复相乳化法制备海藻酸钙微球及其释放行为

采用复相乳化法制备了载牛血清白蛋白(BSA)的海藻酸钙微球，通过正交实验和单因素分析，以BSA包埋率、微球的载药率和平均粒径为考察指标，优化了该方法的制备参数，使最终制备的微球平均粒径小于10 mm，球形度较好，包埋率约70%，载药率达4%. 随着海藻酸钠质量分数的降低和BSA质量的增大，微球的包埋率下降、载药率升高、平均粒径减小. 微囊化BSA的体外释放曲线表明，该系统存在pH响应特性，尤其在磷酸缓冲液中，被包埋BSA的释放速率较快. 电泳结果表明，BSA的分子结构并未受制备过程的影响. 因此，该微囊化方法有望用于蛋白类药物的控释制剂，使其免受胃酸等的破坏，达到肠部释药的目的.

Preparation and Release Behavior of Alginate Microspheres Containing BSA by Emulsification

Alginate (ALG) microspheres containing bovine serum albumin (BSA) were prepared by an emulsification technique. Soybean salad oil used widely in food industry was chosen as an oil phase. Orthogonal experimental design was used to find the optimal preparation conditions by comparing the encapsulation efficiency of BSA, loading capability and average diameter of microspheres. The fine spherical alginate microspheres with an average diameter of 10 mm were obtained under the appropriate conditions. The encapsulation efficiency of BSA and the BSA loading capability were 70% and 4% (w), respectively. As the concentration of ALG increased and the amount of BSA decreased, the encapsulation efficiency of BSA increased, however, BSA loading capability decreased. The in vitro release profile showed a fast release rate of encapsulated BSA, particularly in phosphate buffered saline solution, owing to the excellent pH responsive properties of alginate microspheres. Finally, electrophoresis experiment illustrated that the process of encapsulation had no effect on the molecular weight of the entrapped protein.