Paeonol Nanoemulsion for Enhanced Oral Bioavailability: Optimization and Mechanism

The aim of this work was to optimize a nanoemulsion formulation and explain its absorption mechanism in improving the oral bioavailability of paeonol.The bioavailability of paeonol was compared between paeonol nanoemulsion group and paeonol suspension group. The in situ single-pass intestine perfusion method, in vitro everted gut sacs method, Western blot analysis and Caco-2 cell transport studies were used to investigate the absorption mechanism of nanoemulsion.Nanoemulsion was proved to enhance the bioavailability of paeonol. P-glycoprotein (P-gp) mediated efflux might be the main reason affecting the oral absorption of paeonol. The prepared nanoemulsion prevented the P-gp-mediated efflux and enhanced the bioavailability of paeonol.The overall results revealed that nanoemulsion was an effective vehicle to improve the oral bioavailability of paeonol which resulted from the prevention of P-gp efflux probably.