ABSTRACTS 53 analysis. The results obtained show that cocoa polyphenols exhibit a positive action on the parameters assessed, and the dose at which they improve the most parameters associated with skin tonus and elasticity was determined. Their activity was compared with a commercially available product, and the results obtained show that their effi cacy is equivalent. Moreover, an enhancing effect of cocoa butter on activity of cocoa polyphenol was highlighted. Now that the properties of cocoa polyphenols on ex vivo skin restructuring parameters have been assessed, the next step could include their evaluation in vivo. Properties of a new hydrotrope hydrophobic molecule and its potential applications E. Schnell*, D. Touraud*, R. Gick_and W. Kunz* *Institut für Physikalische und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg and _CABB GmbH, Ludwig-Hermann-Strasse 100, D-86368 Gersthofen, Germany Werner Kunz, Institut für Physikalische und Theoretische Chemie, Universität Regenburg, D-93040 Regensburg, Germany. Tel.: +49 941/943 4044 fax: +49 941/943 4532 e-mail: Werner.kunz@chemie.uni-r.de In the present contribution, the properties of dipropylene glycol isobornyl ether (Pribelance_) are discussed, especially in the context of microemulsion and emulsion formulations. Pribelance_ is a new low-toxic anti-foaming hydrotrope with excellent co-surfactant properties that has some similarities with long-chain alcohols, but in contrast to them, it is liquid at room temperature. In combination with another, more hydrophilic cosurfactant, it allows signifi cant amounts of oil to be solubilized in water. Possible applications such as in cosmetics, as an anti-foaming agent or as additive to cooling lubricants are discussed. Further potential applications are plasticizers, fermentation systems, agrochemicals and waste-water treatments. Screening of Nepalese crude drugs traditionally used to treat hyperpigmentation: in vitro tyrosinase inhibition A. Adhikari*, H. P. Devkota*, A. Takano_, K. Masuda_, T. Nakane_, P. Basnet* and N. Skalko-Basnet* *The School of Pharmaceutical and Biomedical Sciences, Pokhara University, Pokhara, PO Box 427, Pokhara, Nepal, _Medicinal Plant Garden and _Department of Phytochemistry, Showa Pharmaceutical University, Machida, 194-8543, Tokyo, Japan A. Adhikari, The School of Pharmaceutical and Biomedical Sciences, Pokhara University, Pokhara, PO Box 427, Pokhara, Nepal. Tel.: +977 61 528 467 fax: +977 61 539 218 e-mail: adhikarianjana@gmail.com South-East Asian population is daily exposed to strong sunlight. As a result, the majority of population will have darker, ethnic skin. Moreover, many people suffer from dark spots, hyperpigmentation, which is considered to be a skin disorder and causes psychological disturbance. To treat dark spots, most of the population will still rely on traditionally used crude drugs, knowledge about which is transferred from generation to generation. Fifty-two crude drugs were selected based on the survey performed among local healers and beauticians of different ethnic origin. These crude drugs were screened for mushroom tyrosinase inhibitory activity, as tyrosinase inhibitors are becoming increasingly important as cosmetic and medicinal products, primarily to control hyperpigmentation. Among the tested crude drugs, methanolic extracts of Glycyrrhiza glabra, Morus alba, Syzygium aromaticum, Citrus aurantifolia, Cypreae moneta, Punica granatum and Citrus aurantium, at the fi nal concentration of 50 lg mL)1, showed mushroom tyrosinase inhibitory activity of 78.9%, 71.0%, 69.4%, 59.0%, 56.0%, 53.4% and 51.9%, respectively, with 91.4% inhibitory activity of kojic acid taken as positive control. To our knowledge, this is the fi rst report that extracts of Cypreae moneta shell and Syzygium aromaticum fl owering bud have tyrosinase inhibitory activity. These potent extracts were further evaluated at different concentration. The fi nal concentration of the extracts in reaction mixtures was 50, 25 and 5 lg mL)1 for the initial concentration of 1000, 500 and 100 lg mL)1, respectively. They showed concentration- dependant inhibition of mushroom tyrosinase. Those extracts expressing relatively weak tyrosinase inhibitory activity may act through different inhibition pathway which is not based on tyrosinase activity. Further evaluation of the most potent tyrosinase inhibitors in in vivo conditions would be recommended. Adaptation of the protocol for determining in vitro the sun protection factor of anti-solar sticks B. Choquenet, C. Couteau, E. Paparis and L. J. M. Coiffard Université de Nantes, Nantes Atlantique Universités, LPiC, MMS, EA2160, Faculty of Pharmacy, 1 rue G. Veil - BP 53508, Nantes F-44000, France

