J. Cosmet. Sci., 67, 175–183 (May/June 2016) 175 Comparison of skin hydration in combination and single use of common moisturizers (cream, toner, and spray water) LI YUANXI, HUA WEI, XIONG LIDAN, and LI LI, Department of Dermatovenereology, Sichuan University, Chengdu, Sichuan Province (L.Y., H.W.), Sichuan Cosmetic Engineering Research Center Center of Cosmetic Safety and Effi cacy Evaluation of West China Hospital, Chengdu, Sichuan Province (X.L.), and Department of Dermatovenereology, Sichuan University, and Sichuan Cosmetic Engineering Research Center, Chengdu, Sichuan Province (L.L), China. Accepted for publication July 6, 2016. Synopsis This study aims to assess the moisturization in combination or single use (including seven general applications) of three common moisturizers: cream, toner, and spray water. Groups were set as C: cream only T: toner only C+T, T+C: cream or toner applied successively within a few minutes C-T, C-S: cream applied with repeated toner or spray water every 2 h T-T: toner applied with repeated toner every 2 h and N: untreated group. Outcomes were the change in skin hydration from baseline at 2, 4, 6, and 8 h after applications. All treated zones displayed a signifi cantly higher degree of hydration compared with the untreated zone (p 0.05). For normal skin (hydration value at baseline 35 a.u.), C-T led to greatest hydration change rate compared with others, followed by C+T, T+C, and C. Those three applications exhibited analogous hydration at each test point (p 0.05). The hydration rate of C-S differed slightly from T-T, followed by those four mentioned above, with T being the last. For dry skin (hydration value at baseline 35 a.u.), no statistical signifi cance could be detected between C-T zone and C+T, T+C, and C zones ( p 0.05), the other results were identical. When cream and toner were applied successively, the application order has little effect on skin hydration. The application of cream only was an effective and brief way to achieve favorable moisturization especially for dry skin. As a complement, repeated application of toner rather than spray water is effi cacious for skin hydration. INTRODUCTION As skin moisturization plays a vital role in skin care, receiving a higher skin hydration is essential for major skin types, especially for dry skin and some related skin conditions (1–3). Because moisturizers serve as routine care, the availability of creams and lotions, including toner and sprays, gels, emulsions, oleaginous mixtures, milks, serums, and Address all correspondence to Prof Li Li at lily2058@126.com.

JOURNAL OF COSMETIC SCIENCE 176 other skin moisturizers options, has allowed customers to select optimal treatment regi- mens that are better for individual management (4). Development of moisturizers is a scientifi c and artistic discipline, since the consumers’ insights also need to be taken into considerations (5). In the current market, there is a plethora of moisturizer options available for customers, since many skin care products and varieties of applications are promoted to the public (4). Excessive consumption often oc- curs, and customers may arbitrarily apply moisturizers they have. In our country, many ladies are used to applying spray water or toner when they feel dry, some of them even apply 3–4 times a day in the air-conditioned offi ce. Yet, there is no guarantee that fre- quent application of spray water or toner can reach the corresponding moisturizing effect. However, positive effects from the use of moisturizers cannot always be granted, but ex- cessive application or improper use may bring about dermatitis. Moisturizers are usually free from strong irritants, while repeated exposure of sensitive areas to mildly irritating preparations may deteriorate skin barrier function. Although strong irritants are gener- ally easy to identify, weak irritants are less obvious to avoid (6,7). Most of the moisturizers have humectants, occlusives, and/or emollients as main ingredi- ents. The majority of humectants used in moisturizers are low molecular weight sub- stances with hydrophilic properties. A few high molecular weight substances are also used (e.g., polymers such as hyaluronic acid). Humectants differ in water-binding capacity as well as in their ability to penetrate and infl uence the degree of skin hydration (8). Occlu- sives generally minimize water loss to the external environment. The complementary occlusive activity of emollients contributes to stratum corneum hydration as well (9). Ap- parently, moisturizing effi cacy varies due to distinct emulsion formations, and approach- ing the maximum effect with less concentration can reduce dermatitis caused by overuse. Current studies have scarcely mentioned whether the use of moisturizers with different applications would result in different moisturizing effects. In the present study, we com- pared the effects of seven general application ways of using three common moisturizers (cream, toner, and spray water) and provided a way for making a rational choice for a bet- ter moisturizing effect. MATERIALS AND METHODS This study was reviewed by Biomedical Ethics Committee of local hospital. The process of selecting volunteers and the testing procedure followed the principles of International Ethical Guidelines for Biomedical Research Involving Human Subjects. Eligible volunteers were healthy young females between 20 and 35 years of age. Exclu- sion criteria were a history or current disease or condition of skin (e.g., eczema, psoriasis, atopic skin disease) wounds or scars on the forearm and leg test sites, with known aller- gies or sensitivities to cosmetic products or its components and currently or has been using external prescription drugs on limbs within the last 1 month. Topical use of body products on limbs was paused for 7 days prior to the study, and the cleansers were avoided on any application area 12 h before and throughout the test. Furthermore, the volunteers must have few body hairs on test zones inherently, averting the infl uence on corneometer readings caused by body hair and potential effect of shaving test areas. Those volunteers who met the criteria for inclusion completed a study participation questionnaire and signed an informed consent form before participating in our study.