Preparation and characterization of a solid dispersion containing curcumin and octenylsuccinate hydroxypropyl phytoglycogen for improved curcumin solubility.

Curcumin (CCM) is a natural and potent bioactive compound; however, its poor water solubility limits its performances and applications. In this study, octenylsuccinate hydroxypropyl phytoglycogen (OHPP), a dendrimer-like, amphiphilic phytoglycogen derivative, was used to solubilize CCM and enable its inhibitory effect against pathogen Helicobacter pylori. The CCM-OHPP solid dispersion (CCM-OHPP SD) was prepared using spray drying and characterized for its molecular interaction (with FTIR), crystallinity (with X-ray powder diffraction), solubility, and minimal bactericidal concentration (MBC) against three H. pylori strains. The results showed the presence of hydrogen bonds between CCM and OHPP in CCM-OHPP SD and the transformation of CCM from crystalline to amorphous state due to its incorporation with OHPP. For CCM-OHPP SD, the soluble amount of CCM was over 16,000 times that of CCM alone, and the dissolution rate reached 60-99% in 30-60 min. Against three strains of H. pylori, MBC values of CCM were 20 μg/mL for CCM-OHPP SD, which were comparable with that of DMSO-assisted CCM solutions. Overall, the results showed that OHPP was a highly effective solubilizer of CCM to enable its inhibitory efficacy against H. pylori.