318 JOURNAL OF COSMETIC SCIENCE Selective Adsorption of Fatty Acids for the Prevention of Foundation Makeup Deterioration* Koichi Nomura** ,Yutaka Takasuka'• Hirochika Nishimura", Katsuhiro Motoyoshi**,nShoji Yamanaka*** Products R&D Laboratories, POLA Chemical Industries, Inc.**, Faculty of Engineering, Hiroshima University*** L•Deterioration of applied makeup remains a serious concern for the busy modern woman, but little research has been published on this topic. Currently available "long-lasting" makeups do not perform satisfactorily, and a different approach is needed. Many forms of makeup film deterioration exist our international survey of makeup users identified shiny spot formation following foundation application to be the problem most frequently complained of. Our goal was to identify those factors responsible for optical degradation and develop an effective means of countering this phenomenon. Our research confirmed that the secretion of sebum plays a key role in shiny spot tbrmation. We studied the components of sebum causing optical degradation, and identified particular unsaturated free fatty acid (FA) as the main culprits. By lowering the melting point of sebum, unsaturated tYee FA caused wetting of the makeup substrate, altering its optical properties, leading to the formation of shiny spots. Understanding of the basic cause of optical degradation of the makeup film enabled us to design a new compound which can selectively adsorb specific FA. By chemically modifying the structure of certain clay minerals, we developed unique interlayered compounds having precisely controlled spacing of the silicate layers of the clay and selective adsorption properties. One compound we developed consists of zinc oxide precursor loaded in alumina pillar interlayered clay (ZA-pilc). In vitro and in vivo testing on powder foundations incorporating ZA-pilc proved that the compound was remarkably effective in suppressing optical degradation, prolonging the life time of makeup in actual usage conditions. Besides preventing optical degradation of makeup film, incorporation of ZA-pilc in cosmetic formulations may offer an additional benefit of reducing acne formation through selective adsorption of FA. Our experimental results indicate that ZA-pilc suppresses comedo formation in the ear of rabbits, suggesting the possibility of application in anti-acne preparations. LJKey words: questionnaire, deterioration, sebum, shininess, gloss meter, foundation, composition, fatty acid, makeup, montmorillonite, clay[] Effects of Long-Term UVA Exposure of Human Skin Fibroblasts on Cell Growth and Extracellular Matrix Formation* Munehiro Iketani, Yukiko Matsunaga, Toshio Nishiyama, Minorn Fukuda, Tasuku Takamatsu Skin Biology Research Laboratories, Life Science Research Center, Shiseido Co., Ltd. ** []Repeated exposures to sunlight cause sagging skin or deep wrinkles. These morphological changes, called photoaging, depend on the characteristics of dermal extracellular matrices (ECM), of which type I collagen is a major component. We studied cell growth and ECM tbrmation of human skin fibroblasts under long-term UVA exposure. Secretion of type I procollagen was almost the same as that of the control, while cell growth and ECM formation were greatly inhibited. Reactive oxygen scavengers did not affect this inhibition. The effect of UVA was reproduced when the cells were cultured in UVA-irradiated medium, even though they were not exposed directly to UVA. The growth arrest was not seen when fresh fetal bovine serum was added to the UVA-irradiated medium. These results suggest that the inhibition of cell growth and ECM formation induced by long-term UVA exposure is due to denaturation of growth factors and/or chemokinetic factors rather than to direct cytotoxicity of reactive oxygen. NKey words : photoaging, UVA, fibroblast, extracellular matrix (ECM), cell growth, collagen, C-terminal peptide, reactive oxigen scavenger, FBS, growth factor, chemokinetic factor Liposomal Linoleic Acid Is Useful as a Skin Lightening Agent* Hiromichi Imanaka, Hideya Ando, Atsuko Ryu, Yasutami Shigeta, Satomi Kishida, Ayako Mori, Taketoshi Makino Central Research Institute, SUNSTAR Inc. ** LJLinoleic acid, one of the essential fatty acids, has a remarkable inhibitory efibct on melanin synthesis by cultured melanoma cells. The activity of tyrosinase, an enzyme critical to melanin synthesis, was inhibited by linoleic acid but the level of tyrosinase mRNA was not affected, indicating that linoleic acid regulation ofmelanogenesis was due to post-transcriptional events. The inhibitory mechanism of linoleic acid was that it enhanced the proteolytic degradation of tyrosinase and led to a decrease in melanin production. In order to improve

