Bioequivalence of long half-life drugs--informative sampling determination--using truncated area in parallel-designed studies for slow sustained-release formulations.

A simulation study was done to determine if 72 h is the most informative sampling duration for bioequivalence (BE) determination in parallel-designed BE studies with drugs that have half-lives of at least 30 h. The impact of absorption and elimination half-lives on informative sampling was evaluated. Two-treatment parallel-designed BE studies using a one-compartment oral absorption model with half-lives of 30 and 350 h was simulated.