Fixing bad tasting infant drops when a 'spoonful of sugar' doesn't work

Now researchers from the University of Bradford are working with colleagues from China to make some of the most bitter tasting medicines, from both Western and traditional Chinese medicine (TCM), easier to swallow. The aim of the research is to develop a suite of technologies that can mask the horrid taste of essential children's medicines in liquid form for use across the world.

Liquids are often seen as the most appropriate formulation for use with children, as they are easier to administer and enable adjustment of the dose for different age groups. Although many medicines are still not available in liquid form, that is only the first part of the problem. They also need to be palatable to ensure children complete a course of treatment. Adding sugar or sweeteners is only partially effective and can create additional dietary and dental problems.

"It is possible to reason with an older child and persuade them to take a medicine despite the taste," explains Dr Marcel de Matas from the University of Bradford's Science Bridges China programme.

"But with a six-month old baby, reasoning won't get you very far. Sweetness is much shorter-lived than bitterness, so even where a sweetener is used, you'll often get a nasty aftertaste. A young child will remember that the medicine tasted horrible, and will spit it out, refuse to swallow or simply refuse to take it at all.

"There are also significant differences between countries and cultures as to what tastes 'nice'. By making a medicine taste neutral, it can be mixed easily with food and drink, which means it will work effectively anywhere in the world."

The project will focus on two approaches to taste masking. One involves adding a barrier to the medicine to prevent the molecules that create the bitter taste interacting with taste receptors in the mouth; the other will use molecules that bind to the taste receptors in place of the medicine to prevent the taste being registered. Both methods will need to ensure the active ingredient is still functional and fully taken up by the body. Traditional Chinese medicine provides a particular challenge because it includes multiple ingredients which contribute to its taste.

The scientists will initially target medicines where a liquid formulation exists for children, but where taste causes poor compliance with recommended doses. Possible targets include ibuprofen, a widely used anti-inflammatory drug, for which some formulations for young children have a very bad aftertaste, and Shuang Huang Lian, a TCM medicine used to treat flu and cold symptoms such as fever, coughs and sore throats. The foul taste of Shuang Huang Lian means children often fail to benefit properly from treatment.

The team from the University of Bradford will develop the taste masking formulations and study molecular activity at taste receptors. The Chinese partners will analyse the composition of the target TCM compounds and test the effectiveness of the technologies with an 'electronic tongue', using chemical measures of taste to avoid the need for human 'guinea pigs' in the early stages of the research. The Chinese scientists will also assess the impact of the additives on the active ingredients and take up in the body.

Also involved in the project is a UK company, BioSuspensions Ltd, who will provide new technologies for creating liquid formulations from otherwise insoluble medicines. A large proportion of essential medicines are insoluble, making the creation of formulations for children even more difficult.

The project was developed during an open innovation workshop run by the University of Bradford in Changzhou as part of their Science Bridges China programme. It is being funded by the city government in Changzhou, with the aim of generating new technologies within two years which can be commercialised through a jointly-owned spin-out company based in China.

Bradford's Science Bridges China programme aims to forge partnerships and develop collaborative research into new drugs and healthcare products with top universities and healthcare companies across China. The taste masking collaboration is one of 11 projects currently funded through the programme.