目的:研究一种制备聚乳酸聚乙醇酸(PLGA)微球的新工艺,即将海藻酸钠与钙离子螯合形成缓释凝胶的原理与复乳法制备微球的工艺相结合。方法:以牛血清白蛋白(BSA)为模型药,以包封率、载药量、产率作为评价指标,研究PLGA黏度、海藻酸钠浓度及外水相1中氯化钙浓度对微球性质的影响,并通过L9(34)正交试验设计优选微球制备的工艺条件。结果:优选的制备工艺重现性好,微球形态圆整,结构致密,平均粒径为67.5μm,载药量、包封率和产率分别为0.669%、53.38%和80.08%。结论:本研究获得了较为满意的制备PLGA微球的新工艺,微球的理化性质良好。 OBJECTIVE: To study a new technology for preparation of polylactic polyglycolic acid (PLGA) microspheres by combining the principle of chelating sodium alginate with calcium ion to form sustained release gel and the process of preparing microspheres by double emulsion method. Methods: Bovine serum albumin (BSA) was used as a model drug. The entrapment efficiency, drug loading and yield were used as indexes to evaluate the effects of PLGA viscosity, sodium alginate concentration and calcium chloride concentration in external aqueous phase 1 Nature of the impact, and by L9 (34) orthogonal experiment design microspheres preferred process conditions. Results: The preparation method showed good reproducibility. The microspheres were round in shape and dense in structure with an average particle size of 67.5 μm. The drug loading, entrapment efficiency and yield were 0.669%, 53.38% and 80.08%, respectively. Conclusion: This study obtained a more satisfactory preparation of PLGA microspheres of new technology, physical and chemical properties of microspheres well.