Studies Of Venlafaxine Hydrochloride Drug-resin Liquid Sustained-release System

In this paper, drug resin liquid sustained-release delivery system(DRLRDS) was prepared using antidepressant drug- Venlafaxine Hydrochloride(VH) as model drug and new style excipient-strong acidic cationic exchange resin as carrier. And we made systematic studies on VH sustained-release suspension based on ion exchange resin. The research work was composed of following parts:1) UV spectrophotometry was developed for in vitro assay of physicochemical properties, content and drug release. High-performance liquid chromatography (HPLC) was applied in the determination of plasma drug concentration in Beagle dogs. And we investigated VH in various solvents of the equilibrium solubility and stability.2) Drug -resin complex(DRC) was prepared by bath method or column method. The factors affecting loading of drug were explored, such as reaction temperature, concentration of VH solution, resin particle size. It was proved that the exchange reaction between VH and resin could self-react. Higher drug-loading could be reached by reducing resin particle size, increasing reaction temperature and using fitting drug concentration. Compared with batch method, column method was better for manufacture of DRC.3) The combination mechanism of VH-resin was investigated by DSC, IR spectrum method and so on. It was ascertained that the combination force between VH and resin was chemical interaction instead of physical interaction.4) The factors affecting drug releasing from DRC was explored by similar factor. It was proved that drug release behavior had relative stability. And 500ml 0.15mol·L^-1NaCl solution was selected as release medium in vitro, release temperature was 37℃, rotate speed was 75rpm. To study the mechanism of in-vitro release of DRC, it was showed that simple DRC could not provide sustained-release behavior for VH.5) The use of drug-resins along with a suitable coating material was to prepare a prolonged release type of microcapsules by the method of intra-liquid desiccation. Based on the results of single factor tests, the optimum coating formula was acquired...