Development and Validation of a Method for the Semi-Quantitative Determination of N-Nitrosamines in Active Pharmaceutical Ingredient Enalapril Maleate by Means of Derivatisation and Detection by HPLC with Fluorimetric Detector

Analytical Methodologies to Detect N-Nitrosamine Impurities in Active Pharmaceutical Ingredients, Drug Products and Other Matrices

Since 2018, N-nitrosamine impurities have become a widespread concern in the global regulatory landscape of pharmaceutical products. This concern arises due to their potential for contamination, toxicity, carcinogenicity, and mutagenicity and their presence in many active pharmaceutical ingredients, drug products, and other matrices. N-Nitrosamine impurities in humans can lead to severe chemical toxicity effects. These include carcinogenic effects, metabolic disruptions, reproductive harm, liver diseases, obesity, DNA damage, cell death, chromosomal alterations, birth defects, and pregnancy loss. They are particularly known to cause cancer (tumors) in various organs and tissues such as the liver, lungs, nasal cavity, esophagus, pancreas, stomach, urinary bladder, colon, kidneys, and central nervous system. Additionally, N-nitrosamine impurities may contribute to the development of Alzheimer's and Parkinson's diseases and type-2 diabetes. Therefore, it is very important to control or avoid them by enhancing effective analytical methodologies using cutting-edge analytical techniques such as LC-MS, GC-MS, CE-MS, SFC, etc. Moreover, these analytical methods need to be sensitive and selective with suitable precision and accuracy, so that the actual amounts of N-nitrosamine impurities can be detected and quantified appropriately in drugs. Regulatory agencies such as the US FDA, EMA, ICH, WHO, etc. need to focus more on the hazards of N-nitrosamine impurities by providing guidance and regular updates to drug manufacturers and applicants. Similarly, drug manufacturers should be more vigilant to avoid nitrosating agents and secondary amines during the manufacturing processes. Numerous review articles have been published recently by various researchers, focusing on N-nitrosamine impurities found in previously notified products, including sartans, metformin, and ranitidine. These impurities have also been detected in a wide range of other products. Consequently, this review aims to concentrate on products recently reported to contain N-nitrosamine impurities. These products include rifampicin, champix, famotidine, nizatidine, atorvastatin, bumetanide, itraconazole, diovan, enalapril, propranolol, lisinopril, duloxetine, rivaroxaban, pioglitazones, glifizones, cilostazol, and sunitinib.

Occurrence of N-nitrosamines in the atmosphere and human health risk: A case study in an urban area of Chuncheon, Gangwon State, South Korea

This study aimed to investigate the occurrence of eight nitrosamines (NAs) in particulate (PM2.5) and gaseous phases and assess the human health risk associated with these compounds in an urban area of Chuncheon, Gangwon State, South Korea, across four sampling seasons. The findings revealed that the total concentrations of eight NAs measured during the sampling period exceeded the public health recommendation of 0.3 ng/m3 provided by the Norwegian Institute of Public Health, indicating a potential human health risk from NA exposures. In particular, the average total NA concentration observed in the gaseous samples during the winter of 2021 was 18.1 ± 6.46 ng/m3. The primary emission sources could potentially impact the concentrations of NAs in the atmosphere due to their significant positive correlation with primary emission species such as NO2, CO, and SO2. Moreover, the levels of particulate NAs during the summer were negatively correlated with O3, suggesting that their formation might be influenced by ozonation in the aqueous aerosol phase. In addition, the total NA concentrations measured in the gaseous phase were four to six times higher than those measured in the PM2.5 phase throughout the sampling period. Thus, domestic sources have the potential to impact the pollution levels of the research area more significantly than long-range atmospheric transport. In particular, the highest concentrations of NAs in the gas phase were observed during the winter, while the lowest concentrations were recorded in the summer, possibly influenced by photolysis. Nevertheless, the study suggested that tertiary amines might contribute to the presence of gaseous NAs in sunlight. Consequently, further studies focusing on the occurrence of tertiary amines in the gas phase should be considered. The cumulative lifetime cancer risks estimated from inhalation exposure exceeded the acceptable risk level of 10⁻6 for all age groups across all four seasons. Therefore, it is crucial to implement effective control measures to mitigate potential health risks associated with exposure to NAs.

Nitrosamines crisis in pharmaceuticals - Insights on toxicological implications, root causes and risk assessment: A systematic review

The presence of N-nitroso compounds, particularly N-nitrosamines, in pharmaceutical products has raised global safety concerns due to their significant genotoxic and mutagenic effects. This systematic review investigates their toxicity in active pharmaceutical ingredients (APIs), drug products, and pharmaceutical excipients, along with novel analytical strategies for detection, root cause analysis, reformulation strategies, and regulatory guidelines for nitrosamines. This review emphasizes the molecular toxicity of N-nitroso compounds, focusing on genotoxic, mutagenic, carcinogenic, and other physiological effects. Additionally, it addresses the ongoing nitrosamine crisis, the development of nitrosamine-free products, and the importance of sensitive detection methods and precise risk evaluation. This comprehensive overview will aid molecular biologists, analytical scientists, formulation scientists in research and development sector, and researchers involved in management of nitrosamine-induced toxicity and promoting safer pharmaceutical products.

