Development of a parenteral and of an oral formulation of albendazole withcyclodextrins

Albendazole is a benzimidazole derivative with a broad spectrum of activity against human and animal helminthe parasites. Albendazole has a very poor aqueous solubility. It has been shown that cyclodextrins are able to form i nclusion complexes with albendazole and that they are able to increase its aqueous solubility. The solubility of albendazole also depends on the pH. T he purpose of this study was to investigate the influence of both cyclodext rins and different acids on the solubility of albendazole. It was found tha t a synergistic effect existed between cyclodextrins and different acids. T he combination of hydroxypropyl-beta-cyclodextrin (200 mM) and lactic or ci tric acid (50 mM) allowed the dissolution of more than 1 mg/ml of albendazo le. Nuclear magnetic resonance studies confirmed the formation of an inclus ion complex albendazole/beta-cyclodextrin in an acidic medium. These result s demonstrate that it is possible to develop a parenteral and an oral aqueo us solution of albendazole bq the use of cyclodextrins.