Determination of N -nitrosamines in cosmetic products by vortex-assisted reversed-phase dispersive liquid-liquid microextraction and liquid chromatography with mass spectrometry

Development of a sensitive LC-MS/MS method for determination of N-nitrosopiperazine in levocetirizine

Levocetirizine is one of the widely used antihistamines and has the potential to form N-nitrosopiperazine (NPZ) during drug synthesis, manufacturing, or storage. NPZ classified as a nitrosamine is a genotoxic impurity with carcinogenic properties. Controlling the presence of NPZ in the active pharmaceutical ingredient (API) and drug products is crucial with levels ideally maintained below 80 ppm. Herein, we developed a highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique to analyze NPZ levels in levocetirizine API and various formulations. Chromatographic separation was carried out using an F5 column with mobile phases consisting of 2 mM ammonium formate in water and acetonitrile, employing gradient elution mode at a flow rate of 0.2 mL min-1. The column oven temperature was set at 30 °C, and the injection volume was 2 μL. NPZ quantification was achieved using positive electrospray ionization (ESI) in the multiple reaction monitoring (MRM) mode. The developed method underwent rigorous validation according to regulatory guidelines. The limit of quantification (LOQ) was established at 1 ng mL-1 within the range of 1-50 ng mL-1, covering 10-500% of the specified NPZ limit in drugs. The effectiveness of the method was shown by utilizing it to analyze the NPZ impurity in both levocetirizine API and various drug products, including tablets, capsules, chewables, and syrups. The proposed method and the resulting data would be valuable for determining potentially present impurities in drug substances or products for quality assessment.

A Novel Method for Monitoring N-Nitrosamines Impurities Using NH2-MIL-101(Fe) Mediated Dispersive Micro-Solid Phase Extraction Coupled with LC-MS/MS in Biopharmaceuticals

A highly efficient and convenient method for the simultaneous determination of 12 N-nitrosamines (NAs) has been developed using an amine-functionalized metal-organic framework (NH2-MIL-101(Fe)) as sorbent for dispersive micro-solid phase extraction (D-μSPE) coupled with LC-MS/MS in biopharmaceuticals. The experimental variables involved in the extraction process (i.e., amount of the sorbent, extraction time, desorption time, ionic strength, desorption solvent and volume) were optimized to achieve the best extraction efficiency of the target analytes. Under the optimum conditions, the method was successfully validated, showing good linearity in the range of 0.5-3.0 μg/L with determination coefficients (R2) higher than 0.990, repeatability (RSD ≤ 10.0%, spiked level at 2.0 μg/L) and precision (RSD ≤ 8.2%). The limit of detection (LOD) and limit of quantitation (LOQ) were in the range of 0.005-0.025 μg/L and 0.010-0.250 μg/L, respectively. Satisfactory recoveries ranging from 82.4 to 116.8% were obtained by spiking standards at three different concentrations (0.5 μg/L, 2.0 μg/L and 3.0 μg/L). Other validation parameters, including specificity, stability, and robustness, met the validation criteria. More importantly, the plausible adsorption mechanism on NH2-MIL-101(Fe) was proposed by Fourier-transform infrared (FTIR) spectra technique. Finally, this method was successfully applied to detect trace nitrosamines in biopharmaceuticals.

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.

NDMA formation Due to Active Ingredient Degradation and Nitrite Traces in Drug Product

N-nitrosamines are genotoxic compounds which can be found as impurities in drug substances and drug products used in the pharmaceutical industry. To date, several possible nitrosamine sources in drug products have been reported and this study aims to illuminate another one. A case of afatinib drug product was investigated, in which up to 50 ppb N-nitrosodimethylamine (NDMA) traces were detected. Afatinib was found to degrade to the secondary amine dimethylamine (DMA), forming NDMA with traces of nitrite in crospovidone. Two series of film-coated tablets were prepared with crospovidone from two different manufacturers, containing different levels of nitrites. Tablets were subjected to an accelerated stability study (40 °C/75% relative humidity) or stored at room temperature and levels of NDMA, DMA and nitrite in tablets were monitored. NDMA and nitrite were found on ppb levels, whereas DMA was detected on ppm levels. NDMA formation in the drug product was found to be time, temperature and nitrite dependent and it was emphasized that DMA and nitrite should be reduced. The accelerated stability study proved to be a useful tool for predicting nitrosamine formation in the drug product.

