Influence of hydroxypropyl-β-Cyclodextrin and hydroxypropyl-γ-Cyclodextrin on the aqueous solubility of ellagic acid

Abstract

Ellagic acid has great potential for commercial development and clinical application due to its diverse therapeutic properties, including antioxidant, anti-inflammatory, anticancer, neuroprotective, hepatoprotective and cardioprotective. However, its poor solubility and bioavailability overshadow its prospects for development and application as a new drug. To increase the solubility and hence bioavailability of ellagic acid, hydroxypropyl-β-cyclodextrin and hydroxypropyl-γ-cyclodextrin were used for the formation of cyclodextrin-ellagic acid complexes. Following phase solubility studies, solid complexes were prepared by lyophilization and then characterized by fourier transform infrared spectroscopy. The results of the phase solubility studies showed a 3.12- and 6.40-fold increase in the real solubility of ellagic acid in the presence of hydroxypropyl-β-cyclodextrin and hydroxypropyl-γ-cyclodextrin, respectively. In addition, an Ap-type diagram was obtained with both derivatives of natural cyclodextrins. Fourier transform infrared spectroscopy revealed the presence of interactions between the hydroxyl groups of ellagic acid and those of cyclodextrins.