Novel Therapeutic Hydrogel Contact Lenses for Glaucoma: Analysis of Release Kinetics and Polymeric Structural Kinetics

Glaucoma is the leading cause of irreversible blindness, affecting 60 million people worldwide, and there is currently no cure. Topical therapeutics are used to reduce intraocular pressure, which can substantially delay the progression of glaucoma. Eye drops dominate 90% of the ocular therapeutics market, but they result in low bioavailability and have compliance issues. There is a need for better drug delivery technology that provides more consistent, efficacious treatment to the eye. This study focuses on the development of a novel therapeutic contact lens, for glaucoma treatment, that is designed to release latanoprost (LP), a prominent prostaglandin analog prodrug on the market today. LP is an isopropyl ester hydrolyzed by corneal esterases into its active form, latanoprost acid (LPA).

Through the implementation of macromolecular memory, a drug-specific functionality, our group has shown successful in vivo and in vitrorelease of ocular therapeutics. This promising technology involves engineering the polymer matrix by manipulation of non-covalent interactions between the template drug and functional monomers. Drug elution is delayed due to the reversible interactions between the template and monomers in the flexible memory sites that remain even after drug release.

Analysis of transport characteristics provide further insight into the interdependence of kinetics on mesh size; an ideal mesh size will result in effective drug residence and release time. Dynamic releases are observed in a large volume dissolution system and a novel microfluidic device that mimics the quick tear turnover rate in the human eye, respectively. Bounds for network crosslinking architecture are set by constraints such as solubility, optical clarity, rigidity, and oxygen permeability. Also, mechanical property testing is necessary to assure lens characteristics match those of currently commercialized lenses.

Macromolecular memory lends itself as a more effective and efficient alternative to current ocular disease treatment methods. Such advancements in the field of ocular drug delivery can substantially improve the quality of life of patients.

Acknowledgements: NIH Grant G00008141