The Contact Lens as a Medical Device for Delivering Glaucoma Drugs

Abstract

Abstract: : Purpose: This work was conducted to determine if hydrogel contact lenses could be used to deliver various glaucoma medications either individually or in combination. Methods: Diluted drugs were passively transferred to contact lenses under aseptic conditions. The uptake and release of soluble drugs were evaluated by liquid chromatography. Efficacy of the released molecule was done in humans. Results: Analytical data showed that timolol maleate and brimonidine tartrate were passively transferred to contact lens materials with three hours. These diluted molecules were used to treat patients with pre-existing glaucoma. Diluting the drugs was the key factor in eliminating the acute toxicity previously observed by this delivery method. Analytical data showed that the two molecules were well separated upon assay and that their chemical structure did not change upon release from the lens materials. This was true whether the drugs were passively transferred individually or together in the same lens material. Materials of different water contents and ionicity were evaluated. Conclusion: The data show that diluted glaucoma medications may be delivered to patients with glaucoma and their interocular pressure is controlled by this treatment. Dilution of the drugs below their usual formulations was a key in eliminating the toxic reactions previously reported. Dilution of other glaucoma drugs may be used in this contact lens system described.

Keywords: contact lens • drug toxicity/drug effects • intraocular pressure