Development Of Tripteryguim Wilfordii Hook.f Sustained-release Pellets

Tripterygium wilfordii Hook.f.(TW) which belongs to the Celastraceae Tripterygium plant,it's extraction was used in clinic care,the Primary component is epoxy terpenoid lactone. TW is a herbal medicine which has many functions such as heat-clearing and resolving the exterior,coursing wind and Opening venation,blood and causing muscles and stimulating the circulation of the jointing to relax dehygrosis,eliminating edema and alleviating pain. At Present the extraction aacetylacetic ester has been widely used in some immune disorder diseases such as rheumatoid arthritis, the total efficiency is higher than oral preparations . Whereas there have found many side effects in the application. So how to search different new preparations to decrease the side effects is a imperative clinic Problem needed to be resolved.Choosing triptolide (TP)as the objective component to control the content of the TW. Extraction and the sustained-release pellets by High Performance Liquid Chromatography(HPLC). All method have good linearity, sufficient recovery and good accuracy.The TW sustained release pellets was developed by mini-fluidized bed spray coater in this research. The release pellets consist of four laminar layers from the center to the outside : the core , the drug layer ,the swelling agent layer and the controlled layer. Using L9(34) orthogonal experiment to select the recipe or the floating pellet's recipients and study the release action of the sustained-release pellets in vitro by rotational method. Based on the characteristic of the cumulate-release curve,filtrate the best recipe. The description of dissolution profiles suggested that among the different kinetics model fitting by nonlinear least square model , the first-order equation model became the most appropriate model to describe the release kinetics.A reversed-phase HPLC method was developed for determination of TW pellets in rat's plasma. In this paper conventional tablets were used as a comparison to study the pharmacokinetics and bioavailability of sustained-release pellet in rats. Parameters of pharmacokinetics of rats were individually calculated with a 3p97 program。The results showed that concentration- time curve was explained was accorded with oral two-compartment and first-order absorption by compartment model. Compared with conventional tablet, Tmax and MRT were prolonged and Cmax was reduced significantly. In addition, AUC value was increased remarkably. The relative bioavailability value was 135.4%. Linear regressive equation was established between the absorption percentage in vivo and the accumulate dissolution percentage in vitro Fa = 1.2013Q-0.3342 , R = 0.9218. There was a significant correlation between them.