Nicastro, S.C. and G.S. Ladics. Further Evaluation of the EpiDermÔ and EpiOcularÔ In Vitro Irritation Models. The Toxicologist 1999. 48(1S): 77. Abstract #360.

benzyl alcohol - 00100-51-6; propylene carbonate - 00108-32-7;

Both EpiDermÔ and EpiOcularÔ are commercially available in vitro models for assessing the skin and eye irritation potential, respectively, of chemicals. The EpiDermÔ and EpiOcularÔ 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 EpiDermÔ and EpiOcularÔ for their ability to access 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 EpiDermÔ and EpiOcularÔ ; benzyl alcohol; dibasic ester, heptyl acetate, propylene carbonate; N-methylpyrrolidone; sodium lignosulfate; sodium alkylnaphthadodecylbenzene sulfonate. The following were examined only with EpiDermÔ ; 2 and 100% 1-octyl-2-pyrrolidinone and an aromatic hydrocarbon. One or 0.3% Triton X-100 were used as positive controls for EpiDermÔ and EpiOcularÔ , respectively. Of the 13 compounds evaluated, EpiDermÔ correctly identified 10 (77% concordance with in vivo data). EpiDermÔ overpredicted the remaining 3 compounds. EpiOcularÔ correctly 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.