J. Cosmet. Sci., 62, 361–369 ( July/August 2011) 361 Skin moisturizing effects of panthenol-based formulations FLÁVIO B. CAMARGO, Jr., LORENA R. GASPAR, and PATRÍCIA M. B. G. MAIA CAMPOS, Universidade de São Paulo, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Av. do Café s/n, Bairro Monte Alegre, Ribeirão Preto, SP, Brazil 14040-903. Accepted for publication April 16, 2011. Synopsis This study aims to evaluate the skin moisturizing effi cacy of formulations containing different concentrations of panthenol. Formulations supplemented with or without 0.5%, 1.0%, or 5.0% panthenol were applied daily to the forearms of healthy subjects. Skin conditions in terms of moisture and transepidermal water loss (TEWL) were analyzed before and after 15- and 30-day periods of application. The formulations were also applied after skin washing with sodium laureth sulphate (SLES) to evaluate the immediate effects on TEWL and skin moisture. Panthenol-containing formulations (1.0% and 5.0%) produced signifi cant decreases in TEWL after 30-day applications. In skin washed with SLES, signifi cant reduction of TEWL was evident two hours after application of formulations loaded with panthenol when compared with control and vehicle. It is con- cluded that skin integrity is maintained by the improved protective effect of 1.0% panthenol added to the formulation. INTRODUCTION Moisturizing products are among the most important cosmetic types. Their use helps to prevent cutaneous early aging and may act as support in the treatment of several skin disorders (1–3). Skin dryness or hydration, considered respectively as a sign of compromised skin or healthy skin, is the subject of many studies showing the importance of moisturizing ac- tive substances and products in different skin conditions (dry skin disorders, atopic skin, ichthyosis, and contact dermatitis) (4,5). The studies emphasize the infl uence of the care- ful choice of raw materials, which should have good sensorial and hydration properties. Amino acids, lactic acid, silicones, vegetable and mineral oils, ceramides, and polymers are some of the several moisturizing agents used in cosmetic products. These agents act by different mechanisms, such as occlusion or water carried into the skin surface. Hydro- philic polymers have plasticizing and fi lm-forming properties, which are able to suppress evaporation of water from the stratum corneum. Vitamins A, C, and E and panthenol are also moisturizing active substances, which play an important role in keeping skin in good condition e.g., they can stimulate collagen production, act on epithelization in dry and rough skin, enhance skin hydration, and restore a healthy skin barrier (6–9).

JOURNAL OF COSMETIC SCIENCE 362 Panthenol, the biologically active alcohol analogue of pantothenic acid is a pro-vitamin of the B-complex group that is a normal constituent of skin and hair. When applied topically, panthenol is converted to pantothenic acid, a component of coenzyme A and holo-fatty acid synthase that is essential to normal epithelial function (10). Dermatologists have long been aware of the value of panthenol in the preservation of skin health. Clinical observations have reported that topically applied panthenol is an aid in superfi cial wound healing in burns, fi ssures, corneal lesions, and allergic dermatitis, and it is well tolerated, with minimal risks of skin irritancy (10,11). Indeed, it has been shown that panthenol has protective effects against skin irritation (12). In one irritation model, pretreatment with dexpanthenol cream resulted in signifi cantly less damage to the stratum corneum barrier when compared with no pretreatment (13). However, its exact mechanism of action is not yet fully understood. Moisturizers infl uence the skin barrier function of healthy skin, but the base formulation composition and the concentration of active substances may infl uence the hydration effect of the cosmetic product. The chemistry and function of dry skin and moisturizers is a challenging subject for the practicing dermatologist, as well as for those who develop these agents in the pharmaceutical/cosmetic industry (5). Consequently, more studies are needed to evaluate by objective noninvasive techniques the hydration effect of panthenol- containing cosmetic formulations on human skin. New biochemical approaches and noninvasive instruments will increase our understand- ing of skin barrier disorders and facilitate optimized treatments. Among these methods are noninvasive validated skin biophysical techniques, which are widely used, as they al- low evaluation of cosmetic products under actual conditions of use (1,14,15). They have been used to determine viscoelastic and moisturizing properties, and human skin barrier function, which is an important aspect of skin biology (16). However, alongside the de- velopment of anti-aging cosmetic products, it has become necessary to standardize the new methodologies employing noninvasive techniques, to evaluate benefi ts attributed to a given product (17–19). Despite the fact that panthenol is often used in topical formulations in order to improve or maintain good skin conditions and the rate of wound healing, its optimal concentra- tion and the correct choice of vehicle in terms of sensorial and stability properties have not been suffi ciently studied. This study constitutes a clinical objective evaluation of the hydration and protection effects of cosmetic formulations containing panthenol in differ- ent concentrations by noninvasive biophysical methods. The results contribute to the elucidation of the effects of panthenol on skin barrier function and may also be helpful in maintaining homeostasis in healthy skin that is frequently compromised by continuous UV radiation and pollution. MATERIAL AND METHODS FORMULATIONS STUDIED Experimental formulations, (Table I), containing 2.0% (w/w) of sclerotium gum (Ami- gel®, Alban Muller International, Vincennes, France) and 2.0% (w/w) of methylphenyl polysiloxane (Net FS®, Nikko Chemicals, Tokyo, Japan) were prepared in a Heidolph