Documents & Resources

Protocol Considerations for Testing Surfactants and Surfactant-based Formulations in the Bovine Corneal Opacity and Permeability Assay

March 23, 2015

The Bovine Corneal Opacity and Permeability (BCOP) assay is an ex vivo test for predicting ocular irritation. For regulatory classification, OECD Test Guideline (TG) 437 specifies that liquid and solid surfactants may be tested as 10% aqueous dilutions for 10 minutes, although alternate dilutions and exposure times may be conducted with scientific rationale. Without question, surfactant solids should not be tested using the solid chemical protocol, since overexposure conditions are likely. In the absence of clear guidance from these regulatory documents, we present on the testing of a few common surfactant ingredients (sodium lauryl sulfate, Triton X-100, and benzalkonium chloride), and surfactant-based liquid and solid formulations in BCOP using standard and modified dilutions and exposures to evaluate the impact of these variables.