Daily insulin injections to control blood sugar is a common routine for those living with diabetes, but less disruptive oral treatment options are on the way. Researchers at Niagara University in the US are building on this approach by developing a new method of encapsulating the insulin so that it reaches its target intact.

The problem with delivering insulin orally is the acidic environment of the stomach, which degrades the protein before it can get to the intestine and then travel through the bloodstream where it is needed.

The Niagara University approach is based around the use of a patented particles known as Cholestosomes to encapsulate the insulin. These vesicles (fluid filled sacks) are made of lipid molecules, which are building blocks of fats, but the method differs from other approaches that use lipid-based drug carriers (liposomes), according to the researchers.

"Most liposomes need to be packaged in a polymer coating for protection," says Lawrence Mielnicki, Ph.D. "Here, we're just using simple lipid esters to make vesicles with the drug molecules inside."

Using computer modeling, the research team demonstrated that once the lipids are assembled into the spherical Cholestosomes, they form neutral particles that are not vulnerable to the acids in the stomach. The spheres can be loaded with drugs and go through the stomach without being harmed.

From the stomach, they will reach the intestine, where they will be recognized as something that needs to be absorbed. From there, the spheres will get into the bloodstream, where they will be broken apart and the insulin released.

During lab tests, the researchers looked into the optimal PH and ionic strength of the solution carrying the drug to find out how much insulin the Cholestosomes could carry. The tests showed that certain formulations of Cholestosomes loaded with insulin resulted in higher bioavailability, that is, the vesicles take insulin where it is needed more efficiently.

The team is now looking into ways to further optimize the formulations before conducting more testing on animal and eventually human models.

In the following video, Mary McCourt, Ph.D., Lawrence M. Mielnicki, Ph.D. and Jamie Catalano of Niagara University present the findings at the 252nd National Meeting & Exposition of the American Chemical Society.