Toxicological evaluation of cyclosporine eyedrops

Purpose: The short-term toxicological effects of two cyclosporine A eyedrop formulations are compared. Methods: Formula A was based on Sandimmune(R) (Novartis, Switzerland) infus ion concentrate with a final ethanol concentration of 1% (w/w), and formula B on Sandimmune(R) oral solution, Both formulations were diluted in steril e peanut oil (10 mg/ml), The left eyes of 12 rabbits were treated with the cyclosporine eyedrops over a two-week period, The right eyes served as cont rols. Slit-lamp and scanning electron microscopic examinations were perform ed, and the total protein concentration in aqueous humor was measured in tr eated and control eyes. Results and Conclusion: Both Sandimmune oral solution and infusion concentr ate-derived eyedrops mere found to be non-toxic to rabbit eyes and there we re no significant differences between the two formulations. More definite c onclusions as to the safety of these cyclosporine formulations cannot be ma de without long-term trials.