Australian scientists created a special capsule that could make delivering insulin and other protein drugs painless in the future. Many people with diabetes currently have to endure multiple daily insulin injections, which can be uncomfortable and costly for healthcare.

According to Dr. Jamie Strachan from RMIT University, the capsule is designed to protect the drug as it goes through the stomach and reaches the small intestine safely. The capsule has a special coating that prevents it from breaking down in the acidic stomach environment. Once it reaches the higher pH levels of the small intestine, the capsule dissolves. Inside the capsule, insulin is packaged in a fatty nanomaterial that helps hide it and allows it to pass through the intestinal walls.

The new oral capsules work similarly to the Pfizer and Moderna Covid vaccines. Just like those vaccines, the capsules contain a special type of material called mRNA, which is like DNA. This material carries instructions to make a specific protein safely inside our bodies, which then activates our immune system.
Dr. Celine Valery, a pharmaceutical scientist from RMIT and a co-author of the study, mentioned that they used the same amount of insulin in the oral capsules as they do in regular injections.

The study, published In Biomaterials Advances, tested the new oral capsule with insulin in an early test phase prior to clinical trials. They evaluated how well the oral capsules performed with both fast-acting and slow-acting insulin.

Professor Charlotte Conn, a biophysical chemist from RMIT University and co-lead researcher, explained that fast-acting insulin is necessary to quickly control blood sugar after meals. In contrast, slow-acting insulin works over a longer duration, sometimes lasting up to a whole day, to maintain stable insulin levels in the body. Many people with diabetes use a combination of both types of insulin to manage their condition.

Professor Charlotte Conn mentioned that the slow-acting form of insulin had really good absorption results in the oral capsule—about 50 percent better than insulin injections with the same amount. The capsule also showed good absorption results for fast-acting insulin, but it took longer for the insulin to start working compared to injections, which could make it less convenient for use.

Professor Charlotte Conn stated that the use of oral capsules for slow-acting insulin shows significant potential. In the future, individuals with diabetes might take these capsules in addition to their fast-acting insulin injections. The capsules could be designed to release insulin over specific time periods, similar to injections. However, further exploration, effective methods, and rigorous testing in human trials are needed to make this a reality.