Drug Stability: Factors, Testing, and Shelf-Life Determination

Question 1

Which chemical degradation pathway is most commonly observed in drug molecules?

Accepted Answer

Hydrolysis

Answer

Oxidation

Answer

Photolysis

Answer

Decarboxylation

Question 2

Which of the following is a primary cause of photolytic degradation in drug molecules?

Accepted Answer

UV radiation

Answer

Visible light

Answer

Gamma radiation

Answer

Microwave radiation

Question 3

To determine the shelf-life of a drug product, which information is typically considered?

Accepted Answer

Results from both accelerated and real-time stability testing

Answer

Results from accelerated stability testing alone

Answer

Results from real-time stability testing alone

Answer

Results from neither accelerated nor real-time stability testing

Question 4

How does a low pH environment typically affect the hydrolysis of drugs containing an ester functional group?

Accepted Answer

Accelerates hydrolysis

Answer

Retards hydrolysis

Answer

Has no significant effect on hydrolysis

Answer

The effect cannot be determined without additional information

Question 5

Which of the following factors does NOT directly affect drug stability?

Accepted Answer

Dosage form

Answer

Temperature

Answer

pH

Answer

Light

Question 6

Which of the following factors does not significantly influence drug stability?

Accepted Answer

Molecular size

Answer

Temperature

Answer

Light

Answer

pH

Question 7

What is the primary objective of accelerated stability testing?

Accepted Answer

To predict the shelf-life of a drug product under accelerated conditions.

Answer

To determine the optimal storage conditions for a drug product.

Answer

To assess the stability of a drug product under real-world conditions.

Answer

To evaluate the impact of excipients on drug stability.

Question 8

Which method is commonly employed to determine the Arrhenius activation energy?

Accepted Answer

Van't Hoff plot

Answer

Eyring plot

Answer

Half-life method

Answer

pH-rate profile

Question 9

Which storage condition is typically recommended for highly unstable drug products?

Accepted Answer

Freezing

Answer

Refrigeration

Answer

Room temperature

Answer

Light exposure

Question 10

What is the predominant degradation pathway for drugs containing an amide bond?

Accepted Answer

Hydrolysis

Answer

Oxidation

Answer

Photolysis

Answer

Decarboxylation

Question 11

What type of study design is used to evaluate the stability of a drug product under real-world conditions?

Accepted Answer

Long-term stability study

Answer

Accelerated stability study

Answer

Photostability study

Answer

In vitro stability study

Question 12

Which factor is crucial to consider when interpreting accelerated stability data?

Accepted Answer

Temperature extrapolation

Answer

Drug concentration

Answer

Storage container

Answer

Sample size

Question 13

Which of the following is NOT a key factor affecting drug stability?

Accepted Answer

Altitude

Answer

Temperature

Answer

Light

Answer

pH

Question 14

What is the primary purpose of accelerated stability testing?

Accepted Answer

Predicting the shelf-life of a drug product under exaggerated conditions.

Answer

Verifying the stability of a drug product under normal storage conditions.

Answer

Identifying unknown degradation products.

Question 15

How does increased temperature generally affect the rate of drug degradation?

Accepted Answer

Increases the rate of degradation

Answer

Decreases the rate of degradation

Answer

Has no significant effect on the rate of degradation

Question 16

Which type of light is most damaging to drug stability?

Accepted Answer

Ultraviolet (UV) light

Answer

Visible light

Answer

Infrared (IR) light

Answer

Light has no effect on drug stability.

Question 17

What is the primary role of antioxidants in drug formulations?

Accepted Answer

Inhibiting oxidation reactions

Answer

Neutralizing acids

Answer

Preventing microbial growth

Answer

Enhancing drug absorption

Question 18

Why is moisture control crucial in drug stability?

Accepted Answer

Moisture can promote hydrolysis reactions, leading to drug degradation.

Answer

Moisture has no significant impact on drug stability.

Answer

Moisture can enhance the stability of certain drugs.

Question 19

Which of the following storage practices is recommended to maintain drug stability?

Accepted Answer

Storing drugs in original, tightly sealed containers.

Answer

Exposing drugs to direct sunlight

Answer

Storing drugs in humid conditions

Answer

Mixing different drugs in the same container

Question 20

Which of the following factors does NOT affect drug stability?

Accepted Answer

Molecular weight

Answer

pH

Answer

Temperature

Question 21

Which of the following pH ranges is generally considered optimal for most drug products?

Accepted Answer

4-8

Answer

10-12

Answer

2-4

Answer

8-10

Question 22

What is the primary mechanism of drug degradation caused by light?

Accepted Answer

Photolysis

Answer

Hydrolysis

Answer

Oxidation

Question 23

Which of the following storage conditions is most likely to minimize drug degradation?

Accepted Answer

Cool, dry, and dark

Answer

Frozen, humid, and light

Answer

Warm, humid, and light

Answer

Room temperature, dry, and light

Question 24

Which of the following is an example of a physical instability of a drug?

Accepted Answer

Color change

Answer

Decomposition

Answer

Loss of potency

Answer

Formation of impurities