ABSTRACTS 3 ! 9 the stability of linoleic acid, liposomes were employed, which occurred skin permeation and resulted in a substantial amount oflinoleic acid in the skin. Clinical trials with liposomal linoleic acid for skin hyperpigmentary disorders, such as melasma, showed hypopigmenting effects, suggesting that liposomal linoleic acid is useful as a skin lightening agent. I]Key words : liposome, linoleic acid, skin, fatty acid, melanin, melanoma, tyrosinase, melanogenesis, proteolytic degradation, permeation, clinical trial, melasma •lKey words : UVA-irradiation, foundations, squalene, oxidation, catalytic activity, inorganic powder, TBA [3 method, nude-mouse, cutaneous damages, titanium oxide The Relationship between Moisture Content of Human Fingernails a and the Mechanical Properties of the Fingernail* Tooru Sugawara, Mizue Kawai, Hitoshi Hosokawa, Toshiyuki Suzuki Cosmetic Research Laboratories, Kao Corporation** Evaluation of Foundations under the Influence of UVA Irradiation* Hirochika Nishimura, Tsutomu Kamata, Yuko Takeda, Katsuhiro Motoyoshi Products R&D Laboratories, POLA Chemical Industries, Inc. ** []It was found that the foundation exposed to ultraviolet rays could accelerate the oxidization of squalene, a sebum component. This fin. ding was based on the following experiment: 1)squalene and 2) squalene and foundation were applied individually on the human arm and exposed to sunlight for 1 h. Then, the levels ofoxidization of l) and 2) were compared by the TBA method. The result of this experiment led us to the above mentioned finding. Thus the oxidization level of the squalene exposed to ultraviolet rays was examined with regard to each powder component of the foundation in order to determine the causative factors involved. As a result, titanium oxide was identified as one of the factors. Hence, the powder component which has the titaniumi2oxide surface coated with silica was developed, thereby to make a prototype of foundation that will not allow•3the oxidization ofsqualene to be accelerated. The effect of this new foundation on the skin was compared with[that of the conventional foundation using the back of a hairless mouse. The result verified that the newly developed foundation surpassed the conventional product in terms of mitigating the scale and induration in an epithelial change on hand, and inflammatory cell infiltration in a dermal change on the other hand. This suggests that•3inhibiting the accelerated oxidization cased by the foundation exposed to ultraviolet rays can help mitigate theirE adverse effect on the skin as well. f•3 •31t is well known that nail damages such as yellowing, split nails and peeled nails (onychoschisis) are caused by continuous use of nail enamel for a long period. Within serious nail damages, we aimed at split nails and peeled nails and basically investigated the relationship between fingernail moisture content and the mechanical properties of fingernails to make clear the factors affecting those nail damages. As a result, we newly developed the bending tester to evaluate split nail and peeled nail and established the method of evaluation of those nail[•damages •. Moreover it is suggested that fingernails split easily under low fingernail moisture content and peel easily under high fingernail moisture content. []Key words : moisture content, fingernail, mechanical property, nail enamel, trouble, split nail, peeled nail, evaluation, bending test, SEM image Novel Deodorizing Method with Glycosidically Bound Volatiles* Takeshi Ikemoto, Bun-Ichi Okabe, Naohisa Yamamoto, Hiroko Nakatsugawa Cosmetics Laboratory, KANEBO Ltd.** 73Glycosidically bound volaties (GBVs) have been known as fragrance precursors in essential oil plants, but little attention has been paid to them as cosmetic ingredients. In this study, we investigated the possibility of GBVs as deodorant ingredients. After incubation of skin microflora with various kinds of GBVs, the amount of generated fragrance materials and remaining glycosides were analyzed with GC and HPLC. Thes• results showed that most of GBVs could be metabolized gradually by skinmicroflora to