ORIGINAL RESEARCH article

Front. Pharmacol.

Sec. Drug Metabolism and Transport

Bioequivalence Study of Testosterone Undecanoate Soft Capsules in Healthy Postmenopausal Women Under Fed Conditions: A Single-Center, Four-Period, Repeated Crossover Trial

  • 1. Research and Development Center, Zhejiang Medicine Co., Ltd, Shaoxing, Zhejiang, China

  • 2. School of Engineering, China Pharmaceutical University, Nanjing, China

  • 3. Department of Clinical Pharmacology, Xinxiang Central Hospital, Xinxiang, China

  • 4. Xinxiang Central Hospital, Xinxiang, China

  • 5. Shanghai Xihua Scientific Co., Ltd, Shanghai, China

The final, formatted version of the article will be published soon.

Abstract

Purpose: This study aimed to systematically evaluate the pharmacokinetics, bioequivalence, and safety of a single postprandial oral dose of testosterone undecanoate (TU) and its originator drug Andriol Testocaps® in healthy postmenopausal Chinese women, providing theoretical support for optimizing hormone replacement therapy protocols. Methods: A randomized, open-label, two-treatment, four-period, single-center, single-dose crossover clinical trial was conducted at Xinxiang Central Hospital. Participants received single oral doses of 40 mg TU or Andriol Testocaps® in each period. Serial blood samples were collected from 0 to 24 hours post-dose. Results: The average adjusted geometric mean ratios (GMR) (90% CI) for the primary PK parameters Cmax, AUC0-t, and AUC0-∞were 102.20% (90.32% - 115.63%), 99.85% (92.82% - 107.41%), and 99.79% (92.90% - 107.20%). All 90% CI for Cmax, AUC0-t, and AUC0-∞fell within the 80% - 125% bioequivalence range. The two drugs showed comparable results for the other PK parameters. These results indicate that the two drugs were bioequivalent. Conclusion: TU demonstrated bioequivalence to Andriol Testocaps® under fed conditions in Chinese healthy participants, with comparable safety and tolerability profiles. These results advocate the clinical application of generic TU as a potential alternative to originator drug Andriol Testocaps® in the treatment.

Summary

Keywords

Bioequivalence, Chinese healthy participants, pharmacokinetics, Safety, Testosterone Undecanoate

Received

09 December 2025

Accepted

18 February 2026

Copyright

© 2026 Li, Zhu, Zhao, Zhu, Wu, Zuo, Shi, Qian, Zhang, Hu, Lv, Chen and Zhang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Jing Chen; Tiandong Zhang

Disclaimer

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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