Improving glyburide solubility and dissolution by complexation with hydroxybutenyl-beta-cyclodextrin.

OBJECTIVES Glyburide, an important drug for type 2 diabetes, has extremely poor aqueous solubility and resulting low bioavailability. This study describes the ability of hydroxybutenyl-beta-cyclodextrin (HBenBCD) to form complexes with glyburide, with enhanced solubility and dissolution rate in vitro. METHOD Glyburide and glyburide-HBenBCD were evaluated in various test media known to simulate human gastrointestinal conditions in the fasted and fed states, respectively. KEY FINDINGS At approximately 14 wt% drug load, in the presence of HBenBCD, an almost 400-fold increase in glyburide aqueous solubility was observed. In the presence of HBenBCD, glyburide solubility was also significantly improved in all physiologically relevant test media. Subsequent dissolution experiments confirmed the solubility study results; the dissolution rate and total amount of drug released were significantly increased. CONCLUSIONS Complexation with HBenBCD may be an effective way to increase the bioavailability of glyburide.