黄芪多糖/壳聚糖微球复合温敏凝胶的制备及理化特性研究

Preparation and characterization of thermosensitive chitosan hydrogels containing astragalus polysaccharides/chitosan microshperes

目的 制备载黄芪多糖/壳聚糖微球（Astragalus polysaccharides/Chitosan Microshperes,APS-MS）的壳聚糖温敏凝胶（Thermosensitive hydrogels,HG）并考察其理化特性。方法 采用喷雾干燥法制备APS-MS,用扫描电镜和激光粒度仪观察微球的形态和粒径。以适宜的成胶温度和时间为指标,采用单因素实验优化黄芪多糖/壳聚糖微球复合温敏凝胶（APS-MS-HG）的制备工艺,扫描电镜观察微球在温敏凝胶中的存在状态,并考察APS-MS、黄芪多糖温敏凝胶（APS-HG）和APS-MS-HG的体外释药行为。结果 APS-MS为球形,表面有少许皱褶,分布均匀,无明显粘连,表面积平均粒径D[3,2]为8.078μm。最佳APS-MS-HG（APS-MS-HG J）的制备工艺为加入3.012%的APS-MS,磁力搅拌3h。电镜扫描显示APS-MS以球形不规则的分散在温敏凝胶中,而空白温敏凝胶的多孔结构消失。体外释放结果表明,p H6.8的磷酸缓冲溶液中,APS-MS-HG J没有突释现象,36h累计药物释放量为74.75%。结论 APS-MS-HG J具有良好的缓释作用,且能改善APS-MS和APS-HG J的突释现象,有望成为鼻粘膜给药的良好载体。

Objective To prepare thermosensitive chitosan （CTS） hydrogels containing astragalus polysaccharides （APS）/CTS microshperes （MS）, and evaluate its physicochemical properties. Methods The APS/CTS MS （APS-MS） were prepared by spray drying method, and characterized by Scanning Electron Microscopy （SEM） and Laser Granularity Analyzer. Depending on the gelation temperature and gelating time,thermosensitive CTS hydrogels （HG） containing APS-MS （APS-MS-HG） were optimized by signal factor experiments, and the morphological characteristics were observed by SEM. In vitro release behaviors of APS-MS, hydrogels containing APS （APS-HG） and APS-MS-HG in pH 6.8 phosphate bufFer were evaluated by dialysis tube method. Results The APS-MS were well dispersed with nearly spherical shapes and slightly wrinkled surfaces. The surface weighted mean D[3,2] of APS-MS was 8.078jim. The optimal APS-MS-HG, APS-MS-HG J, contained 3.012% APS-MS which were agitated with a magnetic stirrer for 3L Observed by SEM, APS-MS were stayed spherical and dispersed unevenly in HG J,but the porous structure o f HG J was disappeared in APS-MS-HG J. The release of APS fromAPS-MS-HGJ was without initial burst release, and the cumulative amount of APS was about 74.75% after 36h. Conclusion Suppressing the phenomenon o f sudden release at the first stage o f delivery, APS-MS-HG J holds great promise for topical applications as a sustained-release nasal delivery system.