In people with type 1 diabetes, the pancreas does not produce insulin – a hormone that helps glucose to enter cells to give them energy – that's why they take insulin. In people with type 2 diabetes, the body does not produce or use insulin well, so insulin therapy may be necessary.
Insulin can be administered using a needle and syringe, a pen injection, a pump through a needle, an inhaler, an injection port or what is called a jet injection. which sends an insulin spray into the skin at high pressure.
Still, there have been several research efforts around the world to develop pills as another way to take insulin. These efforts are ongoing, but if they are safe and effective, they could change the daily well-being of more than 400 million people living with diabetes worldwide. About 40% of them rely on insulin injections.
"Insulin is currently administered primarily by injections, which is a challenge for type 1 diabetics and a deterrent for type 2 diabetic patients. An oral pill for insulin will facilitate the taking of Insulin by patients, "said Samir Mitragotri. , professor of bioengineering and biologically inspired engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences.
The development of insulin that patients can ingest remains a scientific challenge because insulin can be broken down in the stomach by acids and enzymes before being used in the body, said Mitragotri.
In other words, insulin must survive in the hostile environment of your digestive system.
"Even if some of the insulin gets into the intestine, it can not cross the intestinal wall because the wall is designed to prevent the transport of protein," Mitragotri said.
"The layer of mucus present on the wall of the intestine also makes the transport of insulin from the intestine into the bloodstream very difficult," he said. "Collectively, these obstacles make the oral administration of insulin very difficult."
The science behind insulin that you can swallow
Mitragotri was the main author of a study published Monday in the Proceedings of the National Academy of Sciences that describes how a new liquid formulation of insulin inside the body. an enteric-coated capsule was able to lower blood glucose levels in rats.
Enteric means that the coating can only be dissolved in the small intestine of the body.
For the study, the researchers gave six non-diabetic male rats an oral insulin capsule and three traditional insulin injections to non-diabetic male rats.
The researchers found that blood glucose levels fell rapidly by 38% in capsule-fed rats within two hours and continued slowly but steadily to decrease, dropping by 45% in 10 hours.
In comparison, blood glucose levels dropped 49% within one hour in injected rats. Levels then increased, which is a typical response in non-diabetic rats, before continuing to decline in a typical pattern.
"The administration of oral insulin has been difficult, the study demonstrates a new technology to overcome these challenges," said Mitragotri.
"The next step is to carry out longer-term safety studies and efficacy tests in larger animals," he said. "These studies will provide the information needed to support human clinical trials, which we hope will begin in three to five years."
This study was just the last to experiment with creating an insulin pill; many others involve testing in humans.
Last month, Oramed Pharmaceuticals launched its largest and most advanced clinical trial of its own oral insulin pill, under the direction of the US Food and Drug Administration. The trial involves 240 patients with type 2 diabetes.
"In a year, we will better know the potential of our drug to control and maintain blood glucose and we will have additional evidence of the long-term benefits of taking an oral pill rather than an injection," said Nadav Kidron , CEO of Oramed. released in May.
Other oral experimental insulin pills are Capsulin by the company Diabetology and HDV-Insulin by the company Diasome, which was the first oral insulin approved for the Phase Three trials by the FDA, according to the website of the society.
Insulin that you can swallow has also been studied as a possible way to delay or prevent the development of type 1 diabetes, but this approach has proven ineffective in clinical studies in humans. .
In a separate study published in JAMA in November, researchers examined whether an oral type of insulin capsule could delay or prevent the development of type 1 diabetes in the parents of patients with the disease. over a period of 2.7 years.
This study involved 560 people, some of whom received an insulin capsule and others received a placebo pill.
Although some participants who received the insulin capsule had a longer time before being diagnosed with diabetes, "these results do not support the oral insulin used in this study for the prevention of diabetes." diabetes, "the researchers wrote.
Many questions remain
The future of insulin therapy is one of the research topics on the agenda of the annual scientific conference of the American Diabetes Association this week in Florida.
Research on the oral administration of insulin goes back several decades.
A study published in the journal Diabetes in 1988 involved the administration of insulin nanocapsules to rats. He found that the capsules retained the therapeutic effect of insulin during administration.
Yet more research is needed to better understand the possible risks that could come with insulin tablets. In general, insulin therapy causes changes in blood sugar, so that symptoms of hyperglycemia and hyperglycemia may appear, as shown by insulin injections.
Some studies suggest that the use of insulin might be linked to an increased risk of cancer, but of course, more research is also needed to determine if such a relationship could emerge with the use of insulin. insulin pills.
These pills are far from proven, but they are a new avenue for diabetes care.
