A team at Brown University has built a Tylenol-sized magnetic capsule that can be directed safely through the intestines to a target using an external magnet. This way the gelatin pill can be held in place, ensuring that enclosed drugs are absorbed at the right spot - say at the site of a tumor or infection.
The team has already proved the safety of this drug delivery in rats. Using a miniature cantilever device that bends in response to forces between the internal and external magnets, the researchers determined how to maneuver the pill without harming tissues. Readings from the cantilever fed into a computer system which automatically adjusted the placement of the external magnet to minimize the exerted force. After twelve hours of holding the pill in place in a rat intestine, the team calculated that the magnets had only applied 1/60 of the amount of pressure that it would take to damage the intestinal wall.
Though the rat tests haven't yet been used to treat an ailment, in the future such a system could be useful to cancer or diabetes patients. Additionally, iron particles inside the capsules make them visible to X rays. By tracking exactly where the pill is inside the intestine while the magnet is holding it in place, researchers could presumably look for the optimal sites of drug absorption. In fact, that is the next task of this project. And if this monitoring system could eventually be adapted to work with magnetic fields rather than X rays, tracking the pills would be patient-safe.
For clinical use, outside magnetic forces will need to be carefully controlled or the system will need to wise-up and respond to the environment as well as itself. Still, as team member Bryan Laulicht told the MIT technology review, he ultimately thinks this method could be used in an outpatient setting. Future swallowers saying "that hits the spot" might mean so quite literally.