用恒流泵替代气瓶给压装置得到新型膜乳化器，以改善膜乳化法制备微球的工艺稳定性；以聚乳酸?羟基乙酸共聚物(PLGA)为膜材，利用水包油(O/W)乳化法制备PLGA微球，研究了新型膜乳化器与传统膜乳化器对微球形貌、粒径及粒径分布的影响，考察了搅拌速度、稳定剂浓度、PLGA浓度及分散相流速对微球形貌、粒径及其分布的影响. 结果表明，在微孔膜孔径2 ?m、搅拌速度300 r/min、稳定剂浓度1.0%(?)及PLGA浓度60 mg/mL、分散相流速20 mL/h的条件下，可制得表面光滑、粒径均一(粒径分布系数Rspan<0.50)的PLGA微球，各批产品的粒径相对标准偏差为1.99%，产品批次重复性良好.

A novel pressure control method (constant-flow pump) was introduced to conventional membrane emulsification, for precisely controlling the transmembrane pressure of the dispersed phase, named novel membrane emulsification. Poly(lactic-co-glycolic acid) (PLGA) microspheres was prepared by oil-in-water emulsion method respectively, based on conventional membrane emulsification and novel membrane emulsification. Compared with conventional membrane emulsification, this novel membrane emulsification could remarkably improve the size distribution of PLGA microspheres. The processing conditions, stirring rate, the stabilizer concentration, the PLGA concentration and the dispersed phase flow rate, were optimized to fabricate PLGA microspheres with controllable sizes and narrow size distribution. The results showed that uniform-sized PLGA microspheres (size distribution coefficient Rspan<0.50) were successfully fabricated using 2 ?m microporous membraneunder the conditions of stirring speed about 300 r/min, the stabilizer concentration of 1.0%(?), the PLGA concentration of 60 mg/mL and the dispersed phase flow rate of 20 mL/h. The relative standard deviation was 1.99%, and the product repeatability was good.