Vitamin E Aids Delivery of Glaucoma Meds

GAINESVILLE, Fla.Loading vitamin E into medicated contact lenses can help keep glaucoma medication near the eye almost 100 times longer than possible with normal commercial lenses, according to researchers from the University of Florida. In a presentation at the 239^th National Meeting of the American Chemical Society (ACS) in San Francisco, Anuj Chauhan, Ph.D., described the use of vitamin E to develop contact lenses that enhance the delivery of topical medications into the eye.

Current glaucoma treatment involves using eye drops to relieve the abnormal build-up of pressure in the eye. However, Chauhan explained normal tears generally wash the drug away from the surface of the eye, where it is often absorbed into the bloodstream instead. Instead, Chauhan and colleagues developed an extended-release delivery approach incorporating vitamin E into contact lenses. Aggregates of vitamin E molecules form barriers to slow down the elusion of the glaucoma medication from the lens into the eye.

These vitamin structures are like nano-bricks, Chauhan said. The drug molecules cant go through the vitamin E. They must go around it. Because the nano-bricks are so much bigger than the drug moleculesabout a few hundred times biggerthe molecules get diverted and must travel a longer path. This increases the duration of the drug release from the lenses.

In research with laboratory animals, lenses containing vitamin E nano-bricks administered drugs up to 100 times longer than most commercial lenses. In addition to treating glaucoma, the contacts could help other eye conditions, such as cataract and dry eye.

Chauhan added, Vitamin E is a proven nutraceutical that in small amounts is good for the eye because of its antioxidant properties. Also, vitamin Es presence in the contact lenses blocks UV radiation, leading to increased protection against the UV light. Our research has shown that the vitamin can be loaded into the lenses without any reduction in transparency. We believe it could be helpful in disease treatment and in prevention as well.