米非司酮壳型阴道环的处方与制备工艺研究

Formula and preparation of shell vaginal ring containing mifepristone

目的:制备米非司酮壳型阴道环,确定其最佳处方和制备工艺。方法:首先将药物制备为以PVPK30为载体的固体分散体,然后以硅橡胶为载体,采用热压硫化成型法制备米非司酮壳型阴道环。通过单因素法,考察制备工艺和处方组成对药物释放的影响。结果:根据单因素法的考察结果,筛选出米非司酮壳型阴道环的处方为:硅橡胶3.41 g,PVPK300.03 g,米非司酮0.06 g;最佳制备工艺为:130℃热压硫化3次,每次硫化10 min。含有米非司酮固体分散体的壳型阴道环能够缓慢、持续地释放大剂量的难溶性药物,在21 d内以近似零级速率释放药物。结论:米非司酮壳型阴道环的处方合理,制备工艺简单、重现性好、体外释药更为平稳。

Objective： To prepare shell vaginal ring containing mifepristone, and optimize the formulation and preparation technology. Methods： The solid dispersion of mifepristone with PVPK30 as a carrier was prepared, then the shell vaginal ring containing mifepristone with silastie as a carrier was prepared by the method of heat molding process. The formula and preparation technology markedly affecting drug release from drug loaded ring were optimized via single factor tests. Results： The optimized prescription was composed of 3.41 g silicone elastomer, 0.03 g PVPK30 , and 0.06 g mifepristone in one ring. The ring was moulded three times at 130 ℃ for 10 rain. Sustained release of a large quantity of the insoluble drug was determined from the shell vaginal ring containing solid dispersion of mifepristone. Continuous and near zero-order release rate of mifepristone from the shell vaginal rings was observed in vitro over a period for 21 days. Conclusion： The formulation of shell vaginal ring containing mifepristone is reasonable, and the preparation technology is simple and reproducible, which had a steadier drug release in vitro.