Solubilization and dissolution of tamoxifen-hydroxybutenyl cyclodextrin complexes

Abstract

The solubility and dissolution of tamoxifen base and tamoxifen citrate with and without hydroxybutenyl-beta-cyclodextrin (HBenBCD) in aqueous and organic media were examined. The solubility of tamoxifen was greatly enhanced by complexation with HBenBCD; pH of the medium, and choice of buffer significantly impacted the amount of drug that could be solubilized. Different tamoxifen:HBenBCD formulations were prepared, including liquid fill capsule formulations, and their dissolution profiles were obtained. These dissolution studies demonstrated that enhanced solubilization of tamoxifen with HBenBCD was effective across a wide variety of formulation options. By complexation of tamoxifen base with HBenBCD, it was possible to obtain solubility and dissolution profiles for tamoxifen base that were essentially identical to that of tamoxifen citrate.