A revolutionary insulin pill may allow people with type 1 diabetes to avoid needing to take injections, according to researchers in the US.
A specialist unit at the Massachusetts Institute of Technology has developed a 3cm capsule which could carry similar levels of insulin as a standard injection.
The results of the study suggest the pill is capable of reaching the small intestine intact, and that it can deliver insulin through the gut wall.
Unlike many other medicines already available as pills, insulin is a protein and is broken down in the stomach before it can get to work. This raises difficulties in developing a pill capable of surviving in the acidic environment of the stomach and only releasing the insulin once it reaches the intestines.
The research team has developed a special coating which allows the pill to withstand stomach acid and then disperse the insulin upon reaching the small intestine. The capsule achieves this by having a set of tiny arms that have 1 mm microneedles on them.
In the small intestine, the arms unfold, and the needles penetrate through the surface of the wall of the small intestine and deliver the dose of insulin. The microneedles dissolve and the rest of the capsule passes out of the body as waste.
However, further work will be required on the timing of the insulin release. The pill’s arrival in the intestine depends on how quickly a person digests their food, making it difficult to gauge the correct dose around mealtimes.
The capsule has so far been tested on pigs and the researchers found that the speed of action of the insulin was quicker via the capsule than it was for conventional subcutaneous (beneath the skin) injections of insulin.
Prof Robert Langer, one of the authors of the research, stated that by fine-tuning how long the pill takes to open in the intestine, the team could start to tailor the time span of insulin delivery.
He added: “We are really pleased with the latest results of the new oral delivery device our lab members have developed with our collaborators, and we look forward to hopefully seeing it help people with diabetes and others in the future.”
Karen Addingto, UK Chief Executive of type 1 diabetes charity, JDRF, said: “Adults and children diagnosed with type 1 diabetes must take insulin every day, simply to stay alive. Being able to take this insulin orally, rather than via injections or a pump, could make life significantly easier. We await the next stages of this particular research with interest.”
The study is published in the Nature Medicine journal.
Photo: Felice Frankel / Massachusetts Institute of Technology