Slow-release pill could answer medication adherence problems
A multi-dose capsule drug delivery system is being developed that could solve one of medicine’s more vexing problems: delivering oral drugs over an extended period of time with one dose. The capsule, once swallowed, expands into a star-shaped form that prevents it from passing into the small intestine but allows other food to pass. It releases medicine over the course of days, before breaking apart and passing through the digestive tract. Currently, fewer than half the world’s patients under treatment for chronic illnesses take their medicine as prescribed, and this could solve the problem of “medication non-adherence.”

A meeting between Bill Gates and Boston researchers four years ago has led to the development of a multi-dose capsule that, researchers said, could solve one of medicine’s more vexing problems: delivering oral drugs over an extended period of time with one dose.

The new device has so far only been tested on pigs, not humans, but results published Wednesday in Science Translational Medicine could pave the way for human trials next year.

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“There’s a reason nobody’s ever been able to do this before,” said Dr. Andrew Bellinger, cofounder of Lyndra, a health care company that licensed the capsule technology from the Massachusetts Institute of Technology and Brigham and Women’s Hospital, where he is a practicing cardiologist. “It was pretty challenging.”

The capsule, once swallowed, expands into a star-shaped form that prevents it from passing into the small intestine, but allows other food to pass. It releases medicine over the course of days, then, after releasing the final dose, breaks apart and passes through the digestive tract without being absorbed.

The capsule represents the latest effort to solve a major flaw in drug delivery: Because the human stomach clears its contents multiple times daily, pill takers must dose themselves frequently.

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Diana Saville and Dr. Giovanni Traverso

Extended-release pills on the market today can reduce the frequency of doses, but they still pass through the stomach as quickly as other contents do. For dosage over days or weeks, drug makers currently turn to non-oral formulations of drugs, for instance in patches or under-skin implants.

Meanwhile, fewer than half the world’s patients who are under treatment for chronic illnesses take their medicine as prescribed. In some cases, it’s because of pure forgetfulness or neglect, researchers said, while in other cases people are reluctant to take their medication because of the stigma of their illness, or they simply don’t wish to be reminded about their health issues.

Whatever the reason, so-called medication non-adherence carries a huge cost in both human and financial terms, resulting in unnecessary disease progression and hospitalizations, as well as preventable deaths from uncontrolled disease.

Dr. C. Giovanni Traverso, a gastroenterologist at Brigham and Women’s, said the idea started after he was introduced by MIT engineer Bob Langer to Bill Gates, who asked about drug delivery issues. Subsequent discussions with Gates Foundation staff, Traverso said, led to a challenge: devise an oral capsule that could, by itself, deliver a full course of treatment.

The Gates Foundation partly funded the research, and suggested the researchers focus initially on anti-malaria drugs, which are a central focus of the foundation. Traverso and Bellinger’s team designed the expanding capsule to deliver the anti-parasitic drug ivermectin, and tested it in Yorkshire pigs of between 77 pounds and 110 pounds, whose gastric anatomy is similar to that of humans. The researchers found that the capsule delivered sustained doses of the drug for up to 10 days.

In its current form, the capsule is best suited for drugs with “daily doses of less than 20 to 50” milligrams, researchers said, because of structural limits of the materials used in the design. Whatever the dosage sizes, Bellinger and Traverso said the delivery device could improve treatment for a range of medical problems where non-adherence is common, including hypertension, diabetes, neurological disorders, and opioid use disorder, among others.

Lyndra plans to seek FDA approval to test the capsule in humans, but that will bring some challenges — and perhaps more animal testing first. Pigs move food from their stomachs more slowly than humans, so the researchers suggested testing in animals with faster gastrointestinal “transit times,” and who, like humans, also experience strong stomach compressions.

It is also unclear whether medications like ivermectin may be rendered less effective by protracted time in the stomach, even inside the protection of the capsule.