on mixing
• Examples: Sodium sulphate crystals, Ferrous sulphate, Caffeine
• Handling: Use the anhydrous (dried) form

C. DELIQUESCENT POWDERS

• Substances that absorb moisture from the atmosphere and become liquid
• Examples: Potassium hydroxide, Calcium chloride, Pepsin
• Handling:
  • Avoid mixing with other hygroscopic substances
  • Use anhydrous forms
  • Dispense in well-sealed, airtight containers

D. HYGROSCOPIC POWDERS

• Absorb moisture from the air but do not completely liquefy (less extreme than deliquescent)
• Examples: Dried extract of belladonna, Potassium iodide
• Handling: Add an adsorbent (magnesium carbonate or kaolin), seal well

E. EXPLOSIVE MIXTURES

• Certain combinations are dangerous if mixed together
• Examples:
  • Potassium permanganate + Glycerin → explosion
  • Potassium chlorate + Sulfur → explosion
• Handling: NEVER mix; dispense separately

F. DOUBLE DECOMPOSITION MIXTURES

• Chemical reaction occurs between two ingredients forming a new compound
• Example: Chalk + Acid compounds → CO₂ gas produced

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8. EFFERVESCENT GRANULES ⭐

• A special powder preparation that produces effervescence (fizzing/bubbling) when dissolved in water
• The effervescence is due to CO₂ produced when acid and base react in the presence of water

Ingredients:

Ratio of acids (important!):

• Citric acid : Tartaric acid = 1:2 (commonly used ratio)
• Using both acids together improves the granule texture
  • Citric acid alone → sticky granules
  • Tartaric acid alone → friable/crumbling granules
  • Together → firm, stable granules ✅

Methods of Preparation:

1. Wet method (Heat method / Fusion method):
   • Heat drives off water from citric acid monohydrate → CO₂ released → binds granules
   • Mix all ingredients → apply gentle heat → granulation forms → pass through sieve → dry
2. Dry method:
   • No heat used
   • All materials must be in anhydrous (dry) form
   • Strict humidity control required (below 25% relative humidity)

Packaging: In airtight containers, away from moisture

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9. SIEVING/SIFTING OF POWDERS

Dusting powders must pass through sieve #120 (superfine)

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10. CONTAINERS FOR POWDERS

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11. LABELING OF POWDERS

• Internal powders: White label, name of drug, dose, frequency, directions
• External powders: Colored label (blue/yellow), "FOR EXTERNAL USE ONLY"
• Dusting powders: "NOT TO BE TAKEN" label

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12. IMPORTANT EXAM QUESTIONS (KUHS Pattern) 📝

• Eutectic mixtures with examples and handling
• Effervescent granules - preparation and ratio of acids
• Dusting powders
• Geometric dilution method
• Deliquescent vs. Hygroscopic powders

• Classify powders and describe the preparation of effervescent granules
• What are the problems encountered in powder preparation? How are they handled?
• Write a note on divided powders and bulk powders

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QUICK REVISION TABLE ⚡

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• ⭐ Eutectic mixtures
• ⭐ Effervescent granules (acid ratio + methods)
• ⭐ Geometric dilution
• ⭐ Dusting powders

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📚✨ PHARMACEUTICS I - POWDERS & GRANULES

🎓 KUHS Pharm.D First Year | Based on R.M. Mehta

📋 Syllabus Ref: Topic 5 - "Classification, advantages & disadvantages, Preparation of simple, compound powders, Insufflations, Dusting powders, Eutectic & Explosive powders, Tooth powder & Effervescent powders and granules"

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🔵 1. DEFINITION

💬 "A powder is a dry, solid dosage form consisting of finely divided drug(s) and/or chemical(s), which may be intended for internal or external use." (R.M. Mehta - Pharmaceutics)

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🟢 2. ADVANTAGES OF POWDERS

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🔴 3. DISADVANTAGES OF POWDERS

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🟡 4. CLASSIFICATION OF POWDERS

📌 A. Based on Use:

📌 B. Based on Composition:

📌 C. Based on Dispensing:

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🔵 5. TYPES OF POWDERS (KUHS SYLLABUS) 📝

💊 A. Simple Powder

• Contains one ingredient
• Example: Zinc Oxide Powder

💊 B. Compound Powder

• Contains two or more medicaments mixed together
• Example: Compound Powder of Ipecacuanha

📦 C. Divided Powders (Chartulae)

• Individual doses folded in paper
• Each wrap = one dose
• Folding method = Pharmacist's Fold
• Example: Aspirin divided powder

🍶 D. Bulk Powders

• Not divided - patient measures dose with a teaspoon
• ⚠️ Disadvantage: Dose inaccuracy is possible

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⭐ 6. DUSTING POWDERS - IMPORTANT!

