Dusting powders MCQs With Answer

Introduction: Dusting powders are finely divided, free-flowing formulations applied to skin and mucosa to protect, absorb moisture, reduce friction, and deliver APIs. For B. Pharm students, mastering dusting powder formulation means understanding excipients (talc, starch, zinc oxide, kaolin), particle size and flow properties (angle of repose, Carr’s index, Hausner ratio), compatibility, sterility for surgical dusting powders, and evaluation tests (sieve analysis, bulk/tapped density, spreadability, microbial quality). Key concepts include glidants (colloidal silicon dioxide), anti-caking strategies, adhesion enhancement, packaging (sifter-top, puffer, sterile sachets), and safety/labeling. Clinical applications commonly include antifungal and protective powders. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Dusting powders are primarily intended for which route and purpose of administration?

• External application to protect skin, absorb moisture, and reduce friction
• Oral administration for rapid systemic absorption
• Parenteral administration for depot action
• Rectal administration for local laxative effect

Correct Answer: External application to protect skin, absorb moisture, and reduce friction

Q2. Which excipient is most commonly used as a glidant/flow aid in dusting powders?

• Starch
• Zinc oxide
• Colloidal silicon dioxide (Aerosil)
• Kaolin

Correct Answer: Colloidal silicon dioxide (Aerosil)

Q3. The ideal angle of repose for a dusting powder intended to pour easily from a sifter-top container is:

• Less than 30°
• 30–45°
• 45–60°
• Greater than 60°

Correct Answer: Less than 30°

Q4. Which statement best describes the role of talc in dusting powders?

• Primary antimicrobial agent
• Lubricant/glidant that improves flow and reduces friction
• Strongly hygroscopic desiccant
• Effervescent base for rapid dispersion

Correct Answer: Lubricant/glidant that improves flow and reduces friction

Q5. Surgical dusting powders must be:

• Buffered to pH 7.4
• Colored for easy identification
• Sterile and non-irritant
• Effervescent to enhance spreadability

Correct Answer: Sterile and non-irritant

Q6. Which sterilization method is most suitable for heat- and moisture-sensitive surgical dusting powders?

• Steam sterilization (autoclaving)
• Dry heat sterilization at 180°C
• Gamma irradiation
• Boiling in water

Correct Answer: Gamma irradiation

Q7. Which material primarily acts as an absorbent and soothing agent in dusting powders?

• Starch
• Menthol
• Sodium lauryl sulfate
• Ethanol

Correct Answer: Starch

Q8. A key reason to avoid applying non-sterile dusting powders to broken skin is:

• They cause immediate vasoconstriction
• They can support microbial growth or introduce contaminants
• They evaporate too quickly
• They neutralize wound exudate pH

Correct Answer: They can support microbial growth or introduce contaminants

Q9. Which antifungal agent is commonly formulated as a medicated dusting powder for tinea infections?

• Clotrimazole
• Paracetamol
• Amlodipine
• Ranitidine

Correct Answer: Clotrimazole

Q10. Which test is primarily used to assess particle size distribution of dusting powders?

• Loss on drying
• Sieve analysis
• pH determination
• Viscosity measurement

Correct Answer: Sieve analysis

Q11. A Carr’s index in the range of 10–15% typically indicates:

• Poor flow
• Excellent flow
• Very poor compressibility
• High hygroscopicity

Correct Answer: Excellent flow

Q12. Which excipient contributes primarily to skin protection and mild astringency in dusting powders?

• Zinc oxide
• Sodium chloride
• Magnesium carbonate
• Lactose monohydrate

Correct Answer: Zinc oxide

Q13. Excessively coarse particles in dusting powders are undesirable mainly because they:

• Cause excessive foaming on application
• Produce grittiness and poor cosmetic elegance
• Explode upon friction
• Increase volatility

Correct Answer: Produce grittiness and poor cosmetic elegance

Q14. Which combination best improves anti-caking and flow in a moisture-prone dusting powder?

• Add glycerin and increase humidity
• Add colloidal silicon dioxide and use moisture-proof packaging
• Add sucrose and store at high temperature
• Add sodium bicarbonate and citric acid

Correct Answer: Add colloidal silicon dioxide and use moisture-proof packaging

Q15. What is the primary advantage of a narrow particle size distribution in dusting powders?

