Inclusion Complexes of Hesperidin with Hydroxypropyl-β - Cyclodextrin. Physico-chemical Characterization and Biological Assessment

The aim of this research was to prepare the inclusion complexes formed by hesperidin and (2-hydroxypropyl)-β-cyclodextrin by different techniques (kneading, co-evaporation and lyophilization methods), to carry out phase solubility studies, in vitro dissolution, antioxidant and antimicrobial tests. To confirm the inclusion compounds formation, spectroscopic (UV-Vis, FTIR, 1 H-NMR) and thermal (DSC) methods were used. The obtained thermodynamic parameters proved that the inclusion process is spontaneous and is influenced both by temperature and cyclodextrin concentration. Moreover, for all obtained inclusion complexes the dissolution of hesperidin increased, the process being more effective for the lyophilization method in gastric pH 1.2 medium. Also, the inclusion complexes presented improved antimicrobial and antioxidant activities as compared to free hesperidin. The best antimicrobial activity was obtained against Candida albicans for the compound obtained by co-evaporation. The compound obtained through lyophilization showed an enhanced antioxidant activity according to the results obtained through two methods (DPPH free radical scavenging assay and lipoxygenase inhibition assay), while through the third technique (determination of the reducing capacity) the best results were obtained for the compound prepared by kneading. Thus, hydroxypropyl-β-cyclodextrin can be used to improve the biological properties of hesperidin.