COMPARISON OF HUMAN PATCH TEST AND 3D HUMAN SKIN MODEL RESULTS WITH CLASSIFICATION OF CHEMICALS BASED ON RABBIT DRAIZE TEST.
As stated in the “Conclusions” section, this study by scientists at the National Institute of Public Health (CZ), St. John’s Institute of Dermatology, Unilever SEAC, ZEBET, and MatTek Corp. demonstrated that in vitro 3D models derived from human skin cells (MatTek’s EpiDerm), if used in appropriate test designs and optimized by reference to human hazard data, may prove to be more useful than animal tests for the prediction of human hazard from previously untested substances. Efforts to replace the in vivo rabbit Draize test for skin irritation have been underway for many years. Special emphasis on this subject occurred in the last few years in Europe as a result of the Cosmetics Directive, which requires the test be eliminated by March 2009, end the new EU regulatory framework for the Registration, Evaluation and Authorisation of Chemicals (REACH). To this end, various in vitro protocols, often involving 3D skin models, have been/are being assessed. However, one key difficulty in determining the validity of any particular protocol/prediction model is that the in vivo rabbit data is both scarce and often of limited utility for the prediction of the biological effect in man. Consequently, using the 4h human patch test (HPT), scientists at the National Institute of Public Health (CZ), St. John’s Institute of Dermatology, Unilever SEAC, ZEBET and MatTek Corp. examined a number of chemicals whose EU classification is known to be borderline. These human skin irritation hazard data were compared with available rabbit data and with results obtained using a 3D human epidermis model (EpiDerm™). The present study suggests that EpiDerm exposure time can influence predictivity towards humans or rabbits. The best agreement between the rabbit test and the other analysed methods was achieved using the EpiDerm 60 min assay (68%). The best agreement between the HPT and the other methods was achieved using the EpiDerm 15 min assay (76%).
Cosmetic directive, EPI-200, EU classification, EpiDerm, Hill top chamber, Human patch test, REACH, Rabbit Draize test, Skin irritation
1-(2-isopropylphenyl)-1 phenylethane, 1-(spiro[4.5]dec-7-en-7-yl)pent-4-en-1-one, 1-Bromo-4-chlorobutane, 1-Bromohexane, 1-Decanol, 10-undeconic acid, 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 20% SLS, 4-Methylthio-benzaldehyde, Alpha terpineol, Butyl methocrylate, Decanoic acid, Dodecanoic acid (lauric acid), Heptaldehyde, Heptyl butyrate, Hexyl salicylate, Hydroxycitronellal, Linalyl acetate, Napthalene acetic acid, Nonanoic acid , Terpinyl acetate, bis[(1-methylimidazol)-2/ethyl-hexanoate)], zinc complex, di-Propylene glycol, di-n-Propyl disulphide
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