(93f) Therapeutic Contact Lenses: Antihistamine Delivery Via Biomimetic Recognitive Hydrogels for the Treatment of Rhinoconjuctivis

Release of inflammatory mediators, such as H1-receptor binding histamine prompt vascular permeability, bronchodilation, and decrease exudation of effector cells. It is possible to downregulate the effects of histamine by site specific delivery of anti-histamine drugs such as ketotifen fumurate to treat and prevent such problems.

Currently, therapeutic treatment for both seasonal and perennial allergic rhinoconjunctivitis consists of oral and topical treatments. With bioavailabilities of oral and topical systems being lower than 7%, it is necessary to design systems with improved delivery of antihistamines on the surface of the eye. Using configurational biomimetic imprinting techniques we are able to control and tailor the loading and release of antihistamines via biomimetic recognitive contact lenses. Host-guest chemistry was rationalized using non-covalent interactions of the critical amino acids for histamine interactions and resulted in significantly enhanced partitioning. Polymer networks were synthesized via free-radical UV-photopolymerization and dynamic and equilibrium binding studies demonstrated that recognitve hydrogels could bind a therapeutic amount of drug which was 2 to 6 times greater than that of a conventional network depending on composition. In vitro release studies confirmed that a therapeutic dosage could be delivered within an extended period of time (15 hrs to days). Novel networks such as these could prove to be valuable for a variety of ocular therapies.