Pharmaceutical Nitrosamines: A Comprehensive Review of Health Risks, Detection, Mitigation Strategies Supplemented with CYP450 Interactions as Molecular Simulations for Mechanistic Insight into Carcinogenicity

Nitrosamines, identified as unexpected impurities in several drug substances and drug products, have raised significant concern due to their mutagenic and carcinogenic properties. Extensive research has shown that a majority of nitrosamines are potent carcinogens, affecting various organs in multiple species. This article comprehensively analyzes pharmaceutical nitrosamine impurities, their potential health risks, detection, and mitigation strategies, along with a molecular simulation-based exploration of nitrosamine interaction with CYP450 isoforms. The article also explores the chemistry behind nitrosamine formation, their reactions, and the role of cytochrome P450 enzymes in their metabolism. Detection methods like HPLC, LC-MS, and GC-MS, alongside regulatory guidelines from agencies such as the FDA, EMA, ANVISA, TGA, and Health Canada, are discussed in detail. The review further emphasizes the significance of stringent quality control, comprehensive risk assessment methodologies, and effective risk mitigation strategies to address nitrosamine contamination in pharmaceuticals. Nitrosamine impurities require metabolic transformation into electrophiles, which can readily react with DNA and result in mutagenic or carcinogenic effects. This molecular-level understanding can extensively help explore promising nitrosamine scavengers to minimize the chances of possible health hazards due to nitrosamine exposure. Therefore, the interactions of nitrosamine impurities with CYP450 isoforms are explored to get mechanistic insight into carcinogenicity using molecular docking with Xtra precision, along with molecular dynamics studies. Thus, the review provides a detailed spectrum of nitrosamine impurities in pharmaceuticals, covering their sources, toxicological mechanisms, current regulatory overview, risk assessment, and mitigation strategies to ensure drug safety.