by Joel Harrison
19. September 2010 11:13
Numerous diseases, such as glaucoma, require taking eye drops daily or even several times a day. This fact, apart from being a major inconvenience for active people, raises the question of the effectiveness of such a way of drug administration. Studies have shown that only one to seven percent of the dose is absorbed by the eye. Researchers from the Laboratory for Biomaterials and Drug Delivery at Children's Hospital Boston have been investigating the problem and developed contact lenses that gradually dispense medications. Moreover, the rate at which the drugs are dispensed can be modified to suit each patient’s needs.
Though drug-releasing contact lenses have been developed by other groups of researchers as well, the previous ones did not dispense medications steadily enough. As a result, after some time, the doses were too low to have therapeutic effects.
The new lenses consist of two layers made of polymers already approved for ocular use. During tests the lenses released an antibiotic called ciprofloxacin for 30 days and the dispensed doses were high enough to kill the targeted pathogens. The researchers are currently planning to start testing the lenses on human subjects.