Engineered polysaccharide carboxylate matrices for ocular drug delivery

Two to three million Americans suffer from glaucoma. There exist treatments such as beta blockers, but their ability to deliver drugs to the eye is minimal (<5%). The overall goal of this project is to develop a biocompatible, biodegradable, in situ-gelling, ocular drug delivery system using proprietary cellulosic/starch carboxylate copolymers. Sustained drug delivery in topical formulations for treating glaucoma, inflammation, infection and dry eye will be targeted. There is a need for an ocular drug delivery system that has the characteristics of long retention time, ease of use, ease of manufacture and overall acceptance by the patient as evident by many review articles on the subject. This product would be formulated with current topical ophthalmic drug preparations to provide a longer retention time reducing the overall dosing frequency and increasing bioavailability of the drugs. It would use the physiological properties of the eye (pH, temperature and ionic strength) to turn a clear, topical application into a gelling matrix when placed in the eye. The kinetics of the starch and cellulose oxidation are shown to fit a third order model. Drug release studies were conducted using ofloxacin and the matrices are shown follow Higuchi's model for diffusion from a hydrogel.