Skin Corrosion
CeeTox has developed screens that offer alternatives to animal testing in support of the European regulations in REACH and Amendment 7 to the Cosmetics Directive. These in vitro assays produce reliable outcomes at reasonable cost. Two reconstituted human epidermal skin models are used by CeeTox to test for skin corrosion by cosmetic ingredients and chemicals. The OECD 431 protocol is followed for these models.
CeeTox uses validated 3D skin models to test for skin corrosion. Either raw materials or finished goods can be tested with the models. In addition, histology can be performed to visualize the morphological changes to the models caused by the test compounds. The histological evaluation improves interpretations and reduces false negatives.
Skin corrosion refers to localized toxic effect resulting from a topical exposure of the skin to a substance. The Globally Harmonized System of Classification and Labeling of Chemicals (GHS) defines skin corrosion as “the production of irreversible damage to the skin; namely, visible necrosis through the epidermis and into the dermis, following the application of a test substance …]” (UNECE, 2004).
Source: http://www.lionden.com/SkinLayers.jpg. Used with permission.
The two major mechanisms of skin corrosion are the destruction (erosion or solubilization) of the skin penetration barrier (stratum cormeum) including the viable skin cells underneath, and the rapid penetration of highly cytotoxic chemicals through the skin barrier without involving its destruction.
The in vitro skin model corrosion assay measures cell viability. It is based on the experience that corrosive chemicals show cytotoxic effects following short-term exposure of the stratum corneum of the epidermis. The test predicts and classifies the skin corrosivity potential of a chemical by assessment of its effect on a reconstituted three-dimensional human epidermis model. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT.
The corrosivity potential of the test material is predicted from the relative mean tissue viabilities obtained after exposure compared to the negative control tissues concurrently treated with H2O.
CeeTox has a number of Corrosion assays for you to choose from:
EpiSkin™ Skin Corrosivity Test
This assay assesses the corrosion resulting from a topical exposure of the skin to a substance.
- Cell Model: The EpiSkin (SkinEthic Corporation)
- Assays Performed:
- Solubility Assay
- MTT
- IL-1α release (optional)
- Histology
- Exposure: 3 minutes, 1 hour, 4 hours (optional)
- Incubation: 42 hours
- Number of Replicates: 3
- Standard Turn Around Time: 4 weeks from sample and tissue receipt
- Scientific Endorsement: ECVAM
- International Regulatory Acceptance: OECD Test Guideline 431
EpiSkin™ Skin Corrosivity Test
This assay assesses the corrosion resulting from a topical exposure of the skin to a substance.
- Cell Model: The EpiDerm SIT (MatTek Corporation)
- Assays Performed:
- Solubility Assay
- MTT
- IL-1α release (optional)
- Histology
- Exposure: 3 minutes, 1 hour
- Incubation: 42 hours
- Number of Replicates: 3
- Standard Turn Around Time: 4 weeks from sample and tissue receipt
- Scientific Endorsement: ECVAM
- International Regulatory Acceptance: OECD Test Guideline 431
EpiDerm™ Combined Skin Irritation and Corrosion Test
This assay assesses both irritation and corrosion of a test article.
- Cell Model: EPI-200 (MatTek Corporation)
- Assays Performed:
- Solubility Assay
- MTT reduction
- IL-1α release (optional)
- H&E stained histology slide (optional)
- Controls: MTT direct reduction, water-killed (if needed), blank, 1 positive for irritation, 1 positive for corrosion, negative;
- Exposure: 1 hour
- Incubation: 42 hours
- Number of Replicates: 3
- Standard Turn Around Time: 3 weeks from sample and tissue receipt
- Scientific Endorsement: ECVAM
- International Regulatory Acceptance: Draft OECD Test Guideline OECD for irritation and Test Guideline 431 for corrosion
- National/ Regional Regulatory Acceptance: EU test method B.46 in COM regulation 440/2008/EC for irritation
Let CeeTox scientists become an extension of your R&D team when we put our 10+ years of experience to work for you interpreting the data that enables you to make the best decisions and bring safer products to market faster and at lower cost.
Literature Cited
United Nations-Economic Commission for Europe (UN/ECE) (2003). Globally Harmonised System of Classification and Labelling of Chemicals (GHS). UN, New York and Geneva, 2003. http://www.unece.org/trans/danger/publi/ghs/ghs.html
NIH Publication No: 02-4502. ICCVAM Review of In Vitro Dermal Corrosivity Methods, p. 59.