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体外研究瓜尔胶/乙基纤维素混合包衣小丸的结肠靶向性。以5-氟尿嘧啶为模型药,采用流化包衣技术以瓜尔胶/乙基纤维素混合物的水/醇混悬液对载药小丸进行喷液包衣。瓜尔胶/乙基纤维素混合包衣小丸的释药行为取决于包衣处方中瓜尔胶与乙基纤维素的比例和包衣厚度。分别以混合包衣液中瓜尔胶与乙基纤维素的比例及包衣增重为自变量,以T5和T90(药物释放5%和90%所需要的时间)为效应,进行3×4析因设计/效应面优化,筛选较优处方。结果表明随着乙基纤维素在衣层中所占比例的增大及包衣厚度的增加,药物释放时滞增加。当瓜尔胶与乙基纤维素的比例在0.2~0.7,并且包衣增重在250%~500%时,T5%为5.1~7.8 h,T90%为9.8~16.3 h。并且在释药时滞之后,进入模拟结肠微菌群酶解作用的释放环境中(pH 6.5)药物释放速度加快,T90%缩短到9.0~14.5 h。由此可以看出适当的瓜尔胶/乙基纤维素混合衣层既可以保护药物顺利通过上消化道而不释放,达到结肠后药物开始释放,并且可在结肠微菌群的酶解作用下加速药物的释放,实现结肠定位释药的目的。
In vitro study of colon targeting of guar gum / ethyl cellulose mixed coated pellets. The drug-loaded pellets were spray-coated with 5-fluorouracil as a model drug using a fluidized coating technique using a water / alcohol suspension of guar gum / ethylcellulose mixture. The release behavior of guar gum / ethyl cellulose mixed coated pellets depends on the ratio of guar gum to ethyl cellulose and the thickness of the coating in the coating formulation. The ratio of guar gum to ethylcellulose in the mixed coating solution and the weight gain of the coating were taken as independent variables. The effects of T5 and T90 (time required for drug release by 5% and 90%) were taken as 3 × 4 Factorial design / effect surface optimization, screening superior prescription. The results showed that with the increase of the proportion of ethyl cellulose in the coating and the increase of the coating thickness, the delay of drug release increased. When the ratio of guar gum to ethyl cellulose is between 0.2 and 0.7, and the weight gain of coating is between 250% and 500%, the T5% is 5.1 ~ 7.8 h and the T90% is 9.8 ~ 16.3 h. And after the drug release lag, release into the simulated colon microbiota release environment (pH 6.5) accelerated drug release, T90% shortened to 9.0 ~ 14.5 h. It can be seen that the appropriate guar gum / ethyl cellulose mixed layer can not only protect the drug smoothly through the upper digestive tract without release of drugs to reach the colon after the start of release, and in the colon microflora enzymatic hydrolysis Accelerate the release of drugs to achieve the purpose of colon positioning release.