MPharm Master of Pharmacy Master of Pharmacy: Pharmaceutical Formulations and Dosage Forms 4 — Questions and Answers
Question 1: Which inhalation device generates particles through vibration of a liquid droplet mesh or membrane, requiring no propellant?
- Pressurized metered-dose inhaler (pMDI)
- Dry powder inhaler (DPI)
- Soft mist inhaler (SMI) / vibrating mesh nebulizer (Correct answer)
- Jet nebulizer
Correct answer: Soft mist inhaler (SMI) / vibrating mesh nebulizer
Vibrating mesh nebulizers use a piezoelectric-driven mesh with thousands of apertures to produce a fine aerosol without propellants or compressed air.
Question 2: For ophthalmic solutions, which tonicity value (mOsmol/kg) is considered isotonic with lacrimal fluid?
- 150 mOsmol/kg
- 308 mOsmol/kg (Correct answer)
- 500 mOsmol/kg
- 100 mOsmol/kg
Correct answer: 308 mOsmol/kg
Lacrimal fluid is isotonic at approximately 308 mOsmol/kg (equivalent to 0.9% NaCl), and ophthalmic formulations are adjusted to this tonicity to minimize irritation.
Question 3: In freeze-drying (lyophilization), the primary drying stage removes water by:
- Evaporation above the melting point
- Sublimation of ice under vacuum below the product's collapse temperature (Correct answer)
- Spray evaporation at high temperature
- Osmotic extraction into desiccant
Correct answer: Sublimation of ice under vacuum below the product's collapse temperature
Primary drying sublimates frozen water directly to vapor under low pressure, bypassing the liquid phase, while maintaining the product below its collapse temperature.
Question 4: Which parameter describes the fraction of a drug dose absorbed from a solid oral dosage form relative to an IV dose?
- Volume of distribution (Vd)
- Absolute bioavailability (F) (Correct answer)
- Clearance (CL)
- Mean residence time (MRT)
Correct answer: Absolute bioavailability (F)
Absolute bioavailability (F) is calculated as (AUC_oral/AUC_IV) × (Dose_IV/Dose_oral), reflecting the fraction of drug that reaches systemic circulation.
Question 5: Capping and lamination defects during tablet compression are most often caused by:
- Excessive binder concentration
- Air entrapment in the die and excessive compression speed or elastic recovery (Correct answer)
- Too high a concentration of lubricant
- Insufficient disintegrant
Correct answer: Air entrapment in the die and excessive compression speed or elastic recovery
Capping occurs when entrapped air or high elastic recovery causes the top or bottom cap to separate from the tablet body after ejection.
Question 6: Enteric coatings are designed to remain intact in the stomach (pH ~1–2) and dissolve in the small intestine (pH ~5.5–7.5). Which polymer achieves this?
- Hydroxypropyl methylcellulose (HPMC)
- Cellulose acetate phthalate (CAP) / Eudragit L (Correct answer)
- Ethylcellulose
- Polyvinyl alcohol (PVA)
Correct answer: Cellulose acetate phthalate (CAP) / Eudragit L
Cellulose acetate phthalate and Eudragit L contain carboxylic acid groups that ionize and dissolve above pH 5.5, protecting the stomach while releasing drug intestinally.
Question 7: The Biopharmaceutics Classification System (BCS) categorizes a drug with high solubility and low permeability as:
- BCS Class I
- BCS Class II
- BCS Class III (Correct answer)
- BCS Class IV
Correct answer: BCS Class III
BCS Class III drugs dissolve readily but are poorly absorbed due to limited membrane permeability, making permeation enhancement strategies relevant.
MPharm Master of Pharmacy Master of Pharmacy: Pharmaceutical Formulations and Dosage Forms 4
Which inhalation device generates particles through vibration of a liquid droplet mesh or membrane, requiring no propellant?