A new capsule has been designed by Australian scientists that could allow diabetics to potentially ingest their insulin rather than having to inject it.
This innovative design also presents possibilities for administering other protein drugs, such as antibiotics and cancer treatments.
The immune system of individuals with Type 1 diabetes attacks the beta cells of the pancreas resulting in little to no insulin being secreted. As a result, those with Type 1 diabetes as well as some with Type 2 diabetes must inject insulin multiple times throughout the day.
Diabetics typically require two types of insulin: fast-acting and slow-acting. Fast-acting insulin is absorbed rapidly after injection and is utilized to manage blood glucose levels during meals and snacks as well as to correct high blood glucose.
On the other hand, long-acting insulin is generally given once per day as it is absorbed slowly and maintains a basal level of insulin to regulate blood glucose throughout the day.
A group of researchers from RMIT University located in Melbourne, Australia have created an innovative oral capsule capable of delivering insulin showing potential as a novel method of administering the medication.
Insulin is composed of peptides which are smaller versions of proteins. Previous efforts to create an orally ingested insulin medication have discovered that the peptides are degraded by the severe pH levels present in the gastrointestinal tract, leading to a loss of efficacy. This issue also arises with other protein drugs.
To overcome this challenge, the team of scientists developed a unique approach involving the encapsulation of insulin within a lipid-based nanomaterial, which is then housed in an enteric capsule.
The polymeric coating of the enteric capsule offers protection against the high acidity (low pH) of the stomach.
According to Jamie Strachan, lead author of the study. “The capsule has a special coating designed to not break down in the low pH environment of the stomach before the higher pH levels in the small intestine trigger the capsule to dissolve. We package the insulin inside a fatty nanomaterial within the capsule that helps camouflage the insulin so that it can cross the intestinal walls.”
In animal trials, the researchers evaluated the effectiveness of the capsule using both fast-acting and slow-acting insulin formulations.
The fast-acting insulin capsule was observed to be adequately absorbed however, there was a notable delay in the onset of insulin’s action compared to traditional injection-based delivery making it unfeasible. The slow-acting insulin capsule yielded more favorable outcomes.
Charlotte Conn, corresponding author of the study said. “We had excellent absorption results for the slow-acting form – about 50% better than injection delivery for the same quantity of insulin, Our results show there is real promise for using these oral capsules for slow-acting insulin, which diabetics could one day take in addition to having fast-acting insulin injections.”
The researchers have noted that their capsule design is an encouraging initial step towards achieving non-invasive insulin delivery and it also holds potential for the administration of other protein-based drugs like antibiotics and monoclonal antibodies used in cancer treatment.
They intend to refine the design further aiming to establish a system for dosing the drug over precise time intervals before progressing to clinical trials involving human subjects.