• Improves acidity
• Enhances uniformity, smooth feel, and predictable flow
• Increases density variability
• Reduces covering power

Correct Answer: Enhances uniformity, smooth feel, and predictable flow

Q16. Geometric dilution is used during dusting powder preparation primarily to:

• Reduce microbial counts
• Ensure uniform mixing of potent, low-dose drugs
• Improve perfume retention
• Decrease the angle of repose

Correct Answer: Ensure uniform mixing of potent, low-dose drugs

Q17. Which is the most appropriate labeling statement for dusting powders?

• For intravenous use only
• For external use only
• For inhalation use only
• For ophthalmic use only

Correct Answer: For external use only

Q18. In formulating a surgical dusting powder, which packaging is most appropriate?

• Open-mouthed jar without seal
• Single-use sterile sachets or sterile puffer bottles
• Paper pouches with no liner
• Glass ampoules for reconstitution

Correct Answer: Single-use sterile sachets or sterile puffer bottles

Q19. Which component can enhance adherence and water-repellency on skin but must be used cautiously due to inhalation concerns?

• Zinc stearate
• Sodium citrate
• Calcium phosphate
• Polyethylene glycol 400

Correct Answer: Zinc stearate

Q20. Why are aqueous preservatives generally not included in dusting powder formulations?

• They significantly increase pH
• They can convert the system into a paste and promote caking
• They decrease drug potency instantly
• They are required only for injectables

Correct Answer: They can convert the system into a paste and promote caking

Q21. The addition of fragrance in dusting powders should be:

• High, to mask medicinal odors
• Moderate, to enhance microbial preservation
• Minimal, to reduce risk of sensitization and irritation
• Mandatory in surgical powders

Correct Answer: Minimal, to reduce risk of sensitization and irritation

Q22. Which test pair best assesses flow properties of dusting powders?

• Viscosity and refractive index
• Angle of repose and Carr’s index
• pH and osmolarity
• Melting point and boiling point

Correct Answer: Angle of repose and Carr’s index

Q23. The primary role of kaolin in medicated dusting powders is to:

• Act as a strong antiseptic
• Increase solubility of APIs
• Act as an absorbent for exudates and moisture
• Provide effervescence

Correct Answer: Act as an absorbent for exudates and moisture

Q24. During mixing, when should a small quantity of glidant (e.g., colloidal silica) be added for best performance?

• At the very beginning before all other excipients
• In the middle of blending
• As the last step to coat the blend uniformly
• It does not matter

Correct Answer: As the last step to coat the blend uniformly

Q25. Which property most directly influences the covering power and tactile feel of a dusting powder?

• Refractive index
• Particle size and shape
• Conductivity
• Freezing point

Correct Answer: Particle size and shape

Q26. Which statement regarding talc quality for pharmaceutical dusting powders is most appropriate?

• Any industrial-grade talc is acceptable
• Pharmaceutical grade talc free from asbestos is required
• Talc must contain asbestos to improve slip
• Talc is prohibited in all topical formulations

Correct Answer: Pharmaceutical grade talc free from asbestos is required

Q27. Excessive moisture in dusting powders primarily leads to:

• Improved flow and spreadability
• Caking and reduced pourability
• Increased sterility
• Enhanced fragrance stability

Correct Answer: Caking and reduced pourability

Q28. Which method can be used to evaluate the spreadability of dusting powders on skin or skin-mimic surfaces?

• Rotational viscometry
• Glass plate and ring method measuring spread area
• UV absorbance at 254 nm
• Capillary rise test

Correct Answer: Glass plate and ring method measuring spread area

Q29. Which statement about medicated dusting powders containing antifungals is most accurate?

• They must always be sterile
• They are typically non-sterile but require low bioburden and appropriate packaging
• They require organic solvents for activation
• They are unsuitable for intertriginous areas

Correct Answer: They are typically non-sterile but require low bioburden and appropriate packaging

Q30. Which excipient is discouraged for use in infant dusting powders due to toxicity risk upon absorption?

• Boric acid
• Kaolin
• Talc
• Zinc oxide

Correct Answer: Boric acid

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