Nature has equipped us remarkably well to avoid swallowing harmful substances. The taste buds on the tongue contain taste receptors, which detect the ingredients in whatever we eat or drink and relay information about tastes such as sweet, salty, sour and bitter to the brain. Their purpose is to alert us to dangerous or toxic things we have put in our mouths by mistake, things that frequently taste bitter.
This creates a problem when the active ingredient of a medicine is itself bitter, as it naturally activates these “warning sensors” on the tongue. Taking the correct amount is essential if the body is to recover completely, yet some medicines taste so bitter that children refuse to take them. Besides the active ingredient, medicines also contain other ingredients known as excipients, which are used, for instance, to turn a medicine into a liquid syrup or a solid form such as a tablet or capsule. These can be thought of as the “sidekicks” of a medicine: they play no part in fighting the illness, but they help the active ingredient do its job better, perhaps by making it last longer or improving its taste.
The article from which this text is taken was written by a team of scientists dedicated to designing medicines for children, and it explains how researchers are trying to make medicines taste better.
Designing such medicines is far from simple. Children’s taste buds and taste receptors are more sensitive than those of adults, so the bitterness of some medicines seems considerably stronger to them. Sour tastes, too, are more intense for children, who also tend to like sweet things more than adults do. If a medicine tastes unpleasant, a child may refuse to take it, in which case their medical problem will not improve. What is more, because children’s bodies differ from adults’, certain ingredients that are safe for grown-ups can harm them, and scientists must therefore make sure that every excipient in a children’s medicine is safe. The challenge, then, is to produce medicines that are safe, palatable enough for children to be willing to take them and easy to swallow.
To disguise unpleasant tastes, scientists rely on clever tricks known as taste-masking techniques. One of these is the use of palatable excipients, “palatable” meaning tasty, enjoyable and pleasant. Some of these improve the taste by making a medicine sweet or adding flavor, while others improve the texture, making a medicine feel smoother in the mouth. Sweet ones are especially common, as they can make a medicine taste good enough to take. Some medicines contain a type of sugar called sucrose, which can cause tooth decay, so it is advisable to rinse your mouth with water after taking them. Alternatively, sugar-free options such as artificial sweeteners or sugar substitutes, which are used in low calorie or “diet” foods and drinks, can make a medicine sweeter without adding sugar. Appealing flavors such as strawberry, orange or vanilla are often added as well, to help cover up the bad taste still further.
