【作者】 奚利飞；

【导师】 郑俊萍；

【作者基本信息】 天津大学 ， 材料学， 2004， 硕士

【摘要】 蒙脱土（MMT）是一种层状硅酸盐，它具有适宜的阳离子交换容量（CEC）、、选择性吸附作用、口服安全等特点。利用它的这些特点，探索作为新型药物缓释载体的研究既具有重要的理论意义，又具有广阔的应用前景。 本文采用溶液插层技术制备了三种含不同类型胺基药物（阿昔洛韦、替加氟、普鲁苯辛）/MMT 缓释体系和一种含羧基药物布洛芬/MMT 缓释体系。考察了插层反应温度，反应时间，反应体系 pH 值以及初始药物浓度等因素对于 MMT载药量的影响。利用紫外可见分光光度计(UV-spectrophotometer)、X-射线衍射仪（XRD）、傅立叶红外变换光谱仪（FT-IR）、热重分析仪（TGA）等手段进行了表征。通过体外释放实验来考察缓释体系在各种释放介质中的释放规律和内在机理。 结果表明，初始药物浓度对于 MMT 载药量有很大的影响。在反应初始阶段，随着初始药物浓度的增大，MMT 载药量大幅增加。当浓度达到一定值时，MMT载药量的增加幅度变的很小，说明 MMT 载药量是由 MMT 上可反应位点决定。反应温度和反应时间对 MMT 载药量的影响不大。XRD、红外光谱图和 TGA 证明药物成功地插入到 MMT 片层中，形成了插层结构。 缓释体系的体外释放是扩散和离子交换两种形式同时存在的释放行为，所不同的是三种含不同胺基药物/MMT 缓释体系在释放时主要是靠扩散和阳离子交换进行，而含羧基药物布洛芬/MMT 缓释体系释放时主要是靠扩散和阴离子交换进行。体外释放实验显示，略显酸性的阿昔洛韦和弱酸布洛芬所形成的缓释体系更倾向于在pH值较高的磷酸盐缓冲溶液(pH＝7.4)中释放，具有pH 敏感性，说明这两种缓释体系更倾向于在肠道释放，适合于制成缓释口服制剂。更多还原

【Abstract】 Montmorillonite(MMT), a layered silicate, has character of suitablecapability of cation exchange, selected absorption and nontoxic. Studies based onthese properties to investigate MMT as a novel sustained-release drug carrier areimportant both on theoretical and practical. In this study, three drugs with different type of amino group (acyclovir,tegafur, propantheline bromide) and one drug with carboxy group were employedto prepare drug/MMT sustained-release systems by solution intercalation method.The effect of reaction temperature, reaction time, the pH value and initialconcentration of drug on drug-loaded amount of MMT was investigated. Thesamples were characterized by UV spectrophotometer, XRD, FT-IR, and TGA. Thein vitro release experiment was employed to investigate the release behavior ofthem. The effect of initial concentration of drug on drug-loaded amount (DLA) ofMMT was significant in the intercalation process. At the initial stage, DLAincreased with increasing the initial concentration. But the degree of this trendbecame slow when it arrived certain amount. It indicated that DLA was determinedby the reacting sites of MMT. However, reaction temperature and reaction time hadlittle effect on DLA. XRD, FT-IR, TGA proved that all drugs had successfullyintercalated into the interlayers of MMT, formed intercalation structure betweenthem. The in vitro release behavior of these systems was determined by two factors:diffusion and ion exchange. The drug/MMT sustained-release systems with amidodepended on diffusion and cation exchange. However, drug/MMTsustained-release systems with carbxy group depended on diffusion and anionexchange. The in vitro release experiments showed that acyclovir/MMT andibuprofen/MMT sustained-release system had larger release percentage in thephosphate buffer (pH 7.4). It suggested that these systems were pH-sensitive andcould be prepared as sustained-release oral administrations in the future.更多还原