The aim of this study was to evaluate the intra subject variability of progesterone 200 mg soft capsules of Test product with Prometrium® (Progesterone USP) capsules 200 mg (Reference) marketed by Solvay Pharmaceuticals Inc., Marietta, GA in healthy adult, human, post menopausal female volunteers. This study was an open label, randomized, balanced, single-dose, two sequence four period, full replicate, crossover oral bioequivalence study was conducted in 30 healthy adult, human, post menopausal female volunteers under fed conditions in two equal groups. Subjects received progesterone 200 mg of either test or reference formulation with a washout period of 11 days. After study drug administration, serial blood samples were collected over a period of 36 hours post dose. The plasma concentrations of progesterone were determined using validated LC/MS/MS method. Pharmacokinetic parameters Cmax, Tmax , AUC0-t, AUC0-∞, Kel and T1/2 were determined for both the formulations. The 95% upper confidence bound of Cmax, AUC0-t and AUC0-∞ of progesterone was found to be -0.37246%, -0.02535%, and 0.04630% respectively were less than zero (0.0000) and the T/R ratios for Cmax, AUC0-t and AUC0-∞ of progesterone were found to be 77.25%, 76.20%, and 61.64% respectively were lie outside the acceptance range of 80.00-125.00%. Within subject standard deviation of reference product (SWR) for Cmax, AUC0-t and AUC0- ∞ was found to be 1.13304, 0.72073 and 0.78637 respectively were found to be >0.294. The test formulation in this study fails to show the bioequivalence in comparison with that of reference formulation in terms of scaled average bioequivalence criteria under fed conditions.