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⭐ 7. INSUFFLATIONS

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🦷 8. TOOTH POWDERS (Dentifrices)

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🧪 9. PREPARATION OF POWDERS

Steps of Preparation:

🔄 Methods of Mixing:

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🌟🌟 10. EUTECTIC POWDERS - MOST IMPORTANT! 🌟🌟

🔥 What is Eutectic Mixture?

⚠️ When two substances are mixed together, their melting point becomes LOWER than either substance alone → the mixture becomes wet/sticky/liquid!

🔥 Eutectic Pairs (Memorize These!):

✅ How to Handle Eutectic Mixtures:

1. Triturate each ingredient SEPARATELY with an inert adsorbent:
   • Light Magnesium Carbonate
   • Kaolin
   • Starch
2. Then mix together
3. OR: Dispense separately in papers and instruct patient to mix just before use

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💥 11. EXPLOSIVE POWDERS - DANGER! ⚠️💥

🚨 NEVER mix these combinations - they can EXPLODE!

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💧 12. HYGROSCOPIC, DELIQUESCENT & EFFLORESCENT POWDERS

💧 A. Hygroscopic Powders

• Absorb moisture from air but don't completely liquefy
• Examples: Potassium iodide, Dried extract of belladonna
• ✅ Handling: Add magnesium carbonate as adsorbent; use airtight container

💧💧 B. Deliquescent Powders

• Absorb so much moisture they completely turn to liquid
• Examples: Potassium hydroxide, Calcium chloride, Pepsin
• ✅ Handling: Use anhydrous forms; dispense in airtight container

🌬️ C. Efflorescent Powders

• Lose their water of crystallization when exposed to dry air → become moist
• Examples: Sodium sulphate crystals, Ferrous sulphate, Caffeine
• ✅ Handling: Use the anhydrous (dried) form

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🌟🌟🌟 13. EFFERVESCENT GRANULES - VERY IMPORTANT! 🌟🌟🌟

🧪 What are they?

💬 Granular preparations that produce fizzing/bubbling (CO₂ gas) when dissolved in water

🧪 Ingredients:

⭐ MOST IMPORTANT - Acid Ratio:

🔴 Citric Acid : Tartaric Acid = 1 : 2

🛠️ Methods of Preparation:

🔥 Method 1: WET METHOD (Heat / Fusion Method)

1. Weigh all ingredients
2. Apply gentle heat → water from citric acid monohydrate is released
3. CO₂ produced → binds the mass into granules
4. Pass through sieve → dry carefully
5. Package in airtight container

🧊 Method 2: DRY METHOD

1. No heat used
2. All ingredients must be in anhydrous (dry) form
3. Strict humidity control required (below 25% relative humidity)
4. Work in a dry environment only

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🔢 14. SIEVE CLASSIFICATION OF POWDERS

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📦 15. CONTAINERS & LABELING

🏷️ Labels:

• 🔵 Internal powders: White label - name, dose, frequency
• 🟡 External powders: Colored label - "FOR EXTERNAL USE ONLY"
• 🚫 Dusting powders: "NOT TO BE TAKEN"

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🎯 QUICK REVISION - EXAM CHEAT SHEET ⚡

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📝 KUHS EXAM IMPORTANT QUESTIONS

Short Notes (2-5 marks):

Long Questions (10 marks):

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• Simple & compound powders
• Insufflations, Dusting powders
• Eutectic & Explosive powders
• Effervescent powders & granules

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📚 PHARMACEUTICS I - POWDERS

🎓 KUHS Pharm.D First Year | 📖 R.M. Mehta - Dispensing & General Pharmacy

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🔵 1. DEFINITION

💬 "Powders are intimate mixtures of dry, finely divided drugs and/or chemicals that may be intended for internal or external use." (R.M. Mehta, Pharmaceutics I)

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🟢 2. ADVANTAGES OF POWDERS

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🔴 3. DISADVANTAGES OF POWDERS

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🟣 4. METHOD OF PREPARATION OF POWDERS

💬 Definition: The method of preparation of powders involves reducing the particle size of drugs and mixing them uniformly to produce a homogeneous, stable powder preparation suitable for the intended use.

