Preparation And Evaluation Of Carrier-controlled Triperygium Wilfordii Sustained-release Preparations

In this paper,a Traditional Chinese Medicine,Tripterygium wilfordii Hook.f.(TWH)was selected as a model drug to prepared solid dispersion by Hot-melt extrusion technology(HME),and TWH sustained-release tablets was fabricated by direct powder compression.The release behavior in vitro was evaluated by UV spectrophotometer and High-performance liquid chromatography(HPLC).In order to meet with the necessity of multi-criteria quality control for multi-component in extract of Leigongteng,UV spectrophotometer was established to determine the content of TWH and release behavior in vitro.The fingerprint of the extracts and sustained-release tablets of leigongteng was established to evaluate the synchronized-releasing behavior of various components in the sustained-release tablets.The solid dispersion was prepared by HME using proper carrier material.By study on the formulations and processes,the optimal formulation of solid dispersion was as follow:10%Extract of TWH?70%Kollidon VA 64?20%GMS.Results of X-ray diffraction,diifferential scanning calorimetry showed that TWH in solid dispersion existed in amorphous state.Dissolution test indicated that the accumulative dissolution of TWH solid disperson was distinctly higher than ETW in 0.1%SDS solution.The TWH were prepared by direct powder compression.The formulation of direct powder compression was as follow:50%solid dispersion powder?48%Ludipress?2%Talc.Dissolution test showed that the accumulative dissolution of sustained-release tablets could reach more than 90%in 8 hours.The result of release curve of the tablets showed that the in vitro release mechanism was according to Higuchi equation,which meaned the release mechanism was controlled by both bulk erosion and drug diffusion.The release mechanism of TWH from sustained tablets was mainly bulk erosion by bulk relative water uptake rate and bulk erosion experiments.HPLC fingerprint of tablets and the fit factors f2 were used to evaluate drug-release behavior.The drug-release were calculated and the release curve were drew by comparison the peak area of sample with standard products.The results indicated that the value of similarity factors of components of the fingerprint peaks were 50?f2?100,and proved that the various components in the tablets could release synchronously while sustained-releasing.That complies with the organic whole conception of compound compatibility of traditional Chinese medicinal compound recipe.