Prediction of ocular irritancy of prototype shampoo formulations by the isolated rabbit eye (IRE) test and bovine corneal opacity and permeability (BCOP) assay

The isolated rabbit eye (IRE) test and bovine corneal opacity and permeabil ity (BCOP) assay were evaluated for their ability to predict the eye irrita tion potential of a range of hair shampoo formulations, some containing a n ovel non-surfactant ingredient known to be an ocular irritant. The addition al endpoints of corneal swelling and histological examination were incorpor ated into the standard BCOP protocol. Historic Draize data were available f or several of the formulations and served as a reference. The standard BCOP assay (without histology) failed to distinguish between shampoos of low an d high irritant potential, when exposure times of 10 and 60 min were employ ed (for undiluted and 10% dilution of the shampoos, respectively) and the i n vitro score classified the majority of formulations as mild. The incorpor ation of the histological endpoint to the BCOP protocol allowed discriminat ion between formulations of differing irritancy, and should be included to augment the standard BCOP protocol. Corneal swelling values did not, howeve r, correlate with the irritant potential of the shampoos tested. The IRE wh ich includes the endpoints of corneal swelling and histopathological scorin g produced classifications of irritancy that were fairly consistent with in vivo data and distinguished between the high and low irritant potential sh ampoos. (C) 2001 Elsevier Science Ltd. All rights reserved.