丙戊酸钠缓释片体外释放特性

 目的：研究自制丙戊酸钠缓释片的体外释放特性，并与市售丙戊酸钠片和丙戊酸钠缓释片（德巴金）体外释放特性进行比较。方法：按中国药典2000年版二部附录XD释放度测定第一法，以磷酸缓冲液为释放介质，采用HPLC测定介质中丙戊酸钠含量，并计算其累积释放度。对三种制剂的释放数据分别以零级释放、单指数模型、希古切（Higuchi）方程、威布尔(Weibull)分布模型和Regter-pappes模型进行拟合，求出相应的特征参数，探讨其体外释放规律。结果：丙戊酸钠片以希古切（Higuchi）为最佳拟合模型；自制丙戊酸钠缓释片与德巴金释放度的最佳拟合模型均为威布尔(Weibull)分布模型。结论：从Ritger-peppas模型拟合结果表明，丙戊酸钠缓释片释放为骨架溶蚀机制，德巴金为Fick扩散机制。

Study on releasing characteristic of sodium valproate sustained-release tablet in vitro

OBJECTIVE To study the releasing characteristic of sodium valproate sustained-release tablet compared with commercial tablet, DEPAKINE CHRONO tablet. METHODS Using phosphate buffer as dissolution medium, to determine the content of sodium valproate by HPLC, explore the releasing characteristic parameter of the three preparation by single exponent model, Higuchi model，Weibull model and Regter-pappes model. RESULTS The profile analysis of the releasing rate showed that the Higuchi model is more suitable for sodium valproate tablet, the Weibull model is more suitable for sodium valproate sustained-release tablet and DEPAKINE tablet. The result infer from Ritger-peppas model showed that the mechanism of release for sodium valproate sustained-release tablet is framework corrosion, and DEPAKINE tablet is fick diffusion. CONCLUSIONS The profile of sodium valproate sustained-release tablet which be prepared by us showed the characteristic of sustained-release.