Insulin Pills for Diabetes Get a Boost
About 25 percent of people in the United States who have diabetes need to take daily insulin shots. What if instead they could take insulin pills for diabetes and forever put aside those painful needles?
Scientists have been working on developing insulin pills for some time, trying to overcome the challenges associated with ingesting the hormone rather than delivering it directly to the bloodstream. Now a research team in India has completed some research that brings insulin pills one step closer to reality.
Two significant hurdles have hindered the progress of insulin pills: enzymes in the digestive tract metabolize insulin before it can work and the gut also has difficulty absorbing insulin. The end result is that insulin cannot reach the bloodstream.
The Indian team bypassed these hurdles by putting insulin in liposomes, which are fatty substances found in cell membranes. Then they covered the liposomes with a protective coating so digestive enzymes could not destroy the insulin inside.
These protected liposomes are called layeromes. As a final touch, the scientists attached folic acid to the layeromes, as this B vitamin has the ability to transport liposomes through the intestinal wall and into the bloodstream.
To test whether these layeromes could reach the bloodstream, the researchers used diabetic rats. One group received the layeromes while another group was given injected insulin.
The results? The insulin pills reduced blood glucose levels in the treated rats nearly as much as did the injected insulin. As an added bonus, the effects of the new insulin delivery system lasted longer than the injectable insulin.
More research is needed before it is known whether this approach will work in people who need insulin. However, the authors noted that their work is “expected to contribute significantly” to the quest for effective insulin pills.
In an interview in Health with Sanyog Jain, the lead researcher of the insulin pill study, the reporter asked several pressing questions concerning potential cost of an insulin pill and also when patients might expect to see the pills on the market.
Jain pointed out that manufacturing companies decide the price of drugs, but that in his opinion, “the expected cost would be lesser or comparable with current formulations.” When asked about when such pills might be available on the market, he noted that thus far animal studies alone have been done and that human studies would be next.
However, the researchers are in need of backing from the pharmaceutical industry to continue their work and to advance to clinical trials. If such support is forthcoming, “then this drug can be sold commercially in the next three to five years.”
More insulin pill research
Another team of researchers that has been working on insulin pills reported on their progress in a recent study. Edith Mathiowitz, professor of medical and engineering at Brown University, and her colleagues found that the small intestine may be better able to absorb insulin that originally believed, which may open the door to more efficient ways to deliver the hormone.
They also conducted research that seems to be a preface to the current study. That is, they reported that use of a special coating applied to nanoparticles increased absorption in rats and could transport substances (like insulin) to tissues anywhere in the body.
It appears that researchers are well on the path toward developing insulin pills. When they will be available is not yet known, but you can be sure people with type 1 and type 2 diabetes who need insulin shots will welcome them.
Agrawal AK et al. Improved stability and antidiabetic potential of insulin containing folic acid functionalized polymer stabilized multilayered liposomes following oral administration. Biomacromolecules 2013 Nov 27.
Bakhru SH et al. Oral delivery of proteins by biodegradable nanoparticles. Advanced Drug Delivery Reviews 2013 Jun 15; 65(6): 811-21
Health interview. 2013 Dec 23