Magnetic pill could boost body's absorption of drugs
By Karen Sprey
January 18, 2011
Many people take pills to help manage or cure serious illness, and some of these life-saving drugs can only be absorbed in very specific parts of the intestine. The problem with oral administration is that pills often don’t dissolve at exactly the right site in the gastrointestinal tract where medicine can be absorbed into the bloodstream. A new drug delivery system developed by scientists at Brown University uses a magnetic gelatin capsule and an external magnet that can precisely sense the force between it and the pill and vary that force, as needed, to hold the pill in place. The team has successfully used the technology with rats and in future it could provide a new way to deliver many drugs to humans, including those with cancer or diabetes.
The system is not the first attempt to guide pills magnetically – Gizmag recently reported on the use of magnetically guided pills to conduct endoscopes – but it is the first in which scientists can control the forces on a pill ensuring it is safe to use in the body. The system was designed to sense the position of pills and hold them there with a minimum of force.
Edith Mathiowitz, professor of medical science in Brown’s Department of Molecular Pharmacology, Physiology, and Biotechnology, said: “With this technology you can now tell where the pill is placed, take some blood samples and know exactly if the pill being in this region really enhances the bioavailability of the medicine in the body.”
The team knew that it was critical to monitor how much force was being exerted on the pill to avoid damaging the surrounding tissue. Just a little more force than necessary could pull the pill to the external magnet.
To prevent this happening, the team including lead author and former graduate student Bryan Laulicht, built the external magnet system with sophisticated computer control and feedback mechanisms.
“The greatest challenges were quantifying the required force range for maintaining a magnetic pill in the small intestines and constructing a device that could maintain intermagnetic forces within that range,” said Laulicht.
Even after holding a pill in place for 12 hours in the rats, the pressure on the intestinal wall was less than 1/60th of what would be damaging.It could also act as a powerful research tool to help scientists understand exactly where in the intestine different drugs are best absorbed.
The external magnet can sense the pill’s position, but because the pill is opaque to x-rays, the researchers were also able to see the pill in the rat’s bodies during their studies
The next stage of the research is to measure the absorption of drugs delivered via the system. They will then move to larger animal models and ultimately into the clinic.
“It is my hope that magnetic pill retention will be used to enable oral drug delivery solutions to previously unmet medical needs," said Laulicht.