Medroxyprogesterone acetate: steady-state pharmacokinetics bioequivalence of two oral formulations

Two micronized oral formulations of medroxyprogesterone acetate (MPA) (Farlutal and Clinovir) were compared in order to evaluate their relative bioavailability. Sixteen female patients with metastatic breast cancer were entered in a randomized cross-over study on 500-mg MPA tablets repeatedly administered (twice daily for 20 days). At the steady state, similar mean +/- SD serum levels of MPA were obtained (131 +/- 44 ng/ml for Farlutal and 136 +/- 45 ng/ml for Clinovir) and the two formulations proved to be bioequivalent (confidence interval at a significance level of 0.95 = 93%-107%).