2006 ANNUAL SCIENTIFIC MEETING 205 THE USE OF 1,2-ALKANEDJOLS IN PERSONAL CARE FORMULATIONS Steve Schnittger1 and Joachim Roeding2 1 Estee Lauder Companies 2 Symrise Objective: 1,2-Alkanediols are good moisturizers and skin/hair conditioners. Besides, they are increasingly being used in cosmetic formulations because of their anti-microbial properties to help reduce preservatives. The anti-microbial activity of a material in a formulation, especially an emulsion, depends to a great extent on whether the material is present in the water phase. This paper investigates the influence of solubility and distribution of l ,2-A1kanediols and their mixtures in cosmetic formulations on preservative efficacy. Methods: It has been reported that the minimum inhibitory concentrations (MICs) of a 1: 1 mixture of 1,2-Hexanediol/1,2-Octanediol against microbes like E. coli, P. aeruginosa, S. aureus, C. albicans and A. niger are equal to or even better than that of 1,2-Octanediol, though the MICs of 1,2-Hexanediol are much lower than that of 1,2-Octanediol. In our first study we evaluated the distribution ratio of 1,2-Hexanediol, 1,2-Octanediol and their 1: 1 mixture between water and oil phases. For that purpose we made 1: 1 mixtures of paraffin oil-water and added 1 % each of the individual diols or their mixture. The water and oil phases were mixed, then separated and the concentration of the diols in the water phase was analyzed by reverse phase HPLC and refractive index detection. In the second study we investigated if having the 1,2-Alkanediols in the water phase of an emulsion has an effect on the anti-microbial efficacy of the diols. Three oil-in-water emulsions were prepared by using the same formulation containing 0.3% of a 1: 1 mixture of the two 1,2- Alkanediols and with no preservatives the only difference between the emulsions was the order of addition of the dial mixture- one was made by adding the dial mixture to the water phase, the other was made by adding it to the oil phase and the third was made by adding it after the emulsion was formed. All the three emulsions were then tested as per standard preservative challenge protocol. The test was repeated with emulsions containing 0.5% of the diol mixture. Results and Discussion: The results of our first study indicated that using a 1: 1 mixture of the 1,2-Alkanediols results in a higher concentration of the diols in the water phase of an emulsion compared to using 1,2-Octanediol alone. The preservative challenge tests with three different emulsions showed that the formulation in which the diol mixture was added after the emulsion was formed, has a faster rate of kill. We believe that the addition of the diols to an oil-in-water emulsion after the emulsion was formed helped keep the diols in the external water phase, thereby providing more anti-microbial efficacy. Adding the diols in the water phase did not help as some of the material would have got emulsified during the subsequent emulsification step. Conclusion: The antimicrobial efficacy of 1,2-Alkanediols in formulations is greatly determined by their availability in the water phase. We have showed that it is advisable to have the diols in the water phase of formulations for getting better anti-microbial efficacy from the diols. While making oil-in-water emulsions this is achieved this by adding the diols after the emulsion is formed. These observations greatly help cosmetic chemists to make formulations with better stability against microbial contaminations.

206 JOURNAL OF COSMETIC SCIENCE THE INFLUENCE OF FACIAL EXPRESSION ON THE AGE-DEPENDENT CHANGES IN f ACIAL WRINKLING Kukizo Miyamoto, Ph.D. and Greg Hillebrand, Ph.D. Procter & Gamble Introduction Facial expression helps define who we are. Happy, sad, angry, pensive - these emotions are manifested in the unique facial wrinkle patterns that help us communicate with one another. While skin color, evenness and hyperpigmentation are for the most part static and independent of facial expression, facial wrinkling is a dynamic skin appearance feature exhibiting a large range of variation depending on the particular facial expression. Years and decades of repeated skin folding from everyday facial expressions eventually lead to the character lines and wrinkles that persist in the absence of expression. These include transverse forehead wrinkles, glabellar frown lines and periorbital or crow's feet wrinkles around the eyes. It is generally believed that environmental stress, especially chronic sun exposure, can accelerate this process of persistent wrinkle formation. We were curious about how facial expression influences the age dependence of facial wrinkling and the impact expression might have on how we assess wrinkling clinically. Indeed, the traditional methods for quantifying clinical facial wrinkling have been to use subjective visual grading or objective 2D and 3D measurements of study subjects without any facial expression. At the time we were starting this work, we were conducting large base size cross-sectional surveys on the skin condition in different ethnic populations around the world1 . So as part of those studies, we began collecting images of subjects under both smiling and non-smiling facial expression conditions. A smiling expression was chosen because it accentuates the crow's feet wrinkles around the eyes, an area of particular concern for many people. In this paper we present results of those cross-sectional surveys as well as results of a randomized-controlled clinical trial to evaluate the product performance benefits of a facial moisturizer designed to lessen the appearance of the facial wrinkling that accompanies facial expression. Methods Facial wrinkling was quantified under both smiling and non-smiling facial expression conditions using a facial imaging booth consisting of a high resolution digital camera combined with standardized illumination and fixed head positioning. (VISIA Complexion Analysis System, Canfield Scientific, Inc.). Subjects were prepared for image capture using standard procedures for face wash, equilibration (20 minutes) and use of matt black head and shoulder apparel. VISIA image analysis (IA) software was employed to objectively quantify facial features (wrinkling, texture, pores and hyperpigmented spots) on the left and/or right sides of the face. The same exact area of the face was analyzed for both smiling and non-smiling images and the image analysis overlays were reviewed to confirm the accuracy of skin feature detection. When left and right image views were captured, the average IA value for the left and right measurements was used. For some experiments, measurement error associated with reproducibility of facial expression was further reduced by capturing 3 or more images of the subject in a non-smiling and smiling expression and then calculating the average IA value from each of the images. Results and Discussion Facial wrinkling and hyperpigmentati.on were measured in 147 Japanese women ages 30-55 living in and around Tokyo, Japan. Images of the face (left and right sides) were captured with and without a smiling expression. The graphs below show that both wrinkling and hyperpigmentati.on increased with increasing age. The lines are the best fit curves for the smiling and non­ smiling data. As expected, smiling greatly increased the amount of facial wrinkling but had no affect on hyperpigmentation. Wrinkling Hyperpigmentation 0.14 0.10 C 0.12 Non-Smiling Non-Smiling 0 Smiling C 0.08 Smiling :g 0 0.10 oO :g u: � 0.06 ro 0.08 0 0 u. 0 0 �- � � 0 ro oO �- 0 00 0 �oglio oe ( 0.06 O 0 � 0 go Q) 00 ( 0.04 0 .o oo o Oo �s o �e� 32 0.04 0 oo 0 0 C 00 � . ft 0.02 oe oe 0.02 .. 0.00 0.00 30 40 50 60 30 40 50 60 Age AQe