Pharmaceutics 1: Powders Quiz

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Questions and Answers

What is an advantage of using unit dose powders over liquid dosage forms?

More difficult to mask flavors

Accurate dosing (correct)

Easier to swallow

Less stable than liquid forms

Which material is commonly used to make hard capsules?

Silicon

Cellulose

Gelatin (correct)

Polyethylene

What are the disintegrators in tablet formulations used for?

To improve the taste of the tablet

To bind ingredients together

To ensure the tablet breaks down after ingestion (correct)

To enhance the solubility of active ingredients

What is a disadvantage of using single dose oral powders?

May be difficult to swallow Signup and view all the answers

What is a common use of paper sachets for powdered medications?

For children dosages of drugs not commercially available Signup and view all the answers

Which of the following is considered a filler in tablet formulation?

Lactose Signup and view all the answers

Which of these substances is unsuitable for paper sachets?

Deliquescent substances Signup and view all the answers

What role do lubricants play in tablet manufacturing?

To assist in the flow of materials into tablet dies Signup and view all the answers

What is a key advantage of using bulk oral powders over liquid dosage forms?

More stable than liquid equivalents Signup and view all the answers

Which type of powder formulation is useful for non-potent or bulky drugs?

Bulk oral powders Signup and view all the answers

Which of the following is NOT a disadvantage of bulk oral powders?

Requires refrigeration Signup and view all the answers

Why are bulk oral powders considered less preferable for potent drugs with low doses?

Inaccuracy in dosage due to spoon measurement. Signup and view all the answers

Which type of powder is used for administration to the ear, nose, and throat?

Insufflation powders Signup and view all the answers

What is a significant disadvantage when using bulk oral powders?

Inability to administer volatile substances Signup and view all the answers

In what form are bulk oral powders typically sold for administration?

Wide-mouth jars or boxes Signup and view all the answers

Which of the following powdered forms is NOT conventionally restricted for internal use?

Dusting powders Signup and view all the answers

What is a primary use of bulk external powders?

Treatment of skin diseases Signup and view all the answers

Which of the following inhalers is specifically used for asthma treatment?

Turbohaler ® Signup and view all the answers

What is a common characteristic of dry powder dosage forms compared to liquid forms?

More stable and longer shelf life Signup and view all the answers

What is induced when a hygroscopic powder is exposed to high humidity?

Deliquescence Signup and view all the answers

What happens when powders of hydrated salts undergo efflorescence?

They lose water of hydration and form a wet mass Signup and view all the answers

What is the purpose of using inert diluents in dusting powders?

To provide bulk for low concentration active ingredients Signup and view all the answers

What is a likely consequence of improper storage of powder for injection?

Physical and chemical degradation Signup and view all the answers

What indicates that a powder has caked?

Is difficult to pour due to sticking together Signup and view all the answers

What is the purpose of trituration when mixing powders?

To ensure even dispersion of all ingredients. Signup and view all the answers

Which option best describes the packaging for bulk oral powders?

Glass, plastic, metal, or other containers with a wide mouth. Signup and view all the answers

Why is it crucial to sieve powders before weighing them?

To ensure an accurate weight is obtained. Signup and view all the answers

What is the minimum amount that should be weighed using the balance in the lab?

100mg Signup and view all the answers

What should be done if the particle size of powders appears grossly different?

Grind the powder to equalize the particle sizes. Signup and view all the answers

Which of the following describes the geometric mixing method?

Mixing powders by doubling proportions. Signup and view all the answers

What is the first step in the general method of mixing powders?

Comminution of drug. Signup and view all the answers

What is a common size for wrapping powders?

120mm x 100mm Signup and view all the answers

Study Notes

Course Information

Course title: PHARMACEUTICS 1: PHYSIOCHEMICAL SCIENCE AND MEDICINES DESIGN
Course code: PHAR1027
Lecturer: TUNG WH
Topic: POWDERS

Lecture Overview

What is...
Stability and storage
Small-scale manufacture practicals

Powders

Definition: A solid material in a finely divided state.
Dosage form: Mixtures of powdered drugs (with or without excipients) to create final products.
Traditionally restricted to internal use (oral powder).
Alternative titles exist (e.g., dusting powder) for external use.

Categories of Powders

Bulk oral powders (undivided):
- Convenient for large doses.
- Patient takes spoonful of powder mixed with water or milk.
- Packaged in wide-mouth containers with measuring spoons.
- Suitable for non-potent/non-toxic bulky drugs.
Rare drawbacks: Inconvenience to carry; inaccuracies in measuring dose.
Example preparations: Indigestion remedies/bulk laxatives (e.g., Methylcellulose granules, Compound Mg trisilicate oral powder, dietary food supplements).

Advantages of Bulk Oral Powders

Potentially more stable than liquid equivalents.
Suitable for dispensing drugs with large doses.
Relatively easier administration than tablets.
Faster dispersion and absorption than capsules or tablets.
Flexible dosage form (easy preparation).

