SKIN MOISTURIZATION: SHORT-TERM MEASUREMENTS 15 FORMULATIONS A full 3 x 3 factorial design with levels of NaC1 of 0%, 1.5%, and 3.0% and glycerin levels of 0%, 5%, and 10% was used in this study, making a total of nine formations. Besides salt and glycerin, all formulations contained 3% mineral oil, 1% cetyl-stearyl alcohol, 4% surfactant (1.5 % stereth-2 and 2.5 % stereth-20), 0.5 % hydroxyethylcellu- lose (thickener), 0.1% Germaben © II, and deionized water. All formulations had suitable flowability, allowing convenient application of the products by a micropipet. The com- ponents of the formulations are listed in Table I. SUBJECTS Twenty-three female subjects were recruited for the study. All subjects were in good general health and between ages 18 and 65. The skin types ranged from Fitzpatrick type I to Fitzpatrick type V. The study was approved by the University of Cincinnati Institutional Review Board, and all subjects signed informed consent forms prior to entering the study. Exclusion criteria were as follows: 1. Systemic steroid or topical therapy one week before the study 2. Tattoos, erythema, or pre-existing dermatological conditions such as skin cancer, psoriasis, eczema, skin cracking, or lesions at test sites 3. Any type of weight-control diet 4. Insulin-dependent diabetes 5. Known sensitivity to cosmetic products 6. Participation in any other clinical study (dermal patch, investigational drug or de- vices, etc.) PREPARATION OF THE TESTING SITES Prior to the beginning of the study, the subjects were instructed to refrain from using moisturizers on the test sites for seven days. No shaving of legs was permitted during the 48 hours before the study. All nine products were used on each subject. Five areas of 3 x 5 cm on the outer calf region of each leg were used for the treatments. The areas were marked with a surgical marking pen (Surgical Skin Marker, Precision Dynamics Corp., San Fernando, CA). A Table I Nine Formulations From a Full 3 x 3 Factorial Design by Alternating NaCl and Glycerin Levels for Short-Term Study (water phase) Formula no.** Ingredients* 1 2 3 4 5 6 7 8 9 NaC1 0 1.5 3.0 0 1.5 3.0 0 1.5 3.0 Glycerin 0 0 0 5.0 5.0 5.0 10.0 10.0 10.0 * W/W% of ingredients in the formula. ** All formulations contained 3.0% mineral oil, 1.0% cetyl stearyl alcohol, 1.5% stereth-2, and 2.5% stereth-20 in the oil phase and 0.5 % hydroxyethyl cellulose, 0.1% Germaben II, and deionized water in the water phase.

16 JOURNAL OF COSMETIC SCIENCE quantity of 40 pl of product was applied to each skin site in a randomized design, with one skin site serving as an untreated control. MEASUREMENT SETTINGS All measurements were conducted in controlled temperature and humidity conditions (22 + 2øC and 45 _+ 5% relative humidity). Subjects acclimated to the room conditions during a 20-minute equilibration period prior to each set of measurements. The data were collected at baseline, one hour and two hours after application of the products. STATISTICAL ANALYSIS Statistical analysis was performed with SAS for Windows © 6.12 package. PROC GLM, PROC CORR, and PROC REG were the main procedures used to analyze the data and select suitable models. Options for multiple comparison of means of different groups were used. RESULTS AND DISCUSSION The results are given with the respective means, standard deviations, and significance levels in Table II (a-c) and are illustrated in Figure 1. PROC GLM procedures were used to compare the means of the different measurement modes (baseline, one-hour, and two-hour), salt levels, and glycerin levels. In general, there was very good agreement among the three instruments, with some differences. A small but statistically significant difference (P 0.05) was observed between baseline measurements on the untreated site and those at the one-hour and two-hour time points with the Nova © and the Skicon ©, but not with the Corneometer ©. Table IIa Summary of Measurements by Nova © DPM 9003, at Baseline, and at One Hour and Two Hours After Using the Emulsions P-value Nova © DPM 9003 Mean capacitance ñ SD Baseline Baseline 1 Hour Glycerin vs vs vs (%) NaC1 Emulsion Baseline 1 Hour 2 Hours 1 hour 2 hours 2 hours 0 1 100 +_ 8 131 _+ 40 128 ñ 36 0.001 0.003 0.79 0 1.5 2 101 _+ 9 123 _+ 20 124 _+ 24 0.000 0.000 0.86 3 3 103 _+ 9 114 ñ 14 113 _+ 14 0.003 0.008 0.76 0 4 102 _+ 9 201 _+ 17 191 +_ 69 0.0001 0.0001 0.55 5 1.5 5 102 _+ 9 258 _+ 79 231 _+ 75 0.0001 0.0001 0.16 3 6 102 _+ 9 218 _+ 76 209 _+ 77 0.0001 0.0001 0.63 0 7 103 ñ 8 234 _+ 55 234 _+ 51 0.0001 0.0001 0.96 10 1.5 8 101 ñ 8 340 _+ 78 314 _+ 74 0.0001 0.0001 0.17 3 9 100 _+ 7 313 ñ 67 229 ñ 74 0.0001 0.0001 0.42 Control 100 _+ 8 112 _+ 16 111 _+ 13 0.002 0.006 0.74