Why are impurity regulations different for food and drugs?

The food and pharmaceutical industries each have a host of regulations and government agencies in place to ensure the safety of the items that we consume. Although their regulations are often similar, there are differences between them – possibly driven by a view that ‘naturally derived molecules’ are likely to be safer than new man-made ones.

In the early 2000s, pharmaceutical regulators began to be interested in trace impurities that could be potentially genotoxic (PGIs). This created a great deal of concern and activity, especially given that, as one of my colleagues remarked, it’s pretty difficult to make organic molecules without using electrophiles.

Due to a significant amount of effort within the pharmaceutical industry and by regulators, a series of guidelines were developed (including ICH M7) that enabled the industry to pretty much deal with this new perceived risk. I say perceived, because like many within the industry, I think the premise that initially drove these guidelines – that there is no such thing as a safe dose of a genotoxic impurity – is likely flawed in most cases. Our bodies use a range of DNA-repair mechanisms to protect us from genotoxic compounds and each day we are exposed to levels of these compounds well in excess to that we are likely to be exposed to by taking any medicine. Indeed, if one looks at levels of PGIs in common foods, they are often at levels thousands of times above what is permitted in drugs.