Review of Preclinical Outcomes of a Topical Cationic Emulsion of Cyclosporine A for the Treatment of Ocular Surface Diseases

Cyclosporine A (CsA) has been used as a topical treatment for various ocular surface diseases including dry eye disease (DED). Several CsA formulations are available as solutions or emulsions.This review describes the development and the preclinical testing of a cationic oil-in-water emulsion of CsA (CE-CsA) in terms of pharmacodynamics, pharmacokinetics, and ocular tolerance. Due to the cationic charge, CE electrostatically interacts with the negatively-charged ocular surface, improving its residence time. Compared to other CsA formulations, CE-CsA and CE itself were found to reduce the signs and symptoms of DED, by restoring tear film stability and properties, and inhibiting the expression and secretion of pro-inflammatory factors. No delay in wound healing nor ocular toxicity were observed using CE formulations.these findings indicate that the type of vehicle can significantly affect the performance of eye drops and play an ancillary role in DED treatment. CE appears as a promising strategy to deliver drugs to the ocular surface while maintaining its homeostasis.