Bioavailability of a new oral formulation of medroxyprogesterone acetate compared with the standard formulation: a single dose randomized study.

Twenty-six female patients with breast cancer participated in an open, randomized, cross-over study comparing single dose bioavailability of a recently developed oral medroxyprogesterone acetate (MPA) formulation (200 mg sachet where MPA is loaded in a polyvinylpyrrolidone cross-linked polymer, MPA/PVP) with the standard formulation (500 mg tablet). Blood tests were performed under standardized conditions for 120 h in all patients and MPA plasma concentrations determined by means of HPLC. Dose-normalized AUC(0-tz), AUC (0-infinity) and Cmax were all significantly higher for the MPA/PVP formulation than for the standard formulation. The relative bioavailability of the MPA/PVP formulation was on average three times superior to that of the standard formulation. This new MPA formulation might have important clinical implications for the treatment of hormone-sensitive cancer.