Study Design of EpiSkin-In Vitro Skin Corrosion (OECD 431)
The EpiSkin-In Vitro Skin Corrosion Test, based on the OECD Guideline 431, is a validated, non-animal alternative for assessing the corrosive potential of chemicals and mixtures. It utilizes reconstructed human epidermis (RhE) models, like EpiSkin™, to predict their ability to cause irreversible damage to the skin, similar to what occurs in humans.
Test System:
EpiSkin™: A commercially available RhE model composed of non-transformed human keratinocytes cultured to form a multi-layered, differentiated epidermis closely resembling the structure and function of the human skin barrier.
Test Procedure:
- Test substance preparation: The test substance is prepared in appropriate concentrations and dilutions according to the OECD 431 protocol.
- Application to EpiSkin™: The test substance is applied topically to the surface of the EpiSkin™ model in specific volumes and exposure times.
- Incubation: The EpiSkin™ model is incubated under controlled conditions for a predetermined period, typically 24 hours, to allow the test substance to interact with the tissue.
- Viability assessment: After incubation, the viability of the EpiSkin™ cells is assessed using a vital dye, such as MTT or NRU, to determine the extent of cell damage caused by the test substance.
Scoring and Interpretation:
- Reduced animal use: Eliminates the need for live animals, aligning with ethical considerations and animal welfare principles.
- Cost-effective: Generally faster and less expensive compared to traditional in vivo studies.
- Standardized protocol: Ensures international harmonization and data comparability.
- Predictive accuracy: Proven to be reliable in predicting skin corrosion potential with high sensitivity and specificity.
Limitations:
- Limited tissue complexity: EpiSkin™ models lack certain components of the human skin, like blood vessels and nerves, which may influence the response to some substances.
- Not suitable for all chemicals: Certain highly volatile or reactive substances may not be adequately assessed using this method.
- Validation limitations: Although validated for specific categories of chemicals, ongoing research and validation efforts are necessary for broader applicability.
Additional Resources:
- https://www.oecd.org/env/ehs/testing/test-no-431-in-vitro-skin-corrosion-reconstructed-human-epidermis-rhe-test-method-9789264264618-en.htm
