Insulin in a pill: Why daily injections for diabetics could become obsolete
For people with diabetes, the Holy Grail and dream delivery method for insulin has always been to figure out how it could be delivered by pill instead of by shots. It looks like that day may have arrived. Researchers have been working on this for years and they now have developed an oral delivery method that could dramatically transform the way in which diabetics keep their blood sugar levels in check.
The necessity of insulin for people with diabetes
There are more than 400 million people worldwide living with diabetes and about 40% of them rely on daily insulin injections to keep their blood glucose levels in check. Anyone with Type 1 diabetes and for some Type 2 diabetics, injecting themselves with insulin or using an insulin pump anywhere from one to multiple times a day, can be a challenge. For some, there is the fear of pain, phobia of needles, and interference with normal activities, all of which can lead to poor adherence to a regimen they need to follow to stay healthy preventing serious medical complications.
Many have questioned why insulin has to be delivered and injected by shot and why it can’t simply be taken as a pill. Insulin is a hormone made by the pancreas and is necessary to help transport glucose from the bloodstream into the cells in the body to be used for energy. Without insulin, glucose will build up to dangerous levels in the bloodstream. When the body cannot make enough or no insulin at all, it must be taken by injection directly into the bloodstream. Since insulin is a protein, if a person were to take insulin by mouth, by the time it would reach the stomach, it would be degraded or digested by strong acids in the stomach and other enzymes which would inactivate it making it useless. That is why for decades, the most effective and logical way to administer insulin into the body has been by giving oneself a shot or injection of insulin directly into the bloodstream, bypassing the stomach and intestinal tract altogether.
Even if insulin was able to bypass the stomach and make it into the intestinal tract, it is unable to cross the intestinal wall since the wall is designed to prevent the transport of proteins such as insulin.
The problem has always been to figure out how to bypass the hostile environment of the digestive system without it becoming inactivated. The mucus layer present on the wall of the intestine makes transport of insulin from the intestine into the bloodstream very challenging, just one more hurdle which has made making oral delivery very difficult.
Published in the Proceedings of the National Academy of Sciences, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences have revealed their findings of developing a new liquid formulation of insulin inside an enterically coated capsule capable of lowering blood glucose in rats. By encapsulating the insulin-ionic liquid formulation in an enteric coating, this makes it resistant to breakdown by strong gastric acids in the gut. This polymer coating dissolves when it reaches a more alkaline environment in the small intestine where the ionic liquid carrying liquid is released.
This development of orally ingested insulin would more closely mimic the way in which the pancreas of someone without diabetes makes and delivers insulin. This could also transform better compliance to taking insulin shots for those who need to and to reduce possible side effects of lumps, swelling and other side effects of taking daily insulin shots.
More research is still needed to better understand how effectively these pills will help manage and treat diabetes. They are far from proven yet at this time, but it is a big step in the right direction of a future free from daily injections for those who must have insulin to manage their diabetes.