160 JOURNAL OF COSMETIC SCIENCE carbomer resin and tested in vivo in six subjects for evaluating its protection potential against the UV (200--400 nm) using an artificial UV source consisting of a high pressure metal halide discharge lamp. Based on erythema evaluation, it was found that erythema appeared after 4 h and reached a peak at 24 h o n control site. On the contrary, no erythema was observed in any of the six subjects on black tea gel applied sites. Therefore, it was concluded that black tea gel protected the skin from a broad range UV (200--400 nm) radiation. The black tea gel can be safely applied in large amounts on large skin surfaces without any toxicological concerns. Influence of different parameters on droplet size and size distribution of sprayable sunscreen emulsions with high concentration of UV-filters L. Durand*, N. Habran_, C. Denis_, L. Meulders_, V. Henschel* and K. Amighi* *Laboratory of Pharmaceutics and Biopharmaceutics, Universite· Libre de Bruxelles, Brussels, _Eurocos Consult, Dion-Valmont and _Lambiotte & Cie S.A./N.V., Bruxelles, Belgium K. Amighi, Laboratory of Pharmaceutics and Biopharmaceutics, Universite' Libre de Bruxelles, 1050 Brussels, Belgium. Tel.: +3226505252 fax: +3226505269 In vivo persistent pigment darkening method: proposal ofa e-mail: kamighi@ulb.ac.be new standard product for UV A protection factor determination D. Moyal*, M. Pissavini_, F. Boyer_, V. Perier and J. H. FreAlon§ - *L'Ore'al Recherche, 25/29 Quai Aulagnier, 92665 Asnie'res Sur Seine, France, _Coty-Lancaster, International Research & Development Center, 2 Rue de la Lujemetta, 98000 Monaco, _Pierre Fabre Dermo Cosme'tique, Alle'e Camille - Soula Vigoulet Auzil, 31322 Castanet Tolosan, France and §Fe'deration des Industries et de Ia Parfumerie, 33 Champs Elyse· es, 75008 Paris, France Dominique Moya!, L'Ore'al, 25/29 Quai Aulagnier, 92600 Asnie'res Sur Seine, France. Tel.: +33 147568134 fax: +33 147567995 e-mail: gmoyal@rd.loreal.com The European Commission (EC) has recommended assessing the level of ultraviolet A (UV A) protection afforded by sunscreen products using the in vivo persistent pigment darkening (PPD) method or other methods giving equivalent results. In this context, the reproducibility of the in vivo PPD method is ofimportance. To check the validity of the UV A protection factor (UVAPF) tests, the Japanese Cosmetic Industry Association (JCIA) recommends using a standard product (JCIA standard) with an expected UV APF 3.75 (SD 1.01). However, considering the increase in UVA efficacy of the new sunscreen products available in the market, with UV APF up to 30, it seemed useful to develop a new standard product to be used when testing products with expected UVAPF tl0. The PPD method was used in six centres to determine the UVAPF of the two products. Reproducibility of results was also studied by testing two batches of the new product at two different times. There was no statistical difference between the six centres with regard to the JCIA standard. The ring study showed that the mean value ofUVAPF (4.3) was higher than that given by JCIA (3.75). These data enable the proposal of a new acceptance range for the JCIA standard product (3.4-5.2) derived from actual results from European laboratories. Whereas this range is different from that proposed by JCIA (2.74-4.76), there is an overlapping of the values. Data on the new standard product show that reproducibility is not influenced by the batches of this product. The mean UV APF value obtained is 12.1. An acceptance range (9.6- 14.6) is proposed for the new standard. Data presented here demonstrate that if an identical protocol is used, reproducible results can be expected and that the PPD method is reproducible and reliable. The purpose of this study was to evaluate the possible influence of different formulation and technological parameters such as sunscreen type and concentration, viscosity, propellant gas, actuator and valve type on size and size distribution of droplets in emulsions of waterproof sunscreens conditioned in aerosol cans. Different kinds of emulsion, W/Si and W/O, were prepared with high concentrations of organic and inorganic UV-filters. These formulations were incorporated in aerosol cans with gas (a blend of butane, propane and isobutane). The size and size distribution of the droplets were analysed by laser diffraction using a Malvern_ Spraytec. The results showed that the sprayability of the formulation and the particle size characteristics of the emitted sprays are dependent on the physicochemical properties of the formulations. Sprayable waterproof sunscreen emulsions, with a high sun protection factor and negligible percentage of emitted droplets below 30 Im, were successfully developed by optimizing formulation parameters and using appropriate actuators and valves. Review Article Global and systematic demonstration for the practical usage of a direct in vivo measurement system to evaluate wrinkles T. Fujimura, K. Haketa, M. Hotta and T. Kitahara Biological Science Laboratories, Kao Corporation, 2606, Akabane, lchikai-machi, Haga-gun, Tochigi 321-3497, Japan Tsutomu Fujimura, Biological Science Laboratories, Kao Corporation 2606, Akabane, lchikaimachi, Haga Tochigi 321-3497, Japan. Tel.: +81 285 68 7871 fax: +81 285 68 7469 e-mail: fujimura.tsutomu@kao.co.jp The global and systematic demonstration for the practical usage of a direct three-dimensional in vivo measurement system (PRIMOS) to evaluate wrinkles was investigated. Ten repetitive measurements of the comer of the eye of a subject showed that the coefficient of variation (CV)% value was 7 .0% in a typical line-length roughness parameter Ra (the arithmetic mean of roughness), and that the CV% value in a typical surface area roughness parameter Sa was 2.4%. The relationships between the roughness values obtained from the comers of the eye and the age or wrinkle scores of Japanese women aged 10-70

