Cytotoxicity of potential ocular permeation enhancers evaluated on rabbit and human corneal epithelial cell lines

A series of prospective ocular permeation enhancers. benzalkonium chloride (BAC), cetylpyridinium chloride (CPC), ethylenediaminetrtraacetic acid (EDTA), polyoxyethylene (20) stearyl ether (PSE) and polyelhoxylated castor oil (PCO) were tested for cytotoxicity on cultures of rabbit (RCE) and human (HCE) corneal epithelial cells. The cells were treated for 5, 15 and 60 min with different concentrations of the test substances, in serum-free medium and in medium containing 15% foetal bovine serum (FBS). The cytotoxicity was evaluated by WST-1 test. The EC50 values For HCE, after 15 min exposure and in the presence of FBS, indicate the following order of cytotoxicity: PSE greater than or equal to BAC > CPC > EDTA > PCO. After 1 h exposure the order of decreasing cytotoxicity was PSE greater than or equal to BAC > CPC > PCO > EDTA. In all cases the presence of FBS appeared to exert a protective effect against the cytotoxic effect. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.