Todo Hiroaki
Graduate School of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan.
Department of Pharmaceutical Sciences, Faculty of Pharmacy and Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan.
Pharmaceutics. 2017 Sep 6;9(3):33. doi: 10.3390/pharmaceutics9030033.
Excised human skin is utilized for in vitro permeation experiments to evaluate the safety and effect of topically-applied drugs by measuring its skin permeation and concentration. However, ethical considerations are the major problem for using human skin to evaluate percutaneous absorption. Moreover, large variations have been found among human skin specimens as a result of differences in age, race, and anatomical donor site. Animal skins are used to predict the in vivo human penetration/permeation of topically-applied chemicals. In the present review, skin characteristics, such as thickness of skin, lipid content, hair follicle density, and enzyme activity in each model are compared to human skin. In addition, intra- and inter-individual variation in animal models, permeation parameter correlation between animal models and human skin, and utilization of cultured human skin models are also descried. Pig, guinea pig, and hairless rat are generally selected for this purpose. Each animal model has advantages and weaknesses for utilization in in vitro skin permeation experiments. Understanding of skin permeation characteristics such as permeability coefficient ( ), diffusivity ( ), and partition coefficient ( ) for each skin model would be necessary to obtain better correlations for animal models to human skin permeation.
切除的人体皮肤用于体外渗透实验，通过测量其皮肤渗透和浓度来评估局部应用药物的安全性和效果。然而，伦理考量是使用人体皮肤评估经皮吸收的主要问题。此外，由于年龄、种族和解剖供体部位的差异，人体皮肤标本之间存在很大差异。动物皮肤用于预测局部应用化学物质在体内的人体渗透情况。在本综述中，将每种模型中的皮肤特征，如皮肤厚度、脂质含量、毛囊密度和酶活性与人体皮肤进行比较。此外，还描述了动物模型中的个体内和个体间差异、动物模型与人体皮肤之间的渗透参数相关性以及培养的人体皮肤模型的应用。猪、豚鼠和无毛大鼠通常为此目的而被选用。每种动物模型在体外皮肤渗透实验中的应用都有优缺点。了解每种皮肤模型的渗透特性，如渗透系数（ ）、扩散系数（ ）和分配系数（ ），对于使动物模型与人体皮肤渗透获得更好的相关性是必要的。
