【作者】 魏秀莉； 孙宁云； 吴伟； 徐惠南；

【Author】 Wei Xiuli, Sun Ningyun, Wu Wei*, Xu huinan (Department of Pharmaceutics, School of Pharmacy, Fudan University, Shanghai 200032, China)

【机构】 复旦大学药学院药剂学教研室；

【摘要】 目的:研究钙离子诱导的果胶分子在体交联度松弛的机理。方法:分别考察了果胶/钙骨架片中钙离子的释放,骨架对亚甲基兰的吸附,骨架与水接触后环境扫描电镜的微观结构、骨架质构和宏观表面结构的变化,以及钙离子浓度对果胶溶液表观粘度的影响。结果:钙离子在最初2h内的释放速率较快,且从不同果胶/氯化钙用量比骨架中的释放行为相似。不论氯化钙的用量多少,果胶/钙骨架片对亚甲基兰均没有吸附。果胶/钙骨架片与水接触后因在体交联作用形成网络状结构,且随时间的不同网络结构可发生较大的变化,以及反映骨架内聚力及粘附力的力均呈减小趋势。氯化钙溶液的加入可明显增加果胶溶液的表观粘度。结论:果胶/钙骨架中钙离子释放、骨架动态环境扫描电镜及其质构变化特点,在一定程度上验证了“交联度松弛”理论。果胶/钙骨架体系通过“交联度松弛”影响药物的释放。更多还原

【Abstract】 OBJECTIVE: To study the relaxation of in situ crosslinking degree induced by calcium cations in the pectin-based matrix tablets. METHODS: The tests of calcium ions release, methylene blue adsorption, the microstructure and macrostructure of pectin matrix tablet observed by gun emission environmental scanning electron microscope and digital camera, respectively, and the texture analysis were investigated. In addition, the calcium content on rheological characteristic and erosion of pectin was also investigated. RESULTS: The rate of calcium ions release was fast in initial 2 h and the profiles were similar to matrix tablets containing various pectin/calcium chloride ratio. Pectin/calcium chloride matrix tablets hardly adsorbed methylene blue molecular. Network microstructure was formed once pectin/calcium chloride matrix tablet contacted with water through in situ crosslinking. This network structure and the inherent cohesion and adhesion of matrix determined by texture analysis had obvious different at various time point. In addition, adding calcium chloride to pectin solution could increase its apparent viscosity. CONCLUSIONS: The results of calcium ions release, dynamic matrix microstructure variation and texture analysis verified the mechanism of “relaxation of crosslinking degree” at some extent. The drug release from pectin/calcium chloride matrix tablet was controlled by the mechanism of “relaxation of crosslinking degree”.更多还原