New hydrogels may address ophthalmology’s need for sustained-release drug delivery

WAILEA, Hawaii — Thermoreversible hydrogels, though not yet available for ocular use, present great promise for sustained-release drug delivery, according to a speaker here.

William F. Mieler, MD, said the aqueous-based delivery system consists of a drug dissolved in a solution of temperature-sensitive polymer. For diseases such as age-related macular degeneration, a sustained-release drug delivery system could enable physicians to reduce the number of injections needed, he said.

“At room temperature, the constituted product exists as a solution. After injection and upon exposure to body temperature, the product gels,” Dr. Mieler said during Retina 2006, held in conjunction with Hawaiian Eye 2006.

Dr. Mieler said three companies are currently working on such hydrogels: MacroMed, RxKinetics and Pike. None have formulated an ocular application to date.

Another company, QLT Inc, has created Atrigel, a compound that acts similarly to a gel, solidifying at body temperature. Atrigel has been used subcutaneously in human beings for delivery of a handful of drugs, and it is currently in early animal studies for ocular applications, he said.

Dr. Mieler said it is a matter of time before these compounds are adapted for ophthalmic use.

“While this talk is quite theoretical, we have the team in place to take this all the way,” he said.