锐孔法是制备微胶囊的常用方法之一。文中根据微通道法乳化技术原理,改进了锐孔法实验装置并用于聚乳酸微球的制备;应用简化的聚乳酸微球制备模型,研究了油相注入速率、搅拌器转速、聚乳酸浓度和锐孔内径大小等因素对聚乳酸微球平均粒径d和粒径分布系数(C V)的影响。结果表明,油相注入速率小于1.2 mL/min时,对d和C V影响较小;提高搅拌器转速能降低d;随着聚乳酸浓度的增大,d和C V均呈增大趋势;当锐孔内径处于200μm~550μm时,d和C V与锐孔内径无明显关系。用内径50μm玻璃毛细管针头代替金属针头,成功地制备出粒径均一的聚乳酸微球(d=77.93μm,C V=17.59%)。
The orifice method widely used in microcapsules is improved referring to the principle of microchannel emulsification and applied to prepare poly(lactic acid)(PLA) microparticles.Based upon the simplified model,the effect of some important parameters such as the oil phase flow rate,the stirred rate,the PLA concentration,and the orifice inner diameter on the PLA mean diameter(d) and the coefficient of variation(CV) were examined in detail.The results indicat that the oil phase flow rate has limited effect on d and CV when it is lower than 1.2 mL/min.With the increase of the stirred rate,the diameter decreases.With the rising of the PLA concentration,both d and CV are elevated.The orifice inner diameter has no effect on d and CV when it is between 200 μm~550 μm.Fine particles are successfully o-diameter glass capillary instead of the metal needle.