B.Pharm. Bachelor of Pharmacy Bachelor of Pharmacy (B.Pharm.) Pharmaceutics 4 — Questions and Answers
Question 1: The Biopharmaceutics Classification System (BCS) Class II drugs have:
- High solubility and high permeability
- Low solubility and high permeability (Correct answer)
- High solubility and low permeability
- Low solubility and low permeability
Correct answer: Low solubility and high permeability
BCS Class II drugs are poorly soluble but highly permeable; dissolution is the rate-limiting step for absorption.
Question 2: Which sterilization method is most appropriate for thermolabile ophthalmic solutions?
- Autoclaving at 121°C
- Dry heat at 160°C
- Filtration through a 0.22 µm membrane (Correct answer)
- Ethylene oxide gas sterilization
Correct answer: Filtration through a 0.22 µm membrane
Membrane filtration (0.22 µm) removes microorganisms without heat, preserving thermolabile drug integrity.
Question 3: In a two-compartment pharmacokinetic model, the initial rapid decline in plasma drug concentration after IV bolus represents:
- Renal elimination of unchanged drug
- Distribution of drug from central to peripheral compartment (Correct answer)
- First-pass hepatic metabolism
- Biliary excretion of conjugated drug
Correct answer: Distribution of drug from central to peripheral compartment
The alpha (distribution) phase reflects rapid drug transfer from plasma into peripheral tissues following IV injection.
Question 4: Crospovidone (cross-linked PVP) is classified as a:
- Film-forming polymer for coating
- Superdisintegrant (Correct answer)
- Lubricant
- Solubilizing agent for BCS IV drugs
Correct answer: Superdisintegrant
Crospovidone rapidly wicks water and swells, functioning as a superdisintegrant to facilitate tablet breakup.
Question 5: The critical micellar concentration (CMC) is the surfactant concentration above which:
- Surfactant molecules begin to precipitate
- Micelles spontaneously form in solution (Correct answer)
- Emulsion breaks and coalesces
- HLB value becomes irrelevant
Correct answer: Micelles spontaneously form in solution
Above the CMC, surfactant monomers aggregate into micelles, dramatically improving solubilization of lipophilic drugs.
Question 6: In lyophilization (freeze-drying), the primary drying step involves removal of:
- Bound water by desorption
- Free ice by sublimation under vacuum (Correct answer)
- Residual solvent by evaporation
- Crystal water by controlled heating above Tg
Correct answer: Free ice by sublimation under vacuum
Primary drying sublimates free frozen water directly from ice to vapor under reduced pressure without melting.
Question 7: Which route of drug administration completely bypasses first-pass metabolism?
- Oral
- Rectal (proximal)
- Sublingual (Correct answer)
- Buccal via portal drainage
Correct answer: Sublingual
Sublingual administration allows drug to absorb directly into systemic circulation via the sublingual veins, bypassing the liver.
B.Pharm. Bachelor of Pharmacy Bachelor of Pharmacy (B.Pharm.) Pharmaceutics 4
The Biopharmaceutics Classification System (BCS) Class II drugs have: