Optimization and evaluation of Oridonin-loaded Soluplus®-Pluronic P105 mixed micelles for oral administration

Abstract In this study, a new type of mixed micelles was developed using Soluplus ® (SOL) and Pluronic ® P105 (P105) for the encapsulation of Oridonin (ORN). Oridonin-loaded micelles (ORN-M) were simply prepared using solvent evaporation and characterized for particle size, particle morphology, encapsulation efficiency, and drug loading. In addition, the in vitro drug release behavior of ORN-M was assessed using the widely applied dialysis bag technique. The pharmacokinetic property of ORN was explored in rats after oral administration of ORN-M. Optimized ORN-M were of a small size (137.2 ± 1.65 nm) and spherical shape when the ratio of SOL:P105 was 3:1, with entrapment efficiency 90.48 ± 1.85% and drug loading 15.08 ± 0.38%. Oral absorption capacity of ORN was greatly enhanced with a relative bioavailability of 210.55% in comparison to that of in-house suspensions, which suggests that ORN-M shows significantly improved bioavailability and drug absorption characteristics. Overall, the optimized SOL-P105 dual mixed micelles show great potential for use as oral drug carriers for cancer treatment.