Assessment of Pharmacokinetic Parameters of Daidzein-Containing Nanosuspension and Nanoemulsion Formulations After Oral Administration to Rats

Background and Objectives Daidzein has several biological effects such as antioxidation, anti-inflammation, chemoprevention, and anticancer effects. The aim of this study was to evaluate the impact of nano-formulations (nanoemulsion-NE and nanosuspension-NS) prepared to increase the oral bioavailability of daidzein, a poorly water-soluble isoflavone, on the pharmacokinetic parameters of daidzein in rats. Methods A high-performance liquid chromatography-ultraviolet (HPLC-UV) method was successfully developed for daidzein analysis in rat plasma. The pharmacokinetics studies of the nano-sized formulations, compared to coarse daidzein suspension, were carried out in the rats by a single oral dose at 10 mg/kg ( n = 6/group). Area under the plasma concentration-time curve from time zero to extrapolation to time infinity (AUC 0–∞) , maximum plasma concentration ( C max ), time to reach maximum plasma concentration ( t max ), and elimination half life ( t 1/2 ) values for coarse daidzein suspension, daidzein-NS, and daidzein-NE were estimated by a non-compartmental analysis. Results The AUC values of daidzein-NE and daidzein-NS were approximately 2.62 and 2.65 times higher than that of coarse daidzein suspension, respectively ( p