✨ MIXING OF POWDERS

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🔹 A. SPATULATION

💬 Definition: Spatulation is a method of mixing powders by moving a spatula back and forth over the powder placed on a tile or pill slab until a uniform mixture is obtained.

• Uses a flat-bladed spatula and a porcelain tile or glass slab
• Suitable for small quantities of powder
• Used for powders that are non-gritty and non-incompatible
• ⚠️ NOT suitable for potent drugs or large quantities
• Simple, quick, and easy method

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🔹 B. TRITURATION

💬 Definition: Trituration is the process of reducing particle size and mixing powders simultaneously by rubbing them in a mortar with a pestle in a circular motion.

• Uses a mortar and pestle
• Two purposes: ① Comminution (size reduction) ② Mixing
• Suitable for crystalline or coarse substances
• Circular motion is used to mix and grind
• Most commonly used method in dispensing pharmacy
• ⚠️ NOT ideal for very potent drugs (hard to ensure uniform distribution without geometric dilution)

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🔹 C. 🌟 GEOMETRIC DILUTION ⭐ (MOST IMPORTANT)

💬 Definition: Geometric dilution is a method used to mix a small quantity of a potent drug with a large quantity of diluent in a step-by-step manner to ensure uniform distribution of the active ingredient throughout the mixture.

• Used when the drug quantity is very small compared to the total powder
• Ensures uniform distribution of potent drugs
• Prevents dose variation which could be dangerous
• The drug is mixed with an equal amount of diluent at each step, doubling the quantity each time

📐 PRINCIPLE OF GEOMETRIC DILUTION:

🔑 "Mix the drug with an equal amount of diluent first, then add another equal portion of diluent, and continue doubling until all the diluent is incorporated."

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📝 EXAMPLE 1: Prepare and Dispense Codeine Phosphate 7 mg in 3 Packets

• Codeine phosphate = 7 mg per packet
• Number of packets = 3
• Total codeine phosphate needed = 7 × 3 = 21 mg
• Diluent (e.g., Lactose) = to make each packet = 200 mg (standard) → Total = 600 mg - 21 mg = 579 mg lactose

💡 (In dispensing, total powder per packet is usually made up to 200 mg or 300 mg with diluent)

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📝 EXAMPLE 2: Prepare and Dispense Codeine Phosphate 4 mg in 3 Packets

• Codeine phosphate = 4 mg per packet
• Number of packets = 3
• Total codeine phosphate = 4 × 3 = 12 mg
• Total powder = 3 × 200 mg = 600 mg
• Lactose required = 600 - 12 = 588 mg

⚠️ Why geometric dilution for Codeine Phosphate? Codeine phosphate is a potent narcotic analgesic. Even a small variation in dose can be dangerous. Geometric dilution ensures every packet has the exact correct dose. 🔑

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🔹 D. SIFTING / SWIFT TUMBLING

💬 Definition: Tumbling (Swift Tumbling) is a method of mixing powders by placing them in a closed container and rotating or tumbling it, causing the powders to mix by rolling over each other.

• Used for large quantities of powder
• The container is sealed and rotated on a tumbling machine or by hand
• Suitable for powders that are similar in particle size and density
• Produces a gentle, uniform mix without grinding
• Used mainly in industrial/large-scale manufacturing
• ⚠️ NOT suitable for potent drugs (geometric dilution is preferred first)

💡 Note: Sifting through a sieve is often done alongside tumbling to break up aggregates and improve uniformity.

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🟡 5. CLASSIFICATION OF POWDERS

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📦 CLASS 1: BULK POWDERS FOR INTERNAL USE

💬 Definition: Bulk powders for internal use are powders dispensed in bulk (not divided into individual doses) in a wide-mouthed container, intended to be taken orally. The patient measures each dose using a teaspoon (5 mL).

