J. Cosmet. Sci., 60, 7–14 (January/February 2009) 7 Address all correspondence to Yiyang Dong. Moisturizing and anti-sebum secretion effects of cosmetic application on human facial skin YAN CHENG, YIYANG DONG, JUNBING WANG, MEIXIAN DONG, YUNDONG ZOU, DONGMEI REN, XIAORAN YANG, MING LI, ANDREAS SCHRADER, MATHIAS ROHR, and WEI LIU, Beijing Sino-German Union Cosmetic Institute Co., Chinese Academy of Inspection and Quarantine, Beijing, Peoples Republic of China 100123 (Y.C., Y.D., J.W., Y.Z., D.R., X.Y., M.L.), Procter & Gamble (China) Ltd., Guangzhou, Guangdong, Peoples Republic of China 510620 (M.D.), Institute Dr. Schrader, Holzminden, Germany D-37603 (A.S., M.R.), and Department of Dermatology, General Hospital of Air Force, Beijing, Peoples Republic of China 100036 (W.L.). Accepted for publication September 29, 2008. Synopsis For human skin, high water content and low sebum secretion are considered to be main features of fair skin. To explore the proper personal care regimen for facial skin, we investigated the change of skin physiologic pa- rameters after cosmetic application by measuring the skin water content, transepidermal water loss, and skin sebum secretion on facial skin before and after the cosmetic application using the Corneometer, Tewameter, and Sebumeter, respectively. The results indicated that the cosmetics application kept a higher water content and a lower transepidermal water loss, and at the same time, a lower sebum secretion 4 h and 8 h after the cosmetic application, compared with those before it. The situation was maintained in the succeeding three- week continuous use of the cosmetics. It could be concluded that the cosmetic application on human facial skin might provide some moisturizing effect and at the same time an anti-sebum effect, which favors the mainte- nance of good skin physiological function after applying skin care products. Our results might provide a scientifi c personal care regimen for human facial skin to prompt the balance for the hydrolipid fi lm on skin. INTRODUCTION The hydration in the surface layer of the skin, stratum corneum (SC), gives important information on the biophysical properties and function of the skin barrier (1). With an adequate amount of water in the SC, the skin maintains its intact barrier function, feels soft and fl exible, and looks smooth and healthy. Additionally, the human face is covered by a lipid fi lm. Sebum excreted from the sebor- rheic glands keeps the skin surface supple and moist, and is known to control moisture

JOURNAL OF COSMETIC SCIENCE 8 and to protect skin from microbiological infections. However, too much sebum secretion could make the skin surface very oily and might promote acne for some people (2,3). Thus, sebum control is an important factor for facial skin care, especially for young adults with excess sebum secretion. It is generally accepted that the water content of the SC and skin sebum secretion are coordinative and important factors in the appearance and function of skin. A high water content, low transepidermal water loss (TEWL), and low sebum secretion are considered to be main features of fair skin. Thus, optimized facial care cosmetics should be developed that can supply a proper moisturizing effect and at the same time remove excessive amounts of sebum in facial skin (4). To substantiate the effi cacy claimed for cosmetic products, non-invasive bioengineering instruments have been introduced into cosmetology (5). The Corneometer has gained worldwide acceptance as an effi cient instrument to detect water content variation in the SC, based on electrical capacitance measurement (6,7). The Tewameter is the device com- monly used to determine TEWL, which measures the water vapor pressure gradient ac- cording to Fick’s law, to evaluate skin barrier function integrity (8,9). The Sebumeter has become an acceptable method for detecting sebum secretion levels, which is determined by the photometric transparency of absorbed sebum onto a plastic fi lm (10,11). To explore the proper personal care regimen for facial skin, we have investigated the pro- tection effect of some cosmetics on human skin under a simulated rigorous environment (12). Here, we investigated moisturizing and anti-sebum secretion effects by measuring skin water content, TEWL, and skin sebum secretion before and after cosmetic applica- tion on human facial skin. MATERIALS AND METHODS TEST PRODUCTS The test products, including product 1, product 2, and product 3, were mainly composed of glycosyl trehalose, Laminaria ochroleuca extract, sodium hyaluronate, niacinamide, glyc- erin, panthenol, and tocopherol, and were provided by Procter & Gamble (China) Ltd. Some of the ingredients were newly researched actives claimed by P&G. For example, Laminaria ochroleuca extract was extracted from a plant that grew in a desert environ- ment and could survive the rigorous droughty climate. Product 1 was colorless, non- aromatic, and water-like product 2 was a white and faintly scented cream and product 3 was a white sun protection cream with 2-ethylhexyl salicylate and titanium dioxide as the sunscreen actives, and labeled as SPF18, PA++. Product 1 was applied fi rst and then fol- lowed by product 2. While product 3 was required to be used according to a test protocol, it was applied following the application of product 2. SUBJECTS Thirty healthy female subjects, with normal or slight oily types of facial skin, partici- pated in this study. Their ages ranged between 25 and 34 years, and the average age was 29 ± 3 years. The criteria for non-inclusion were the presence of any dermatitis and/or