No more needles? How an insulin pill could revolutionise diabetes treatment

The diabetic holy grail of an oral pill to supply insulin, instead of an injection, has so far stumped scientists - but a promising new attempt has been described as a 'smart pill'.

The team, led by Dr Nick Hunt of the University of Sydney, have developed a nanotechnology-based insulin pill.

They have completed animal trials and are headed to human clinical trials next year.

Hunt told Saturday Morning they are hopeful their pill could be the answer, or at least a big step towards the end goal.

Approximately 75 million people with diabetes need to inject themselves daily with insulin. To work effectively, a pill needs to provide precise dose control, be fast acting, safe and cost effective, he says.

Their design uses a nano-scale material that is 1/10,000th the width of a human hair. The material protects it from being destroyed by stomach acid and instead surrounds the individual insulin molecules and becomes a 'nano carrier' - acting like a courier to ferry insulin molecules in the body to the places it needs to act.

Insulin balances sugars - but it's a difficult balance

We need sugar as an energy to fuel our body, but either too much or too little sugar can cause serious harm and become fatal.

Insulin is an enzyme that helps our body break down the sugar, releasing energy our body can use.

"Insulin is a naturally occurring material," Hunt said.

"In our body we... have blood sugar that we accumulate as we have meals throughout the day, and what happens for type 1 diabetics is they have an immune- mediated destruction of the cells that make insulin. So those people aren't able to produce their own insulin - so we need to dose it ourselves.

"All we're really able to do is do an injection of insulin and try and control that as much as possible - and you of course can give too much or too little, much like most drugs, and it's a very fine margin about how best you can control that."

Your brain is reliant on sugar to power it - but if someone takes too much insulin and the brain doesn't get enough: "That's when you can start get some really scary symptoms and signs for patients and people around them, where they could potentially lose consciousness or need to go to hospital."

So synthetically made insulin is life-saving, but difficult to dose perfectly as our bodies are such changeable systems - leaving diabetics vulnerable.

And the scale of the problem is considerable; diabetic emergencies that require either emergency treatment or hospital treatment happen 64,000 times year in Australia, Hunt said.

Not too little, not too much

The new smart insulin is designed to be taken as a pill that provides a varying dose, according to exactly what that person's body's needs are at that moment.

"The advantage of having a smart insulin is it can be... coded in a way to have a controlled release component, based on what your blood sugar levels were in the first place," Hunt said.

For healthy people, our pancreas does that work - it releases just the right amount of insulin naturally: "Our pancreas... is a smart sensor that allows you to control the amount of release of insulin that you precisely need.

"What we've done is now just now is do that synthetically ourselves. So for our particular technology that we developed, it's smart because it's able to sense glucose, or more precisely a particular enzyme in the body that's released when glucose is also present in the same system."

If the person taking the pill has too much sugar in their blood, the insulin in the pill kick starts the process to break it down.

But, "if you don't have a high enough blood sugar, you don't get the release of the insulin from product. So it means you can't have an adverse or an underdose from it."

The challenges

Globally, more than 50 years research and $60b of investment have already been spent on trying to find a way to provide insulin as a pill, Hunt said.

"The trouble we've really faced is insulin is a really sensitive material."

The digestion which occurs in the stomach naturally breaks down insulin, and previous attempts to mix insulin with materials to protect it as it travels through the stomach have produced other side effects, such as gastrointestinal upsets.

Earlier attempts to make a pill also ran into problems with how much insulin was needed in the formulation for it to work. One version made it to clinical trials, but required so much insulin that it was not cost-effective.

Hunt said while insulin is not costly to produce, pharmaceutical companies could charge a lot for it, particularly in the US. So to be useful, a pill needed to be effective without vast quantities of insulin.

Earlier research, and partnerships with other teams helped Hunt's team, and he described the goal as a "marathon".

"But there's a lot of really good people out there in the world working really hard to try and get this technology developed, and hopefully at least one of us will have success in doing it in the next coming decade," he said.

"We're not just trying to solve oral formulation challenges for insulin, there's a lot of other injectable technologies out there that would really benefit from having an oral tablet instead of an injection - particularly for daily management for people who need to have it for several days, years and potentially for the rest of their life."