• Used when accuracy of dosage is not critical
• Supplied in wide-mouthed glass or plastic bottles
• Patient uses a teaspoon to measure dose
• ✅ Advantages:
  • Convenient for frequent dosing
  • Easy to prepare
  • Economical
• ❌ Disadvantages:
  • Dose may be inaccurate (teaspoon variation)
  • Not suitable for potent drugs
  • Risk of contamination with each opening

• Antacid powder (Magnesium trisilicate compound powder)
• Laxative powders (Compound senna powder)
• ORS (Oral Rehydration Salts) powder

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🧴 CLASS 2: BULK POWDERS FOR EXTERNAL USE

💬 Definition: Bulk powders for external use are powders applied externally on the skin or body surfaces, not intended to be taken internally. They are supplied in bulk and applied as needed.

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🔸 A. DUSTING POWDERS

💬 Definition: Dusting powders are fine, dry, free-flowing powders intended for external application to the skin for local effects such as antiseptic, antifungal, absorbent, or lubricant action.

• Must be very finely powdered - pass through sieve #120 (Superfine) ⭐
• Must be free from gritty particles (to avoid irritation)
• Must be sterile if applied to open wounds or raw surfaces ⚠️
• Should have good spreadability and covering capacity
• Applied by dusting onto the skin surface

• Base/Vehicle: Talc, Zinc oxide, Starch, Kaolin
• Active ingredient: Boric acid (antiseptic), Antifungal agents

• Zinc Dusting Powder (Zinc oxide + Starch + Talc)
• Boric Acid Dusting Powder
• Antifungal Dusting Powder

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🔸 B. INSUFFLATIONS

💬 Definition: Insufflations are very fine powders that are blown into body cavities such as the nose, throat, ear, or vagina using a device called an Insufflator to produce a local therapeutic effect.

• Must be in a very fine state of subdivision
• Delivered using an Insufflator (powder blower)
• Used for local action in body cavities
• Must not cause irritation to delicate mucosal surfaces

• Penicillin insufflation (blown into throat for tonsillitis)
• Boric acid powder blown into the ear
• Antibiotic powders for nasal use

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🔸 C. SNUFFS

💬 Definition: Snuffs are medicated powders that are inhaled through the nostrils to produce a local effect in the nasal mucosa, such as decongestant or antiseptic action.

• Inhaled/sniffed into the nose
• Must be very fine to avoid irritation
• Used for nasal congestion, rhinitis
• The drug acts locally on nasal mucosa

• Compound Menthol Snuff
• Medicated snuff for nasal congestion (containing menthol, camphor, zinc sulphate)

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🔸 D. DENTIFRICES (Tooth Powders) 🦷

💬 Definition: Dentifrices are tooth-cleaning preparations in powder form used to clean and polish teeth, freshen breath, and maintain oral hygiene.

• Also called Tooth Powders
• Applied to teeth using a toothbrush or finger
• Should be mildly abrasive to clean without damaging enamel
• Should have a pleasant taste and odor

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💊 CLASS 3: SIMPLE AND COMPOUND POWDERS FOR INTERNAL USE

💬 Definition: These are powders divided into individual doses, each wrapped separately in paper (called Chartulae), intended for oral administration.

🔸 Simple Powder:

💬 Definition: A simple powder contains only one medicament in a divided form.

• Example: Aspirin powder 300 mg in divided papers

🔸 Compound Powder:

💬 Definition: A compound powder contains two or more medicaments mixed together and divided into individual doses.

• Example: Compound Powder of Ipecacuanha (Ipecac + Opium + Potassium sulphate)

• Each dose is accurately weighed
• Placed on a square of paper
• Folded using the Pharmacist's Fold (double fold)
• Placed in a box or envelope
• Label: Dose, frequency, and instructions

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📦 CLASS 4: POWDERS ENCLOSED IN SACHETS AND CAPSULES ⭐

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🔹 A. SACHETS (CACHETS)

💬 Definition: Cachets (sachets) are solid unit dosage forms in which the drug powder is enclosed in a shell of rice paper (wafer paper) or a sealed foil/plastic sachet, designed for oral administration or external use.

