非离子型乳化剂形成的o/w型乳膏液晶胶网结构的稳定性研究

Stability of o/w Cream with Liquid-crystalline Gel Network Formed by Non-ionic Emulsifiers

基于液晶胶网结构理论,研究由非离子型乳化剂、两亲性化合物等形成的o/w型乳膏的液晶胶网结构及其稳定性。分别采用甲基葡萄糖苷倍半硬脂酸酯-甲基葡萄糖苷聚乙二醇-20醚倍半硬脂酸酯、单硬脂酸甘油酯-Myrj 52或Span40-Tween 60(重量比均为1∶1)为乳化剂,十六十八醇为两亲性化合物制备了o/w型的乳膏1～3。结果表明,在25℃贮存100 d期间,乳膏1和乳膏3稳定性较好;而乳膏2稳定性较差。经偏光显微镜、热重分析、电导率和流变学分析表明,乳膏2中形成的层状液晶结构较少且形状不规则,电导率升高、自由水增多,乳膏结构受外力易被破坏。

Based on the theory of the liquid-crystalline gel network, the microstructure and the stability of o/w cream formed by non-ionic emulsifiers, amphiphile, etc were investigated. Three o/w creams （product 1 - 3） were respectively prepared with mixed emulsifiers （weight ratio of 1 ： 1） of methyl glucoside sesquistearate-PEG-20 methyl glucoside sesquistearate, glyceryl monostearate-Myrj 52 or Span 40-Tween 60 and cetostearyl alcohol as amphiphile. The results showed that after storing at 25 ~C for 100 d, the product 1 and product 3 were rather stable while the product 2 was unstable. The results of polarized light microscope, thermogravimetric analysis, conductivity measurement and rheological analysis indicated that the conductivity and ratio of bulk water of the product 2 with less formation of lamellar liquid crystal structure were increased and the microstructure could be easily destroyed by external forces.