Influence of cetylpyridinium chloride on corneal permeability to penicillin

The epithelial surface or the deepithelialized anterior stromal surface of isolated rabbit corneas was perfused for 3 hr with 14C-penicillin in 25 mM Ringer-bicarbonate solution with or without 1% albumin and with or without 0.02% cetylpyridinium chloride. The intact epithelium acted as a barrier to penicillin and impeded the flux rate by 66% when compared to the flux rate across the deepithelialized cornea. The presence of 0.02% cetylpyridinium chloride increased the penicillin flux rate across corneas with an intact epithelial layer to that of deepithelialized corneas. Cetylpyridinium chloride, 0.02%, had no effect on penicillin flux across deepithelialized corneas. The penicillin flux rate across corneas, with or without epithelium, was increased slightly following the inclusion of 1.0% albumin in the bathing solution. The flux rates across deepithelialized corneas in the presence of albumin, with or without cetylpyridinium chloride, were similar to fluxes found in the absence of albumin. Albumin-penicillin "binding" was not a significant factor in impeding penicillin flux, and this binding apparently was not altered by cetylpyridinium chloride. The surfactant appeared to alter epithelial permeability physiologically.