Improved solubility and oral bioavailability of apigenin via Soluplus/Pluronic F127 binary mixed micelles system

The aim of this study was to develop a novel mix micelles system composing of two biocompatible copolymers of Soluplus (R) and Pluronic F127 to improve the solubility, oral bioavailability of insoluble drug apigenin (AP) as model drug. The AP-loaded mixed micelles (AP-M) were prepared by ethanol thin-film hydration method. The formed optimal formulation of AP-M were provided with small size (178.5nm) and spherical shape at ratio of 4:1 (Soluplus (R):Pluronic F127), as well as increasing solubility of to 5.61mg/mL in water which was about 3442-fold compared to that of free AP. The entrapment efficiency and drug loading of AP-M were 95.72 and 5.32%, respectively, and a sustained release of AP-M was obtained as in vitro release study indicated. Transcellular transport study showed that the cell uptake of AP was increased in Caco-2 cell transport models. The oral bioavailability of AP-M was 4.03-fold of free AP in SD rats, indicating the mixed micelles of Soluplus (R) and Pluronic F127 is an industrially feasible drug delivery system to promote insoluble drug oral absorption in the gastrointestinal tract.