308 JOURNAL OF COSMETIC SCIENCE Development of Long - Wearing Lipstick Using Self - Organizing Color Fix Polymers Masashi Shibata, Kazuhiko Nojima, Koji Yoshino, Momoko Shimizu, Hitoshi Hosokawa, Toshiyuki Suzuki Skin - Care Products Lab., Kao Corporation A novel long - lasting lipstick has been developed using self-organizing silicone polymers. The polymer we adopted is polyoxyethylene modified organopolysiloxane (EOS). It is in a liquid state and soluble in common cosmetic oils under water-free conditions it forms a gel - like film with a small amount of water that exists on the surface of the lips. This film is soft, flexible and yet tough enough to stay on the lip, holding the oils and pigments of the lipstick. The lipstick containing EOS exhibits excellent long - lasting properties however, it tends to detach from the lip when oily or greasy food is eaten. To avoid this defect, another silicone polymer, alkylglyceryl ether modified organopolysiloxzane (GES), is admixed with EOS. GES is soluble to EOS and helps the EOS gel to stably adhere to the surface of the lip. The lipstick containing the mixture of EOS and GES provides beautiful make-up appearance for a prolonged period of time even after an oily or greasy meal, and the color does not come off onto tableware such as coffee cups. Furthermore, unlike conventional lipstick containing a volatile oil, it provides a glossy application and a moist feeling. Cross - Linking Structure and Mechanical Properties of Wool and Hair Kozo Arai Textile Research Institute of Gunma Hair and wool fibers have a complex hierarchial structure composed of cuticle, cortex and cell membrane complex and their substructures. Mechanical properties such as elasticity, pliability and durability are governed by the interactions of proteins in the cortex. The cortex is a complicated, disulfide (SS) cross - linked polymer system comprising the crystalline low - sulfur (LS) proteins and the globular matrix of high - sulfur (HS) proteins. The LS and HS proteins are the so - called intermediate filament (Ifs) and the intermediate filament associated proteins (IF APs). The bending set is important in the cosmetic process for human hairs. There are two different models for the mechanism of bending set, which have been argued for many years. On the one hand, the stress - strain relationship was explained in terms of the molecular structure of Ifs. On the other hand, it was proposed that the IF APs play a major role at high strain level. The cuticle contributes very little to the stress - strain relationship, but it is uncertain whether it does to bending behavior. It is not clear which is the more appropriate model because the current knowledge does not provide sufficient information such as the molecular conformation and the location of the end regions oflfs, the structural sites of SH/SS interchange reaction, and either the number or type of SS cross - linkages in the microstructures. Recent advances in research on SS cross - links in hair and wool keratin are significant. The distribution of SS cross - links both within and between the Ifs and IF APs has been analyzed by using the relationship between the equilibrium force and the strain of the swollen fiber provided under specific conditions. Our understanding of the mechanical properties of wool and hair would be promoted if detailed information on cross - links were to be presented. In this review, the mechanical behavior of keratin fiber is discussed on the basis of the chemistry of thiol and disulfide. Possibility of Antiseptic Formula Employing Pionin Combination with 1,2 - Pentanediol in the Cosmetic Field Noriko Mori, Y oshihito Fujinami, Hiroshi Hara, Keiji Oguma, Yoshinori Nakagawa, Masaaki Hayami Hayashibara Biochemical Laboratories, Inc. Department of Bacteriology, Okayama University Graduate School of Medicine and Dentistry It has been reported that parabene, the most frequently used antiseptic in the cosmetic field, has adverse effects. We have evaluated bacteriologically whether Pionin could be used in place of parabene as an antiseptic agent. When Pionin was added to various commercially available cosmetics, if exerted potential antimicrobial activity. In a lotion, Pionin in combination with 1,2 - pentanediol exceeded parabene in the antimicrobial activity. Furthermore, a cream containing Pionin and 1,2 - pentanediol fulfilled the requirements of antiseptics in The Japanese Pharmacopeia (14th edition) adequately. When the cream was applied to brachial arm skin of healthy men and women at 24 h intervals for 7 days, the total aerobic and anaerobic bacterial numbers of skin micro - flora were not significantly different from those of control (without cream - application). Therefore, Pionin together with 1,2 - pentanediol might be a novel antiseptic formula in cosmetics having less bactericidal activity to skin micro-flora. Palo Azul Prevents Dryness - Induced Decrease in Filaggrin and Amino Acids Hiroshi Fjuita, Chika Katagiri, Naomi Ooat, Genji Wada, Masahiro Oota, Tetsuji Hirao Life Science Research Center, Safety & Analytical Research Center Material Science Research Center, Shiseido Co., Ltd. Natural moisturizing factor (NMF), which is mainly composed of free amino acids and their derivatives, aids the retention of water in the stratum comeum (SC), preventing skin dryness caused by various

ABSTRACTS 309 environmental stimuli. Low levels of amino acids have been reported to be associated with a low hydration state in the SC of dry skin, but the mechanism underlying the decrease in amino acids is not well understood. The protein filaggrin is the major source of amino acids in the SC. We exposed cultured human keratinocytes to air by removing their medium and recognized a decrease in mRNA and protein expression of profilaggrin, a precursor of filaggrin. We employed the result to search for active ingredients to prevent the decrease and discovered that the extract of a Mexican plant, Palo Azul, effectively prevented the decrease in profilaggrin mRNA. We also confirmed that lotion containing the extract increased the hydration state and amino acid content in the SC of humans SDS - induced dry skin. These findings suggest that air exposure of cultured human keratinocytes might be a useful model of human dry skin, and could be used for screening active ingredients to treat dry skin. In addition, it appears that dryness itself might lower profilaggrin mRNA expression, resulting in a decrease in amino acid content in the SC.