[Preparation of herpetolide A nanosuspension lyophilized powder and evaluation of its anti-hepatitis B virus activity].

To prepare the herpetolide A nanosuspension lyophilized powder(HPA-NS-LP), in order to investigate its anti-hepatitis B virus(HBV) activity and the dissolution in vitro. Herpetolide A nanosuspension(HPA-NS) was prepared by ultrasonic precipitation method. The formulation and process of HPA-NS were optimized by the single factor experiment. Lyophilized powder(HPA-NS-LP) was prepared by freeze-drying method. Scanning electron microscopy was used to observe morphology of HPA-NS-LP. Paddle method was used to determinate the dissolution of HPT-NS-LP in vitro. The anti-HBV activity of herpetolide A coarse suspension lyophilized powder(HPA-CS-LP) and HPA-NS-LP was evaluated by HepG2.2.15 cell model. The mean particle size of optimized HPA-NS was(173.46±4.36) nm, with a polydispersity index of 0.110±0.012. After redispersion, the mean particle size and the polydispersity index of HPA-NS-LP increased, with changes within a rational range. Scanning electron microscopy showed that HPA-NS-LP was spherical in shape. Cumulative dissolution rate of HPA-NS-LP was more than 90% in 2 hours, which was higher than that of HPA-CS-LP. Both HPA-CS-LP and HPA-NS-LP could effectively inhibit the secretion of HepG2.2.15 cell antigens(HBsAg and HBeAg), and the inhibitory effect of HPA-NS-LP was significantly higher than that of HPA CS-LP(P<0.05). HBV-DNA test showed that high, medium and low-dose HPA-NS-LP(50, 25, 12.5 mg·kg~(-1)) significantly decreased the level of HBV-DNA(P<0.05), and the effect was better than that of the same dose of HPA-CS-LP(P<0.05). The results revealed that HPA-NS-LP exhibited anti-HBV activity in vitro, and its effect was superior to that of HPA-CS-LP.