Improved bioavailability of a micronized megestrol acetate tablet formulation in humans

Megestrol acetate, a progestogen widely used in the palliative treatment of endometrial carcinoma and breast cancer is currently administered orally a s a solid dosage form. Bioavailability of the drug following oral administr ation is closely related to the effectiveness and safety profile of the dru g in formulation. Improved immediate release formulations should allow impr oved drug delivery into the systemic circulation and, at the end to the sit e of action. The micronization of drugs is one of the technological procedu res to achieve such a purpose. This paper reports the design and results ob tained in an in vivo study of the bioavailability of a micronized megestrol acetate tablet formulation compared to a conventional form. A significant increase in the drug bioavailability was observed in either the rate or the extent of absorption. in vitro dissolution data of the two study formulati ons reflected the in vivo findings.