奥硝唑结肠定位片的制备及其体外释放度评价

目的制备奥硝唑结肠定位片，并评价其体外释药情况。方法制备奥硝唑含药片芯，依次包被隔离层、时滞层和肠溶层制备奥硝唑结肠定位片，并考察包衣片的体外释药情况。结果最佳包衣液处方为隔离层增重约1．0％，肠溶层增重3％，PVP用量为60％，Eudragit L100和Eudragit S100质量比为2：3；体外释放度研究表明，制得的奥硝唑结肠定位片在pH1．0 HCl溶液中未释药，在pH6．8的磷酸盐缓冲液中4h累积溶出小于5％，在pH7．6的磷酸盐缓冲液中2h释药大于90％。结论奥硝唑结肠定位片在体外具有结肠定位释放的特性，能达到治疗结肠部位疾病的目的。

Preparation and in vitro release evaluation of ornidazole colon-specific tablets

Objective To prepare ornidazole colon-specific tablets and investigate its in vitro release. Methods The colon-target tablet containing ornidazole was coated sequentially with isolated layer, time-dependent layer and outermost enteric coating layer. The in vitro release of coated tablets was investigated in artificial gastrointestinal environment. Results Optimal coating formulation was 1.0% weight gain of isolated layer,3.0% weight gain of enteric coating layer, the dosage of PVPP is 60%, and the proportion of Eudragit LI00 and Eudragit S100 was 2： 3. No release was found in pH 1.0 hydrochloric acid solution,in pH 6.8 phosphate buffer solution （PBS） the amount of release was less than 5% in 4 h and in pH 7.6 PBS the amount of release was more than 90% in 2 hours. Conclusions Ornidazole colon-specific tablets had characteristics of colon-specific release and could treat the disease of colon site.