Preterm infants are routinely exposed to pharmaceutical excipients at levels which could potentially be toxic, according to researchers at Leicester Royal Infirmary in the UK.
The team documented exposure to excipients in medicines given to 38 premature babies cared for in the hospital’s neonatal unit over the course of a year, and concluded that at least some were being exposed to concentrations in excess of the maximum exposure limits for adults.
The excipients are added to oral liquid medicines – a common route of administration for preterm babies – in order to improve their taste and absorption and to prolong their shelf-life.
While the study was not designed to look for any link between excipients and side effects in the infants, the authors maintain that the level of exposure identified “will understandably generate concern among parents, nurses, pharmacists and paediatricians.”
They say that medicines should be developed for preterm infants that are specifically designed with lower levels of excipients as a matter of urgency. At the moment, they add, oral liquid medications tend to be developed based on adult human and animal studies which may not be relevant to preterms.
Of the 38 infants whose records were analysed, seven had chronic lung disease (CLD), which is a common complication of preterm delivery.
Records indicated that the infants were exposed to eight oral liquid medications containing 20 excipients, including propylene glycol and ethanol which have been linked to neurotoxicity, as well as high levels of sorbitol. As might be expected, the seven babies with CLD were exposed to higher levels of excipients.
The analysis, published January 20 in the Fetal & Neonatal edition of Archives of Disease in Childhood, also uncovered the use of the colorant Ponceau 4R in an iron supplement formulation, which the UK Food Standards Agency has recommended be removed due to fears over its effect on neurodevelopment and behaviour.
“We feel it is important that the European Medicines Agency/Medicines and Healthcare Products Regulatory Agency ... only ensures that all manufacturers provide detailed labelling of the excipient content of their products,” said the researchers, led by Dr Hitesh Pandya.
“We are planning further studies on the chemicals to understand exactly what these effects might be,” added Pandya.
The regulatory bodies should also “lead action to determine whether existing practice constitutes a risk and, if so, how this might be dealt with,” they conclude.