PANTHENOL IN SKIN MOISTURIZATION 363 RZR 2021 shaker at approximately 650 rpm, and supplemented or not (vehicle/placebo) with 0.5%, 1.0%, or 5.0% (w/w) panthenol (D-panthenol, DSM Nutricional Products, Basel, Switzerland). DETERMINATION OF CLINICAL EFFICACY Study design. The one-sided blind, placebo-controlled study was approved by the Faculty of Pharmaceutical Sciences Ethics Committee (CEP/FCFRP 40/2005) and complied with the Declaration of Helsinki. A total of 40 healthy female subjects, 20–35 years old and having Fitzpatrick (20) skin types II and III, participated in this study after having given their written informed consent. The exclusion criteria were (a) the presence of any derma- titis and/or other skin or allergic diseases and (b) a smoking habit. Volunteers were in- structed not to apply any topical products such as moisturizers, sunscreens, and anti-aging formulations on the test sites for two weeks before and during the study. During the test period the subjects were allowed to wash normally, but did not use any other skin care products on their arms. Formulations were applied daily on the volunteers’ forearm skin, and prior to all measurements they stayed in the testing room for at least 30 min in order to allow temperature (20° ± 2°C) and humidity (45-60%) adaptation. An analy- sis of skin conditions, according to a standardized study protocol, was conducted before and after 15- and 30-day periods of daily application (six to ten hours after the last ap- plication). It consisted of measurements of skin moisture (capacitance method), transepi- dermal water loss (TEWL), and viscoelasticity (skin deformation in response to suction). Study of long-term effi cacy. After the baseline measurements, all subjects were instructed to apply 0.2 grams of two of the formulations (one on each forearm—in an area of approxi- mately 100 cm2), twice daily, in the morning and in the evening. The applications sites of the four formulations studied (placebo and formulations containing 0.5%, 1.0%, and 5.0% of panthenol) were randomized between groups and between subjects’ left-right forearms (parallel-group, investigator-blinded randomization) in order to guarantee that the four formulations under study were applied to an equal number of participants and to an equal number of right and left forearms. As an example, the fi rst volunteer applied the vehicle to the right forearm and the formulation containing 0.5% of panthenol to the left one the second volunteer applied formulations containing 1.0% and 5.0% of panthenol to the left and right forearms, respectively the third one applied the formulation contain- ing 5.0% of panthenol and the vehicle to the left and right forearms, respectively and the Table I Formulation Composition Components Percentage (w/w) Sclerotium gum 2.0 Methylphenyl polysiloxane 2.0 Propyleneglycol 2.5 Glycerin 86% 2.5 Phenoxyethanol and parabens 0.8 Hydrogenated and ethoxylated castor oil 40 OE 2.0 Deionized water 100.0

JOURNAL OF COSMETIC SCIENCE 364 fourth volunteer applied formulations containing 0.5% and 1.0% of panthenol to the left and right forearms, respectively, and so on. Another group of 20 volunteers (control group) did not receive any formulation and were exposed to the same conditions as the 40 experimental volunteers. Immediate effects—SLES wash test. The volar forearms of 20 new volunteers were divided into three areas (six areas for each person) after the baseline measurements each area was submitted to a 1% SLES (sodium laureth sulphate - 3EO), (∼ 3.7%, Genapol ZRO Liq, Clariant) wash test once a day for fi ve days. The standardized wash test was performed on the forearm as follows: a foam roller was soaked in 1.0% SLES (test solution) and moved up and down ten times on the volar forearm within one minute. Then, another foam roller was soaked with test solution and the whole procedure was repeated altogether fi ve times. Finally, the forearm was rinsed with clear tap water and dried carefully with a paper towel (21). For each washing procedure 50 ml of test solution was used. In two groups tap water was used instead of SLES. At the end of the fi fth day, new measurements were car- ried out. After this, 0.1 grams of the four different formulations under study (containing 0.5%, 1.0%, and 5.0% of panthenol and the vehicle) were applied to the areas previously established (in an area of approximately 40 cm2) and new measurements were carried out after two hours to evaluate their infl uence on TEWL. A control site was submitted to the SLES wash test but did not receive the application of any formulation. The four formula- tions studied and the control sites were randomized over the areas in the volar forearm. INSTRUMENTATION Corneometer® measurements. The stratum corneum moisture content was determined with a noninvasive, skin capacitance meter (Corneometer® CM 825, Courage + Khazaka, Co- logne, Germany), which makes use of the relatively high dielectric constant of water (22). This device determines the water content of the superfi cial epidermal layers down to a depth of about 0.1 mm and expresses the values obtained in arbitrary units. The averaged values of twenty measurements were used for subsequent calculations. (2). Tewameter® measurements. Transepidermal water loss was determined by an evaporimeter (Tewameter® CM 210, Courage + Khazaka, Cologne, Germany). TEWL values were reg- istered for two minutes following a 30-second period of equilibration of the probe on the skin (2, 21). The Tewameter® is based on Fick’s diffusion law, indicating the quantity being trans- ported per a defi ned area and period of time. By using the data obtained from thermo- and hydro-sensors, and after processing the information by an inbuilt microprocessor, a numerical value of the TEWL is obtained, commonly shown in g/m2/h (14,23). Cutometer® measurements. Viscoelastic properties of the skin were determined using a noninvasive, in vivo suction skin-elasticity meter (Cutometer® SEM 575, Courage + Khazaka, Cologne, Germany). The instrument consists of a microprocessor-regulated pneumatic system that applies suction via a 2-mm circular opening in the handheld probe. Evalua- tion of skin viscoelasticity is based on the measurement of skin deformation in response to suction. Each measurement consisted of fi ve consecutive cycles of a two-second suction application period followed by a two-second relaxation period. The suction load was 450 mbars. The ratio of viscoelastic to elastic distension, Uv/Ue (related to viscoelastic prop- erties) was analyzed (19).