格列吡嗪控释片体外药物释放特征和体内外相关性研究

目的 考察格列吡嗪控释片体外药物释放特征和体内外相关性。 方法 分别采用3种不同pH值的缓冲溶液作为释放介质，并对pH 6.8的释放介质分别采用3种不同的转速来测定格列吡嗪控释片的体外药物释放度，考察释放介质pH值和转速对释放度的影响。用Loo-Riegelman法计算格列吡嗪控释片在健康男性受试者体内吸收百分数，并与相应时间体外累积释放度线性回归，进行体内外相关性考察。结果 格列吡嗪控释片在不同pH值释放介质中的释放度一致，均符合零级动力学，且不受转速影响。将体内累积吸收百分数y与相应时间在pH 6.8释放介质中的体外释放百分数x进行线性回归（n=7），回归方程为y=0.690 4x+22.941,r=0.952 8。结论 格列吡嗪控释片的释放度不受释放介质pH值和转速的影响，释药恒速。体外释放累积百分数与体内吸收百分数呈A级相关，具有良好的体内外相关性。

Drug release characteristics in vitro and in vitro-in vivo correlations study of glipizide controlled-release tablets

Objective To study the drug release characteristics in vitro and the correlation between the dissolution in vitro and the absorption in vivo of glipizide controlled-release tablets. Methods Three kinds of release media with various pH values were used respectively to study the effect of pH value on the drug release characteristic of glipizide controlled-release tablets. And for the release media of pH 6.8, three rotating speeds were taken to study the effect on the drug release. The in vivo absorption percents in healthy male volunteers were calculated by Loo-Riegelman method. The correlation between the dissolution in vitro and the absorption in vivo was studied. Results The drug release profiles in different media with various pH values were similar. The drug release was not affected by the rotating speed within the range studied. The linear regressive equation established between the absorption percent in vivo and the dissolution percent in vitro of glipizide controlled-release tablets was y=0.690 4x+22.941,r=0.952 8. Conclusion The pH value of release media and the rotating speed had no effect on the drug release. The drug release in vitro was of zero-grade dynamics. There was a significant correlation between the absorption in vivo and the drug release in vitro of glipizide controlled-release tablets.