EFFECT OF A UREA-BASED COMPOUNDED MOISTURIZER 205 The site of application of each product was added on the label according to the random- ization list by an independent person. The investigator who performed the assessments was unaware of the site of application of each product. BIOMETRIC ASSESSMENT Skin bioph ysical parameters, including transepidermal water loss (TEWL), stratum corneum hydration, friction coeffi cient, skin surface lipid index, and pH, were measured before intervention, and 1 and 4 h after single application, as well as after 24 h and 1 week of twice-daily applications. Before each measurement, the participants rested in a room with climate control of 22 ± 2°C and relative humidity of 30–40% for 30 min. At the end of the study, the last application was performed at least 12 h before fi nal measure- ment. All measurements were performed using respective calibrated probes of a TEWAmeter, Corneometer, Frictometer, Sebumeter, and pH meter (MPA 580, Courage & Khazaka electronic GmbH, Cologne, Germany) in controlled room temperature and humidity conditions as previously reported by the authors (10). The skin pH measure- ment is based on a glass H+ ion sensitive electrode, which is connected to a voltmeter. A drop of deionized water was used to get good contact. Furthermore, any local adverse events at the site of applications were recorded, and the participants answered a questionnaire regarding tolerability and acceptance of each prod- uct on a fi ve-grade Likert scale (5 = extremely satisfi ed, 4 = very satisfi ed, 3 = moderately satisfi ed, 2 = slightly satisfi ed, and 1 = dissatisfi ed). STATISTICAL A NALYSIS For statistic al analysis, we performed descriptive statistics (mean, standard deviation, and percentages). In each time point, statistical differences were tested between four test sites for each parameter, using repeated measure analysis of variance (ANOVA) test. The signifi cance level was set as p 0.05. In case of signifi cance, the post hoc Bonferroni test were performed for pairwise comparison. Statistical signifi cance level was defi ned as p 0.05. RESULTS Thirt y partic ipants were enrolled in the study in two cohorts. Each cohort included 15 volunteers (14 women and one man). Mean age and standard deviation in cohorts 1 and 2 were 36.06 ± 9.08 and 35.93 ± 9.03, respectively (range 21–56 years). In each cohort, the baseline data for each parameter compared among four sites using repeated-measure ANOVA test showed no signifi cant difference for any of the evaluated parameters. COHORT 1 (5% UREA ) Both products sig nifi cantly increased skin hydration compared with the site of application of the cream-based formulation and no-treatment area in all measurement time points (p-value for ANOVA with repeated measure 0.01). No signifi cant differences were ob- served between the two products in any of the time points (Figure 1A).

JOURNAL OF COSMETIC SCIENCE 206 Following a 1-week application, TEWL decreased signifi cantly in sites of application of both products compared with the control site (p-value 0.049 and 0.03 for commercial and com- pounded product, respectively) (Figure 1B). Four hours after single application, signifi cant decrease occurred in the site of application of commercial moisturizer compared with the control site. This reduction was also signifi cant compared with the site of application of com- pounded urea-based preparation (9.42 ± 2.01 vs. 10.18 ± 1.65 g/m2.h, p-value = 0.04). No signifi cant differences were detected in TEWL between two products in other time points. One and 4 h after sin gle application, skin surface lipid content was signifi cantly higher at the site of application of both products than at the untreated area (Table II). No difference was detected in skin serum lipid content between commercial and compounding product in any time point. We also did not fi nd any signifi cant differences in other skin parameters measured (in- cluding skin pH and friction coeffi cient) between the two products in this cohort using urea 5% (Table II). COHORT 2 (10% UREA) I n the second group, the improvement in skin water content was also signifi cant compared with the site of application the cream-based formulation and no-treatment area, in all time Figure 1. Skin hydration (A) and TEWL (B) for commercial and compounded moisturizers containing urea 5%, after 1, 4, and 24 h as well as 1-week application (*signifi cant compared with cream-based formulation and untreated site, p 0.05) (#signifi cant compared with compounded product p 0.05).