The strategy of incorporating the histopathological examination into the Bovine Corneal Opacity and Permeability (BCOP) test - Application for the chemicals -

Abstract

[Introduction] The BCOP test is an alternative method commonly used to predict the ocular irritancy potential. Based on OECD TG 437, the chemicals producing an in vitro irritancy score (IVIS) < 3 are classified as UN GHS No Category, and an IVIS > 55 as UN GHS Category 1. While the chemicals producing 3 < IVIS < 55 are classified as UN GHS No stand-alone prediction can be made. We propose the combined use of histopathological examination with IVIS to provide further information on the chemicals classified as No stand-alone prediction can be made. [Purpose] To investigate the usefulness of the histopathological examination in combination with IVIS in the BCOP test. [Materials and Method] Sixty-four UN GHS-classified chemicals (physical property, both liquid and solid) were applied to the bovine corneas, and then IVISs were measured. Furthermore, corneas classified as UN GHS No stand-alone prediction can be made were histopathologically examined. [Result] The histopathological evaluation enabled more accurate classification as follows: 13 of the 30 chemicals classified as UN GHS No stand-alone prediction can be made could be correctly classified as Category 2, and 6 of them could be correctly classified as No Category.