A Commercially Available Skin Care Lotion with a pH of 4.5 and 10% Urea Improves Skin Surface pH, Stratum Corneum Hydration and Epidermal Barrier Function in Subjects with Dry Skin and Atopic Diathesis  

作　　者：Jürgen Blaak Christiane Theiss Marina Schleißinger Isabel Simon Nanna Y. Schürer Peter Staib Jürgen Blaak;Christiane Theiss;Marina Schleißinger;Isabel Simon;Nanna Y. Schürer;Peter Staib(Department of Research & Development and Regulatory Affairs, Kneipp GmbH, Würzburg, Germany;Department of Dermatology, Environmental Medicine and Health Theory, University of Osnabrück, Osnabrück, Germany)

机构地区：[1]Department of Research & Development and Regulatory Affairs, Kneipp GmbH, Würzburg, Germany [2]Department of Dermatology, Environmental Medicine and Health Theory, University of Osnabrück, Osnabrück, Germany

出　　处：《Journal of Cosmetics, Dermatological Sciences and Applications》2020年第3期116-133,共18页化妆品、皮肤病及应用期刊（英文）

摘　　要：<strong>OBJECTIVE:</strong> <span style="font-family:;" "=""><span style="font-family:Verdana;">The physiological skin surface pH is crucial for several epidermal barrier functions, like stratum corneum integrity, cohesion and restoration. Alterations of the “normal” acidic nature of the skin surface have been shown to correlate with specific skin conditions like aged or inflamed skin and are leading to impaired skin barrier function and formation. It is previously demonstrated that topical acidification in atopic dermatitis improves stratum corneum function, skin barrier structure and clinical signs in dermatitis. Against this background, we examined the impact of a slightly acidic skin care product containing urea on stratum corneum hydration, skin surface pH and epidermal barrier function in subjects with dry skin and atopic diathesis. </span><b><span style="font-family:Verdana;">METHODS:</span></b><span style="font-family:Verdana;"> Stratum corneum hydration, skin surface pH and transepidermal water loss were biophysically measured before and after a 4-week treatment period with the test product (pH 4.5, 10% urea) compared to the reference product in 25 volunteers. In addition, dynamic epidermal barrier parameters like stratum corneum integrity, cohesion and recovery were investigated by using a previously described tape stripping approach. </span><b><span style="font-family:Verdana;">RESULTS:</span></b><span style="font-family:Verdana;"> It was shown that the test product (pH 4.5, 10% urea) significantly elevated stratum corneum hydration and improved the acidic nature of the skin surface by lowering the skin surface pH to a greater extent compared to the reference product. After the 4-week treatment period a significant faster barrier restoration was detected on the test site treated with the test product compared to the reference product. Moreover, the test product strengthens the skin barrier integrity and cohesion. </span><b><span style="font-family:Verdana;">CONCLUSION: </span></b><span style="font-<strong>OBJECTIVE:</strong> <span style="font-family:;" "=""><span style="font-family:Verdana;">The physiological skin surface pH is crucial for several epidermal barrier functions, like stratum corneum integrity, cohesion and restoration. Alterations of the “normal” acidic nature of the skin surface have been shown to correlate with specific skin conditions like aged or inflamed skin and are leading to impaired skin barrier function and formation. It is previously demonstrated that topical acidification in atopic dermatitis improves stratum corneum function, skin barrier structure and clinical signs in dermatitis. Against this background, we examined the impact of a slightly acidic skin care product containing urea on stratum corneum hydration, skin surface pH and epidermal barrier function in subjects with dry skin and atopic diathesis. </span><b><span style="font-family:Verdana;">METHODS:</span></b><span style="font-family:Verdana;"> Stratum corneum hydration, skin surface pH and transepidermal water loss were biophysically measured before and after a 4-week treatment period with the test product (pH 4.5, 10% urea) compared to the reference product in 25 volunteers. In addition, dynamic epidermal barrier parameters like stratum corneum integrity, cohesion and recovery were investigated by using a previously described tape stripping approach. </span><b><span style="font-family:Verdana;">RESULTS:</span></b><span style="font-family:Verdana;"> It was shown that the test product (pH 4.5, 10% urea) significantly elevated stratum corneum hydration and improved the acidic nature of the skin surface by lowering the skin surface pH to a greater extent compared to the reference product. After the 4-week treatment period a significant faster barrier restoration was detected on the test site treated with the test product compared to the reference product. Moreover, the test product strengthens the skin barrier integrity and cohesion. </span><b><span style="font-family:Verdana;">CONCLUSION: </span></b><span style="font-

关 键 词：Skin Barrier Skin Physiology Acidic Formulation UREA Atopic Skin 

分 类 号：O17[理学—数学]