Microextraction by packed sorbent of N-nitrosamines from Losartan tablets using a high-throughput robot platform followed by liquid chromatography-tandem mass spectrometry

The development of a fast, cost-effective, and efficient microextraction by packed sorbent setup was achieved by combining affordable laboratory-repackable devices of microextraction with a high-throughput cartesian robot. This setup was evaluated for the development of an analytical method to determine N-nitrosamines in losartan tablets. N-nitrosamines pose a significant concern in the pharmaceutical market due to their carcinogenic risk, necessitating their control and quantification in pharmaceutical products. The parameters influencing the performance of this sample preparation for N-nitrosamines were investigated through both univariate and multivariate experiments. Microextractions were performed using just 5.0 mg of carboxylic acid-modified polystyrene divinylbenzene copolymer as the extraction phase. Under the optimized conditions, the automated setup enabled the simultaneous treatment of six samples in less than 20 min, providing reliable analytical confidence for the proposed application. The analytical performance of the automated high-throughput microextraction by the packed sorbent method was evaluated using a matrix-matching calibration. Quantification was performed using ultra-high-performance liquid chromatography-tandem mass spectrometry with chemical ionization at atmospheric pressure. The method exhibited limits of detection as low as 50 ng/g, good linearity, and satisfactory intra-day (1.38-18.76) and inter-day (2.66-20.08) precision. Additionally, the method showed accuracy ranging from 80% to 136% for these impurities in pharmaceutical formulations.

Current status and prospects of development of analytical methods for determining nitrosamine and N-nitroso impurities in pharmaceuticals

Nitrosamine impurities in pharmaceuticals have recently been concerned for several national regulatory agencies to avoid carcinogenic and mutagenic effects in patients. The demand for highly sensitive and specific analytical methods with LOQs in the ppb and sub-ppb ranges is among the most significant challenges facing analytical scientists. In addition, artifactual nitrosamine formation during sample preparation and injection leading to overestimation of nitrosamines has received considerable attention. Numerous analytical methodologies have been reported for quantifying nitrosamine impurities in active pharmaceutical ingredients and medicinal products at the interim limit criteria as preventive measures. In this review, we meticulously discuss those reported gas and liquid chromatographic methods for nitrosamine determination in pharmaceuticals in aspects of chromatographic conditions and sensitivity of detection. We also introduce the potential of novel fluorescence-based methods recently developed to rapidly screen nitrosamine impurities. In addition, the review assesses the nitrosation assay procedure (NAP test), which is expected to be a future preventive measure for screening potential nitrosation and identifying suspected contamination with N-nitroso or other potential mutagenic impurities during the drug development process.

Development and Validation of an HPLC-FLD Method for the Determination of NDMA and NDEA Nitrosamines in Lisinopril Using Pre-Column Denitrosation and Derivatization Procedure

In order to meet the analytical requirements of the European Medicines Agency (EMA), a new HPLC-FLD method was successfully developed using dansyl chloride for the derivatization and determination of the genotoxic impurities N-Nitrosodimethylamine (NDMA) and N-Nitrosodiethylamine (NDEA) in Lisinopril API and its final product. Samples’ pretreatment includes liquid–liquid microextraction, denitrosation, and derivatization steps. To optimize the process, the parameters contributing to high sensitivity and yielding reliable results were thoroughly studied and optimized using one-factor-at-a-time and experimental design approaches. The analytes were pre-column derivatized with Dansyl-Cl and analyzed by HPLC-fluorescence (λem/λem = 340/530) using a C18 column and a mixture of phosphate buffer (pH = 2.8; 20 mM)/acetonitrile 55:45 v/v as the mobile phase. The six-level concentration calibration was shown to be linear, with R equal to 0.9995 for both analytes. The limit of detection (LOD) was satisfactory and equal to 4.7 and 0.04 ng/mL for NDMA and NDEA, respectively. Precision was less than 13.4% in all cases, and the average recoveries were equal to 109.2 and 98.1% for NDMA and NDEA, respectively. The proposed procedure is relatively easy, rapid, and suitable for the determination of the two nitrosamines in routine analysis tests.

Absolute Quantitation of N-Nitrosamines by Coulometric Mass Spectrometry without Using Standards

Carcinogenic N-nitrosamines were recently found in the sartan family of drugs and caused many drug recalls. Both of their detection and quantification are therefore important. Methods reported for N-nitrosamine quantitation rely on the use of standards and are just applicable to simple N-nitrosamines. There is an urgent need to quantify N-nitrosamines derived from drugs with a complicated structure that lack standards. To tackle the issue, this study describes a novel absolute quantitation strategy for N-nitrosamines using coulometric mass spectrometry (CMS) without standards. In our approach, N-nitrosamine is first converted into electrochemically active hydrazine via zinc reduction under acidic condition and the resulting hydrazine can then be easily quantified using CMS. To validate our method, six simple N-nitrosamines, N-nitrosodiethylamine (NDEA), N-nitroso-4-phenylpiperidine (NPhPIP), N-nitrosodiphenylamine (NDPhA), N-nitrosodibutylamine (NDBA), N-nitrosodipropylamine (NDPA), and N-nitrosopiperidine (NPIP), were chosen as test samples, and they all were quantified with excellent measurement accuracy (quantitation error ≤1.1%). Taking this one step further, as a demonstration of the method utility, a drug-like N-nitrosamine, (R)-N-(2-(6-chloro-5-methyl-1'-nitroso-2,3-dihydrospiro[indene-1,4'-piperidin]-3-yl)propan-2-yl)acetamide (VII), was also synthesized and successfully quantified using our method at 15 ppb level in a complex formulation matrix, following solvent extraction, N-nitrosamine isolation, and reductive conversion. Because of the feature of requiring no standards, CMS provides a simple and powerful approach for N-nitrosamine absolute quantitation and has great potential for analysis of other drug impurities or metabolites.