JOURNAL OF COSMETIC SCIENCE 48 R&D Department, POLA Chemical Industries, Inc.**, Japan Synchrotron Radiation Research Institute***** 27-1, Takashimadai, Kanagawa-ku, Yokohama 221-0833, Japan*** 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679- 5198 Japan We investigated the use of Surface Free Energy (SFE) measurements, describing coherence between surfaces of two solids, in evaluation of affi nity between skin surface and foundation, a possible predictor of makeup longevity. We found that the gp values of skin varied signifi cantly among subjects. After discovering that the SFE values of most available conventional foundation products were very different from that of skin, specially formulated experimental foundations with SFE values close to that of the skin surface were prepared using conventional powder ingredients and novel powder ingredients coated with polyethylene glycol. In our usage tests, the SFE-controlled foundations demonstrated superior performance to that of conventional foundations and most of subjects preferred the SFE-controlled foundations. Examination with a digital microscope revealed that SFE-controlled foundations adhered evenly all over the skin surface, while conventional foundations tended to localize on the skin surface, offering support to the usage test result. Key words : surface free energy, contact angle, adherability, skin properties, surface treatment, makeup foundation Development of Longwearing Lipstick Using Inorganic- organic Hybrid Aggregate *1 Yu Baba* 2, Hiroshi Kawamukai* 3, Yoshiaki Matsui* 3, Tadashi Igarashi * 3, Fumihiko Nakamura * 4, Masashi Shibata * 2, 5 Beauty Cosmetic Research Laboratory * 2, Materials Development Research Laboratory * 3, Analytical Science Research Laboratory * 4, Kao Corporation, School of Bioscience and Biotechnology, Tokyo University of Technology * 5 * 2 2-1-3, Bunka, Sumida-ku, Tokyo 131-8501, Japan * 3, 4 1334, Minato, Wakayama 640-8508, Japan * 5 1404-1, Katakura-cho, Hachioji 192-0982, Japan As a popular method for longwearing lipsticks, self-organizing polymers (e.g. glyceryl ether modifi ed dimethicone (GE)), which can form a gel with a small amount of water are used. However, these polymers have the defect that they tend to inhibit the dispersibility of pigments, especially in a lipstick containing a large amount of liquid isoparaffi n that has high moisturizing properties. In this study, the compatibility of the longwearing property and the high dispersibility of pigments in isoparaffi n-rich lipstick has been investigated. The introduction of alkyl chain moieties to the GE structure markedly improved the pigment dispersibility. However, random copolymerization type structure inhibited the longwearing properties. On the other hand, the introduction of an alkyl chain to the both ends of GE did not affect the longwearing properties. For further improvement of the pigment dispersibility, fi ne silica particles were investigated as a dispersant. The compatibility of longwearing properties and good dispersibility of pigments was achieved with silica particles. TEM observation and 1H-NMR measurement revealed that GE was absorbed on silica particles and the silica formed a network in the lipstick composition. We assume that this organic-inorganic hybrid aggregate has no adverse effect on the properties of pigments in the lipstick, hence no fl occulation of pigments occurs. Establishment of Ex Vivo Stratum Corneum Lipid Ordering Analysis by Electron Spin Resonance *1 Eiichiro Yagi *2, Kouichi Nakagawa *3, Kazutami Sakamoto *4 Shiseido Research Center *2, RI Research Center, Fukushima Medical University *3, Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science *4 *2 2-2-1, Hayabuchi, Tsuzuki-ku, Yokohama 224-8558, Japan *3 1, Hikarigaoka, Fukushima 960-1247, Japan *4 2641, Yamazaki, Noda 278-8510, Japan Electron spin resonance (ESR) spectra have been used for studying stratum corneum (SC) lipid ordering. Order parameter S obtained from ESR spectra is a good index for evaluating the fl uidity of SC lipids in vitro. However, the method for evaluation of ex vivo SC lipids has not been established. A glass plate using a cyanoacrylate resin was used to strip the SC lipids. A single-chain aliphatic spin probe, 5-Doxylstearic acid (5-DSA), was used. The SC samples were incubated in the 0.001% 5-DSA in a 0.1% ethanolic aqueous solution for 60 min at 37°C. After the incubation, the excess spin probe was removed with distilled water, and then an ESR glass holder with the incubated SC sample was mounted in the ESR cavity. The newly designed ESR glass holder improved accuracy and reproducibility of sample preparations as well as ESR measurements. In conclusion, we have optimized the preparation method of ex vivo SC specimen and established accurate ex vivo ESR analyses of SC lipid ordering.

J. Cosmet. Sci., 60, 49–50 (January/February 2009) 49 Water, water everywhere…? Paul J. Matts Research Fellow, The Procter & Gamble Company, Rusham Park Technical Centre, Egham, Surrey, UK Visiting Professor, School of Pharmacy, University of London, UK Life on earth would not be possible without skin, meaning that it must have unique properties that allow us to exist here. These properties are discussed in this short review, in particular, the physical and chemical barrier characteristics of the stratum corneum, which we now know are only possible due to the presence of water at precise and carefully controlled levels and locations. The review discusses the pivotal role water plays in both stratum corneum mechanics/integrity and stratum corneum regulation/maturation and reinforces the critical role played by cosmetic products, which »moisturize« and augment stratum corneum barrier function. Paper presented as a keynote lecturw at the IFSCC Conference 2007, Amsterdam, The Netherlands Detection and Identifi cation of Free Radicals Generated by UV and Visible Light in Ex Vivo Human Skin Leonhard Zastrow1, Norbert Groth2, Frank Klein2, Dieter Kockott3, Jürgen Lademann4, and Louis Ferrero1 1 Coty/Lancaster SAM, International R&D Center, 2 rue de la Lüjernetta, 98000 Monaco, Monaco 2 Privatinstitut Galenus GmbH, Volmerstrasse 7a, 12489 Berlin Germany 3 UV- Technik, Vogelsbergstrasse 27, 63456 Hanau, Germany 4 Charité-Universitätsmedizin, Department of Dermatology, Center of Experimental and Applied Cutaneous Physiology, Schumannstr. 20/21, 10098 Berlin, Germany Contrary to the skin biological end points used for determination of the sun protection factor and UVA protection factor, generation of excess free radicals in skin - mainly reactive oxygen species - is potentially the source of much skin damage and so represents a more general biophysical answer to the effects of sun exposure of different wavelengths. By applying electron spin resonance spectroscopy to human skin biopsies, we determined in previous work a free radical action spectrum covering the ultraviolet and visible light range. Convolution of the action spectrum with sunlight spectral irradiance (280nm-700nm) showed the importance of visible light in free radical generation. This unexpected fi nding led us to perform further investigations. Firstly, an existing sun simulator was modifi ed so that its output truly mimics the sun’s full spectrum, including visible light. Human skin biopsies were irradiated either by this device or a conventional UV source, confi rming our previous calculations: half of the free radicals are generated in the 400-700nm visible wavelength range. Secondly, the visible spectrum of the modifi ed sun simulator was divided into narrow-band lights using different pairs of short- and long- pass fi lters. Human skin biopsies impregnated with specifi c spin traps were exposed to the different narrow-band lights in order to identify different types of free radicals. Generation of dangerous radical species like • O2-, • OH and • CH-R was observed in different parts of the visible range, confi rming the relevance of the free radical action spectrum and its ability to predict skin protection. Abstracts IFSCC Magazine Vol. 11, No. 3, 2008* * These abstracts appear as they were originally published. They have not been edited by the Journal of Cosmetic Science.