FPGEE for National Association of Boards of Pharmacy (NABP) Practice Exam

For a generic drug to be considered bioequivalent, how many subjects must be measured according to FDA regulations?

1. 40

2. 80

3. 20

4. 10

The correct answer is: 80

A generic drug is considered bioequivalent to its brand-name counterpart when it demonstrates pharmacokinetic parameters such as absorption, distribution, metabolism, and excretion that fall within specified limits. According to FDA regulations, a minimum of 80 subjects is typically required to achieve statistical power in bioequivalence studies. This number allows for a robust analysis that can account for variability among subjects and helps ensure that the generic formulation delivers a similar bioavailability profile compared to the reference listed drug. In clinical bioequivalence studies, assessing a larger number of participants helps to mitigate the risk of random variation affecting the outcome. Sampling fewer subjects would yield less reliable data, thereby increasing the likelihood of failing to demonstrate true equivalence. By establishing a standard of 80 subjects, the FDA sets an expectation for consistency and reliability in the evaluation of generic drugs' effectiveness and safety.