Fürtjes Theresa, Weiss Katharina T, Filbry Alexander, Rippke Frank, Schreml Stephan
Department of Dermatology, University Medical Center Regensburg, Regensburg, Germany.
Skin Pharmacol Physiol. 2017;30(6):292-297. doi: 10.1159/000480300. Epub 2017 Oct 4.
Human skin surface has a physiologically acidic pH (pHss). In cases of increased pHss, the acidity of the skin can be restored by topical formulations. We tested a pH 5 oil-in-water (O/W) emulsion for pHss regeneration and stabilization.
We performed 2 experiments with 10 female study subjects in each. In both experiments, 2D imaging with luminescent sensor foils was used to determine pHss. Alkalization was reached by washing the volar forearm with a soap bar and warm running tap water for 20 min. Experiment 1: after defining the baseline pHss, we alkalized the respective area and measured pHss over a duration of 5 h, while applying emulsion every hour. Experiment 2: study subjects used the emulsion twice daily for 1 week. Then, pHss was measured before and after 5 min of washing a treated and an untreated area on the volar forearm.
(1) 5 h after alkalization, the treated arm showed a significantly lower pHss than the untreated one (5.87 ± 0.03 vs. 6.05 ± 0.03); (2) after washing, the treated area had a significantly lower pHss than controls (6.13 ± 0.03 vs. 6.27 ± 0.05).
The tested pH 5 O/W emulsion seems to improve regeneration and stabilization of pHss.
人体皮肤表面具有生理酸性pH值（皮肤表面pH值）。在皮肤表面pH值升高的情况下，可通过局部制剂恢复皮肤的酸度。我们测试了一种pH值为5的水包油（O/W）乳液用于皮肤表面pH值的再生和稳定。
我们进行了2项实验，每项实验有10名女性研究对象。在两项实验中，均使用带有发光传感器箔片的二维成像来测定皮肤表面pH值。通过用肥皂和温自来水冲洗掌侧前臂20分钟来实现碱化。实验1：在确定基线皮肤表面pH值后，我们对相应区域进行碱化，并在5小时内测量皮肤表面pH值，同时每小时涂抹一次乳液。实验2：研究对象每天使用两次乳液，持续1周。然后，在冲洗掌侧前臂上一个处理过的区域和一个未处理的区域5分钟前后测量皮肤表面pH值。
（1）碱化5小时后，处理过的手臂显示出比未处理的手臂显著更低的皮肤表面pH值（5.87±0.03对6.05±0.03）；（2）冲洗后，处理过的区域的皮肤表面pH值显著低于对照组（6.13±0.03对6.27±0.05）。
所测试的pH值为5的水包油乳液似乎能改善皮肤表面pH值的再生和稳定。
