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

320 JOURNAL OF COSMETIC SCIENCE release various fragrance materials. Further, in situ examinations were carried out. After applying the solution of each GBV on various regions of the body, such as scalp, foot and forearm, the generated fragrance materials were analyzed by using headspace technology. And we confirmed thatGBVs, particularly 13-D-glucoside derivatives, also gradually changed to fragrance materials on the skin. In conclusion, odorless GBVs possess an alternative effect of its unusal sustained-release deodorancy as deodorant ingredient on the skin. This approach, specifically studied for the deodorant ingredients, could be applied to improve the durability of the active ingredient for cosmetics. []Key words : glycosidically bound volatiles, fragrant precursor, deodorizing method, skin microflora, headspace analysis, eugenyl [3-D- glucoside, raspberry ketone[3-D-glucoside, phenylethyll•-D-glucoside, olfactory evaluation, deodorant efficacy The Relationship between Sensitive Skin and Stratum Corneum Morphology* Nobuo Kashibuchi**, Naoko Ota***, Masakazu ß ** . .. ** M•yazawa , Norlo Fuj•wara , Atsushi Kishita**,•Yoshikazu Hirai** Products R&D Laboratories**,•Safety & Analytical Research Center***, POLA Chemical Industries Inc. []"Sensitive skin" is an important problem in cosmetics research. Nowaday, there are still a few research studied in this field. To evaluate the sensitive skin, in self consciousness, we studied are as follows: 1) factors affecting on the conscious sensitive skin, 2) seasonal variation affecting on the skin sensitivity, 3) relationship between sensitivity of the skin and morphology of the stratum corneum obtained by tape-stripping method. As theEresults, it was suggested that 1) there are similar experience in the forming of the skin consciousness, 2) proportion of the conscious skin sensitivity is not changed within a year, but individuals are changed, 3) some orE the stratum corneum parameters correlated to the skin consciousness, projected surface area of the corneocyte[available for substantiate the skin sensitivity. Especially, the separation value of surface area which calculated[]from theoretical value is most useful in the parameters. Questionnaire and separation value of corneocyte's surface area are useful tools to evaluate the skin sensitivity. •]Key words: skin sensitivity, stratum corneum, corneocyte surface area, nucleated cell, tape- stripping, gentian[violet, brilliant green, thick abrasion, cellular arrangement, seasonal variation[] Vol. 33, No. 4, 1999 Development of Titanium Dioxide-Containing Silicone Polymer and Applications in Cosmetics* Ryuichi Inaba, Eiichi Saito, Toshiaki Kobayashi, Yoshio Fujiyama Nippon Shikizai, Inc.** •3Trimethylsiloxysilicate (TMS) is used in various types of cosmetics because it forms a protective film that is[highly water repellent, lubricating, and lasting. The authors tried to develop silicone polymers that contain titanium dioxide : (trimethylsiloxysilicate containing titanium dioxide TMST) to improve the optical properties of TMS. We prepared TMST by exploiting the sol-gel reaction to co-hydrolyze and polymerize silicone alkoxide Dand titanium (IV) alkoxide, while trimethylsilylating the intermediates. The TiO2 units in TMST were strongly bound to and homogeneously incorporated in the-=Si-O-Si- = network structure, rather than the simple[dispersion of particles of a fine titanium dioxide in TMS. The component units of TMST are [(CH•)DSiO•n]: [SiO2]:[TiO2](mol ratio 1.4: 1.2: 0.4). TMST is capable of forming film, which, although containing 9.0% titanium dioxide by weight, has good transparency because the titanium dioxide is highly dispersed and anchored. TMST retains the solubility of TMS, which has been a popular material for cosmetics, as well as the functional (transfer resistant and water repellent) film forming capabilities of TMS. In addition, TMST has the unique optical characteristics (higher refractive index and ultraviolet screening function) attributable to the titanium dioxide contained. These results demonstrated that TMST is very useful as a new functional film forming agent in cosmetics. •3Key words : silicone, silicone oils, silicones, silicone derivatives, titanium dioxide, polymers, metal alkoxides, hydrolysis, polymerization, soles, gels, film forming agents, solubility, transparency, adhesives, water resistance, sunscreens, lipsticks