In bioequivalence, which parameter is commonly compared?

• A. Cmax
• B. Tmax
• C. Half-life
• D. Clearance

Answer: (A)

In bioequivalence, the goal is to compare how quickly and how much of the drug reaches systemic circulation between products. The parameter commonly compared is the maximum plasma concentration, Cmax, because it directly reflects the rate of absorption and helps detect formulation differences that could affect peak exposure and safety or efficacy. While the total amount absorbed is also important and assessed by the area under the curve (AUC), Cmax is the standard measure for rate of absorption and is highly sensitive to changes in release or absorption. The other options describe how the body eliminates the drug (half-life, clearance) or the time to reach peak concentration (Tmax), which are less central as primary BE endpoints and can be more variable. Therefore, Cmax is the best answer.