Capsule May One Day Replace Insulin Injection for Diabetics

Scientists in Melbourne have designed a new type of oral capsule that could mean pain-free delivery of insulin and other protein drugs.

“These types of drugs (protein) are typically administered with an injection — thousands of diabetics in Australia need insulin injections up to several times a day, which can be unpleasant for the patient and results in high healthcare costs,” said Conn, from RMIT’s School of Science.

The team has tested the new oral capsule with insulin in a pre-clinical study and the results have been published in the international journal Biomaterials Advances.

“We think the results are really exciting, and we’re doing a suite of pre-clinical testing so we can move to clinical trials as soon as possible,” Conn said.

“When controlling the blood-sugar, you need a very fast response if you’re eating a meal. That’s known as fast-acting insulin,” Conn said.

A slow-acting form acts over a much longer timeframe — up to a day or so — to keep the insulin in the body steady. Most diabetics take a combination of both types of insulin.

“We had excellent absorption results for the slow-acting form — about 50% better than injection delivery for the same quantity of insulin,” Conn said.

“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,” Conn said.

“The oral capsules could potentially be designed to allow dosing over specific time periods, similar to injection delivery. We need to investigate this further, develop a way of doing so and undergo rigorous testing as part of future human trials.”

Dr Céline Valéry, a pharmaceutical scientist from RMIT and study co-author, said they used the same amount of insulin in the oral capsules and in the injection delivery.

“For many pre-clinical trials the oral formulations by necessity contain much higher levels of insulin to achieve the same response as the injection delivery. This is not a very cost-effective way to deliver protein drugs which tend to be expensive,” said Valéry, from RMIT’s School of Health and Biomedical Sciences.

“It’s a great starting point but we need to do further trials to develop an alternative, pain-free method for the delivery of insulin and other protein drugs.”


Jamie B. Strachan, Brendan Dyett, Stanley Chan, Brody McDonald, Ross Vlahos, Celine Valery, Charlotte E. Conn. A promising new oral delivery mode for insulin using lipid-filled enteric-coated capsules. Biomaterials Advances, 2023; 148: 213368 DOI: 10.1016/j.bioadv.2023.213368

RMIT University. “Wonder drug-capsule may one day replace insulin injection for diabetics.” ScienceDaily. ScienceDaily, 19 April 2023. <>.

Images from:

Photo by Christine Sandu