ABSTRACTS 161 years was examined. The values of several roughness parameters within the evaluation line length or surface area increased with age and showed a good correlation coefficient (r 0.743). Similar relationships between the wrinkle scores and the values of roughness parameters were observed (r 0.699). The roughness values were widely distributed even in the same wrinkle score because the measurement areas were limited and the values of skin roughness, including the microreliefs and/or small warts, were included in the calculation. However, changes in roughness values are considerable following treatment with potent active ingredients such as retinoic acid, so that this in vivo evaluation method is sufficient to objectively evaluate wrinkles. We conclude that the direct three- dimensional analysis of wrinkles in vivo should become a popular method to objectively evaluate wrinkles in clinical tests of wrinkle-smoothing ingredients or following cosmetic surgery to provide evidence of quantitative results. Nanostructured lipid carriers as novel carrier for sunscreen formulations Q. Xia*, A. Saupe_, R.H. Mu .. lier_ and E. B. Souto_,_ *Department of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China, _Department of Pharmaceutics, Biopharmaceutics and Biotechnology, Free University of Berlin, Kelchstr. 31, D- 12169 Berlin, Germany and _Department of Pharmaceutical Technology, Faculty of Health Sciences, Fernando Pessoa University, Rua Carlos da Maia, 296, S3, P-4200-150 Porto, Portugal Eliana B. Souto, Department of Pharmaceutical Technology, Faculty of Health Sciences, Fernando Pessoa University, Rua Carlos da Maia, 296, S3, P-4200-150 Porto, Portugal. Tel.: +351 225 074630 fax:+ 351 225 074637 e-mail: eliana@ufb.pt Incorporation of sunscreens into lipid carriers with an increased sun protection factor (SPF) has not yet been fully accomplished. In the present paper, the effectiveness of a sunscreen mixture, incorporated into the novel topical delivery systems, i.e. solid lipid nanoparticles {SLN) and nanostructured lipid carriers (NLC), used as ultraviolet (UV) protector enhancers with a distinctly higher loading capacity has been developed and evaluated. SLNand NLC were produced by hot high pressure homogenization technique in lab scale production. Size distribution and storage stability of formulations were investigated by laser diffractometry and photon correlation spectroscopy. Nanoparticles were characterized by their melting and recrystallization behaviour recorded by differential scanning calorimetry. Lipid nanoparticles produced with a solid matrix (SLN and NLC) were established as a UV protection system. The loading capacities for molecular sunscreens reported before now were in the range of 10- 15%. It was possible to load NLC with up to 70% with molecular sunscreen, which is appropriate to obtain high SPFs with this novel UV protection system. The developed formulations provide a beneficial alternative to conventional sunscreen formulations. The UV protective efficacy of the lipid particles varied with the nature oflipid and UV wavelength. Review Article Pores in the epidermis: aquaporins and tight junctions J. M. Brandner Department of Dermatology and Venerology, University Hospital Hamburg Eppendorf, Martinistrasse 52, D-200246 Hamburg, Germany Johanna M. Brandner, Department of Dermatology and Venerology, University Hospital Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany. Tel.: +49 40 42803 5819 fax: +49 40 42803 2630 e-mail: brandner@uke.unihamburg.de Water homeostasis of the epidermis is important for the appearance and physical properties of the skin, as well as for water balance in the body. It depends on several factors, e.g. barrier quality, uptake of water into the epidermis, concentration of water-retaining humectants, and external humidity. Aquaporins (AQPs) are pores in the plasmamembranes of cells. Monomeric AQPs fonn barrel- like structures that are primarily water selective, some AQPs also transport glycerol and possibly other small solutes. In the epidermis, AQP3 is the predominant AQP. It is localized mainly in basal but also in suprabasal layers of the epidermis and is permeable for water as well as for glycerol, a humectant. Mice deficient in AQP3 exhibit reduced stratum comeum (SC) hydration and impaired SC barrier recovety after SC removal. In skin diseases associated with elevated transepidermal water loss (TEWL) and reduced SC hydration, altered expression of AQP3 was shown. Tight junctions (TJ) are cell-cell jun ctions, which play a central role in sealing the intercellular space of cell sheets and thereby establishing a paracellular barrier. Within the TJ, pores are postulated to exist, which allow the controlled diffusion of water and solutes via the paracellular pathway. In the epidermis, TJ structures were demonstrated in the stratum granulosum whereas TJ proteins were found in all viable layers. Mice which overexpress or are deficient of key-proteins of TJ die soon after birth because of a tremendous TEWL. In various skin diseases that are accompanied by elevated TEWL and reduced skin hydration, staining patterns ofTJ proteins are altered. This review will summarize our current knowledge of the involvement of AQPs and TJ in the water homeostasis of the epidermis.