Lab and analysis
Elemental impurities
Definition
Trace metals and other elements in a product, controlled for medicines by ICH Q3D.
ICH Q3D sets permitted daily exposures for elements such as lead, arsenic, cadmium, mercury and catalyst metals like palladium. The main pharmacopoeias have largely moved from the older colour based heavy metals test to this approach, measured with methods such as ICP-MS and ICP-OES.
API suppliers are often asked for a risk assessment or a statement on elemental impurities, in addition to test results.