One of the less appealing aspects of diabetes, especially type 1, is the requirement for injecting insulin — sometimes several times each day. Insulin is a protein hormone, and as such it can't be taken as a pill because it gets broken down by the stomach acid before it can reach the circulation to control blood sugar levels. Thus the necessity for injecting it. But that may soon change.
Researchers have been trying to figure out a way to circumvent the necessity for injecting insulin for quite a while. One method was the development of an inhalable form of the hormone, which worked, but didn't sell. Another means is some sort of protective coating for insulin — and a new one has just been reported.
A group of researchers from Niagara University in Lewistown, NY, reported at the meeting of the American Chemical Society that they have developed a new pill that can protect insulin (and probably other protein hormones) from stomach acid and allow it to reach the small intestine. From there it can be absorbed into the blood.
Team leader Dr. Mary McCourt reports that by using a lipid vesicle called a CholestosomeTM, they can package the insulin in a way that can protect it. This is not an entirely new idea, but Dr. McCourt commented that other types of lipid vesicles had to have protective coatings to make it through the stomach. This new one does not. Once the lipid spheres are constructed, they form neutral particles that can resist stomach acid. When they reach the small intestine they are absorbed into the bloodstream like other lipid particles.
So far, the researchers say that the CholestosomesTM loaded with insulin reached the blood of rats they were tested on, suggesting that this could indeed be a successful means of providing humans with diabetes the insulin they need. Of course, these results are quite preliminary — more animal testing is needed to determine the amounts of hormone needed to have appropriate actions — too much and there's a risk of hypoglycemia which can be life-threatening. Then they can move on to clinical trials to ascertain the kinetics of absorption and action in humans. If all this pans out, and the new type of pill can be manufactured at reasonable cost, insulin-requiring diabetics may be able to toss their syringes in the not-too-distant future.