粒径法筛选微乳固体型表面活性剂

Screening of Solid-type Surfactants in Microemulsions by Particle Size Analysis

目的:建立粒径法筛选微乳表面活性剂的方法。方法:表面活性剂的浓度在达到临界胶束浓度(CMC)时,体系的粒径会发生显著的变化。将达到CMC前体系的粒径定义为S1,达到CMC后,体系的粒径定义为S2。其变化值表示形成胶束能力的强弱,该值用E表示,为S1与S2的比值。通过比较表面活性剂的E,对微乳固体表面活性剂进行筛选。将筛选出的微乳固体表面活性剂制成微乳,并利用激光粒度仪测定该种微乳的粒径和Zeta电位,通过透射电镜观察其形态,设计家兔眼部刺激性试验评价其刺激性。结果:固体表面活性剂的乳化能力相对强弱依次为聚氧乙烯氢化蓖麻油RH40(cremophor RH40)>Kollicoat IR>聚乙烯醇(PVA)>β-环糊精(β-CD)>聚乙二醇4000(PEG4000)>十二烷基硫酸钠(SLS)>泊洛沙姆407>泊洛沙姆188>阿拉伯胶>PEG-CHO改性明胶B>骨制明胶B。以cremophor RH40为表面活性剂制备的微乳的粒径38.50 nm,Zeta电位-18.13 m V,透射电镜结果显示其形态圆整、分布均匀。该微乳对雄性家兔眼睛无刺激性,统计结果无显著性差异。结论:利用粒径法对微乳固体型表面活性剂进行筛选的方法合理、可行。

Objective： To establish a method of screening solid-type surfactants. Method： When surfactants reached critical micelle concentration （CMC）, particle size of systems changed remarkably, we defined three parameters of S1 , S2 and E, SI was size when surfaetants concentration was lower than CMC, S2 was size when surfactants concentration was higher than CMC, E = S1/S2. E value was the key to screen surfactants. Particle size and Zeta potential of microemulsions was determined, its shape was investigated by transmission electron microscope, its irritation was evaluated by rabbit eye irritation test. Result： Relative strength of emulsifying ability was in the order of cremophor RH40 〉 Kollicoat IR 〉 PVA 〉β-CD 〉 PEG4000 〉 SLS 〉 poloxamer407 〉 poloxamer188 〉 arabic gum 〉 PEG-CHO modified gelatin B 〉 bone gelatin B. Microemulsions was prepared with cremophor RH40 as surfactant, its particle size was 38.50 nm, Zeta potential was - 18. 13 mV, its shape was round up and uniform. This microemulsion had no irritation in male rabbit eyes for 7 days. Conclusion： This approach to screen surfactants is reasonable and feasible.