PSI Pharmaceutical Sciences

Question 1

Which route of administration provides 100% bioavailability?

Accepted Answer

Intravenous

Answer

Intravenous administration delivers drug directly into systemic circulation, bypassing first-pass metabolism and absorption barriers, giving 100% bioavailability.

Question 2

What is the Henderson-Hasselbalch equation used to calculate?

Accepted Answer

pH of a buffer solution

Answer

The Henderson-Hasselbalch equation (pH = pKa + log [A-]/[HA]) calculates the pH of a buffer based on the ratio of conjugate base to weak acid.

Question 3

Which process describes drug movement from high to low concentration without energy expenditure?

Accepted Answer

Passive diffusion

Answer

Passive diffusion moves drug molecules down a concentration gradient without requiring energy (ATP). It is the most common absorption mechanism.

Question 4

The volume of distribution (Vd) of a highly lipophilic drug is typically:

Accepted Answer

Large, as drug distributes into tissues

Answer

Lipophilic drugs partition extensively into fatty tissues and plasma proteins, resulting in a large apparent volume of distribution well above actual body fluid volumes.

Question 5

Which excipient acts as a disintegrant in tablet formulations?

Accepted Answer

Croscarmellose sodium

Answer

Croscarmellose sodium is a superdisintegrant that swells rapidly on contact with water, breaking the tablet apart to aid drug dissolution and absorption.

PSI Pharmacy Practice Test

PSI Pharmacy Practice Test

PSI Pharmaceutical Sciences