The characterization, pharmacokinetic and tissue distribution studies of TPGS modified myricetrin mixed micelles in rats.

This study was designed to investigate the bioavailability and targeting of myricetrin-loaded ternary micelles modified with and without TPGS. The particle diameters of myricetrin-loaded micelles and myricetrin-loaded-TPGS micelle were 30.93 +/- 1.34 nm and 26.42 +/- 0.89 nm, respectively, while their respective encapsulation efficiencies (m/m, %) were 83.3 +/- 1.08 and 93.8 +/- 1.18. The release rate of myricetrin in the micellar system clearly exceeded the free myricetrin in the three media (pH 6.8 phosphate buffer, pH 1.2 HCl solution and double distilled water). In vivo studies displayed that the bioavailability of myricetrin mixed micelles was remarkably improved than the free drug after oral administration. Moreover, the results of tissue distribution showed that myricetrin-loaded-TPGS micelles accumulated well in the liver tissue. Based on these results, it was speculated that myricetrin-loaded-TPGS micelles might act as a promising carrier for liver targeting with improved hepatic concentration of myricetrin compared with the myricetrin-loaded micelles.