Department of Pharmaceutical Sciences, University of Catania, V.le A. Doria 6, 95125 Catania, Italy.
Int J Pharm. 2011 Feb 28;405(1-2):162-8. doi: 10.1016/j.ijpharm.2010.11.036. Epub 2010 Dec 1.
The high content of surfactants is one of the major limits to microemulsions (MEs) use in pharmaceutical and cosmetic field. In this work MEs with low surfactant content were prepared by the phase inversion temperature (PIT) method using different oil phases and emulsifiers. The effects of vehicle composition on in vitro release and skin permeation of octylmethoxycinnamte (OMC), one of the most used UVB filter, was evaluated. These MEs showed droplet sizes in the range 32-77nm and a single peak in size distribution. MEs prepared using the most lipophilic lipids (decyl oleate or cetyl stearyl isononanoate) showed the lowest stability. In vitro release and skin permeation profiles were affected by both lipophilicty and structure of the lipid used as internal phase and the formulation that released the lowest amount of OMC provided the lowest active compound skin permeation. It is noteworthy that no OMC release and skin permeation were observed using oleth-20/glyceryl oleate as emulsifiers. Furthermore, a skin permeation enhancement effect was observed depending on the vehicle components. The results of this work suggest that PIT MEs could provide controlled skin drug delivery by choosing proper associations of oil phase lipids and emulsifiers.
表面活性剂含量高是微乳液（MEs）在药物和化妆品领域应用的主要限制因素之一。在这项工作中，通过相转变温度（PIT）法使用不同的油相和乳化剂制备低表面活性剂含量的 ME。评估了载体组成对奥克立林（OMC）体外释放和皮肤渗透的影响，奥克立林是最常用的 UVB 滤光剂之一。这些 ME 的粒径在 32-77nm 范围内，粒径分布呈单峰。使用最亲脂性脂质（癸基油酸酯或鲸蜡硬脂醇异壬酸酯）制备的 ME 显示出最低的稳定性。体外释放和皮肤渗透曲线受内部相所用脂质的亲脂性和结构以及制剂的影响，释放 OMC 量最低的制剂提供了最低的活性化合物皮肤渗透。值得注意的是，使用油醇聚醚-20/甘油油酸酯作为乳化剂时，没有观察到 OMC 的释放和皮肤渗透。此外，还观察到根据载体成分的皮肤渗透增强作用。这项工作的结果表明，通过选择适当的油相脂质和乳化剂组合，PIT ME 可以提供控制皮肤药物输送。
