No abstract

Albendazole is an effective antihelmintic drug, which has an unpredictable therapeutic response due to its low solubility in biological fluids that limits its oral absorption. In an attempt to improve solubility, albendazole hydrochloride, a soluble pharmaceutical salt, was obtained and characterized by X-ray diffraction together with magic angle spinning solid-state nuclear magnetic resonance spectroscopy, Raman and Fourier transform infrared spectroscopies, thermal analysis, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. These studies revealed that the crystalline habit of albendazole hydrochloride is different from that of the albendazole solid forms previously reported. The full structure was elucidated by performing single-crystal X-ray diffraction. The characterization studies showed the participation of the carbamate moiety in the salt formation. In addition, the solubility studies showed a significant increase in the solubility with respect to forms I and II of albendazole. In conclusion, our results indicate that albendazole hydrochloride can be an auspicious salt to be used as a new product in an attempt to counteract unfavorable pharmaceutical properties.

Albendazole, an effective broad-spectrum anthelmintic agent, showed unpredictable therapeutic response caused by poor water solubility and slow dissolution rate. Then, novel binary and multicomponent supramolecular systems of two different solid forms of albendazole (I and II) with maltodextrin alone or with glutamic acid were studied as an alternative to improve the oral bioavailability of albendazole. The interactions and effects on the properties of albendazole were studied in solution and solid state. The solid systems were characterized using Raman and Fourier transform-infrared spectroscopy, thermal analysis, powder X-ray diffraction, and scanning electron microscopy. The solubility measurements, performed in aqueous and simulated gastric fluid, showed that albendazole (form II) was the most soluble form, while its supramolecular systems showed the highest solubility in simulated gastric fluid. On the other hand, the dissolution profiles of binary and multicomponent systems in simulated gastric fluid displayed pronounced increments of the dissolved drug and a faster dissolution rate compared to those of free albendazole forms. Thus, these supramolecular structures constitute an interesting alternative to improve the physicochemical properties of albendazole, with potential application for the preparation of pharmaceutical oral formulations.