Inactive ingredients found in drugs, including fillers and dyes, may not be as inert as they seem, according to a new study. Studies have shown that some of these compounds may have “active” effects on the body and, in some cases, may be harmful. Although inactive ingredients are often an important part of a variety of drugs, the study suggests that additional research is necessary to determine their individual effects.
Drugs are often made up of two types of ingredients: active compounds and excipients, which are inactive compounds used to deliver activity ingredients and other things. In most cases, tablets and certain other types of drugs contain more excipients, although this does not mean that they are not necessary for the entire drug delivery.
A new study by the American Association for the Advancement of Science warns that while most excipients are indeed inactive, some may have effects on body parts targeted by active ingredients, including receptors and enzymes. Inactive ingredients are studied in animals for potential toxicity, but new research warns that there is little research on whether these compounds also affect “medically relevant molecular targets.” As part of the study, 38 approved inactive ingredients were found to have 134 effects on previously unknown molecular targets.
Of particular relevance is the potentially harmful effects of a small number of excipients, the study notes:
… Some excipients show evidence of predictable tissue level toxicity in cell models. Although most of them are suspected of not reaching dangerous levels of exposure, the results show that two types of thiomersal and acetylate 鎓 can reach in vivo concentrations, overlapping their in vitro activity associated with dopamine receptor D3.
The study found that more research was needed on the potential effects of these active ingredients — toxicity aside — to determine whether some inactive ingredients would have their own direct impact on the human body.