文档介绍：摘要 I 摘 要本研究以 5- ***尿嘧啶( 5-Fu )为模型药物,采用物理混合法制备了壳聚糖/聚乙烯醇( CS/PVA )温敏性水凝胶给药系统,对水凝胶的性质和体外药物释放进行了详细的研究。该方法操作简便,条件温和,所得凝胶处方简单,不含任何交联剂,是一种非常具有发展前景的新型给药系统。 通过改变体系内各组成成分的浓度,考察其对凝胶温度的影响,结果表明:只有当体系中 NaHCO 3 浓度在 - mol/L 、 CS 浓度在 - % 范围内时,体系能够形成凝胶,凝胶温度随着 NaHCO 3 和 CS 浓度的增大而降低。对于凝胶温度在 37 ℃以下的处方,凝胶时间随着 CS 和 NaHCO 3 浓度的增大而缩短。溶胶 pH 值测定结果表明:该凝胶体系只有在一定 pH 值范围内才能发生溶胶- 凝胶转变,实验溶胶的 pH 值在 左右。红外光谱测定结果表明: PVA 分子只是物理性的缠绕于 CS 网络结构中,混合过程中分子间没有发生化学反应。扫描电子显微镜观察凝胶的微观结构发现:所得凝胶都具有多孔性,载药凝胶比空白凝胶的结构略微致密。凝胶溶蚀实验结果表明:各处方水凝胶均有一定程度的溶蚀,凝胶溶蚀速率与凝胶组成有关, NaHCO 3 浓度为 mol/L 、 CS 浓度为 % 、 PVA 浓度为 % 的凝胶溶蚀速率最慢。 5-Fu 体外释放实验表明:在 pH 磷酸盐缓冲液中于 37 ℃环境条件下,凝胶对 5-Fu 有一定的缓释作用,对于不同载药量的凝胶,释放速率随着载药量增大而减慢;对于不同处方的凝胶,释放行为与凝胶微观结构有一定关系。关键词 温敏性水凝胶壳聚糖聚乙烯醇 5- ***尿嘧啶 Abstract II Abstract In this study, using 5-fluorouracil as a model drug, a chitosan/poly(vinyl alcohol) thermo-sensitive hydrogel drug delivery system has been prepared by physico-mixing the chitosan and poly(vinyl alcohol). Al so, the properties of the gels and the in vitro drug release behaviors were investigated in detail. As the easy operation, mild condition, simple formulation and no cross-linking agent in this method, it is a potential drug delivery system. The concentrations of NaHCO 3, CS and PVA were changed to inspect the gel temperature. It has been indicated that the gel can form when the concentration scope of NaHCO 3 was - mol/L and CS was - %. With the increasing of the concentration of NaHCO 3 and CS, the gel temperature degr aded. To the gel temperature below 37 ℃ of the formulation, with the increas ing of the concentration of NaHCO 3 and CS, the gel time has been shortened. The pH value of the sol was controlled at . It has been illustrated that the PVA molecules only physically entangled inside the works by IR. The SEM micrographs showed that all the gels had porous structures and the structure of the drug loaded hydrogel was pact than the blank. The erosion behavior indicated