This work describes a method to obtain a Progesterone / HPBCD without insoluble particles and the physico-chemical characterization of the precipitate and the purified inclusion complex. 
Progesterone is a natural hormone utilized as a drug to control reproductive function and for postmenopausal therapy. The current administration routes are oral by soft gel caspules, vaginal by soft gel capsules or cream and intramuscolar oily solution or water suspension injections.

Oral and vaginal routes have low bioavailability and, in addition oral route has a limited usefulness because of its short half-life and extensive degradation after absorption. Therefore the injection route should be the preferred choice, but the oily solution and the water suspension allow only intramuscular administration with a considerable pain during the treatment. This encourages the research of new water soluble injectable pharmaceutical forms with increased patient compliance.