Department of Dermatology, University Hospital Regensburg, Germany.
Skin Pharmacol Physiol. 2012;25(1):34-8. doi: 10.1159/000331204. Epub 2011 Sep 8.
BACKGROUND/AIMS: The effects of a 10% α-hydroxy acid (AHA) oil/water (O/W) emulsion on the pH of human skin surface (pH(ss)) and stratum corneum (SC; pH(sc)) were evaluated in vivo.
The AHA O/W emulsion was applied to an area on the volar forearm of male volunteers (n = 12), and then wiped off after 10 min. Prior to application and over the following 3 h, the pH(ss) was measured. We used glass electrode measurements and time domain dual lifetime referencing (tdDLR) with luminescent sensor foils. In another experiment (n = 5), the impact of the AHA O/W emulsion on the pH(sc) gradient was measured by tape stripping of the SC of the volar forearm after application of the AHA O/W emulsion.
Compared with pH(ss) values prior to treatment [5.2 ± 1.7 (tdDLR) or 4.8 ± 0.5 (electrode)], the pH(ss) was significantly reduced 10 min after application [4.0 ± 0.3 (tdDLR) or 4.1 ± 0.1 (electrode)] and the pH(ss) remained significantly reduced over the measurement period of 3 h [after 3 h: 4.4 ± 0.2 (tdDLR) or 4.5 ± 0.3 (electrode)]. The AHA O/W emulsion significantly reduced the pH(sc) even down to deep layers of the SC.
After a 10-min application time, the 10% AHA O/W emulsion reduces the pH(ss) (for at least 3 h) and pH(sc) in deep layers of the SC.
背景/目的：评估 10%α-羟基酸（AHA）油/水（O/W）乳液对人体皮肤表面（pHss）和角质层（pHsc）的 pH 值的影响。
将 AHA O/W 乳液涂抹于男性志愿者的前臂掌侧（n=12），涂抹 10 分钟后擦拭。在应用前和接下来的 3 小时内测量 pHss。我们使用玻璃电极测量和时间域双寿命参考（tdDLR）与发光传感器箔。在另一项实验中（n=5），通过涂抹 AHA O/W 乳液后在前臂掌侧的 SC 进行胶带剥离，测量 AHA O/W 乳液对 pHsc 梯度的影响。
与治疗前的 pHss 值[5.2±1.7（tdDLR）或 4.8±0.5（电极）]相比，应用 10 分钟后 pHss 显著降低[4.0±0.3（tdDLR）或 4.1±0.1（电极）]，并且在 3 小时的测量期间 pHss 仍显著降低[3 小时后：4.4±0.2（tdDLR）或 4.5±0.3（电极）]。AHA O/W 乳液甚至降低了 SC 深层的 pHsc。
在 10 分钟的应用时间后，10%AHA O/W 乳液降低了 pHss（至少 3 小时）和 SC 深层的 pHsc。
