EFFECT OF COSMETIC EMULSIONS ON STRATUM CORNEUM TABLE 1--MoisTURE Loss FROM THE INNER SURFACE OF THE FOREARM, AFTER THE APPLICATION OF SELECTED COSMETIC RAW MATERIALS (11) 113 Test Material Average Moisture Loss in rag. for 2-Hour Test No. of Average Effect Test Deter- on Moisture Material Control minations Loss Petrolatum, U.S.P. 7.80 14.92 8 Lanolin, anhydrous 9.12 13.39 5 Mineral oil, light tech. 7.94 11.00 4 Lanolin alcohols (25% sol. in mineral oil) 7.46 10.40 3 Isopropyl palmirate 14.65 20.45 3 Silicone oil 7.94 10.72 5 Squalene 9.04 11.70 3 Glyceryl trioleate 8.72 11.30 5 Dewaxed lanolin oil 9.80 12.50 5 Sorbitan sesquioleate 14.50 17.40 3 Polyoxyethylene glycol 200 mono61eate 15.75 15.62 5 Polyoxyethylene glycol 600 mono61eate 12.14 12.12 3 Glyceryl mono61eate (90% mono ester content) 9.70 9.73 4 Safflower Monoglyceride (40% mono ester content) 15.95 16.32 4 Oleyl sarcosine 10.68 10.95 5 Polyoxyethylene glycol 400 mono stearate 12.10 11.60 3 Polyoxyethylene sorbitan mono laurate 12.04 11.48 4 Diethylene glycol mono61eate 11.19 10.28 5 Polyoxyethylene sorbitan mono61eate 12.91 11.26 4 Polyoxyethylene oleyl ether (15-20 Eto) 14.42 11.98 3 Polyoxyethylene oleyl ether (5-10 Eto) 17.75 14.15 5 Propylene glycol, anhydrous 11.55 8.56 5 Glycerine, anhydrous 12.55 8.83 5 48% reduction 32% reduction 28% reduction 28% reduction 28% reduction 26% reduction 23% reduction 23% reduction 22% reduction 17% reduction Nil Nil Nil Nil Nil Nil 5% increase 9% increase 13% increase 22% increase 25% increase 25% increase 43% increase similar moisture loss readings are obtained from the adjacent test sites. However, when the subject is moving about, the moisture loss in one site. may differ from the adjacent site. This difference is probably due to the varying number ofeccrine glands at the different test sites. It is advisable, therefore, to use at least ten control readings for each subject and the results averaged. From these data one can calculate more accurately the percentage difference in moisture loss of the adjacent sites. Calibrating TABLE 2--AVERAGE MOISTURE Loss FROM ADJACENT SITES OF THE INNER PORTION OF TI-IE FOREARM Number of Average Moisture Loss, mg.* Subject Readings Upper Arm Lower Arm Do, %t CK 17 11.0 12.9 18 GB 10 22.5 28.0 25 CF 20 16.6 19.4 17 FM 17 13.3 16.8 26 LF 10 11.0 12.9 17 * Moisture loss is the milligrams of water vapor picked up by the desiccator in a two hour period. •' Dc is the percentage difference of the lower reading compared to the upper reading. L--U D,- X 100 U

114 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS data obtained with the five subjects involved in this test series are shown in Table 2. These values represent the average of 10 to 20 readings, as indicated. It is interesting to note that the lower test site (farthest from elbow) consistently gave the higher readings. T.•Bx.E 3--MoIsTUV. E Loss fRoM Ar)J.•CE•T SITES OF THE I•ER PORTIO• or ThE FORE.•RM (SUBJECT CK), I• .• Two-Hour. TEST PERIOr) Moisture Loss, mg. Upper Lower Date Time R.H. T., øC. Arm Arm Do, %* 6/9 a.m. 55 30 9.2 6/6 p.m. 52 24 11.9 6/10 p.m. 68 26 8.9 6/11 a.m. 65 27 6.9 6/12 p.m. 60 25 8.0 6/17 a.m. 55 24 6.3 6/19 p.m. 57 23 8.9 6/24 p.m. 58 23 10.7 6/26 p.m. 59 26.5 15.4 7/7 a.m. 55 26 11.8 7/8 p.m. 60 25 25.5 7/9 , a.m. 62 24 7.7 7/14 p.m. 69 22 14.1 7/16 p.m. 69 22 12.6 7/17 a.m. 65 22 8.5 7/21 p.m. 62 22 11.5 7/23 a.m. 68 21 9.1 9.7 5.4 12.3 3.4 10.6 19 1 8.5 23 2 8.8 10 0 8.8 39 7 13.0 46 0 13.5 26 2 16.4 6 5 14.4 22 0 33.0 29.4 9.4 22.1 14.1 0 17.3 37.3 9.5 10.8 11.7 1.7 9.4 3.2 AT. Do = 18.0 * Dc = Percentage difference in moisture loss between the L-U D•- X 100 U upper and lower sites. In Table 3 data are shown for the individual readings obtained with a representative subject. Twenty-one cosmetic creams and lotions manufactured by leading companies were then tested for their ability to retard the moisture loss from the skin. A three-quarter gram portion of the test cream or lotion was rubbed into the lower, inner portion of the forearm. The test product was allowed to dry on the skin for fifteen minutes at room temperature and the application repeated followed by a thirty minute drying period. A desiccator was then placed over the test site and a control desiccator was placed directly above and adjacent to it on the untreated portion of the arm. Moisture pick-up readings were taken after the desiccators had been in place for two hours. Ten determinations were made for each product. By calculating the percentage difference in moisture loss between the treated and untreated areas and applying the calibration factor for the subject involved, one can calculate the effect of the test product on moisture loss. The results obtained are presented in Table 4.