Medicines for babies and young children frequently contain additives banned from foods and drinks aimed at under-threes, research shows.
Most medicines contain additives
The Food Magazine examined 41 medicines aimed at the under-threes, and found only one was free of the additives.
No colours or sweeteners are allowed in foods and drinks for the under-threes and most preservatives are banned.
The manufacturers of medicines for the under-threes have insisted their products are safe.
Only additives strictly necessary from a technological point of view and recognised as being without risk to the health of young children are authorised in such foods.
The survey found four azo dye colourings, eight benzoate and two sulphite preservatives, and six sweeteners contained in the products examined.
Preservatives were present in all but 10, and sweeteners in all but four of the medicines surveyed.
Some medicines warned the additives they contained could have harmful side-effects.
The side effects listed included irritation of the skin and eyes, stomach upset and diarrhoea.
Azo dyes are synthetic compounds used to produce a wide range of colours
Tests suggest they produce only a very mild toxic effect - and are probably safe in the concentrations in which they are found in food
But research has linked the compounds to adverse reactions in people with aspirin allergy and asthmatics
The Food Magazine is published by the Food Commission, an independent body campaigning for safer food in the UK.
Spokesman Ian Tokelove said: "Whilst many children will be able to consume these products safely, there will be those who will suffer allergic reactions to these additives.
"It is time for medicine manufacturers to clean up their act and remove any unnecessary additives."
Mr Tokelove said colourings and artificial sweeteners could be replaced with natural alternatives.
He also questioned the need to use preservatives at all.
Helen Darracott, of the Proprietary Association of Great Britain, the trade association for manufacturers of over-the-counter medicines, said: "Unlike foods, additives in medicines are in very small quantities and are only taken for a short period of time.
"If the MHRA decides a product contains additives that are not strictly necessary, it will request that the medicine is re-formulated before it can be given approval."
Medicines and Healthcare products Regulatory Agency said the use of all additives in medicines had to be justified by the manufacturer before a licence was granted.
However, most medicines could not be manufactured, stored or administered without some additional ingredients.
"Medicines can be quite unstable such that preservatives and other additives are necessary to maintain product quality for a reasonable shelf-life.
"Many medicines also have a very unpleasant taste and require sweeteners and other flavours to help ensure palatability, especially for children.
"Some patients have to take multiple medicines and find that easy identification by colour and other means helps ensure they take the right medicine at the right time."