288 JOURNAL OF COSMETIC SCIENCE Studies of Diethyl Phthalate on In Vitro Percutaneous Permeation* Hiroshi Tokunaga, Yourison Chung, Tadashi Uchino, Masanori Ando National Institute of Health Sciences** Since diethyl phthalate (DEP) is imagined as a kind of the endocrine disruptors in cosmetics, the permeation of this substance through the guinea-pig abdominal skin was investigated. After mounting the skin onto the Franz-type diffusion cell, added 10ram sodium dodecyl sulfate (SDS), 10ram benzalkonium chloride (BK) and 0.55% polyoxyethylene (10)oleyl ether (POE.OE) solution in the donor side and stood for 2h at 32. After eliminating the surfactant's solution from the donor side, put 0.05% DEP into the donor side. During 16--24h at 32'C, the amount of DEP permeated to the receptor side were determined by HPLC. HPLC conditions were on the column of Unisil Q C18 (4.6ram i.d. x150mm), the mixture of water and acetonitrile (1:1) as the mobile phase and the spectrophotometer at 255nm. When the skins were treated with SDS, BK or POE.OE, the each flux of DPE was 190, 174 or 110% against the flux of control. The results suggest that any applied surfactants would give the damage to the stratumcomeum of skin. In the case of the treatment of the skin with the mixture of DEP and SDS, BK or POE.OE, the flux of DEP showed 82.0, 105.7 or 99.5% against the flux of control. On the presence of SDS in DEP, the flux of DEP decreased against the flux of control. The cumulative amount of DEP at 24h through the skin was 21 .Sgg/cm2. Application of Malic Acid Monolaurylamide for New Skin Cleansing Agent* 1 Keiiehi Nagai*2, Tomoko Yasumasu*2, Masaru Tamura*3, Akinori Igarashi*4, Masahiko Fujiyama*2, Tetsuo Kobayashi*5 Beauty-Care Research Laboratories *2, Material Science Research Center *3, Analytical Research Center*4, Process Development Research Center*5, Research & Development Headquarters, LION Corporation We studied the application of malic acid monolaurylamide (MAA) for a new skin care cleansing agent. MAA neutralized by potassium hydroxide (MAAK) showed an excellent fresh feeling after washing the skin because of quick Ca-salt formation while rinsing out. The order of the skin tightness after washing was potassium lauratesodium polyoxyethylene lauryl ether sulfate ( 3E.O. ) potassium lauroylglutamate potassium N - !auroyl - N- methyl --{t-alaninate MAAK. The amounts of MAAK residue on the surface and in the deeper portion of the skin were found to be almost 1/10 of those of potassium laurate. In addition, MAAK had selective cleaning ability and showed to minimize the release of the Natural Moisturizing Factor from the skin compared to potassium laurate. The characteristics of MAAK are also significant in mixed surfactant systems. For example, fresh feeling in rinsing out process was maintained even though MAAK was mixed with another surfactant, which has a slimy feeling, such as lauryl dimethylaminoacetic acid betainc. Also, when MAAK was added to potassium laurate, potassium laurate residue on the skin was decreased and the skin tightness became low after washing. Therefore, MAAK is concluded to be a very valuable suffactant for the skin washing agent. An Innovative Method to Measure Skin Pigmentation* 1 Yuji Masuda*2, Motoji Takahashi*2, Tetsuo Sakamoto*2, Miho Shimada*3, Masahide Itoh*4, Toyonobu Yatagai*4 Research Center, Shiseido Co., Ltd.*2, Toi•yo Institute of Psychiatry*3, Institute of Applied Physics, University of Tsukuba*4 It is crucial to develop accurate measuring method for skin pigmentation in preparation of effective whitening agents or cosmetics. We developed a system, it is called REMO-STA1N system, by which we were able to measure the stain at any part and in any area of face. However, this system was slightly influenced by pimples and redness of face because stains were selected using the color difference (AE) between stain and around normal areas. We have developed the method to calculate the concentration of melanin and hemoglobin from skin reflection spectrum using multiple regression analysis, assuming that Lambert- Beer's law is applicable to skin reflection spec•xum among 500--700nm and that the absorption spectra of skin is expressed as linear summation of melanin in epidermis, hemoglobin in vessel blood and absorption in dermis. We applied this method to REMO-STA1N system to develop a new system to estimate skin pigmentation quantitatively without influence of pimples and reddish face. This new REMO-STAIN system can measure the melanin and hemoglobin contents at each pixel in CCD images of the face and calculate the area of pigmentation in the facial skin. So, new REMO-STAIN system seems to be very useful in the efficacy test of alepigmentation products. Influence of Hydration for Optical Properties of Stratum Comeurn* Masahiko Ooe, Keiko Tanida, Tatsuo Yamamura Shiga Research Laboratories, NOEVIR Co. Ltd.** Transparent skin is demanded as the ideal skin condition by the majority of women. Therefore to analyze its characters in scientific aspects is an important study for the development of cosmetics. The recognition survey for skin transparency withdrew that water holding into stratum comeurn was a critical parameter. Therefore, to clarify whether the skin

ABSTRACTS 289 transparency referred by women is related to the decreased. Furthermore, women who had a higher transmittance of stratum comeurn or the water value of water contents or claimed higher transparency contents, the relationship between the transmittance of themselves showed to increase the reflection on skin stratum corncure and water contents were examined by surface under excess hydrated conditions. From these using the peeled human stratumeomeum in vivo. The findings, it was speculated that the skin transparency adequate hydrations in the stratum comeurn (until 38% claimed by women was caused by the transmittance of H20 per SC weight) exhibited gradually to increase the stratum comeurn. In this study, we proposed one the transmission, however, excess hydration conversely possible factor for the skin transparency.