Department of Pharmaceutics, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt.
J Colloid Interface Sci. 2011 Feb 1;354(1):124-30. doi: 10.1016/j.jcis.2010.10.025. Epub 2010 Oct 16.
The use of nano-systems such as the microemulsions is considered as an increasingly implemented strategy in order to enhance the percutaneous transport into and across the skin barrier. The determination of the major pathway of penetration and the mechanisms by which these formulations work remains crucial. In this study, laser confocal scanning microscopy was used to visualize the penetration and the distribution of a fluorescently-labelled microemulsion (using 0.1% w/v Nile red) consisting of (%, w/w) 15.4% oleic acid, 30.8% Tween 20, 30.8% Transcutol® and 23% water. The surface images revealed that the microemulsion accumulated preferentially in the intercellular domains of the stratum corneum. Additionally, by analysis of the images taken across the whole stratum corneum (SC), the penetration was found to occur along its whole depth. The latter result was confirmed using tape stripping and the subsequent sensitive analysis using liquid chromatography mass spectroscopy. Dermatopharmacokinetic parameters were obtained for the microemulsion different components. These values proved the breakage of the microemulsion during its penetration across the stratum corneum. Moreover, the mechanisms of penetration enhancement and the micro molecular effects on the skin stratum corneum were investigated using attenuated Fourier transform infra-red spectroscopy. The results revealed the penetration of all the microemulsion components in the stratum corneum and demonstrated the microemulsion interaction with the skin barrier perturbing its architecture structure.
纳米系统（如微乳液）的使用被认为是一种越来越被广泛应用的策略，以增强经皮输送进入和穿过皮肤屏障。确定主要的渗透途径以及这些制剂的作用机制仍然至关重要。在这项研究中，激光共焦扫描显微镜用于可视化荧光标记的微乳液（使用 0.1%w/v 尼罗红）的渗透和分布，该微乳液由（%，w/w）15.4%油酸、30.8%吐温 20、30.8%Transcutol®和 23%水组成。表面图像显示，微乳液优先积聚在角质层的细胞间区域。此外，通过对整个角质层（SC）拍摄的图像进行分析，发现渗透是沿着整个深度发生的。后者的结果通过胶带剥离和随后使用液相色谱-质谱法进行的敏感分析得到了证实。获得了微乳液不同成分的经皮药代动力学参数。这些值证明了微乳液在穿过角质层时的破裂。此外，还使用衰减全反射傅里叶变换红外光谱研究了渗透增强机制和微分子对皮肤角质层的影响。结果显示所有微乳液成分都渗透到角质层中，并证明了微乳液与皮肤屏障的相互作用，扰乱了其结构。
