PLGA黏度及PVA浓度对微球形成过程中物理性质的影响

采用复乳.溶剂蒸发法制备乳酸.羟基乙酸共聚物(PLGA)微球,并用激光粒度仪测定制备过程中乳滴的体积平均粒径、粒径分布(d_(0.1)、d_(0.5)、d_(0.9))和重量比表面积(SSA)等物理性质的动态变化,考察PLGA特性黏度及聚乙烯醇(PVA)浓度对上述性质的影响.结果表明,在0.5%PVA的体系中,乳滴的平均粒径在60 S内均呈线性急剧下降,SSA迅速增加,粒径下降速度随PLGA黏度的增加而减慢,但5 min后高黏度PLGA体系的粒径升高,SSA减小.增加外水相PVA浓度至2.0%,则高黏度PLGA体系乳滴的物理性质变化趋势与低、中黏度PLGA体系相似.

Effects of PLGA Viscosity and PVA Concentration on Physical Properties of Microspheres in Forming Process

The poly (lactide-co-glycolide) (PLGA) microspheres were prepared by emulsion-solvent evaporation method. The dynamic processes of volume mean diameter, distribution (d_(0.1), d_(0.5) and d_(0.9)) and specific surface area (SSA) of the emulsion drops were determined by particle size analyzer. The effects of PLGA viscosity and poly (vinyl alcohol) (PVA) concentration on the above properties in the microspheres forming process were investigated. In the systems containing 0.5% PVA solution, the diameter decreased linearly and sharply in the initial 60 s accompanied with a rapid increase of SSA. The declining rate of the diameter was slowed down with the increase of PLGA viscosity. While the diameter increased and SSA decreased in the system containing high viscosity of PLGA after 5 min. When the concentration of PVA increased to 2% in external phase, the trends of physical properties of the high viscosity system were similar to the low or medium viscosity system.