A team of researchers at the University of British Columbia working to develop oral insulin tablets as an alternative to daily insulin injections has made a groundbreaking discovery.
The researchers found that the rats absorbed the insulin from the latest version of their oral tablets in the same way as injected insulin.
“These exciting results show that we are well on our way to developing an insulin formulation that will no longer need to be injected before each meal, improving the quality of life and mental health of more than nine million type 1 diabetics worldwide,” says the Professor Dr. Anubhav Pratap-Singh, Senior Research Fellow at the Faculty of Land and Food Systems.
He explains that the inspiration behind the search for non-injectable insulin came from his diabetic father, who has injected insulin 3 or 4 times a day for 15 years.
According to Dr. Alberto Baldelli, principal investigator in Dr. Pratap-Singh’s lab, they now see almost 100% of the insulin in their tablets going directly to the liver. In previous attempts to develop drinkable insulin, most of the insulin was stored in the stomach.
“Even after two hours of labor, we found no insulin in the stomachs of the rats we tested. It was all in the liver, and that’s the perfect target for insulin – that’s really what we wanted to see,” says Yigong Guo, the first author of the study and doctoral student who works closely on the project.
Regarding insulin administration, injections are not the most comfortable or convenient for diabetic patients. But with several other alternatives to oral insulin also being tested and developed, Dr. Pratap-Singh’s team worked to determine where and how to facilitate a higher absorption rate.
Dr. Pratap-Singh’s team has developed another type of tablet that should not be swallowed but dissolves when placed between the gum and cheek.
This method uses the thin membrane found in the lining of the inner cheek and behind the lips (also known as the oral mucosa). It delivered all the insulin to the liver without wasting or breaking down the insulin along the way.
“For injected insulin, we typically need 100 IU per injection. Other ingested pills in development that go to the stomach may require 500 IU of insulin, which is largely wasted, and that’s a major problem that we’ve tried to address,” Yigong explains.
Most developing swallowed insulin tablets tend to release insulin slowly over two to four hours, whereas rapid-release injected insulin can be fully released in 30 to 120 minutes.
“Like rapid-acting insulin injection, our oral tablet is absorbed after half an hour and can last two to four hours,” says Dr. Baldelli.
Extended Potential Benefits
The study has yet to enter human trials, and for that to happen, Dr. Pratap-Singh says they will need more time, funding, and collaborators. But beyond the obvious potential benefits for diabetics, she says the tablet they’re developing could also be more durable, cost-effective, and accessible.
“More than 300,000 Canadians need to inject insulin several times a day,” says Dr. Pratap-Singh. “That’s a lot of environmental waste from plastic needles and syringes that might not be recycled and end up in landfills, which wouldn’t be a problem with an oral tablet.”
He explains that he hopes to reduce the cost of insulin per dose since its oral alternative could be cheaper and easier to manufacture. Transporting the tablets would be easier for people with diabetes, who must remember to keep their doses cold.