Sekkat N, Kalia Y N, Guy R H
School of Pharmacy, University of Geneva, 30, quai E. Ansermet, CH-1211 Genève 4, Switzerland.
J Pharm Sci. 2002 Nov;91(11):2376-81. doi: 10.1002/jps.10220.
The goal of this work was to establish, using biophysical characterization, that porcine ear skin in vitro is a valid model for its human counterpart. Specifically, stratum corneum (SC) barrier function was evaluated during its progressive removal by adhesive tape-stripping using the techniques of transepidermal water loss (TEWL) and impedance spectroscopy. TEWL increased slowly at first and then more rapidly with the degree of SC impairment. In contrast, low-frequency skin impedance declined exponentially as a function of progressive SC removal. The methods provide complementary and correlated information about SC barrier function. Biophysical parameters, including the diffusivity and permeability coefficient of water across the SC, and the thickness of the barrier were determined from the TEWL data using Fick's first law of diffusion. Furthermore, an ionic partition coefficient-mobility product was estimated from the skin impedance measurements. Comparison of the results with those previously reported for human skin in vivo strongly supports the validity of the porcine membrane as an in vitro model.
这项工作的目标是通过生物物理表征确定猪耳皮肤在体外是其人类对应物的有效模型。具体而言，使用经表皮水分流失（TEWL）和阻抗谱技术，在通过胶带剥离逐渐去除角质层（SC）的过程中评估角质层屏障功能。TEWL起初缓慢增加，然后随着SC损伤程度的增加而更快地增加。相比之下，低频皮肤阻抗随着SC的逐渐去除呈指数下降。这些方法提供了关于SC屏障功能的互补和相关信息。利用菲克第一扩散定律从TEWL数据中确定了包括水在SC中的扩散率和渗透系数以及屏障厚度在内的生物物理参数。此外，从皮肤阻抗测量中估计了离子分配系数 - 迁移率乘积。将结果与先前报道的人体皮肤体内结果进行比较，有力地支持了猪膜作为体外模型的有效性。
