435. COMPARISON OF CORROSITEX AND EPIDERM IN VITRO SKIN CORROSION SCREENING ASSAYS TO IN VIVO CORROSIVITY RESULTS.

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Wilson, D.M., McMullin, T.T. Kan, H.L., Golden, R.M. Stott, W.T. Dow Chemical, Midland, MI, USA. Society of Toxicology 46th Annual Meeting, Charlotte, NC, (2007). The Toxicologist, 96, 1, 144 (2007).

Summary:
This study by researchers at Dow Chemical Co. demonstrated that MatTek’s EpiDerm human skin tissue equivalent gave near-perfect concordance with in vivo corrosivity data for a panel of 12 reference chemicals recommended in OECD Guideline 431.

In this study, Dow Chemical scientists objectively compared a battery of chemicals in the EpiDerm™ (MatTek Corp., Ashland, MA) and Corrositex (InVitro International, Irvine, CA) in vitro corrosivity screens to existing in vivo data.

EpiDerm consists of cultured, normal human epidermal keratinocytes in a differentiated epidermal model with organized basal, spinous and granular layers, and a stratum corneum containing intercellular lamellar lipid layers analogous to those found in vivo, Corrosivity is assessed as relative cytotoxicity at 3-min and 1-hr as the mitochondrial reduction of a tetrazolium salt.

Corrositex uses a bio-barrier membrane comprised of a hydrated collagen matrix and supporting filter membrane on top of a vial filled with a chemical indicator dye, with corrosivity assessed according to breakthrough time.

A panel of 12 reference chemicals recommended in OECD Guideline 431 for laboratory validation procedures was used [six corrosive: 1,2 diaminopropane; acrylic acid; 2-tert-butylphenol; potassium hydroxide; sulfuric acid; octanoic acid; and six non-corrosive: 4-amino-l,2,4-triazole; eugenol; phenethyl bromide; tetrachloroethylene; isostearic acid; and 4-methylthio-benzaldehyde], as well as 15 proprietary chemicals [nine corrosives and six non-corrosives in vivo, comprised of one alcohol, three organic acids, seven amines, two acrylic acid derivatives, and two halogenated herbicides].

EpiDerm exhibited 96% in vivo concordance (26 of 27), with 1 of 27 giving a borderline false negative for an organic acid.

Corrositex exhibited 70% (19 of 27) in vivo concordance; with 3 of 27 false negatives (two organic acids and one halogenated herbicide), 2 of 27 false positives (both were amines), and 3 of 27 that didn't qualify due to lack of reactivity with the indicator dye. Erroneous results weren't restricted to false negatives, positives or by chemical class.

One organic acid was a false negative for both in vitro assays, with the borderline EpiDerm result suggesting potential corrosivity in vivo.

In conclusion, EpiDerm gave near-perfect concordance with in vivo corrosivity data.

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EpiDerm Data Sheet

EpiDerm Specifications

EpiDerm Technical References

Dermal Corrosion (EpiDerm Application)

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Applications: Corrosion - skin

Keywords: 1,2 diaminopropane; acrylic acid, 12 reference chemicals, 2-tert-butylphenol, 4-amino-l,2,4-triazole, 4-methylthio-benzaldehyde, Dermal corrosion, EPI-200, EpiDerm, Eugenol, In vitro corrosivity screens, In vivo data, Isostearic acid, Laboratory validation procedures, Mitochondrial reduction tetrazolium salt, Near-perfect concordance, OECD Guideline 431, Octanoic acid, Phenethyl bromide, Potassium hydroxide, Sulfuric acid, Tetrachloroethylene

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