Time-and pH-dependent colon-specific drug delivery for orally administered diclofenac sodium and 5-aminosalicylic acid

作     者：GangCheng FengAn Mei-JuanZou JinSun Xiu-HuaHao Yun-XiaHe 

作者机构：DepartmentofBiopharmaceuticsSchoolofPharmacyShenyangPharmaceuticalUniversityShenyang110016LiaoningProvinceChina SchoolofPharmacyJilinUniversityChangchun130021JilinProvinceChina 

出 版 物：《World Journal of Gastroenterology》 (世界胃肠病学杂志（英文版）)

年 卷 期：2004年第10卷第12期

页      面：1769-1774页

核心收录：

学科分类：1007[医学-药学(可授医学、理学学位)] 10[医学] 

基　　金：SuppoSed by the Foundation of Ministry of Education of China for distinguished Teachers No.903 and the Natural Science Foundation of Liaoning Province No.9910500504 

主　　题：特效药 麻醉药 环氟拉嗪 二氯苯二磺酰胺钠 5-对氨基水杨酸 动力学 

摘      要：AIM: To investigate Time- and pH-dependent colon-specific drug delivery systems (CDDS) for orally administered diclofenac sodium (DS) and 5-aminosalicylic acid (5-ASA), respectively. METHODS: DS tablets and 5-ASA pellets were coated by ethylcellulose (EC) and methacrylic acid copolymers (Eudragit L100 and $100), respectively. The in vitro release behavior of the DS coated tablets and 5-ASA coated pellets were examined, and then in vivo absorption kinetics of DS coated tablets in dogs were further studied. RESULTS: Release profile of time-dependent DS coated tablets was not influenced by pH of the dissolution medium, but the lag time of DS release was primarily controlled by the thickness of the coating layer. The thicker the coating layer, the longer the lag time of DS release is. On the contrary, in view of the pH-dependent 5-ASA coated pellets, 5-ASA release was significantly governed by pH. Moreover, the 5-ASA release features from the coated pellets depended upon both the combination ratio of the Eudragit~ L100 and S100 pH-sensitive copolymers in the coating formulation and the thickness of the coating layer. The absorption kinetic studies of the DS coated tablets in dogs demonstrated that in vivo lag time of absorption was in a good agreement with in vitro lag time of release. CONCLUSION: Two types of CDDS, prepared herein by means of the regular coating technique, are able to achieve site-specific drug delivery targeting at colon following oral administration, and provide a promising strategy to control drug release targeting the desired lower gastrointestinal region.