Assessment of different bioequivalent metrics in Rifampin bioequivalence study

Abstract: The use of secondary metrics has become special interest in bioequivalency studies. The applicability of partial area method, truncated AUC and Cmax/AUC has been argued by many authors. This study aims to evaluate the possible superiority of these metrics to primary metrics (i.e. AUCinf, Cmax and Tmax). The suitability of truncated AUC for assessment of absorption extent as well as Cmax/AUC and partial AUC for the evaluation of absorption rate in bioequivalency determination was investigated following administration of same product as test and reference to 7 healthy volunteers. Among the pharmacokinetic parameters obtained, Cmax/AUCinf was a better indicator or absorption rate and the AUCinf was more sensitive than truncated AUC in evaluation of absorption extent.