非离子表面活性剂包封维生素E微乳液及体外缓释性能研究

制定了Tween80/EL-35/C2H5OH/H2O体系拟三元微乳液相图,研究温度、盐度、酸度对微乳液区域的影响,通过电导率法区分微乳液区域的O/W、W/O和B.C.区域,动态光散射测定微乳液的粒径和多分散度,通过改变剪切速率的粘度变化来观察微乳液流变性,并用渗析-三阶导数紫外光度法研究了微乳液对维生素E(VE)的缓释作用。结果表明,温度的升高和盐度的增加使微乳区域稍有减小,酸度对微乳液区域的影响较小,表明所制得的微乳液有良好的热稳定性和耐盐、酸性;室温下微乳液在水相大于43.4%时,形成高剪切速率下表现为牛顿流体的O/W型微乳液,微乳液粒径和多分散度分别为8 nm和0.11左右;并对维生素E有良好的缓释作用。

Study of nonionic surfactants entrapment of VE microemulsion and its release test in vitro

The microemulsion region of Tween80/EL-35/C2H5OH/H2O system and the influence of temperature,concentration of NaCl and pH were determined with phase diagrams.The O/W,W/O and B.C.regions were divided by conductance methods,using the Dynamic Light Scattering(DLS) to evaluate the particle diameters and the polydispersity of microemulsion.The rheological behavior was observed with dialysis bag-the third order derivative Ultraviolet method.Results showed that the microemulsion kept stable in pH in respect that the area of microemulsion decreased slightly with the increasing of temperature,salt concentration;DLS shows that the microemulsion has its particle diameter 8 nm with polydispersity 0.11,O/W microemulsion was formed when the water content exceeded 42.5% and remain Newtonian up to high shear rates.The microemulsion entrapping VE possessed eminent sustaining release efficiency.