加替沙星结肠定位片的制备及其体外释放

Preparation of gatifloxacin colon-specific delivery tablets and its in vitro release

目的制备加替沙星口服结肠定位给药系统,以提高结肠部位的治疗效果,并测定其体外释放度。方法在片芯的外层压上阻滞层,再进行包衣,制备pH值和时间双重依赖的加替沙星结肠定位片;采用紫外分光光度法测定结肠定位片在不同pH介质中的释放度;采用单因素试验考察增塑剂的种类、柠檬酸三乙酯的用量、抗黏剂的用量、包衣液浓度及衣膜厚度(包衣增重)对药物释放的影响。结果增塑剂的种类、柠檬酸三乙酯的用量、包衣液浓度以及衣膜的厚度(包衣增重)对药物的释放有显著影响;结肠定位片在模拟胃酸环境中不释放,在模拟小肠环境中累积释放小于10%,在模拟结肠环境中累积释放大于80%。结论采取在多层片外层进行包衣的方法,并通过对影响药物释放的包衣因素进行筛选,可制备加替沙星口服结肠定位片,且达到结肠定位释药的目的。

Objective To prepare gatifloxacin colon-specific delivery tablets in order to improve the therapeutic efficacy at colon, and investigate its in vitro release. Methods pH and time dependent gatifloxacin colon-specific delivery tablets were prepared by pressing blockage layer outside the tablets core and then coated. In vitro release amount of gatifloxacin from colon-specific delivery tablets in different pH media were measured by UV spectrophotometry. Effects of plasticizer type, amount of TEC and antiadherent, concentration of coating solution and coating weight on the in vitro release of gatifloxacin were studied through a series single factor experiments. Results Drug release was significantly influenced by the type of plasticizer, amount of TEC, concentration of coating solution and coating weight. gatifloxacin could hardly be released from the colon-specific tablets in simulated gastric acid circumstances, and the cumulative release amount was less than 10% in simulated small intestine circumstances, in contrast, more than 80% of gatifloxacin were released in simulated colon circumstances. Conclusion Through optimizing factors effecting drug release, gatifloxacin oral colon-specific delivery tablets could be prepared by coating the multilayer tablets with an ideal release profile.