Most, if not all, medicines contain both the pharmacologically active and inactive ingredients. The therapeutically inactive components of a medicine are considered excipients. The excipients demonstrate many critical functions including: being diluents, wetting agents, solvents, fillers, binders, emulsifiers, absorption enhancers, sustained release matrices, preservatives, sweeteners, and stabilising, colouring or flavouring agents.1 These excipients serve an important purpose of converting a medicinal compound to an elegant pharmaceutical product with improved delivery for clinical use. It is generally assumed that because the excipients are inert and pharmacologically inactive, they are safe in patients. This assumption, however, may not always be accurate.

A recent study by Whittaker et al2 in this journal documented exposure to over 20 excipients including ethanol, propylene glycol and sorbitol in 36 preterm infants. Further, some infants were exposed to amounts higher than those recommended for adults per kilogramme of body weight. This was not surprising that the infants received these excipients since without excipients they would have been deprived of essential medicines. The question is: are patients at risk of developing undesirable health effects and adverse outcomes from excipients? As the authors stated, this question could not be answered in their study as the clinical effects of excipients were not studied in infants.

A policy statement by the American Academy of Pediatrics on inactive ingredients in pharmaceutical products raised questions about the safety of excipients including antioxidants, propylene glycol, sorbitol, lactose, artificial sweeteners, benzyl alcohol, benzalkonium chloride, and colouring agents. The evidence came largely from small uncontrolled and observational studies or case reports. A mandatory labelling of inactive …