Loading contact lenses with vitamin E can transform the polymeric disks into drug delivery devices. The lenses, developed by chemical engineers at the University of Florida, dramatically extend the amount of time the eye is exposed to an ophthalmic medicine—from a few minutes for eye drops currently in use to up to a month with the new technology—thereby increasing the drug's efficacy.
The work was presented Wednesday afternoon at the ACS national meeting in San Francisco during a session of the Division of Polymer Chemistry.
Anuj Chauhan, Cheng-Chun Peng, and Jinah Kim create the lenses by soaking commercial contacts in a solution of vitamin E and then adding a drug, such as the glaucoma treatment timolol or the antifungal compound fluconazole. The hydrophobic vitamin creates nanobarriers within the lens that make a tortuous path for the hydrophilic medications. Compared with an ordinary lens, the vitamin-treated contact extends the drugs' release by a factor of about 100.
Adding vitamin E to the lens increases its size a bit and slightly reduces its oxygen permeability, but neither is significant enough to make the lenses uncomfortable, Chauhan tells C&EN. On the plus side, the vitamin blocks harmful ultraviolet rays, providing additional eye protection. The researchers hope to get the lenses into human trials within the next couple of years.