New oral insulin could replace injections for diabetics

Researchers have developed a new oral delivery method for insulin, which could allow people with diabetes to avoid frequent and painful injections, according to an August 24, 2016 presentation at the American Chemical Society’s 252nd National Meeting & Exposition in Philadelphia, PA.

The oral delivery method encapsulates insulin in a newly-developed vesicle called a Cholestosome™, researchers explained. “A Cholestosome is a neutral, lipid-based particle that is capable of doing some very interesting things,” said lead researcher Mary McCourt, PhD, Professor of Chemistry at Niagara University, NY.

Importantly, Cholestosomes can survive enzymatic degradation and then pass through the intestinal wall—two impenetrable barriers to previously studied forms of oral insulin.

“The technology is a vesicle that carries the molecules intact to the GI tract, without the obstacles of prior versions that degraded the insulin in the harsh, highly acidic environment of the stomach,” Dr. McCourt explained.

“[The] Cholestosome is resistant to pH and bile salts, which, when met with absorbing lipids, becomes picked up by that carrier and delivered intact,” she added, noting that these results were demonstrated in experiments in rat models. “Cholestosomes also get into cells directly and move into the bloodstream where they're needed.”

The novel vesicles are comprised of naturally-occurring lipid molecules, but they have a different structure than currently used drug-carrying liposomes.

“Most liposomes need to be packaged in a polymer coating for protection,” said co-presenter Lawrence Mielnicki, PhD, Director of Niagara’s Research and Teaching Laboratories. “Here, we're just using simple lipid esters to make vesicles with the drug molecules inside.”

This means that this delivery vehicle can be used for other drug applications, too. “We can package anything inside these vesicles and potentially deliver a lot of therapeutics,” Dr. Mielnicki explained. “So there's a lot of applications for this technology beyond insulin.”

Meanwhile, other researchers are now investigating an oral insulin pill that is entering Phase III clinical trials, Dr. Mielnicki noted. However, Cholestosomes, which were administered as a liquid to the lab rats, have a three- or four-fold greater rate of absorption than the insulin pill, Dr. Mielnicki estimated.

He and his fellow researchers are currently planning to further improve the formulation, conduct additional animal testing, and develop new partnerships to move the technology forward into human trials.