Alternativer til dyreforsøg for øjenirritation.  

English Summary

Models of human tissues can be reconstructed from single cells. Test substances can be applied directly to the tissues, and the potency for local irritancy can be evaluated by measurements of the viability of the cells. A corneal model, the SKIN² ZK1200 tissue equivalent, was evaluated as a possible replacement of tests for ocular irritation using rabbits. The tissue equivalent was used to evaluate 55 cosmetic ingredients and finished products in a large validation study arranged by the European cosmetics industry (COLIPA). The SKIN² ZK1200 model was shown to be very good in predicting ocular irritation (Draize test MMAS values). Moreover, the tissue equivalent assay gave a good prediction of individual tissue reactions in the eye. This was both obtained for cosmetic ingredients and formulations, and all types of materials could be tested. In addition, a new model developed with the tissue equivalent showed promise for prediction of recovery from ocular irritation in a study on nine test substances. The results obtained indicate that the SKIN² ZK1200 tissue equivalent showed promise as a replacement of animal experiments for ocular irritancy testing. After the study was completed, the production of the SKIN² ZK1200 model has ceased. The results obtained with the model are, however, considered to be relevant for the assessment of the prospects for replacement of animal experiments for ocular irritancy with alternative methods.

The results of the COLIPA study did moreover confirm the results of other large validation studies on alternatives to animal experiments for eye irritancy testing. None of the other alternative methods in the COLIPA study were suitable to predict ocular irritation caused by the mixed group of ingredients and formulations. Several alternative methods were, however, very good in predicting ocular irritation caused by surfactants. Tests using hens eggs showed a low interlaboratory reproducibility, whereas the reproducibility of the other alternative methods was good.