ABSTRACTS 543 Juliana Palmeira Portugal Marques, Natura Inovai;:iio e Tecnologia de Produtos Ltda., Rodovia Anhanguera, km 30,5, Polvilho, Cajamar, SP, Brazil. Tel.: +55 (11) 4446 2897 fax: +55 (11) 4446 2889 e-mail: j ul ianamarques@natura.netnop The stratum comeum is the outennost layer of the skin. It constitutes a penneability barrier that keeps micro­ organisms and toxic agents from entering the skin, while retaining water and electrolytes. In order to preserve its colour and elasticity, the skin needs lipids and water. Certain occlusive products in contact with the skin diminish its natural transepidennal water loss (TEWL), and the occlusion potential of such products can be evaluated with the aid of evaporimetry. The purpose of this work was to increase the sensitivity of the method by associating the well-established methodology for measuring TEWL with a technique for removing occlusive products from the skin. The present study was designed to evaluate the procedure of measuring TEWL evaporimetrically (the traditional method) in comparison with our new method, which employs the same evaporimetric measurement combined with a removal technique that uses cotton to remove the physical barrier that occlusive products fonn on the skin. The product used in this study was solid petrolatum (petroleum jelly), which possesses well-known occlusive properties. The TEWL measurements were made over a pre-defined period of time, on different skin sites, and were systematically compared with the results generated by an untreated control site. The TEWL was first detennined by the classic method (without product removal), then the K. Sivasegaran, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3Gl , Canada. Tel.: +I 519 888 4567 fax: +I 519 725 0784 e-mail: jsivak@uwaterloo.ca Pre-screening of cosmetic ingredients is vital for consumer safety. Previous in vivo techniques, such as the Draize test, have proved to be unreliable in predicting ocular irritancy and therefore there is a need for alternate testing methodologies. One such test is the scanning laser in vitro assay system which quantifies irritancy based on the focusing ability of the cultured bovine lens. In combination with confocal microscopy, a more thorough documentation of ocular irritancy can be achieved. This study investigates the response of cultured bovine lenses over time to butyl, methyl and propyl parabens, which are common antimicrobial agents found in cosmetic and ophthalmic products. The focusing ability of the lens was measured with an automated laser scanner over a period of 96 h. At 120 h· post-treatment, the lenses were analysed by using a confocal laser scanning microscope to determine the characteristics of nuclei, and the morphology and distribution of mitochondria within the lenses. Irritancy to the three parabens was investigated at both an optical and cellular level. Each of the parabens was tested at 0.002% and 0.2%, where the 0.2% butyl paraben was found to be the most irritating. product was removed and new readings were taken. Our Growth, survival and inactivation of Pseudomonas results show that the classic technique was unable to show aeruginosa and Staphylococcus aureus strains of various a statistical distinction between the occlusion capability of origin in the presence of ethanol solid petrolatum and the untreated control site, whereas this A. Pinon*, V. Alexandre*, S. Cupfennant, A. Crozier+ and same method used in association with product removal M. Vialette* provided a statistically significant difference between the TEWL measured on the occluded and control sites. *Institut Pasteur de Lille, 1 rue du professeur Calmette, Therefore, our removal technique associated with the BP245, 59019 Lille Cedex, tL'Oreal Recherche, Chevilly­ traditional method for measuring TEWL proved capable of Larue and tL'Oreal DGT, Aulnay sous Bois, France increasing the response sensitivity of evaporimetry with occlusive products. Dose-response of the cultured bovine lens to butyl, methyl and propyl parabens K. Sivasegaran, L. Ho, K. L. Moran, V. Bantseev and J. G. Sivak School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3Gl, Canada Michele Vialette, Institut Pasteur de Lille, I rue du professeur Calmette, BP245, 59019 Lille Cedex, France. Tel.: +33 3 20 87 7853 Fax: +33 3 20 87 7224 e-mail: michele. vialette@pa teur-lille.fr The influence of ethanol on the behaviour of Pseudomonas aeruginosa and Staphylococcus aureus strains was evaluated throughout this study. Strains of different origin were used: collection, clinical and industrial strains were selected. Concentrations of ethanol from O to 20% (v/v) were evaluated by automated optical density measurements

