Researchers are developing an insulin pill that could soon offer a pain-free blood sugar management option to people with diabetes.
“With diabetes, there’s a tremendous need for oral delivery,” says Samir Mitragotri, professor in the chemical engineering department at the University of California, Santa Barbara, who specializes in targeted drug delivery. “People take insulin several times a day and delivery by needles is a big challenge.”
More than 29 million individuals in the United States have undiagnosed or diagnosed diabetes, according to 2014 estimates from the Centers for Disease Control. Many of these people require regular insulin shots.
For those who don’t like needles, the discomfort injections can pose is a huge barrier to compliance, says Amrita Banerjee, a postdoctoral researcher in Mitragotri’s lab. “It can lead to mismanagement of treatment and complications that lead to hospitalization.”
A pill could circumvent the discomfort associated with the needle while potentially providing a more effective dose, researchers say.
“When you deliver insulin by injection, it goes first through the peripheral bloodstream and then to blood circulation in the liver,” Mitragotri says. Oral delivery would take a more direct route, and, from a physiological point of view, a better one.
While oral medications to help the body produce insulin have been around for a while, a pill that delivers insulin remains a highly sought goal of diabetes medicine. The main obstacle to its development has been getting the medication past the hostile proteolytic environment of the stomach and intestine without destroying the protein itself.
In the case of the new pill, the key is a combination of enteric-coated capsules and insulin-loaded mucoadhesive polymer patches that were optimized by Banerjee as part of her research. The new pill has demonstrated its ability to survive stomach acids with the protection of the enteric-coated capsule and deliver its payload to the small intestine.
There, the capsule opens up to release the patches that adhere to the intestinal wall, preventing access of proteolytic enzymes to insulin and, with the aid of a permeation enhancer, depositing insulin that can pass through to the blood.
“This is the first essential step in showing that these patches can deliver insulin,” Mitragotri says, adding that the concept still needs to undergo additional stages of testing and improvement before it can be considered as a viable treatment for diabetes.
The drug-loaded mucoadhesive patches show early promise for other forms of therapy, as well.
“We can deliver many proteins that are currently injected,” Mitragotri says, adding that other protein-based therapies such as growth hormones, antibodies, and vaccines could potentially be put into patch form for painless delivery and improved patient compliance.
The researchers presented their findings at the American Association of Pharmaceutical Scientists’ annual meeting and exposition. The National Institutes of Health funded the work.
Source: UC Santa Barbara