RMIT research paves way for oral delivery of insulin – study

Researchers at Melbourne’s RMIT University have released study findings that appear to open the way to solve one of the biggest issues for diabetics – the need to take insulin via injection.

The researchers, led by students Jamie Strachan and Brendan Dyett have demonstrated a promising new oral delivery mode for insulin using lipid or fat-filled enteric-coated capsules -.

These could be taken orally, ending the inconvenience and possible side effects for diabetics of self-injection.

While diabetics report side effects such as pain as well as inconvenience from injecting insulin, incorrect procedures could also lead to transient and serious hypo- and hyperglycemia.

The study, reported in the journal Biomaterials Advances, said the administration of peptide insulin via subcutaneous (SC) injection was used today because of poor insulin stability following oral administration.

“Enteric capsules, designed to protect against low pH conditions in the stomach by providing a polymeric coating which only breaks down in the small intestine, have failed to significantly increase oral bioavailability for insulin.

“In parallel, amphiphilic lipid mesophases are versatile carrier materials which can protect encapsulated proteins and peptides from undesirable enzymatic degradation.”

The researchers simply combined the two approaches, using an acid-resistant enteric capsule to encapsulate fat encased peptide insulin.

As the researchers concluded: “(We) showed the combined delivery capacity of a hydrated bicontinuous cubic lipid mesophase embedded within an enteric capsule.

“Animal studies demonstrated that the lipid filled enteric capsules could deliver insulin with bioavailabilities (relative to SC injection) as high as 99 percent and 150 percent for fast and slow acting insulin, respectively.

“These results provide a promising starting point towards further trials to develop an alternative, non-invasive mode for the delivery of insulin.”

Picture: RMIT University