• Made from rice paper (wafer paper) - tasteless and edible
• The drug is placed inside and the edges are sealed
• The patient places the cachet on the tongue and swallows with water
• Or the sachet is dissolved in water before taking
• Useful for large doses of drugs that cannot be compressed into tablets
• Useful for drugs with unpleasant taste (masked by rice paper)

• Mask unpleasant taste of drugs
• Accurate dose in each unit
• Elegant and easy to swallow
• Economical preparation
• Suitable for large doses
• Protect drug from atmospheric moisture

• Swallowing may be difficult for some patients
• Rice paper may become soggy if stored improperly
• Limited drug capacity
• Cannot be used for drugs requiring special formulation
• Sealing must be perfect or content may spill

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🔶 WET-SEAL SACHETS (Wet Method of Sealing):

💬 Definition: In the wet-seal method, the edges of the rice paper are moistened with water and then pressed together to seal the sachet.

1. Take a circular piece of rice paper
2. Place the drug powder in the center
3. Place another piece of rice paper on top
4. Moisten the edges with water using a wet finger or brush
5. Press edges together firmly to seal
6. Allow to dry

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🔶 DRY-SEAL SACHETS (Dry Method of Sealing):

💬 Definition: In the dry-seal method, the edges of the rice paper are sealed without water, by pressing two dampened plates or using a special die that interlocks the paper edges mechanically.

1. Take a circular piece of rice paper
2. Place drug powder in center
3. Cover with a second piece of rice paper
4. Use a special cachet press/die to lock edges together mechanically (like a snap-fit)
5. No water or moisture is used

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🔹 B. CAPSULES

💬 Definition: Capsules are solid dosage forms in which the drug (in powder, granule, or liquid form) is enclosed within a gelatin shell that dissolves in the stomach or intestine to release the drug.

• Mask unpleasant taste and odor
• Elegant appearance
• Easy to swallow
• Accurate dose
• Protect drug from light and air
• No binders or coating needed

• Cannot be split or divided easily
• Hygroscopic drugs may affect gelatin shell
• Expensive compared to tablets
• Not suitable for very hygroscopic or deliquescent drugs
• Gelatin is of animal origin (concern for vegans)

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💊 CLASS 5: COMPRESSED POWDERS (TABLET TRITURATES)

💬 Definition: Compressed powders (also called Tablet Triturates) are small, flat, cylindrical tablets prepared by moulding or compression of a moistened powder mass containing a high proportion of lactose (or other diluent), used for potent drugs in small doses.

• Also called Hypodermic Tablets (some can be dissolved and injected)
• Made by compressing powder into a small mould
• Contain mostly lactose or sucrose as base
• Dissolve rapidly in water
• Used for potent drugs needing very precise, tiny doses
• Example: Nitroglycerin tablet triturates (sublingual)

• Very accurate small dose
• Dissolve rapidly
• Suitable for hypodermic use (when sterile)
• Convenient and portable

• Very fragile - break easily
• Cannot contain incompatible mixtures
• Limited dose capacity

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🔥 6. SPECIAL POWDER PREPARATIONS

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🌟 A. DENTIFRICES (Tooth Powders) 🦷

Quick Recap: Used for cleaning and polishing teeth. Main ingredient = Precipitated Chalk. Contains flavoring agents for pleasant taste.

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🔥🔥 B. EUTECTIC MIXTURES (EUTECTIC POWDERS) ⭐⭐

💬 Definition: A eutectic mixture is formed when two or more substances are mixed together and the resulting mixture has a melting point lower than either substance alone, causing the powder to become wet, sticky, or liquid at room temperature.

🔥 Common Eutectic Pairs (Memorize!):

✅ DISPENSING OF EUTECTIC MIXTURES:

🔑 Golden Rule: Never triturate eutectic substances together directly!

1. Triturate each eutectic substance SEPARATELY with an inert adsorbent/diluent in the mortar:
   • Light Magnesium Carbonate
   • Light Kaolin
   • Starch
2. Mix the two separate powders LIGHTLY using spatulation (not trituration)
3. OR: Dispense each substance in a separate divided paper and instruct the patient to mix just before use

Rx: Camphor 500 mg, Menthol 500 mg - for 5 packets

• Triturate camphor with 500 mg light MgCO₃ separately
• Triturate menthol with 500 mg light MgCO₃ separately
• Mix together lightly by spatulation
• Divide into 5 packets

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💥 C. EXPLOSIVE POWDERS ⚠️💥

💬 Definition: Explosive powders are combinations of substances that, when mixed together, can cause fire, explosion, or violent chemical reaction, making them dangerous to prepare together.

