溶剂体系对甘草次酸微球性能的影响研究

Influences of solvent systems on characteristics of glycyrrhetinic acid-loaded microspheres

目的:明确不同溶剂体系对载药PLGA微球性能的影响。方法:摇瓶法测定甘草次酸在不同有机溶剂中的平衡溶解度;单一或混合溶剂用于溶解载体和药物,并经乳化-溶剂蒸发法(O/W法)分别制备甘草次酸-PLGA微球,利用扫描电镜观察表面形态,测定样品熔点、粒径、载药量、包封率及体外释药行为。结果:甘草次酸极微溶于水,但在二氯甲烷(DCM)等有机溶剂中溶解度显著提高;不同溶剂体系制得微球形态圆整,包封率均高于98%;与单一二氯甲烷相比,混合溶剂制得微球的熔点略高,粒径显著增大,迟滞期延长、释药更缓慢。结论:微球制备过程中有机相溶剂体系的改变对载药微球的多种性能存在影响。

OBJECTIVE To elucidate influences of solvent systems on characteristics of drug-loaded microspheres. METHODS Equilibrium solubility of GA was determined by bottle shaking method. GA-loaded microspheres were prepared by O/W solvent evaporation method, and obtained microspheres were then compared for their morphologies, particle sizes, encapsulation efficiencies,DSC and in vitro release. RESULTS GA was very slightly soluble in water,but its solubility can be remarkably im- proved in DCM and other organic solvents. Microspheres prepared by different solvent systems showed tiny spheres with high encapsulation efficiency （〉98%）. Compared with DCM, microspheres prepared by mixed solvents showed larger particle size and higher Tg, presented a prolonged release profile with an longer lag phase. CONCLUSION Variety of characteristics of drug-loaded PLGA microspheres is closely related to its solvent systems used in the process.