2.5 - 2.0 � :I 1.5 0 &&J .. en � +t _§ C IIJ II 1.0 Cl) • m E 0.5 0.0 DRY SKIN BENEFIT FROM IN-SHOWER BODY LOTION 259 P= 0.95 P= 0.89 -- - - - I•• - I•• 1 Hour 3 Hours Time After Treatment P= 0.18 - I•• - 6 Hours E � e .5 Cl) � � CJ c::::J 5 minutes 10 minu es - 15minutes Figure 3. Results from a single application study examining the effect of skin wetting time on visual dry skin improvement from an in-shower body lotion. Wet time did not significantly affect the dry skin benefit. had no significant effect on the in-shower body lotion's effect on stratum corneum hydration (p 0.13, data not shown). In-shower body lotion residence time and rinse time. A factorial study was conducted to examine the effect of residence and rinse times on the in-shower body lotion's potential to improve dry skin. Residence/rinse time combinations of 40 sec/10 sec, 40 sec/30 sec, 90 sec/10 sec, and 90 sec/30 sec were tested to cover the ranges identified in the in-shower body lotion habits and practices study. Skin condition was evaluated at baseline and three hours after the fifth treatment application. After five days neither residence time nor rinse time showed an impact (p 0.57) on the product's potential to improve d ry skin (Figure 4), or on its potential to improve stratum corneum hydration (p 0.17, data not shown). Petrolatum is the primary benefit agent in the in-shower body lotions tested, and the amount of petrolatum deposited on the skin during product use and remaining on the skin after rinsing is a key determinant of dry skin improvement efficacy. The results from this study indicate that that the amount of time the in-shower body lotion remains on the skin has a limited role in the benefit agent deposition process. This outcome is consistent with our experience with certain other rinse-off technologies that deliver petrolatum as a benefit agent, such as body washes. The apparent lack of an effect due to extended rinsing is not surprising for a hydrophobic benefit agent such as petrolatum the material tends to remain on the skin once deposited. DISCUSSION The studies conducted during protocol development show that the petrolatum­ depositing in-shower body lotion technology is robust in terms of its ability to provide dry skin benefits over a range of conditions that is relevant to how consumers shower and use an in-shower body lotion product. The final choice of protocol parameter values was driven by the need to maximize efficiency under clinical test conditions. Thus, the final

260 JOURNAL OF COSMETIC SCIENCE 2.0 C E 1.5 T T T 1 1 1 E :e -W U) U) U) +I 1.0 CD C C ca � a, CE C ·o 0.5 Q. "C C w 0.0 40 sec Residence 40 sec Residence 10 sec Rinse 30 sec Rinse 90 sec Residence 10 sec Rinse 90 sec Residence 30 sec Rinse Residence and Rinse Time Combinations Figure 4. Endpoint expert dryness evaluation (three hours after the fifth application) results from a study examining the effect of skin residence and skin rinsing times on dry skin improvement from an in-shower body lotion. A factorial analysis shows that neither factor has a significant effect on the observed dry skin improvement benefit (p 0.57). application procedure for testing the dry skin improvement potential of an in-shower body lotion is: • Subjects are recruited and their legs are washed with a non-moisturizing cleanser following a published procedure (12). • Wetting is continued for five minutes after rinsing the cleanser. • In-shower body lotion is applied at a dose of 1 µl/cm2 and rubbed on the skin for 20 seconds. • The in-shower body lotion remains on the skin for 40 seconds. • The skin is rinsed for 30 seconds and patted d ry . As noted earlier, two versions of in-shower body lotion were developed that deposit different amounts of petrolatum on the skin and deliver different levels of moisturization benefit. One important question is whether the protocol will discriminate among in­ shower body lotion products that are known to be different. A study was conducted to compare the two in-shower body lotion products and the control. The results, which are summarized in Figure 5, show that the protocol discriminates the in-shower body lotion products from each other and from the control, demonstrating the protocol's ability to show this product form's potential to provide a d ry skin benefit and to distinguish products formulated to provide different levels of dry skin benefit. A second important question is whether the protocol yields reproducible results. To test this, the same in-shower body lotion product was placed in studies conducted approxi­ mately one month apart. The results from this study, expressed relative to the control to account for changes in absolute scores, are summarized in Figure 6. These studies demonstrate the protocol's ability to reproducibly predict dry skin improvement po­ tential for an in-shower body lotion upon product retest.