⚠️ DANGEROUS COMBINATIONS (NEVER MIX!):

✅ DISPENSING OF EXPLOSIVE POWDERS:

1. NEVER mix the ingredients together in a mortar
2. Wrap each ingredient in a separate paper
3. Place both papers in a single outer envelope/box
4. Label clearly: ⚠️ "Mix immediately before use - Do not mix in advance"
5. Counsel the patient to mix just before taking the dose

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🌟🌟🌟 D. EFFERVESCENT GRANULES AND POWDERS ⭐⭐⭐

💬 Definition: Effervescent granules (or powders) are granular or powder preparations that, when dissolved in water, produce effervescence (fizzing) due to the release of carbon dioxide (CO₂) from the reaction between an acid and a carbonate/bicarbonate in the presence of water.

🧪 Reaction:

🔑 Acid + Sodium Bicarbonate + Water → CO₂ ↑ + Water + Salt Citric acid + NaHCO₃ + H₂O → CO₂ ↑ + Sodium Citrate + H₂O

📌 INGREDIENTS:

⭐ ACID RATIO - MOST IMPORTANT!

🔴 Citric Acid : Tartaric Acid = 1 : 2

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🛠️ METHODS OF PREPARATION:

🔥 METHOD 1: WET METHOD (Heat / Fusion Method)

💬 Definition: In the wet method (fusion method), gentle heat is used to release the water of crystallization from citric acid monohydrate, which acts as the binding liquid to form granules.

• Temperature must be carefully controlled (not too high - otherwise premature CO₂ loss!)
• Work quickly to avoid premature reaction
• Dry granules immediately after sieving

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🧊 METHOD 2: DRY METHOD (Anhydrous Method)

💬 Definition: In the dry method, no heat or water is used. All ingredients are in their anhydrous (dry) form and are mixed under strictly controlled low humidity conditions.

• Strict humidity control essential (< 25% RH)
• Citric acid must be anhydrous (not monohydrate)
• Work quickly and seal containers immediately

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📌 COMPARISON: WET METHOD vs DRY METHOD

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📦 Packaging of Effervescent Granules:

• Packed in airtight, moisture-proof containers (glass jars with airtight lids)
• Or in foil-sealed sachets
• Stored in a cool, dry place 🌡️
• Label: "Dissolve __ teaspoonful in water before taking"

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🎯 QUICK REVISION TABLE ⚡

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📝 KUHS EXAM IMPORTANT QUESTIONS ⭐

Short Notes (2-5 marks):

Long Questions (10 marks):

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• 🔢 More calculation examples for geometric dilution
• ❓ Practice questions
• 📖 The next chapter notes
• ✏️ Any topic explained in more detail 😊

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🔄 SIFTING vs TUMBLING

📖 R.M. Mehta - Pharmaceutics I

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🔵 SIFTING

💬 Definition: Sifting is a method of mixing powders by passing them together through a sieve of appropriate mesh size, so that the powders intermingle as they pass through the sieve openings, resulting in a uniform mixture.

• Uses a sieve (mesh/strainer)
• Powders are passed through the sieve together - they mix as they fall through
• Can be done once or multiple times (repeated sifting improves mixing)
• Also helps break up lumps and aggregates
• Removes coarse/oversized particles at the same time
• Suitable for light, fluffy powders of similar density

• When powders need both mixing AND size classification at the same time
• For powders that are non-potent and present in comparable quantities
• For dusting powders where fine particle size is important

• Simple and quick
• Breaks up lumps while mixing
• Classifies particle size simultaneously
• Good for light powders

• Not suitable for dense or heavy powders (they separate again after sifting)
• Not suitable for potent drugs in small quantities
• Powders of very different densities may segregate

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🟡 TUMBLING (Swift Tumbling)

💬 Definition: Tumbling is a method of mixing powders by placing them in a closed container (such as a drum, jar, or double-cone blender) and rotating or tumbling the container, causing the powders to roll and fall over each other to achieve uniform mixing.

