Finding simpler ways to deliver insulin into the blood stream is one important avenue for tackling the diabetes epidemic that is sweeping the developed world.

The preferred option for many patients would be an insulin pill taken orally. But studies have long shown that insulin is easily broken down by the digestive system and that any surviving hormone is not easily absorbed into the bloodstream from the gut.

An insulin inhaler made it as far as the US market in 2006, but was withdrawn a year later because it wasn’t cost effective.

But Robert Doyle, a chemist at Syracuse University in New York state, has a potential solution. He points out that the body has specific mechanisms for protecting and absorbing valuable molecules that would usually be damaged by conditions in the gut.

For example, vitamin B12 is protected by a salivary protein called haptocorrin that binds to it in the mouth and protects it in the stomach. Once haptocorrin reaches the intestines, another chemical pathway takes over to help vitamin B12 pass into the bloodstream.

Doyle suggests binding insulin molecules to vitamin B12 so that it can hitch a ride on this protected supply chain. The insulin could ride all the way into the bloodstream, where it is released to do its work. Doyle and colleagues say early tests on rats appear to work well.

The rodents got their new treatment in liquid form, but chewing gum would be a better delivery method in humans, the team says. Chewing would ensure a plentiful supply of saliva, providing the protein needed for the insulin to make its way into the bloodstream.

Read the full insulin chewing gum patent application.

by Justin Mullins
newscientist.com