Relationship between steroid permeability across excised rabbit cornea and octanol-water partition coefficients.

Permeability rates were determined across excised rabbit corneas for 11 steroids. Permeability coefficients for each steroid were calculated, and their logarithms were plotted against their respective log octanol-water partition coefficients. A parabolic relationship resulted, with an optimum log permeability and coefficient observed at a log Po of 2.9. From these experimental results, an improvement in ophthalmic bioavailability of dexamethasone acetate as compared to dexamethasone is predicted and correlates with literature results.