FURTHER EVALUATION OF THE EPIDERM AND EPIOCULAR IN VITRO IRRITATION MODELS.

Both EpiDerm™ and EpiOcular™ commercially available in vitro models for assessing the skin and eye irritation potential, respectively, of chemicals. The EpiDerm and EpiOcular tissue models are organotypic three-dimensional human skin and corneal analogues derived from human epidermal keratinocytes. Both are colorimetric cytotoxicity models based on the ability of chemically exposed tissues to reduce MTT. An MTT effective time-50 (ET-50; time required to decrease cell viability by 50%) is established for each chemical. The objective of this study was to evaluate both EpiDerm and EpiOcular for their ability to assess the skin and eye irritation potential, respectively, of several water soluble and insoluble compounds previously evaluated in vivo. All animal data was obtained from previously published animal studies. No new in vivo testing was performed. The following compounds were examined with both EpiDerm and EpiOcular: benzyl alcohol; dibasic ester; heptyl acetate, propylene carbonate; N-methylpyrrolidone; sodium lignosulfate; sodium alkylnaphthalene sulfonate; polyethoxylated polyarylphenol; polysorbate 85; and sodium dodecylbenzene sulfonate. The following were examined only with EpiDerm: 2 and 100% 1-octyl-2-pyrrolidinone and an aromatic hydrocarbon. One or 0.3% Triton X-100 were used as positive controls for EpiDerm and EpiOcular, respectively. Of the 13 compounds evaluated, EpiDerm correctly identified 10 (77% concordance with in vivo data). EpiDerm overpredicted the remaining 3 compounds. EpiOcular correct1y identified 7 of the 10 examined compounds (70% concordance with in vivo data). The eye irritancy of 2 compounds was underpredicted, while that of the remaining compound was overpredicted. Although these systems have proved useful for evaluating the irritancy potential of water soluble compounds, further evaluation of their ability to predict the skin and eye irritation potential of various classes of water insoluble compounds needs to be conducted.

Aromatic hydrocarbon, EpiOcular, Eye irritation, MTT, MTT ET-50 tissue viability assay, MTT assay, Ocular irritancy testing, Ocular irritation, Ocular irritation testing, Skin irritation, Water insoluble compounds