结肠用美沙拉秦壳聚糖胶囊的体外释药研究

 目的制备美沙拉秦(5-氨基水杨酸，5-ASA)结肠靶向给药胶囊，并评价其体外释药性能。方法将5-ASA装于壳聚糖胶囊中，再以邻苯二甲酸羟丙基甲基纤维素(HPMCP)包裹胶囊，以紫外分光光度法测定其在pH1.2盐酸溶液及pH6.8磷酸缓冲液中的体外释放性能。将荧光素钠(FS)作为模型化合物在相同条件下进行实验，以激发波长470 nm，发射波长513 nm荧光检测其在模拟大肠液中的体外释放性能。用扫描电镜法评价壳聚糖胶囊在模拟大肠液中的降解作用。结果 载药壳聚糖胶囊在pH1.2盐酸溶液及pH6.8磷酸缓冲液中药物累积释放量6 h内不大于10%，而在模拟大肠液中，4 h释药基本完全。电镜扫描表明，在盲肠内容物中壳聚糖具有明显降解作用。结论 用HPMCP包膜的壳聚糖胶囊具有潜在的结肠靶向释药效果。

Study on colon-specific delivery of HPMCP-coated mesalazine chitosan capsules in vitro

OBJECTIVE To prepare mesalazine (5-aminosalicylic acid,5-ASA) chitosan capsules for colon-specific delivery and to evaluate the release of this dosage form in vitro .METHOD 5-ASA was filled in the chitosan capsules and the capsule then were coated with hydroxypropylmethylcellulose phthalate (HPMCP).The in vitro release of the capsules in the artificial gastric juice or in the artificial small intestinal juice was carried out with the spectrophotometer to determine the contents of 5-ASA.Fluorescein sodium (FS) was chosen as a model compound to observe the release of the capsule in the artificial large intestinal juice.The degradation of the chitosan capsule in the rat cecum medium was evaluated by scanning electron microscope.RESULTS Neither of the accumulated release of selected drugs in the capsule was more than 10% within 6 h in the artificial medium of stomach and small intestine,while the release reached to about 100% in the case of the large intestinal liquid in 4 h.And,the significant degradation of the chitosan capsule was found in the rat cecum content.CONCLUSION HMPCP-coated 5-ASA chitosan capsules had the potential to release the drug in colon.