Experimental Contacts May Ease Pain After Laser Eye Surgery
Study Suggests That Lenses Laced With Pain Meds Could One Day Replace Regular Eye Drops
WebMD News Archive
Delivering Drugs Through Contact Lenses
For his experiment, Chauhan soaked water-permeable contact lenses in a solution that contained the anesthetic drug lidocaine.
In some batches, the contacts were soaked in the drug alone, and in others, the lenses were also soaked in solutions that contained various concentrations of vitamin E.
The lenses absorbed the drug and the nanoparticles of vitamin E, but they stayed clear, suggesting that the added ingredients wouldn’t interfere with vision.
The modified lenses were then blotted and dried and then placed back into a saline solution to test how long it might take them to release their medication.
Those that contained lidocaine alone released 90% of the drug within about two hours, meaning that they lasted about as long as conventional eye drops.
But the lenses that also contained nanoparticles of vitamin E lasted much longer, releasing nearly all their medication within six to 11 hours.
Chauhan explains that the vitamin E, which doesn’t dissolve in water, creates physical barriers in the lens that slow the delivery of the drug.
“The drug molecules have to weave around these vitamin E barriers,” he says. “Vitamin E essentially acts as bricks inside a contact lens to slow down the drug release.”
Chauhan and his team are currently testing the technology in animals. If all goes well, he says they hope to have the lenses on the market in about eight years.
The study was published in the American Chemical Society journal Langmuir.