Researchers in the US have developed an ‘insulin pill’ – a capsule that, when swallowed, can release insulin into the bloodstream via the gut – using an approach that could one day allow people with type 1 diabetes to avoid injections.
The team at the Massachusetts Institute of Technology showed that the 3-centimetre capsule could carry a similar amount of insulin to an injection, and deliver it to the intestines to be taken up into the blood.
Although the research was conducted in pigs, the researchers are now looking at next steps for developing their invention.
Although many medicines can be taken in pill form, insulin is a protein and so is broken down in the stomach before it can get to work.
This makes it challenging to develop a capsule that can survive the harsh acidic environment of the stomach, and only release the insulin once it gets to the intestines.
This capsule is designed with a special coating that allows it to withstand stomach acid, but which triggers it to break open once it reaches the less acidic environment of the small intestine.
When the capsule opens, it releases three folded arms coated with tiny (1 millimetre long) needles.
These needles penetrate the topmost layer of the walls of the small intestine and dissolve, releasing the insulin into the blood.
The rest of the capsule is then passed out as waste.
Still work to be done
The results, published in the journal Nature Medicine, suggest the capsule can reach the small intestine intact, and that it can deliver insulin through the gut wall – important steps towards developing an insulin pill for type 1 diabetes.
However, one important hurdle the researchers still need to overcome is the timing of the insulin release. Because the capsule’s arrival in the intestines depends on how quickly a person digests their food, this could make dosing for meals a challenge.
The team believes that by fine-tuning how long the pill takes to open in the intestine, they could begin to tailor how long it takes to deliver its insulin.
Karen Addington, UK Chief Executive of 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.”
Professor Robert Langer, David H. Koch Institute Professor at MIT and one of the authors of the research, said: “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.”