界面聚合法制备聚α-氰基丙烯酸正丁酯毫微囊

PREPARATION OF THE POLY( n-BUTYL α-CYANOACRYLATE) NANOCAPSULES BY INTERFACIAL POYMERIZATION

采用界面聚合法制备了粒径约 2 0 0nm的聚α 氰基丙烯酸正丁酯毫微囊 ,运用动态激光光散射和透射电镜测定了毫微囊的粒径及其分布 ,系统研究了高分子稳定剂类型、表面活性剂的用量、辅助添加剂的用量、以及后处理条件等因素对毫微囊粒径及其分布的影响 .结果说明 ,在高分子稳定剂中 ,葡聚糖的稳定作用优于Poloxamer 188,而葡聚糖的用量越大 ,毫微囊的粒径越小 ,采用葡聚糖 70比葡聚糖 40更能得到窄分布的毫微囊 .增加表面活性剂吐温 2 0的用量 ,同样减小毫微囊的粒径 .与三油酸甘油酯相比 ,在有机相中加入苯甲醇能够增大毫微囊粒径 ,并改善毫微囊的规整性 .乙醇和丙酮均可作为溶剂添加在有机相中 ,但含乙醇的体系分散较好 ,界面聚合得到聚α 氰基丙烯酸正丁酯毫微囊粒径分布较窄 .此外 ,通过考察浓缩温度发现 ,在2 0℃下真空浓缩时毫微囊粒径基本保持不变 ,而在

Because poly(butyl α cyanoacrylate) was less toxic than poly(isobutyl α cyanoacrylate)and its nanocapsules could be orally absorbed via intestine wall,the polymeric nanocapsules as drug delivery system of peptides was prepared by the interfacial polymerization of butyl α cyanoacrylate other than isobutyl α cyanoacrylate used previously.The aqueous phase contained a surfactant such as Tween 20 and polymeric stabilizer such as dextrin T\|70,dextrin T\|40 as well as Poloxamer 188.And the organic phase composed of monomer butyl α cyanoacrylate and a cosolvent such as glycerol trioleate or benzyl alcohol in bulky solvent ethanol or acetone.The nanocapsule sizes and their distribution were measured by laser scattering technique and transmission electron micrography.It was investigated the influence of the used surfactants,polymeric stabilizers,cosolvents,and temperature in vacuum evaporation on the nanocapsule sizes.The results show that dextrin T\|70 is a better polymeric stabilizer than its low molecular weight analog dextrin T\|40 and Poloxamer 188 for the monomer phase soluble in ethanol to be dispersed in aqueous phase with Tween 20 as a surfactant.The size of the polymeric nanocapsules decreased with increase of amounts of dextrin T\|70 and Tween 20 dissolved in aqueous phase.Compared with glycerol trioleate,benzyl alcohol as cosolvent could made the nanocapsules larger and smoother because benzyl alcohol might make the immigration of the solvent,ethanol,in the monomer phase into aqueous phase more slowly.In addition,when the formed suspension of poly(butyl α cyanoacrylate)nanocapsules was concentrated by evaporation in vacuum at 30℃ instead of 20℃,small nanocapsules would be aggregated into large particles.