The Presence of Nitrosamines and Nitrosamine Drug-Related Substances in Pharmaceutical Products: An Overview of Regulatory Concerns, Analytical Methodologies, and Control Strategies

The presence of N-nitrosamine impurities in pharmaceutical products is well known. In 2019, it resulted in drug recall by the Food and Drug Administration (FDA). Soon, several groups identified the presence of many N-nitrosamines (NAs) in various Active Pharmaceutical Ingredients (APIs) and drug formulations worldwide. Moreover, in the last two years, another type of NAs was identified and detected in several pharmaceutical products. These are easily formed from the parent drug molecule and are known as Nitrosamine drug-related substances (NDSRIs). The amine group plays a major and unique role in the synthesis of many drug molecules, and hence, it is practically impossible to eliminate the presence of NAs and NDSRIs from drug products. The risk assessment of the health hazard to the patient was done, and the FDA has set the maximum daily acceptable intake (AI) at 18 ng/day for NAs. This limit poses a significant challenge in isolating, identifying and quantifying NAs and NDSRIs in APIs and formulations. For small, simple NAs, a lot of toxicological information and carcinogenetic data is available; however, for NDSRIs, such data is practically absent. This review article attempts to gather the toxicological data for a few NAs and NDSRIs and tries to assess the genotoxicity potential of some NDSRIs. The possible sources of NAs and NDSRIs, including synthetic methodology and processes, impurities associated with intermediates or raw materials, stability of the API, packaging materials, imprinting inks, and excipients, are also discussed. A summary of different analytical techniques used for the detection of these NAs and NDSRIs in different pharmaceutical products has also been included. Finally, various strategies employed for the minimization of these impurities along with additional control strategies to mitigate NAs and NDSRIs below acceptable limits, have also been discussed.