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The reproducibility of an in-vitro determination of the UVA INDEX describing the relative UVA protection of sun care products / DGK in IFSCC MAGAZINE, Vol. 5, N° 3 (07-08-09/2002)
[article]
Titre : The reproducibility of an in-vitro determination of the UVA INDEX describing the relative UVA protection of sun care products Type de document : texte imprimé Auteurs : DGK, Auteur ; Task Force "Sun Protection", Auteur Année de publication : 2002 Article en page(s) : p. 161-166 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Produits antisolaires Tags : 'UVA INDEX' protection' 'Méthode de test In-vitro' 'Protection solaire' Reproductibilité Index. décimale : 668.5 Parfums et cosmétiques Résumé : Due to overexposure to UVA and not only to UVB light significant alterations in damage to human skin were observed. Accordingly, the protection against UVA is a major additional requirement for sunscreens beside the effective prevention of sunburn. Despite the intensive debate on the appropriate measurement and labeling, up to now, no proposal was officially accepted in Europe and US. The recently published determination of the in-vitro PPD protection factor [1] was discerned as a candidate for future, harmonized UVA protection measurement? The method combines the merits of in-vitro as well as of in-vivo determinations. The aim of the present study was to investigate the inter-institutional reproducibility of the new UVA parameter and to determine how to express the UVA protection. Concerning the latter aspect, particular emphasize should be given to the importance of the SPF by describing the UVA protection in relation to the UVB protection efficacy. Seven laboratories participated in the Round Robin study and five marketed sunscreen formulations were tested. The sunscreens were selected to represent the major types of sun protection products. The application amount was fixed at 0.75mg/cm2 for all samples and for all institutes after ensuring in a pretest that the absorbance does not exceed the value of 2.0, because otherwise saturation phenomena could occur. Regarding the calculation of the in-vitro PPD protection factors, a high reproducibility was found. The average standard deviation for all five products was less than 15%. The good correlation between in-vitro and in-vivo PPD factors confirms the relevance of this methods. The UVA INDEX was defined as the relation between the in-vitro PPD factor and the labeled in-vivo SPF. Based on the simple transmission measurement and a calculation that takes into account the in-vivo effectiveness as references, it provides a rapid and valid procedure to evaluate and to differentiate the UVA protection of sunscreens. According to these findings, the UVA INDEX is seen as a potential candidate for UVA determinations. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10639
in IFSCC MAGAZINE > Vol. 5, N° 3 (07-08-09/2002) . - p. 161-166[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 003875 - Périodique Bibliothèque principale Documentaires Disponible Importance of substrate roughness for in-vitro sun protection assessment / Louis Ferrero in IFSCC MAGAZINE, Vol. 9, N° 2 (04-05-06/2006)
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Titre : Importance of substrate roughness for in-vitro sun protection assessment Type de document : texte imprimé Auteurs : Louis Ferrero, Auteur ; Marc Pissavini, Auteur ; Adeline Dehais, Auteur ; Stephanie Marguerie, Auteur ; Leonhard Zastrow, Auteur Année de publication : 2006 Article en page(s) : p. 97-108 Note générale : Bibliogr. Langues : Anglais (eng) Tags : 'Sunscreen testing' 'In vitro SPF' 'UVA protection' 'Surface roughness' microtopography' 'Irregularfilm geometry' 'UV filters' Index. décimale : 668.5 Parfums et cosmétiques Résumé : The purpose of this study is to demonstrate the influence of plate roughness on well-known absolute or relative UV
spectroscopic indices such as the in vitro SPF, in vitro UVA PF (PPD), UVA/UVB ratio, critical wavelength and SPF/UVA
PF (PPD) ratio. First a roughness index was measured by non-contact surface topography analysis on different
PMMA plates which are available today on the European market. A large difference between maximum and minimum
plate roughness values could be measured ranging from 1.88 μm to 6.76 μm. Then the PMMA plates were grouped
into five different roughness classes. To measure the different spectroscopic indices, the same sunscreen preparation
was applied at the same amount rate (1 mg cm-2) to each of the selected plates. Large differences were noted for
the absolute in vitro indices SPF and UVA PF (PPD), with the SPF varying in one instance from 13.5 to 40.7. On the other
hand, the relative absorbance indices UVA/UVB ratio and critical wavelength showed a small but significant variation
in relation to roughness. The SPF/UVA PF (PPD) ratio index based on direct in vitro values was found to be very
sensitive to roughness variation. However, adjusting the UV absorbance curve to reach equality between the in vitro
SPF and in vivo SPF is a recognized and efficient mathematical process to limit the variation.
All these results can be interpreted using the irregular sunscreen film theory. Mathematical developments can be
achieved by modeling the height distribution with a gamma function.Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10847
in IFSCC MAGAZINE > Vol. 9, N° 2 (04-05-06/2006) . - p. 97-108[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 008185 - Périodique Bibliothèque principale Documentaires Disponible New systems of broad-spectrum UV protection / Uli Osterwalder in IFSCC MAGAZINE, Vol. 5, N° 3 (07-08-09/2002)
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Titre : New systems of broad-spectrum UV protection Type de document : document électronique Auteurs : Uli Osterwalder, Auteur ; Bernd Herzog, Auteur Année de publication : 2002 Article en page(s) : p. 169-175 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cosmétiques
Peau -- Soins et hygiène
Produits antisolairesTags : 'UVA absorber' 'Broadband UV protection' 'Broad-spectrum Efficacy Safety 'Australian UVA standard' 'Japanese PPD Index. décimale : 668.5 Parfums et cosmétiques Résumé : Sunscreens should protect UVB induced sunburns as well as deeper penetrating UVA radiation, which enhance the risk of skin cancer and premature skin aging. UVA protection is realized either by the conventional UVA filter Butyl Methoxydibenzoylmethane (BMBM), which has to be stabilized against light-induced decay, by microfine Zinc Oxide (ZnO) or by new photostable chemical entities. The European Commission (EC) recently approved two UVA absorbers (Terephthalidene dicamphor sulfonic acid (TDSA) and Disodium Phenyl Dibenzimidazole Tetrasulfonate (DPDT), and three broad-spectrum UV absorbers (Drometrizole Trisiloxane (DTS), Methylene-bis-benzotriazolyl tetramethylbutylphenol (MBBT) and Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine (BEMT). The efficacy of these new UVA/broad-spectrum absorbers is discussed in conjunction with the various UVA assessment methods: The superiority of the new photostable UV absorbers is best documented by in-vivo Persistent Pigment Darkening (PPD) method. The in-vitro UVA/UVB ratio proves to be a more sensitive measure to characterize broadband behavior than the critical wavelength method. Broad-spectrum filters often show a synergistic effect regarding the SPF in combination with UVB filters. The new UV absorbers give the formulator more flexibility to achieve better formulations. The comparison of three products of similar SPF - all with broadband claim - shows that the degree of UVA protection may very greatly. With the modern, photostable broad-spectrum UV absorbers lower amounts of filter may yield the same protection. The chemical development of modern UV filters has lead to substances with higher molecular weight, which is one parameter besides others that determines the skin penetration of a substance. The rigid criteria of the EC approval process guarantee that these new UV filters can be used safely in the protection against the harmful effects of UV radiation. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10640
in IFSCC MAGAZINE > Vol. 5, N° 3 (07-08-09/2002) . - p. 169-175[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 003875 - Périodique Bibliothèque principale Documentaires Disponible