360 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Comparison of Experimental Bar Soap Formulations for Skin Mildness Treatment code Experimental formulation Two week clinical skin grades Smoothness Redness Dryness Composite A. Synthetic (isethionate), 85T/15Cn soap, superfatted 1.70 c,E,G,H,J 1.22B-J 1.99 c-u'G-J 1.64 B. Synthetic (AGS), 60T/40Cn soap 2.35 c 1.94 2.44 2.24 C. Synthetic (AS, AGS), 80 T/20Cn soap 3.11 •)'v'H'l 2.46 2.74 2.77 D. All-tallow soap 2.27 2.13 2.61 2.34 E. 87T/13Cn soap 2.54 2.23 2.57 2.45 F. 87T/13Cn soap, superratted 2.21 2.12 2.37 2.23 G. 70T/30Cn soap 2.53 2.13 2.70 2.45 H. 70T/30Cn soap, superratted 2.39 2.05 2.64 2.36 I. 50T/50Cn soap 2.38 2.27 2.84 2.50 J. All-coconut soap 2.95 v 2.77 B,D,v-H 3.02 u'v 2.91 Superscript product codes indicate statistically significant differences between product grades at p • .05. (For example, the redness grade for experimental product J is statistically different from the redness grades for products B, D, F, G and H at p • .05). The study involved single product design with twenty-seven female subjects per product. Washing proce- dure consisted of a six-second lather work-up on a non-woven paper towel (Masslinn, Chicopee, NJ), ten-second application to the forearm, and a fifteen-second rinse. Subjects were washed four times daily, twice in the morning and twice in the afternoon, for five days, followed by two days without controlled washing, and then they were washed four times daily for an additional four days. Two-week clinical skin grades given in this table have been adjusted for initial condition by covariance analysis. EFFECTS OF CLIMATIC CONDITIONS Kligman et al. (1) stated that warm and humid weather conditions, prevalent during the summer months in much of the U.S., would nullify the possibility of discrimi- nating among soaps for mildness. Results described for Study ! were obtained from clinical testing in the dry climate of Tucson, Arizona, where the average dew point is less than 40øF for seven months of the year. The effect of dew point on the dryness grades produced by two bar soap formulations (an irritating control and a mild control) is illustrated in Figure !. The average dew points were quite low (!7øF. and !!øF.) for both weeks of this test (Study 2). The dryness grades for both products separated after one week, and continued to increase under the influence of drying conditions in the second week. In Study 3 (Figure 1), however, there was a large increase in the average weekly dew point between the first and second week. The dew point averaged !6øF. during the first week of the study, and increases in skin dryness grades were observed for both test products. In the second week of Study 3 the average dew point was 47øF. and there was no change in the irritating control group. There was an improvement (i.e., grade re- duction) in skin condition of the mild control group. We have found that when the dew point is greater than 40øF., it is more difficult to demonstrate differences between bar soaps. It is possible, however, to compensate for adverse climatic conditions by using a wash protocol in which the treatments are ap- plied four times each day (two times at each session) rather than twice. Figure 2 shows

FOREARM WASH TEST FOR MILDNESS 361 FIGURE 1: Study 2 DRYNESS GRADE 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Control Mild Control o 1 2 WEEK FIGURE 1: Study 3 3.0 2.5 2.0 1.5 1.0 0.5 Irrititating 0.0 DRYNESS GRADE 3.0 2.5 2.0 1.5 1.0 0.5 Control Mild Control 3.0 2.5 2.0 - 1.5 - 1.0 - 0.5 Irrititating o.o I I , I o.o o 1 2 WEEK Figure 1. Effect of dew point on the evaluation of skin condition. Dryness grades for two bar soap formu- lations (an irritating control and a mild control) are shown from Study 2, when the average dew point was 17øF in Week 1 and 1 IøF in Week 2. The same products were included in the design of Study 3, when the average dew point was 16øF in Week 1 and 47øF in Week 2.