目的 阐明喘平缓释片的释药机制。方法 采用转篮法结合HPLC测定喘平缓释片的累计释放率，用零级、一级、Higuchi方程、Peppas方程等释药模型对喘平缓释片的释放曲线进行拟合，从溶出过程中各规定时间点取样测定其溶胀率、溶蚀度，体视显微镜观察缓释片的形态变化。结果 喘平缓释片指标成分盐酸麻黄碱和盐酸伪麻黄碱在8 h的累计释放率均达到了80 %，基本实现了均衡释放，用Peppas方程进行拟合后的方程分别为lg（Mt/M∞）=0.5108 lgt-0.5562，R2=0.9991，n=0.5108和lg（Mt/M∞）=0.5150 lgt-0.5386，R2=0.9989，n=0.5150。喘平缓释片的溶胀率在药物约释放60 %时达到了最大值，其后逐渐下降，而溶蚀度则随着药物累计释放率的增加而增加。从体视显微镜观察到遇水膨胀后的缓释片凝胶层和浸润层在一定时间内是逐渐增厚的。结论 喘平缓释片的体外释放机制为药物扩散及骨架溶蚀两种作用。在喘平缓释片的体外溶出实验中，有众多颗粒从片剂表面脱落，提示喘平缓释片释药可能存在着新的释放模式-溶蚀-溶散-扩散机制。

Objective To clarify the release mechanism of Chuanping sustained-release tablets. Methods Stirring basket method combined with HPLC were used to determinate the accumulated release rate of Chuanping sustained-release tablets. The release curves of Chuanping sustained-release tablets were fitted with zero order model，level model，Higuchi equation，and Peppas equation. The swelling rate and the degree of corrosion were measured for the samples obtaining at different time points in the process of dissolution，and the morphological changes of the sustained-release tablets were observed to study the release mechanism of Chuanping sustained-release tablets under Stereo microscope. Results The accumulated release rate of ephedrine and pseudoephedrine，the index components of Chuanping sustained-release tablets，both reached 80 % within 8h，and basically achieved the balanced release. The fitting equations simulated by Peppas equation were lg（Mt/M∞）=0.5108 lgt-0.5562，R2=0.9991，n=0.5108，and lg（Mt/M∞）=0.5150 lgt-0.5386，R2=0.9989，n=0.5150. The swelling rate reached the maximum when the release of tablets was about 60 %，and then gradually declined. The degree of corrosion increased with the drug accumulated release rate. Under stereo microscope，we observed that gel layer and infiltrated layer of sustained-release tablets were gradually thickening in a certain period of time. Conclusion The in vitro release mechanism of Chuanping sustained-release tablets is probably related with drug diffusion and matrix erosion. In the process of in-vitro dissolution experiment，there are amount of particles falling down from the surface of the tablets，indicating the possible new erossion-dissolving-diffusion mode for Chuanping sustained-release tablets.

R284.1

国家自然科学基金项目（81373981）。