Bioequivalence of Water-Soluble Progesterone Injection (GenSci070) in Healthy Chinese Postmenopausal Women Volunteers

•GenSci070 is a water-soluble progesterone injection.•GenSci070 is bioequivalent to the marketed progesterone injection (Lubion).•GenSci070 exhibits a good safety profile.•GenSci070 provides a new treatment option for patients on China's mainland. To study the pharmacokinetic characteristics of progesterone (GenSci070) in healthy Chinese postmenopausal women volunteers and to evaluate the bioequivalence and safety of GenSci070 and reference formulation. In this randomized, open-label, single-center, single-dose, 2-period, 2-sequence, 2-way crossover study, 50 postmenopausal healthy women were recruited and received a single subcutaneous injection of test (GenSci070) or reference formulation 25 mg, respectively. Plasma progesterone concentrations were measured using liquid chromatography–tandem mass spectrometry, and pharmacokinetic parameters were calculated by noncompartmental analysis method using Phoenix WinNonlin 8.3.1 software to evaluate the bioequivalence. The safety profile was evaluated by adverse events, physical examination, vital signs, laboratory tests, 12-lead ECG, etc. The geometric mean ratios (90% CIs) for Cmax, AUC0–t, and AUC0–∞ of the test and reference formulations were 92.70% (87.29%–98.44%), 96.26% (94.02%–98.55%), and 95.46% (93.27%–97.71%), respectively. They were all within the acceptable bioequivalence range of 80% to 125%. Thirty-one treatment-emergent adverse events occurred in 22 participants (44.0%) who received test formulation and 21 treatment-emergent adverse events occurred in 16 participants (32.0%) who received reference formulation, all events were mild. The water-soluble progesterone injection (GenSci070) demonstrated bioequivalence to the marketed progesterone injection (Lubion) and exhibited a good safety profile in this study.