Department of Drug Delivery, PharmBioTec GmbH, Saarbrücken, Germany.
Scienceneering UG, Blieskastel, Germany.
Skin Res Technol. 2021 Sep;27(5):668-675. doi: 10.1111/srt.12998. Epub 2021 Jan 6.
In vitro skin permeation experiments are highly relevant for pharmaceutical, cosmetic, agricultural developments, and regulatory evaluation. A key requirement is the skin barrier integrity, that is accompanied by an intact stratum corneum (SC) which implements high skin quality. A variety of integrity tests are currently available, for example, measurement of transepidermal water loss, monitoring the permeation of tritiated water and the measurement of transdermal electrical resistance (TER).
We aimed for a non-destructive examination of barrier integrity as quality control system, based on TER. Therefore, the in-house developed instrument SkinTER measures electrical resistance on excised human skin samples in a non-invasive and easy-to-use pattern. In this proof of concept study, we compared three human in vitro skin models with focus on their TER and permeation properties. The skin integrity was impaired to mimic conditions of skin during age, lifestyle (eg, shaving) or diseases (eg, obesity, psoriasis, and atopic dermatitis). The OECD permeation marker caffeine was correlated to the corresponding TER value.
A correlation between both was obtained by having a Pearson coefficient of -0.830. Hereby, a minimum TER value for intact skin samples of ~1.77 kΩ*cm was suggested. Intact samples are significantly different (α = ≤0.05) to their impaired counterparts in flux and TER values.
The new SkinTER instrument gives a quick and non-invasive feedback on skin quality before a permeation experiment.
体外皮肤渗透实验与药物、化妆品、农业发展和监管评估高度相关。一个关键要求是皮肤屏障的完整性，这伴随着完整的角质层（SC），它实现了高皮肤质量。目前有多种完整性测试方法，例如测量经皮水分流失、监测氚水的渗透和测量经皮电阻（TER）。
我们旨在基于 TER 建立一个非破坏性的屏障完整性检查作为质量控制系统。因此，内部开发的仪器 SkinTER 以非侵入性和易于使用的方式测量离体人体皮肤样本的电阻。在这项概念验证研究中，我们比较了三种人体体外皮肤模型，重点是它们的 TER 和渗透特性。皮肤完整性受损以模拟皮肤在年龄、生活方式（例如剃须）或疾病（例如肥胖、银屑病和特应性皮炎）期间的状况。OECD 渗透标志物咖啡因与相应的 TER 值相关。
通过获得 Pearson 系数为-0.830 得到了两者之间的相关性。由此，建议完整皮肤样本的最小 TER 值约为 1.77 kΩ*cm。完整样本的通量和 TER 值与受损样本有显著差异（α ≤ 0.05）。
新型 SkinTER 仪器在渗透实验前快速提供皮肤质量的非侵入性反馈。
