Rajeswara Rao P, Someswara Rao K and Subba Rao M
The aim of this study was to evaluate the affect of solubilizers of capmul, labrafil and transcutol on progesterone 100 mg soft capsules of two different Test batches (Test-1 and Test-2) in comparison with that of Prometrium® (Progesterone USP) capsules 100 mg of Reference Product of Abbott Laboratories, USA in healthy adult, human, post-menopausal female volunteers. This study was an open label, balanced, randomized, three treatment, six sequence, three period, cross-over, single-dose comparative oral bioavailability study of Progesterone USP capsules 100 mg of two different Test batches (Test-1 and Test-2) conducted in 18 healthy adult, human, post-menopausal female volunteers under fasting conditions. Subjects received progesterone 100 mg of either test (Test-1 and Test- 2) or reference formulation with a washout period of 7 days. After study drug administration, serial blood samples were collected over a period of 24 hours post dose. The plasma concentrations of progesterone were determined by a validated method using LC/MS/MS. Pharmacokinetic parameters Cmax, Tmax, AUC0-t, AUC0-∞, Kel and T1/2were determined for both test (Test-1 and Test-2) and reference formulations. The formulations were to be considered bioequivalent if the geometric least square mean ratio of test and reference of Cmax, AUC0-t and AUC0-∞ for baseline adjusted data, Cmax and AUC0-t for baseline unadjusted data were within the predetermined bioequivalence range of 80.00% to 125.00%. A total of 18 subjects were enrolled. No significant differences were found based on analysis of variance. The 90% confidence intervals (CI) for Cmax, AUC0-t and AUC0-∞of progesterone baseline adjusted data were 617.99-1488.02%, 270.11-683.70%, and 228.82-523.71% respectively. The 90% confidence intervals (CI) for Cmax and AUC0-t of progesterone baseline unadjusted data were 497.80-1180.16% and 156.81-407.82% respectively. Both the test formulations (Test-1 and Test-2) in this study were fails to show the bioequivalence with that of reference formulation for progesterone and were found to have significantly suprabioavailale. The intra subject variability (%) for Cmax, AUC0-t and AUC0-∞of progesterone baseline adjusted data were found to be 87.49%, 94.16% and 74.66% respectively. The intra subject variability (%) for Cmax and AUC0-t of progesterone baseline unadjusted data were found to be 85.47% and 97.93% respectively. There was a significant intra subject variability was observed for both the test formulations (Test-1 and Test-2) for progesterone under fasting conditions.