The U.S. Food and Drug Administration (FDA) issued a public health alert regarding the presence of N-nitrosodimethylamine (NDMA) in medicines. More recently, NDMA has been reported in ranitidine-, nizatidine-, and metformin-containing drug products. N-nitrosodimethylamine is an N-nitrosamine, a type of compound that has the generic chemical structure R2N–N¼O, a deprotonated amine bonded to a nitroso group. It is a known environmental contaminant found in drinking water and some foods.
A positive association between NDMA exposure and cancer was reported. In 2020, the FDA announced industry guidance to control N-nitrosamine impurities in human drugs. The guidance describes conditions that may introduce nitrosamine impurities into pharmaceutical products. The FDA, in collaboration with regulatory counterparts around the world, has set an acceptable daily intake limit for NDMA of 96 ng/day. If more than one nitrosamine is present in the sample, then the daily intake limit for total nitrosamine is 26.5 ng/day.
Ion chromatography (IC) methods were developed for the determination of these two precursors in drug substances and drug products.