Leiden reconstructed human epidermal model as a tool for the evaluation of the skin corrosion and irritation potential according to the ECVAM guidelines

In the ECVAM validation studies two common skin protocols have been developed, the skin corrosion and skin irritation protocol. Both protocols include next to general and functional conditions that the skin model must meet, also the correct prediction of the activity of certain reference chemicals. For the skin corrosion protocol, the OECD TG 431 defined 12 reference chemicals that should be correctly predicted by the epidermal skin model. For skin irritation 20 test substances should meet the defined criteria. In this study we aimed to subject our Leiden human epidermal (LHE) model to both common protocols according to the ECVAM guidelines. The LHE model generated in this study has been fully characterized and shows very high similarities with the native skin. After minor technical changes in both protocols, corrosion classifications were obtained in concordance with those reported for the validated human skin models EpiSkin™ and EpiDerm™. The results obtained with the common skin irritation protocol were very similar to that of earlier studies with the SkinEthic, EpiSkinTM and EpiDermTM models. This means that the protocols and prediction models developed during the validation studies with a specific skin model can be used with other similar skin models. This study demonstrates that reconstructed human skin equivalents have been proven to be efficient and reliable alternatives to animal testing.