Published On December 17, 2015
COMING UP WITH A MIRACLE CURE IS ONLY STEP ONE. For it to save a life, a patient needs to comply with a physician’s directions, and in the case of oral medications, that is easier said than done. For instance, 34% of patients who have had a heart attack and are given multiple prescriptions stop taking one of them entirely within one month of leaving the hospital.
In developed countries, adherence to long-term treatment therapies happens only about half the time, and in the United States alone, failing to take medications as prescribed is estimated to cost more than $100 billion in avoidable hospitalizations each year, according to a report in the New England Journal of Medicine.
But researchers at MIT and Massachusetts General Hospital have recently developed a possible solution: a polymer that could be used to create a new kind of long-acting medication-delivery system. The system could then be folded into a capsule and taken by mouth, and you get something that releases drugs over many weeks.
“A few years ago, a team from the Gates Foundation asked whether we could help them think of potential solutions to the non-adherence problem—specifically, simplifying the way that medication is administered to malaria patients in the field,” says Giovanni Traverso, a gastroenterologist at Massachusetts General Hospital and an author of the study. “So we began testing ways of delivering medication that would enable extended release of a drug.”
The challenge included a few puzzles. Current extended-release capsules can be active for only about 30 hours—the average time it takes for them to pass through the gastrointestinal tract. Achieving longer-lasting release typically requires a surgically implanted device that avoids the digestive tract.
Would it be possible to engineer a device small enough to take by mouth, but large and stable enough to remain safely in the stomach and not pass through? “One problem we worried most about was having a dosing system pass from the stomach into the small intestine and cause an obstruction,” says Traverso.
They decided to create a ring-shaped device that could be compressed into an oral capsule and then would expand in the stomach. The material for the device had to be both elastic, so it could be folded, and pH sensitive—so that it would be stable in the highly acidic environment of the stomach but would disintegrate if it accidentally passed through to the neutral pH of the small intestine.
They designed a prototype made from a custom polymer with those properties, and tested its effectiveness in pigs. The ring expanded to its original form within 15 minutes, and stayed in the stomach for up to one week. After that, the material broke down and passed through to the small intestine.
The team has also engineered sturdier variations of this initial technology that can reside in the stomach for weeks or even months without disintegrating.
“We are very encouraged by our preliminary work,” says Traverso. “Although our goal is to develop systems that can treat infectious diseases such as malaria, HIV or tuberculosis in sub-Saharan Africa or Southeast Asia, there are many applications here in the U.S. for treating chronic conditions such as heart disease, diabetes or psychiatric illness. We are actively developing these systems through Lyndra, a biotechnology company we have started with Prof. Robert Langer to help bring these technologies to patients.”
Although the technology needs more testing for safety and efficacy, the team hopes to have something useful for patients within the next two to three years. “For patients, the experience is the same—they are just taking a capsule,” he says. “But instead of taking it every day, they are taking it once a week or once a month.”
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