title: Ion exchange resins for ophthalmic delivery.
abstract: A new novel delivery system for ophthalmic drugs was developed using an antiglaucoma agent Betaxolol Hydrochloride as a model. The new delivery system involved both the binding and release of drug from ion exchange resin particles. Betaxolol was studied in-vitro via a release model analysis. The ocular comfort of Betaxolol was greatly enhanced by reducing the availability of free drug molecules in the precorneal tear film. The amount of resin concentration was selected to obtain optimum binding of the drug. The zeta potential of suspended particles was adjusted to produce flocculated suspension. Drug resin particles were then incorporated into the structured vehicle, containing Carbomer 934P as a polymer, to enhance the physical stability and ease of resuspendability of the product. This delivery system also optimized the bioavailability of Betaxolol, reducing the total drug concentration in half to 0.25% Betaxolol in 0.25% BETOPTIC S Ophthalmic Suspension as compared with 0.5% Betaxolol in BETOPTIC 0.5% Sterile Ophthalmic Solution dosage form. Increased comfort of 0.25% BETOPTIC S Ophthalmic Suspension, as well as its bioequivalency data in animal models (rabbits), was confirmed in actual clinical trials of the product 0.25% BETOPTIC S Ophthalmic Suspension. The 0.25% BETOPTIC S Ophthalmic Suspension product has been approved gamma FDA and is marketed in U. S. since February 1990. The 0.25% BETOPTIC S Ophthalmic Suspension formulation has an increased bioavailability (equivalent to BETOPTIC 0.5% Sterile Ophthalmic Solution at half the concentration of drug); and pharmaceutically, is an elegant suspension product which settles slowly providing uniform dosage and increased ocular comfort.
authors.affiliation: Alcon Laboratories, Inc., Fort Worth, Texas.
authors.forename: R
authors.initials: R
authors.lastname: Jani
authors.forename: O
authors.initials: O
authors.lastname: Gan
authors.forename: Y
authors.initials: Y
authors.lastname: Ali
authors.forename: R
authors.initials: R
authors.lastname: Rodstrom
authors.forename: S
authors.initials: S
authors.lastname: Hancock
mesh_terms: D000180:Acrylic Resins; D000818:Animals; D000867:Anterior Chamber / Q000378:metabolism; D015784:Betaxolol / Q000008:administration & dosage* / Q000737:chemistry; D001682:Biological Availability; D003315:Cornea / Q000378:metabolism; D004058:Diffusion; D004337:Drug Carriers; D016503:Drug Delivery Systems / Q000379:methods*; D004355:Drug Stability; D006801:Humans; D009883:Ophthalmic Solutions; D011817:Rabbits; D012117:Resins, Synthetic / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D004337:Drug Carriers; D009883:Ophthalmic Solutions; D012117:Resins, Synthetic; C006903:carbopol 940; C046797:amberlite; D015784:Betaxolol