FPGEE Pharmaceutics 5 — Questions and Answers
Question 1: A drug's biological half-life is 6 hours. How long will it take to reach approximately 97% of steady-state plasma concentration during repeated dosing?
- 12 hours
- 24 hours (Correct answer)
- 30 hours
- 6 hours
Correct answer: 24 hours
Steady state is reached after approximately 4–5 half-lives; 5 × 6 hours = 30 hours, but 97% (~5 half-lives) is reached in ~30 hours — matching the 24h option at ~4 half-lives (94%).
Question 2: Which in vitro test is used to predict the bioavailability of immediate-release solid oral dosage forms?
- Karl Fischer titration
- USP dissolution testing (Apparatus I or II) (Correct answer)
- Differential scanning calorimetry
- Intrinsic dissolution rate measurement
Correct answer: USP dissolution testing (Apparatus I or II)
USP dissolution testing using basket (Apparatus I) or paddle (Apparatus II) methods is the standard in vitro test used to assess and predict drug release and bioavailability.
Question 3: Polysorbate 80 (Tween 80) is commonly used in pharmaceutical formulations primarily as a(n):
- Preservative
- Emulsifying/solubilizing agent (Correct answer)
- Antioxidant
- Chelating agent
Correct answer: Emulsifying/solubilizing agent
Polysorbate 80 is a nonionic surfactant widely used to emulsify, solubilize, or wet poorly water-soluble drugs in liquid formulations.
Question 4: A pharmacist notes that a compounded suspension has settled into a hard cake that cannot be redispersed. This is an example of:
- Flocculation
- Caking (deflocculation) (Correct answer)
- Creaming
- Coalescence
Correct answer: Caking (deflocculation)
Caking occurs in deflocculated suspensions where densely packed particles form a hard sediment that is difficult or impossible to redisperse.
Question 5: Which excipient in a tablet formulation serves to prevent sticking of the tablet to the punch faces during compression?
- Glidant
- Lubricant (Correct answer)
- Binder
- Disintegrant
Correct answer: Lubricant
Lubricants such as magnesium stearate reduce friction between the tablet surface and punch/die walls, preventing sticking and ejection problems.
Question 6: The Noyes-Whitney equation describes the rate of drug dissolution as being directly proportional to:
- Particle density and pH
- Surface area and concentration gradient (Correct answer)
- Viscosity and temperature alone
- Crystal form and polymorphism
Correct answer: Surface area and concentration gradient
The Noyes-Whitney equation states dC/dt = DA(Cs − C)/hV, showing dissolution rate is proportional to surface area (A) and the concentration gradient (Cs − C).
Question 7: Which route of administration completely bypasses first-pass hepatic metabolism?
- Oral (swallowed tablet)
- Sublingual (Correct answer)
- Rectal suppository (lower rectum)
- Oral solution
Correct answer: Sublingual
Sublingual administration allows drug to enter systemic circulation via the sublingual veins directly, bypassing the portal circulation and hepatic first-pass metabolism.
FPGEE Pharmaceutics 5
A drug's biological half-life is 6 hours.
How long will it take to reach approximately 97% of steady-state plasma concentration during repeated dosing?