Researchers from Massachusetts Institute of Technology, spurred by a challenge from Bill Gates, developed a star-shaped drug capsule that can gradually release medication and stay in the stomach for to 2 weeks after being swallowed. The study, published yesterday in Science Translational Medicine, described the team’s work using the capsule to deliver an anti-parasitic drug, invermectin, which could help fight malaria.
The pill has 6 arms that are folded inwards, protected inside a smooth capsule. Drugs are loaded into each arm, which is attached to a core by a linking mechanism that eventually breaks down.
Once the capsule is swallowed, stomach acid dissolves the outer layer and the arms can unfold. The unfolded star is big enough to resist the forces that normally push oral drugs out of the system, but small enough that it won’t cause a blockage.
“When the star opens up inside the stomach, it stays inside the stomach for the duration that you need,” researcher Tyler Grant told Reuters.
The team tested the device in pigs and found that the drug doses were released over 2 weeks, at which point the linking mechanism that join the arms of the star to the core dissolve and break off, enabling the pill to pass through the system. Using mathematical models, researchers analyzed the potential impact of a long-acting capsule with invermectin and found that if it were used along with antimalaria treatments in 70% of a population, malaria transmission would decrease at the same rate if 90% of the population were given antimalaria treatments.
Long-acting drug delivery systems already exist as injections or implants, but researchers have long struggled to find a way to make oral drugs long-acting. Injections and implants involve invasive procedures and aren’t always suitable for the patient. But until now, oral drugs have had to act quickly due to the harsh environment of the stomach.
“Until now, oral drugs would almost never last for more than a day,” MIT professor and researcher Robert Langer told the news outlet.”This really opens the door to ultra-long-lasting oral systems … There are a lot of exciting things this could someday enable.”