544 JOURNAL OF COSMETIC SCIENCE and by enumeration. When growth conditions were against collagen swelling, and at given ionic strength observed, predictive microbiology models were used to (I = 0.4 mo! L- 1 ) swelling attains half values compare to assess quantitatively for the ethanol effect. Primary swelling at low ionic strength (I= 0.06 mo! L - 1 ). There modelling of kinetics was performed to determine growth are characteristic concentrations of both surfactants and rate values secondary modelling was performed on these their mixtures (c, r.o 0.5 - 1.0 mmol L- 1 ) that do not growth rates as influenced by ethanol, and minimum produce swelling. It is assumed that this range of inhibitory concentrations of ethanol were determined for concentrations corresponds to amount of surfactants bound each strain. Staphylococcus aureus strains were more to collagen through electrostatic forces and thus to resistant to ethanol than P. aeruginosa strains, in growth temporary increase in fibre hydrophobity. conditions as well as in inactivation conditions. Furthermore, clinical S. aureus strains were more resistant than the collection strain. The method was promising for management of microbiological safety in cosmetics. Interaction of mixture of anionic surfactants with collagen J. Krejci Effect of fluid intake on skin physiology: distinct differences between drinking mineral water and tap water S. Williams, N. Krueger, M. Davids, D. Kraus and M. Kerscher Division of Cosmetic Sciences (FB 13), University of Hamburg, Martin-Luther-King Platz 6, D-20146 Hamburg, Faculty of Technology, Tomas Bata University in Zlin, Germany nam. TGM 275, 762 72 Zlin, Czech Republic Professor Martina Kerscher, MD, Division of Cosmetic J. Krejci, Faculty of Technology, Tomas Bata University in Zlin, nam. TGM 275, 762 72 Zlin, Czech Republic. Tel.: +420 576 031 526 Fax: 420 577 210 172 e-mail: krejcij@ft.utb.cz Sciences (FB 13), University of Hamburg, Martin-Luther­ King Platz 6, D-20146 Hamburg, Germany. Tel.: +49 40 42838 7235 Fax: +49 40 42838 2592 e-mail: martina.kerscher@uni-hamburg.de Study focused on interaction of collagen fibres of collagen 1 Part of this study was presented as a poster on the 64th I with anionic surfactants sodium dodecylbenzene Annual Meeting of the American Academy of sulphonate (SOBS), sodium dodecyl sulphate (SOS) and Dermatology, 3-7 March 2006 in San Francisco, CA, USA. their mixtures at pH = 6, at two ionic strengths (I = 0.06 mo! L -i and I = 0.4 mo! L - 1 ) and laboratory It is generally stated that drinking plenty of water has a temperature. Surfactants and their mixtures were positive influence on skin condition. However, there is no characterised by their critical micelle concentration The aim of our exploratory 'before-after' study was to (c.m.c.), composition of mixed micelles and interaction evaluate the in vivo influence of drinking more than 2 L of factor � according to Rubingh. Dependency of c.m.c. on mineral water or ordinary tap water per day on skin mixture composition has an opposite tendency at both ionic physiology. Ninety-three healthy subjects were included in strengths, which proves the greater influence of added our prospective study. After an initial run-in phase of electrolyte on behaviour of SOS than of SOBS. Interaction 2 weeks to monitor individual drinking habits, subjects had was evaluated by means of binding isotherms and mass to drink 2.25 L day- 1 of either mineral water (n = 53) or swelling degree Clm- The bound quantity partly depends on tap water (n = 40) for 4 weeks. Bioengineering in vivo mixture composition, partly on ionic strength. SOS and measurements on the volar forearm included sonographic mixtures containing its greater quantities are bound more evaluation of skin thickness and density, determination of than SOBS (approx. 150% related to SOBS). Increased skin surface pH, assessment of skin surface morphology, ionic strength of the environment increases bound quantity and measurement of finger circumference. Eighty-six in approximately same manner, heedless of adsorbate subjects completed the study. In the mineral water group composition. Even composition of the mixture after measurements revealed a statistically significant decrease interaction with fibres does not markedly alter from initial in skin density. Skin thickness increased slightly, albeit not composition. Fibre swelling is affected by composition of at a statistically significant level. However, when swelling mixture similarly to binding - it increases with separately analysing those individuals from the mineral growing quantity of surfactants. Greater ionic strength acts water group, who had routinely drunken comparably little