Disadvantages of Bulk Oral Powders

Bulky and inconvenient to carry.
Difficulty masking unpleasant taste (sprinkling on food).
Less accurate dosing.
Not suitable for administering potent drugs with low doses.
Not suitable for drugs sensitive to stomach acidity.
Not suitable for volatile, deliquescent, hygroscopic or oxygen-sensitive substances.

Single Dose Oral Powders (Divided Powders)

A convenient way to administer an accurate single dose of a drug.
Formulation: Bulk powders.
Wrapped Powders:
- Ideal for substances requiring controlled dosages (small amounts of drug).
- Powder wrapped in paper or foil sachets.
- Foil sachets provide better protection.
Paper Sachets:
- Easier to make on a small scale.
- Convenient dosage form, especially for children.
- Useful for drugs not commercially available for babies, infants, and elderly.
- Mixing with liquid (usually water) before swallowing (not suitable for hygroscopic, volatile, and deliquescent).
- Examples: Antacids, dietary products, effervescent powders, hot/cold drink remedies.

Single Dose Oral Powders / Divided Powders (Hard Capsules)

Single doses of powder enclosed in a two-part shell.
Available in various sizes.
Commonly made from gelatin (animal-derived).
Halagel available (halal gelatin).
Convenient, easy-to-swallow, and cost-effective on a large scale.

Tablets

Single doses of powder compressed by a machine.
Made on a large scale (Year 2 practical).
Excipients (diluents, fillers, binders, adhesives, disintegrators, disintegrating agents, antiadherents, glidants, lubricants) ensure ease of handling, flow properties, and breakdown after ingestion.

Bulk External Powders

Dusting powders (applied to skin) used for therapeutic, prophylactic, lubricant purposes (skin diseases, surgical glove lubrication, sterile dusting powder for open wounds).
Should be free from pathogenic organisms.
May contain one or more medicaments mixed with an inert diluent (e.g. purified talc, starch, kaolin) for diluted active doses.
Suitable for use at low concentrations as diluents.
Flow properties are important factors for external powders.
Examples: Hexachlorophene, talc.

Drug Powder Inhalers

Most effective method for delivering drugs to the respiratory tract.
For treatments of asthma, chronic obstructive pulmonary diseases (COPD).
Commercial preparations and dry powder devices used (e.g., Turbohaler ®, Diskhaler ®, Becotide ®).

Antibiotic Syrups

Many drugs are unstable in solutions or suspensions and instability issues are overcome through preparation of powder or granules in suitable containers for storage/shelf life exceeding 2 years.
Add water (H₂O) to powder/granules immediately prior to supply/use.
Shelf life reduced to 2 weeks.

Powders for Injection

Some medications are unstable in solution.
Prepared as sterile powders and packed in ampoules or vials.
Sterile water for injections (Water for Injections BP) is added prior to use to create the required drug concentration.

Stability and Storage

Dry powder dosage forms are more stable than liquid dosage forms but potentially affected by ingredients' susceptibility to moisture.
Hygroscopic powders absorb moisture and form wet masses.
Deliquescent powders absorb moisture, dissolve in it.
Efflorescent powders lose water of hydration when humidity decreases.
Eutectic mixtures' melting/liquefying points are lower than the components' individual melting points (e.g., Menthol + Camphor).

Other Important Factors

Discoloration, caking (moisture absorption and sticking), heat degradation of powders.
Storage: Store tightly closed in a cool dry place.
Packaging:
- Bulk oral powders: Glass, plastic, metal (wide mouth container, powder measure).
- Divided powders: Sachets (large-scale manufacturing), papers (individually folded).
- Topical powders: Suitable sized containers.

Mixing Powders: General Method

Aim: Even dispersion of all ingredients in the powder mixture.
Problems: Different particle sizes leading to separation, inconsistent ingredient amounts, accuracy limits of balances.
Method:
- Identify the powder with the smallest volume and add to the mortar.
- Add the other ingredients in similar volumes.
- Mix gently and thoroughly until uniform mixture is obtained.
- Use a spatula to loosen powder sticking to the mortar edges.
- Repeat till all powders combined.
Importance of sieving: Sieving before weighing and mixing prevents loss of powder on the sieve/workbench, and ensures consistency in dosage.

Golden Rules of Mixing Powders

Never weigh amounts below the accuracy limit of the balance (e.g., 100mg in this lab).
Equalize particle sizes by grinding and sieving if necessary.
Use geometric mixing but avoid ratios greater than 1 in 10.

Wrapping Powders

Several ways of wrapping powders.
Suitable size: 120mm x 100mm.
Carry out wrapping on a clean tile or sheet of wrapping paper, protecting the product.

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Description

Test your knowledge on the types and applications of powders in pharmaceutics. This quiz covers the definitions, stability, and practical manufacturing of powder dosage forms. Perfect for students in PHAR1027 seeking to enhance their understanding of powdered medicines.