复乳法制备胰岛素PLGA纳米粒影响包封率因素考察

以Poloxamer188为乳化剂，乙酸乙酯为有机溶剂，采用复乳法制备了胰岛素乳酸／羟基乙酸共聚物（PLGA）纳米粒，考察了乳化剂和PLGA的浓度。内水相中胰岛素的浓度为pH，溶剂挥发方法和内水相中加入聚乙烯醇（PVA）等实验各因素对胰岛素PLGA纳米粒包封率的影响。结果表明，乳化剂的浓度较高，PLGA的浓度较小，内水相的pH接近胰岛素的pI(5．3），胰岛素的浓度较低，缩短有机溶剂挥发时间及内水相中加入PVA有利于提高胰岛素的包封率，经实验条件优化后制备的胰岛素PLGA纳米纳平均粒径为149．6nm，多分散性系数小于0．1，包封率提高到42．8％。

Effect of Experimental Parameters on the Encapsulation of Insulin-loaded Poly(lactide-co-glycolide) Nanoparticles prepared by a Double Emulsion Method

Insulin-loaded poly(lactide-co-glycolide) nanoparticles (INS-PLGA-NPs) were prepared by a double emulsion method (w/o/w), using ethyl acetate as organic solvent and poloxamer188 as emulsifier. Experimental parameters such as the emulsifier and PLGA concentrations, the pH and concentration of the insulin solution, the solvent evaporation method and PVA in the internal phase were investigated for the encapsulation efficiency. The results indicated that higher emulsifier concentration, relatively less amount of PLGA and lower insulin concentration would increase the entrapment of insulin. Furthermore, pH of insulin solution approaching to pI (5.3), adding some PVA to the internal phase and a shorter evaporation time helped to enhance the incorporation efficiency of insulin. Optimized preparation parameters led to nanoparticles with well-defined characteristics such as an average size around 149.6 nm, a polydispersity lower than 0.1 and high encapsulation efficiency up to 42.8%.