Researchers developing drug-eluting contact lenses.

Wired (7/22, Leggett) reports that, according to a study published in the July issue of Investigative Ophthalmology & Visual Science, Harvard University scientists "report that they've created a contact lens that can deliver a high concentration of antibiotic at a constant rate for more than 30 days." The investigators "describe their new design like a pita pocket, with a big wad of drug in the middle of a hydrogel exterior." In order "to make their lens, the researchers took a biodegradable polymer called PLGA and dissolved it in an organic solvent, and then they added their drug. As the solvent evaporated, they were left with drug mixed into a polymer film." Next, "they coated the film in a hydrogel called pHEMA, which is the same material that's used to make regular contact lenses." In laboratory dish studies, the "prototype lens" has been tested with the antibiotic "ciprofloxacin, which is commonly used to treat eye infections."