• Uses a closed rotating container
• Powders mix by rolling, falling, and sliding inside the container
• No external force (grinding/pressing) is applied - very gentle mixing
• Commonly used in large-scale industrial manufacturing
• Container is usually filled 30-40% of its capacity for best mixing
• Suitable for powders that are fragile or sensitive to pressure

• For large quantities of powder
• When powders are similar in particle size and density
• When gentle mixing is needed (no grinding/crushing)
• Industrial/bulk manufacturing

• Gentle - does not crush or damage particles
• Suitable for large quantities
• Simple operation
• No contamination (closed container)
• Good for fragile granules

• Not suitable for potent drugs (geometric dilution preferred first)
• Powders of different densities may segregate during tumbling
• Does not break up lumps (unlike sifting)
• Not ideal for small-scale dispensing

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⚡ COMPARISON TABLE: SIFTING vs TUMBLING

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🔑 SIMPLE WAY TO REMEMBER:

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💡 Exam Tip for KUHS: Both sifting and tumbling are NOT suitable as the sole method for potent drugs - always use geometric dilution first, then these methods can be applied for the remaining diluent mixing! ⭐

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🌟 GEOMETRIC DILUTION - YOUR TEACHER'S METHOD

📖 R.M. Mehta | KUHS Pharm.D First Year

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🔑 UNDERSTANDING YOUR TEACHER'S METHOD FIRST

Your teacher starts with 100 mg of pure drug and does geometric dilution with lactose to make 1000 mg Mix I, where every 100 mg of mix = 10 mg of drug. Then repeats the same dilution again (Mix II) and takes the required amount.

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✅ Q1: Prepare and Dispense Codeine Phosphate 7 mg - 3 Packets

🔵 STEP 1: FIRST DILUTION (Mix I)

🔑 1000 mg Mix I contains 100 mg drug ∴ Every 100 mg of Mix I = 10 mg of drug

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🔵 STEP 2: SECOND DILUTION (Mix II)

🔑 1000 mg Mix II contains 10 mg drug ∴ Every 100 mg of Mix II = 1 mg of drug

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🔵 STEP 3: DISPENSING

Need 7 mg drug per packet × 3 packets = 21 mg drug total

• Each 100 mg of Mix II = 1 mg drug
• So for 7 mg drug → take 700 mg of Mix II
• Repeat this 3 times (for 3 packets)
• Each packet = 700 mg mix containing exactly 7 mg drug ✅

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✅ Q2: Prepare and Dispense Codeine Phosphate 4 mg - 3 Packets

🔵 STEP 1: FIRST DILUTION (Mix I)

🔑 1000 mg Mix I = 100 mg drug ∴ Every 100 mg of Mix I = 10 mg drug

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🔵 STEP 2: SECOND DILUTION (Mix II)

🔑 1000 mg Mix II = 10 mg drug ∴ Every 100 mg of Mix II = 1 mg of drug

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🔵 STEP 3: DISPENSING

Need 4 mg drug per packet × 3 packets

• Each 100 mg of Mix II = 1 mg drug
• So for 4 mg drug → take 400 mg of Mix II
• Repeat 3 times for 3 packets
• Each packet = 400 mg mix containing exactly 4 mg drug ✅

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⚡ QUICK SUMMARY TABLE

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🔑 THE LOGIC (Easy to Remember):

1️⃣ 1st Dilution: 100 mg drug → 1000 mg mix → 100 mg mix = 10 mg drug 2️⃣ 2nd Dilution: 100 mg Mix I → 1000 mg mix → 100 mg mix = 1 mg drug 3️⃣ To get X mg drug → take X × 100 mg of Mix II per packet 🎯

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🧴 TYPES OF DUSTING POWDERS

📖 R.M. Mehta - Pharmaceutics I | KUHS Pharm.D First Year

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💬 Definition (Recap): Dusting powders are fine, dry, free-flowing powders applied externally to the skin or body surfaces for local therapeutic effects.

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🔵 CLASSIFICATION OF DUSTING POWDERS

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🟢 1. MEDICAL DUSTING POWDERS

💬 Definition: Medical dusting powders are dusting powders applied to intact, unbroken skin surfaces for local therapeutic effects such as absorbing moisture, reducing friction, or treating skin conditions.