JOURNAL OF COSMETIC SCIENCE 54 L. J. M. Coiffard, Université de Nantes, Nantes Atlantique Universités, LPiC, MMS, EA2160, Faculty of Pharmacy, 1 rue G. Veil - BP 53508, Nantes F-44000, France. Tel.: +33 2 40 41 28 73 fax: + 33 2 40 41 29 87 e-mail: laurence. coiffard@univ-nantes.fr Apart from the protection offered by clothing, the application of sunscreen products suited to each type of skin constitutes one way for decreasing the frequency of skin cancers nowadays. After having adapted an in vitro method for determining the effi cacy of sunscreens in emulsion form, we wished to transpose this technique by adapting it for the anti-solar sticks for the evaluation of sun protection factor (SPF) using a spectrophotometer equipped with an integrating sphere. To do this, we tested 14 products in the market as well as sticks that we ourselves fabricated in the laboratory. In a base common to all of these sticks, we added organic (13 fi lters tested) and inorganic (two fi lters tested, titanium dioxide and zinc oxide) to their maximum permitted concentration in the European Union. In parallel, emulsions containing the same fi lters at the same percentage of use were studied to be in keeping with the results on the products packaging on the one hand, and with the results obtained for the emulsion form on the other hand, we were able to determine the optimal mass which needed to be placed on the support used the in vitro test to determine the SPF. Simultaneous determination of 21 preservatives in cosmetics by ultra performance liquid chromatography T. Wu, C. Wang, X. Wang and Q. Ma Chinese Academy of Inspection and Quarantine, Beijing 100025, China Ting Wu, Chinese Academy of Inspection and Quarantine, Beijing 100025, China. Tel.: +86 1085772625 fax: +86 1085772625 e-mail: ppwtpp@126.com An ultra performance liquid chromatography (UPLC) method has been developed for the simultaneous determination of 21 preservatives: 2-methyl-4- isothiazoline-3-ketone, bronopol, 5-chloro-2-methyl-4- isothiazoline-3-ketone, benzyl alcohol, 2-phenoxyethanol, methyl-p-hydroxy benzoate, ethyl-p-hydroxy benzoate, methyl benzoate, 4-hydroxybenzoic acid iso-propyl ester, propyl-phydroxy benzoate, 4-chloro-3-methylphenol, ethyl benzoate, 2-phenylphenol, 4-hydroxybenzoic acid iso-butyl ester, butyl-p-hydroxy benzoate, 4-chloro- 3,5-dimethylphenol, phenyl benzoate, 2,4-dichloro-3,5- dimethylphenol, 2-benzyl-4-chlorophenol, triclocarban and triclosan in cosmetics. A Waters ACQUITY UPLC BEH C18 column was used with 0.1% formic acid solution as the mobile phase under the condition of gradient elution. Preservatives were extracted with methanol by ultrasonicator, and then they were analysed by UPLC-PDA detector. All these preservatives were baseline separated in 8.5 min. The pre-treatment method of samples and the chromatographic condition of analysis were critically examined in this study. The recoveries ranged from 90.5 to 97.8%, with RSD values below 3.2%, and all correlation coeffi cients (r) were no less than 0.9997. Thus, this method could be used for analysing the preservatives in cosmetic products. Validation of HPLC method for quantitative determination of Tinosorb_S and three other sunscreens in a high protection cosmetic product L. Dencausse*, A. Galland*, J. L. Clamou* and J. Basso_ *Laboratires ASEPTA, Recherche et Développement Analytique, 1–3, avenue Prince Albert II, B. P. 649, MC 98013, Monaco Cedex, France and _Faculté des Sciences, Université de Nice Sophia-Antipolis, Parc Valrose, 06108 Nice cedex 2, France Laurent Dencausse, 1-3, avenue Albert II, B. P. 649, 98013 Monaco, France.Tel.: +377 92057551 fax: +377 92055699 e-mail: ldencausse@asepta.mc A chromatographic method (high performance liquid chromatography) with a diode array detector was developed for simulaneous assay of Tinosorb_S (bisethylhexyloxyphenol methoxyphenyl triazine) with three other sunscreen agents [benzophenone-3, butyl methoxydibenzoylmethane (avobenzone) and ethylhexyl methoxycinnamate] in high protection sunscreen. Separations were performed on a RP-18 Nucleodur_Gravity_column (150 ´ 4.6 mm, 5 lm) eluted with a ternary gradient mixture constituted of tetrahydrofuran, acetonitrile and an aqueous solution of acetic acid. The quantitative analysis was achieved with internal calibration performed with octyl dimethyl paraaminobenzoate (PABA) at 330 nm. In accordance with the analytical references (SFSTP, ICH, ISO...), the accuracy of the method was evaluated using a statistical approach of the validation parameters (specifi city, response function, linearity, precision and trueness). For each studied ultraviolet fi lter, an accuracy profi le was determined on a predicted range. These profi les show a graphical representation of the recovery percentage and confi dence limits centred on 100%. The method is validated and can be used for analysis in cosmetic sunscreen products.