GETTING kids to swallow bitter medicine can be stressful for both children and parents but the ordeal may be about to get a bit sweeter.

Perth researchers are putting a scientific spin on the old ‘spoonful of sugar’ by disguising medicine as chocolate.

Ruby and Isobel Donaldson know firsthand how hard it can be to take medicine. Both have cystic fibrosis and take a concoction of medication each day.

Along with daily medication, the 12 and 10 year old are anaesthetised for a yearly check-up that involves a particularly nasty pre-medication drug.

“When I had to have the pre-med, often they would have to hold me down to try to have me to get it,” said Isobel.

Her mother Christine Donaldson said as a parent, it was hard to watch.

“The girls didn't like the taste of it, it was hard to get them to drink it and they knew after they'd drunk it they were going to be put to sleep, so it was just really stressful,” she said.

That pre-medication drug has become a bit easier to swallow, thanks to a joint project between the University of Western Australia and Perth Children's Hospital (PCH) that disguises the drug as chocolate.

“Certainly Mary Poppins would be very jealous of us because we don't need the spoonful of sugar to get the taste right for this one,” said UWA researcher Dr Sam Salman.

The final blend is a complex balance of ingredients, not just melted chocolate mixed with medicine.

“You have to make sure the taste is adequately masked and there's no compromise in the effectiveness of the tablet or the medication that is being given,” he said.

It's taken five years to reach this point but the drug is ready after the conclusion of a clinical trial involving 150 kids at PCH.

“We found the vast majority who got the chocolate liked the taste - not just kind of neutral about it - but said they liked the taste and many would have taken it again,” said Dr Salman.

Along with his research team, Dr Salman hopes this is just the beginning.

“The next aim is to get antibiotics into this form and that's something that will be used in the community,” he said.

Isobel and Ruby are hopeful the drug will take some stress out of having to go to hospital for their yearly procedures.

“If that tastes nice I would want to have that, it would make everything a lot more easy,” said Isobel.