VANCOUVER, British Columbia — The most common way to administer insulin is under the skin with a small needle or an insulin pen, but this may soon change. Researchers at the University of British Columbia (UBC) are developing an oral insulin tablet that, if successful, could make it easier for people with Type 1 diabetes to take their medicine.
“These exciting results show that we are on the right track in developing an insulin formulation that will no longer need to be injected before every meal, improving the quality of life, as well as mental health, of more than nine million Type 1 diabetics around the world,” says Dr. Anubhav Pratap-Singh, senior author of the study and a researcher at UBC, in a university release.
Dr. Pratap-Singh and his team are using rats to see how the body absorbs insulin from oral tablets compared to injected insulin. The search for an insulin tablet is personal. Dr. Pratap-Singh’s father was a diabetic and needed to inject insulin three to four times a day to stay alive for another 15 years.
Changing how insulin enters the bloodstream can improve a person’s quality of life. Injections are not comfortable or convenient, especially when someone is out at dinner or in another public space. While scientists have dabbled with the idea of an insulin pill, the main concern is how well the body absorbs insulin compared to traditional injections.
Insulin pill dissolves in the mouth
In the current study, the researchers devised a workaround to improve absorption. Instead of a person directly swallowing the pill, they would instead let the tablet dissolve between the gum and cheek. Dissolving will allow the insulin to enter the thin membrane found in the lining of the inner cheek and back of the lips.
“For injected insulin, we usually need 100iu per shot. Other swallowed tablets being developed that go to the stomach might need 500iu of insulin, which is mostly wasted, and that’s a major problem we have been trying to work around,” explains lead study author Yigong Guo.
Swallowed insulin tablets have a slow absorption rate, with insulin released over two to four hours. For comparison, injections fully release insulin within 30 minutes to two hours. Since the insulin bypasses absorption and metabolism in the stomach, the entire insulin amount would theoretically find its way to the liver.
“Similar to the rapid-acting insulin injection, our oral delivery tablet absorbs after half an hour and can last for about two to four hours long,” adds study author Dr. Alberto Baldelli, a senior fellow in Dr. Pratap-Singh’s lab.
Promising results in animal tests
In the current study, rats taking the oral tablet displayed a near 100-percent insulin absorption rate. The released insulin also traveled to the liver directly.
“Even after two hours of delivery, we did not find any insulin in the stomachs of the rats we tested. It was all in the liver and this is the ideal target for insulin—it’s really what we wanted to see,” Guo reports.
While the insulin tablet is still awaiting human tests, the findings are a step forward in creating sustainable, accessible, and cost-effective treatment options. Dr. Pratap-Singh notes there is “a lot of environmental waste from the needles and plastic from the syringe that might not be recycled and go to landfill, which wouldn’t be a problem with an oral tablet.”
The study is published in Scientific Reports.