FPGEE Pharmaceutics 2 — Questions and Answers
Question 1: Which dissolution model describes drug release that is proportional to the square root of time?
- Zero-order model
- First-order model
- Higuchi model (Correct answer)
- Korsmeyer-Peppas model
Correct answer: Higuchi model
The Higuchi model describes diffusion-controlled drug release from a matrix, where cumulative release is proportional to the square root of time.
Question 2: A tablet formulation requires a disintegrant that swells rapidly upon contact with water. Which excipient is MOST appropriate?
- Magnesium stearate
- Sodium starch glycolate (Correct answer)
- Microcrystalline cellulose
- Talc
Correct answer: Sodium starch glycolate
Sodium starch glycolate is a superdisintegrant that rapidly swells in water, promoting tablet disintegration.
Question 3: What is the primary purpose of an enteric coating on an oral solid dosage form?
- Improve taste masking
- Prevent drug release in the stomach (Correct answer)
- Increase drug dissolution rate
- Protect the drug from light
Correct answer: Prevent drug release in the stomach
Enteric coatings resist dissolution at low gastric pH but dissolve at the higher pH of the small intestine, protecting acid-labile drugs or preventing gastric irritation.
Question 4: In a parenteral emulsion intended for intravenous administration, the droplet size of the dispersed phase must not exceed:
- 10 microns
- 5 microns (Correct answer)
- 1 micron
- 0.5 microns
Correct answer: 5 microns
IV emulsions must have droplet sizes below 5 microns to prevent capillary occlusion and ensure safe intravenous administration.
Question 5: Which factor primarily determines whether a drug is classified as BCS Class I?
- High solubility and high permeability (Correct answer)
- Low solubility and high permeability
- High solubility and low permeability
- Low solubility and low permeability
Correct answer: High solubility and high permeability
BCS Class I drugs have both high aqueous solubility and high intestinal permeability, making them ideal candidates for biowaivers.
Question 6: The van't Hoff equation is used in pharmacy to calculate:
- Osmotic pressure of a solution (Correct answer)
- Rate of drug degradation
- Partition coefficient
- Viscosity of a suspension
Correct answer: Osmotic pressure of a solution
The van't Hoff equation (π = iMRT) relates osmotic pressure to molar concentration, temperature, and the number of solute particles.
Question 7: A cream formulation is classified as an oil-in-water (O/W) emulsion. Which of the following is a characteristic of this type?
- It is water-washable (Correct answer)
- It leaves an occlusive film
- It is miscible with oils
- It does not contain an emulsifying agent
Correct answer: It is water-washable
O/W emulsions have water as the external phase, making them water-washable, non-greasy, and easy to spread.
FPGEE Pharmaceutics 2
Which dissolution model describes drug release that is proportional to the square root of time?