Solubilization of phloretin via steviol glycoside-based solid dispersion and micelles

In this study, the solubility of phloretin (PT) was enhanced via steviol glycoside (STE)-based micelle (MC) and solid dispersion (SD). Computer simulation, characterization, interaction with serum albumin (SA) and in vitro release were carried out to investigate the solubilization mechanisms and the difference in their solubilization capacities. For PT-loaded MC (STE-PT MC), PT was encapsulated into the hydrophobic core of a spherical micelle with a droplet diameter of 5 nm. For PT-loaded SD (STE-PT SD), PT was completely dispersed with the amorphous state in STE. Most of those PTs were directly dissolved in water, and few were encapsulated by STE micelles. The amorphous state combined with relatively large micelles contributed to the high solubilization capacity of STE-PT SD. In addition, PT of STE-PT SD exhibited a higher dissolution rate and more effective interaction with SA than that of STE-PT MC. No undesirable chemical interaction between PT and STE occurred.