• Applied on healthy, unbroken skin only
• ❌ Need NOT be sterile (since skin is intact, no risk of infection entering)
• Must be very finely powdered - pass through sieve #120 ⭐
• Must be non-irritating and non-toxic
• Should have good spreadability and adhesion to skin
• Should be free from gritty particles

• ✅ Zinc Dusting Powder - Zinc oxide + Starch + Talc (protective, absorbent)
• ✅ Boric Acid Dusting Powder - antiseptic for skin
• ✅ Talcum Powder - lubricant and absorbent
• ✅ Antifungal Dusting Powder - clotrimazole powder for fungal infections
• ✅ Compound Zinc Dusting Powder - for nappy rash, skin irritation

• Mix ingredients by trituration/spatulation
• Sift through sieve #120
• Pack in a wide-mouthed sifter-top container 🏺
• No sterilization required

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🔴 2. SURGICAL DUSTING POWDERS

💬 Definition: Surgical dusting powders are dusting powders applied to wounds, raw surfaces, ulcers, surgical incisions, or body cavities where the skin or mucous membrane is broken, requiring the powder to be sterile to prevent infection.

• Applied on broken skin, wounds, raw surfaces, surgical sites
• ⭐⭐ MUST BE STERILE - this is the most important difference! ⚠️
• Must pass through sieve #120 (Superfine)
• Must be absolutely free from microbial contamination
• Must be non-irritating to exposed tissues
• Should NOT contain any substance that would delay wound healing
• Packaged in sterile, airtight containers

🔑 Because they are applied to open wounds or broken skin where blood vessels and tissues are exposed. Any microbial contamination can directly enter the body and cause serious wound infection or sepsis. ⚠️

• ✅ Iodoform Dusting Powder - antiseptic for wounds
• ✅ Sulphanilamide Dusting Powder - antibacterial for wounds
• ✅ Zinc Peroxide Dusting Powder - for infected wounds
• ✅ Sterilized Talc - used on surgical gloves (lubricant)
• ✅ Antibiotic Dusting Powders - for wound dressing

• Packed in sterile, sealed, airtight containers
• Sealed under sterile conditions
• Label includes batch number, sterilization date, expiry date

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⚡ KEY DIFFERENCES: Medical vs Surgical Dusting Powders

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🔑 THE ONE THING TO REMEMBER FOR EXAMS ⭐

🏆 "Both types must pass through Sieve #120, but ONLY surgical dusting powders must be STERILE because they are applied to open wounds!"

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🧴 TYPES OF DUSTING POWDERS

📖 R.M. Mehta - Pharmaceutics I | KUHS Pharm.D First Year

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🟢 1. MEDICAL DUSTING POWDERS

💬 Definition: Medical dusting powders are dusting powders applied to intact, unbroken skin for local therapeutic effects such as antifungal, absorbent, or protective action.

• Applied on healthy, unbroken skin only
• ❌ Need NOT be sterile
• Must pass through Sieve #120 (Superfine) ⭐
• Must be non-irritating, non-toxic, free-flowing
• Good spreadability on skin surface

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💊 EXAMPLE: CANDID DUSTING POWDER (Clotrimazole Dusting Powder)

🔑 Candid is a brand of Clotrimazole 1% w/w Dusting Powder - used as an antifungal for skin infections like ringworm, athlete's foot, jock itch.

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🛠️ PREPARATION OF MEDICAL DUSTING POWDER (Candid):

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🔴 2. SURGICAL DUSTING POWDERS

💬 Definition: Surgical dusting powders are dusting powders applied to wounds, raw surfaces, ulcers, or surgical sites where the skin is broken. They MUST be sterile to prevent infection.

• Applied on broken skin, wounds, raw surfaces ⚠️
• ⭐⭐ MUST BE STERILE - most important feature!
• Must pass through Sieve #120 (Superfine)
• Must be absolutely free from microbial contamination
• Non-irritating to exposed tissues
• Should not delay wound healing
• Packed in sterile, airtight containers

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💊 EXAMPLE: NEOSPORIN DUSTING POWDER

🔑 Neosporin is a combination antibiotic dusting powder used on wounds and surgical sites to prevent bacterial infection.

💡 The three antibiotics together give broad-spectrum antibacterial coverage on wounds!

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🛠️ PREPARATION OF SURGICAL DUSTING POWDER (Neosporin):

⚠️ For Neosporin - Gamma irradiation or Ethylene oxide is preferred since antibiotics may be heat-sensitive

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⚡ COMPARISON TABLE

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🔑 ONE-LINE EXAM ANSWER ⭐

🏆 "Medical dusting powder (e.g. Candid) is applied on intact skin and need not be sterile, whereas Surgical dusting powder (e.g. Neosporin) is applied on wounds and MUST be sterile to prevent infection!"

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