大黄结肠靶向微丸在大鼠胃肠道内的分布及释放方法学研究

Study on the Distribution and Drug Releasing in Digestive Tract of Colon-Targeted Pellets of Rhubarb in Rats

目的：研究大黄结肠靶向微丸在大鼠胃肠道内的分布和释药情况。方法：将大黄结肠靶向微丸通过自制大鼠开口器灌胃给药,分别于给药后不同时间点将大鼠处死,剖取胃肠道,观察微丸外观性状并计数,计算给药后不同时间点微丸在大鼠各胃肠道内的分布率;采用HPLC法分别测定剩余微丸中的芦荟大黄素、大黄素和大黄酚的含量和大鼠各胃肠道组织及内容物中大黄素的含量,计算累积释放度,并绘制药物在各胃肠道中的药-时曲线,评价其释药特性。结果：微丸能完整地运动至大鼠结肠,具有明显迟释效应,给药10~12 h后结肠分布率达最高,为52.7%;药物于8~16 h在盲肠和结肠具有较高的药物浓度,最终释药量可达88.99%。结论：大黄结肠靶向微丸具有较好的结肠定位释药特性。

Objective：To investigate the conveying and drug release in vivo of colon target pellets of Rhubarb in rats.Methods：The rhubarb colon-targeted pellets were administered by homemade rat mouth gag.The rats were respectively killed at different time points after administering,and the gastrointestinal tracts were dissected.The appearance of pellets was observed and the sum of pellets were counted.The pellets distribution rates in the digestive tract in rats were calculated at different time point after administering.After the residue level of aloeemodin,emodin and chrysophanol in pellets were respectively determined by HPLC,also the emodin in rats,gastrointestinal tissue and content.The accumulative releasing was calculated and the drug concentration-time curve in the gastrointestinal tract was drawn,then the drug release property was evaluated.Results：The pellets were transferred to colon completely and obvious late release effect.The colon distribution rate could reach the highest after 10~12 h,52.7%.In 8~16 h,drugs had a high concentration in the cecum and colon.Final release dosage percentage was 88.99%.Conclusion：Rhubarb colon-targeted pellets possessed the characteristic of drug release in colon.