|Thin-film delivery system--Courtesy of MIT|
A team of MIT researchers successfully tested a thin-film drug delivery system enabling steady, sustained release of medication for about 14 months, a scientific advancement with major commercial implications.
The thin-film strip consists of layers of drugs attached to poly-L-glutamic acid, which contains two organic compounds and a bioabsorbable amino acid. The film can be injected for localized delivery or coat devices, such as orthopedic implants, MIT said in a news release.
"It's been hard to develop something that releases [medication] for more than a couple of months," MIT chemical engineering professor Paula T. Hammond said in the release. "Now we're looking at a way of creating an extremely thin film or coating that's very dense with a drug, and yet releases at a constant rate for very long time periods."
The professors demonstrated the mechanism using the painkilling nonsteroidal anti-inflammatory drug diclofenac, but believe it can be used to deliver other drugs as well, although the particular drug being delivered will have to be modified so that it binds to the thin-film coating. Still, that would be an improvement over the nondegradable devices that are currently employed to enable long-term release.
|Bryan Hsu and Paula Hammond--Courtesy of MIT|
"You can potentially implant it (the film) and release the drug for more than a year without having to go in and do anything about it," co-author Bryan Hsu said in the news release. "You don't have to go recover it. Normally to get long-term drug release, you need a reservoir or device, something that can hold back the drug. And (the device) is typically nondegradable. It will release slowly, but it will either sit there and you have this foreign object retained in the body, or you have to go recover it."
In addition, the quantity of the drug being delivered can be controlled by adding additional layers of the thin-film coating.
The scientific challenge that was overcome, at least experimentally, involved limiting hydrolysis (by which water severs the drug molecule's bonds) while allowing some degradation in order to ensure steady and sustained release, explains the news release.
In order to achieve commercialization, the team must prove that the process works in bodily environments as well as prove efficacy with the release of other drugs besides diclofenac. More details about the innovation and research method are described in a paper in the Proceedings of the National Academy of Sciences by Hammond and Hsu as well as Samantha R. Hagerman of MIT and Myoung-Hwan Park of South Korea's Sahmyook University.