PANTHENOL IN SKIN MOISTURIZATION 367 It is well known that the skin plays an important role in the prevention of transepidermal water loss by protecting the skin barrier function, which in turn maintains cutaneous homeostasis and prevents skin disorders and physical, chemical, and bacteriological inju- ries (26). Vitamins A, C, and E and panthenol are widely used in dermatological and cosmetic formulations to improve skin conditions, but not many studies address the ef- fects of panthenol on healthy skin, as observed for other entities such as vitamin A (8,27,28). Consequently, the results obtained in this study contribute to a better under- standing of the effects of cosmetic products containing panthenol on healthy skin, when evaluated by clinical studies under actual conditions of use. Immediate effects—SLES wash test. The results obtained in the SLES wash test showed that panthenol has good protection properties for skin barrier function. Formulations contain- ing 1.0% and 5.0% of panthenol signifi cantly reduced TEWL values, when compared with the control site (with SLES washing and without the application of the formulations) and also with the vehicle (formulation without panthenol) (Figure 3B). Considering that skin biophysical techniques may evaluate skin conditions by more than one parameter, the analysis of corneometer and tewameter results may suggest that panthenol acts on skin by protecting its barrier function, since TEWL values were signifi cantly reduced when com- pared with the vehicle and control areas (Figure 3A). Thus, the SLES wash test showed that when skin barrier function was altered, the formulations containing 1.0% and 5.0% of panthenol signifi cantly reduced TEWL. In summary, this study emphasizes the importance of adequate panthenol concentrations re- quired in effective formulations for skin protection as evaluated by clinical objective studies. Figure 3. Water content of the stratum corneum (A) and transepidermal water loss (B) before (baseline val- ues) and after repetitive skin washing with SLES solution for fi ve days (SLES fi ve days) and two hours after a single application of the formulations: vehicle (V), V+0.5%, V+1.0%, and V+5.0% of panthenol and the control site (with SLES washing and without the application of the formulations) (ANOVA test, n = 20 subjects, mean ± SEM). Ë Statistically signifi cantly higher compared to baseline values (p 0.001) • Statis- tically signifi cantly lower compared to baseline values (p 0.001).

JOURNAL OF COSMETIC SCIENCE 368 CONCLUSION This clinical study showed that panthenol-based formulations increased skin moisture and had a signifi cant effect on skin barrier function by decreasing TEWL values. In addi- tion, concentrations of pro-vitamin also infl uenced the improvement of skin barrier func- tion. One percent panthenol added to the basic formulation tested was suffi cient to show effi cacy in this parameter. It seems that the moisturizing effects of panthenol can be attributed mainly to the protection of skin barrier function, and thus it may be used in cosmetic products to maintain physiological skin conditions and to prevent dry skin alterations, since loss of water may adversely impact skin appearance and lead to skin disorders. ACKNOWLEDGMENTS The authors gratefully acknowledge the fi nancial support of Coordenação de Aperfeiçoa- mento de Pessoal de Nível Superior (CAPES), Conselho Nacional de Desenvolvimento Científi co e Tecnológico (CNPq), and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP). REFERENCES (1) R. W. Short, J. L. Chan, J. M. Choi, B. M. Egbert, W. E. Rehmus, and A. B. Kimball, Effects of mois- turization on epidermal homeostasis and differentiation, Clin. Exp. Dermatol., 32, 88–90 (2007). (2) S. E. Dal’Belo, L. R. Gaspar, and P. M. B. G. Maia Campos, Moisturizing effect of cosmetic formulations containing Aloe vera extract in different concentrations assessed by skin bioengineering techniques, Skin Res. Technol., 12, 241–246 (2006). (3) G. R. Leonardi, L. R. Gaspar, and P. M. B. G. Maia Campos, Application of a non-invasive method to study the moisturizing effect of formulations containing the moisturizing effect of formulations con- taining vitamins A or E or ceramide on human skin, J. Cosmet. Sci., 53, 263–268 (2002). (4) Z. D. Draelos, Moisturizing cream ameliorates dryness and desquamation in participants not receiving topical psoriasis treatment, Cutis, 82, 211–216 (2008). (5) M. Lodén, Role of topical emollients and moisturizers in the treatment of dry skin barrier disorders, Am. J. Clin. Dermatol., 4, 771–788 (2003). (6) P. M. B. G. Maia Campos, G. M. S. Gonçalves, and L. R. Gaspar, In vitro antioxidant activity and in vivo effi cacy of topical formulations containing vitamin C and its derivatives studied by non-invasive methods, Skin Res. Technol., 14, 376–380 (2008). (7) S. R. Pinnell, Cutaneous photodamage, oxidative stress, and topical antioxidant protection, J. Am. Acad. Dermatol., 48, 1–22 (2003). (8) P. M. B. G. Maia Campos, G. Ricci, M. Semprini, and R. A. Lopes, Histopathological, morphometric, and stereological studies of dermocosmetic skin formulations containing vitamin A and/or glycolic acid, J. Cosmet. Sci., 50, 159–170 (1999). (9) B. Idson, Vitamins and skin, Cosmet. Toiletr., 108, 79–94 (1993). (10) W. Gehring and M. Gloor, Effect of topically applied dexpanthenol on epidermal barrier function and stratum corneum hydration, Arzneimittelf, 50, 659–663 (2002). (11) F. Ebner, A. Heller, F. Rippke, and I. Tausch, Topical use of dexpanthenol in skin disorders, Am. J. Clin. Dermatol., 3, 427–433 (2002). (12) K. Biro, D. Thac, I. F. Ochsendorf, R. Kaufmann, and W. H. Boehncke, Effi cacy of dexpanthenol in skin protection against irritation: A double-blind, placebo-controlled study, Contact. Derm., 49, 80–84 (2003). (13) I. Buraczewska, B. Berne, M. Lindberg, H. Törmä, and M. Lodén, Changes in skin barrier function fol- lowing long-term treatment with moisturizers: A randomized controlled trial, Br. J. Dermatol., 156, 492–498 (2007).