Pharmacokinetic Bioequivalence and Safety Assessment of Two Venlafaxine Hydrochloride Extended-Release Capsules in Healthy Chinese Subjects Under Fed Conditions: A Randomized, Open-Label, Single-Dose, Crossover Study.

Background And Objective: Venlafaxine hydrochloride extended-release (ER) capsules are commonly used to treat depression and anxiety disorders. Evaluation of the bioequivalence of generic formulations with reference products is essential to ensure therapeutic equivalence. The objective of this study was to evaluate the bioequivalence, safety, and tolerability of Chinese-manufactured venlafaxine hydrochloride extended-release capsules compared with USA-manufactured EFFEXOR XR in healthy Chinese volunteers under fed conditions.

Methods: A randomized, open-label, single-dose, crossover study was conducted. Subjects were randomly assigned to receive the test formulation (one 150-mg ER capsule manufactured in China) or the reference formulation (one 150-mg ER capsule manufactured in the USA). The bioequivalence of the two drugs was assessed using the area under the plasma concentration-time curve from time zero to the last sampling time (AUC) and the maximum observed concentration (C).

Results: A total of 28 subjects were enrolled and randomly assigned to receive a single dose of either the test or reference capsule. All the subjects completed the study and were included in the pharmacokinetic (PK) and safety analyses. The mean AUC and C of venlafaxine and its active metabolite O-desmethylvenlafaxine were comparable between the test and reference products with both parameters close to 100% and the corresponding 90% confidence intervals within the specified 80-125% bioequivalence boundary. Safety was also assessed between the two products and all adverse events (AEs) in this study were mild in severity.

Conclusions: Both the test and reference venlafaxine hydrochloride ER capsules were bioequivalent and showed a similar safety and tolerability profile in the population studied.

Clinical Trials Registration: This study was registered at the Drug Clinical Trial Registration and Information Publicity Platform ( http://www.chinadrugtrials.org.cn/index.html ) with registration number CTR20211243, date: June 1, 2021.