Pharmacy Drug Delivery Systems 4

Question 1

Ophthalmic solutions must be sterile AND typically buffered to a pH of approximately:

Accepted Answer

7.4

Answer

Ophthalmic formulations are buffered near physiologic tear pH of 7.4 to minimize irritation and maintain drug stability.

Question 2

A drug with a narrow therapeutic index is BEST suited for which delivery strategy?

Accepted Answer

Extended-release formulation to minimize peak-trough fluctuation

Answer

Extended-release systems reduce peak-trough fluctuations, keeping plasma concentrations within the narrow therapeutic window.

Question 3

The rate-limiting step in drug release from a reservoir-type transdermal system is:

Accepted Answer

The rate-controlling membrane

Answer

In reservoir systems, the synthetic rate-controlling membrane (not the skin) governs the drug flux into and through the skin.

Question 4

Cyclodextrins improve drug delivery primarily by:

Accepted Answer

Complexing drugs in their hydrophobic cavity to increase solubility

Answer

Cyclodextrins form inclusion complexes with hydrophobic drugs in their central cavity, dramatically improving aqueous solubility.

Question 5

Which of the following is a characteristic of a Class II BCS drug?

Accepted Answer

Low solubility, high permeability

Answer

BCS Class II drugs are poorly soluble but highly permeable; dissolution rate is the rate-limiting step for absorption.

Pharmacy Practice Test