Effect of Micronization on Panax notoginseng: In Vitro Dissolution and In Vivo Bioavailability Evaluations

Panax notoginseng (PN) has become the most widely used dietary supplement and herbal in Asian countries. The effect of micronization on PN is not entirely clear. The aim of this study was to investigate the effects of particle size of Panax notoginseng powder (PNP) and the potential to improve the bioavailability. The results showed that particle size reduction significantly changed the Panax notoginseng saponins (PNS) in vitro dissolution and in vivo pharmacokinetics. The size of the Panax notoginseng powder (PNP) ranges from 60 to 214 μm. The surface morphology and thermal properties of PNP were extensively characterized, and these changes in physicochemical properties of PNP provide a better understanding of the in vitro and in vivo release behaviors of PNS. The in vitro studies demonstrated that the dissolution of PNS and particle size were nonlinear (dose- and size-dependent). The pharmacokinetics parameters of PNP in rats were determined by UHPLC-MS/MS. Powder 4 (90.38 ± 8.28 μm) showed significantly higher AUC(0-T) values in plasma (P < 0.05). In addition, we also investigated the influence of the hydrothermal treatment of PNP. The results showed that the PNS in vitro release and in vivo bioavailability of PNP pretreatment at 40°C were the highest. This suggests that PNP with a particle size of around 90 μm and heat pretreatment at 40°C would be beneficial. These results provided an experimental basis, and it was beneficial to choose an appropriate particle size and hydrothermal temperature when PNP was used in clinical treatment.