Harmful and potentially harmful constituents (HPHCs) in two novel nicotine pouch products in comparison with regular smokeless tobacco products and pharmaceutical nicotine replacement therapy products (NRTs)

BACKGROUND

Tobacco-free nicotine pouches is a novel category of oral nicotine-delivery products. Among current tobacco users such pouches may serve as a low-risk alternative to cigarettes or conventional, tobacco-based oral products e.g., snus and moist snuff. In the United States (U.S.), the market leading nicotine-pouch brand is ZYN®. However, no data on the chemical characteristics of ZYN have been published.

METHODS

We screened for 43 compounds potentially present in tobacco products in seven oral nicotine-delivery products: ZYN (dry and moist), snus (General^®), moist snuff (CRP2.1 and Grizzly Pouches Wintergreen), and two pharmaceutical, nicotine replacement therapy products (NRTs, Nicorette^® lozenge and Nicotinell^® gum). Thirty-six of the tested compounds are classified as harmful and potentially harmful constituents (HPHCs) by the Center for Tobacco Products at the U.S. Food and Drug Administration (FDA-CTP). Five additional compounds were included to cover the GOTHIATEK^® product standard for Swedish snus and the last two compounds were chosen to include the four primary tobacco specific nitrosamines (TSNAs).

RESULTS

The tested products contained nicotine at varying levels. The two ZYN products contained no nitrosamines or polycyclic aromatic hydrocarbons (PAHs) but low levels of ammonia, chromium, formaldehyde, and nickel. In the NRT products we quantified low levels of acetaldehyde, ammonia, cadmium, chromium, lead, nickel, uranium-235, and uranium-238. The largest number (27) and generally the highest levels of HPHCs were quantified in the moist snuff products. For example, they contained six out of seven tested PAHs, and seven out of ten nitrosamines (including NNN and NNK). A total of 19 compounds, none of which were PAHs, were quantified at low levels in the snus product. NNN and NNK levels were five to 12-fold lower in snus compared to the moist snuff products.

CONCLUSIONS

No nitrosamines or PAHs were quantified in the ZYN and NRT products. Overall, the number of quantified HPHCs were similar between ZYN and NRT products and found at low levels.

Determination of nine prohibited N-nitrosamines in cosmetic products by vortex-assisted dispersive liquid-liquid microextraction prior to gas chromatography-mass spectrometry

An analytical method for the simultaneous determination of nine prohibited N-nitrosamines in cosmetic products is presented. N-nitrosamines are banned compounds in cosmetic products due to their harmful effects. Therefore, these compounds are not intentionally added to these products but, however, small amounts of them may be present due to unintentional causes, and thus sensitive methods for their analytical control are required. The proposed method is based on vortex-assisted dispersive liquid-liquid microextraction (VA-DLLME) to extract and preconcentrate the analytes, followed by gas chromatography-mass spectrometry (GC-MS) for their determination. The variables involved in the VA-DLLME process were optimized by using a Box-Behnken design and, due to the different polarity of the N-nitrosamines studied, several approaches for sample treatment were compared to achieve the best results. The method was successfully validated, showing a good linearity at least up to 20 ng mL^-1, enrichment factors from 2 to 100 depending on the target analyte, limits of detection and quantification at the low μg kg^-1 level, and good repeatability values (<13%). Finally, the proposed analytical method was applied to the determination of N-nitrosamines in commercial cosmetic samples of different nature, avoiding the matrix effect by means of standard addition calibration. Significant amounts of some of the N-nitrosamines, even exceeding the established regulatory limit, were found in the samples. The resulting method is fast, simple, and affordable to carry out the quality control of cosmetic products to ensure consumer safety for most laboratories.

Preparation of flower-like molybdenum disulfide for solid-phase extraction of N-nitrosoamines in environmental water samples

In this paper, a flower-like molybdenum disulfide material was prepared by hydrothermal method and was first used as adsorbents in the solid-phase extraction process for enriching N-nitrosoamines. Molybdenum disulfide exhibited three-dimensional petal-like microspheres with about 500 nm in diameter. The relevant analyte extraction and elution parameters (sample volumes, solution pH, washing solvents, elution solvents, and elution volumes) were optimized to improve the solid-phase extraction efficiency. The solid-phase extraction process coupled with high-performance liquid chromatography-tandem mass spectrometry for determining N-nitrosoamines in environmental water samples was established. The limits of detection were in the range of 0.01-0.05 ng/mL. The satisfactory recoveries (68.9-106.1%) were obtained at three different spiked concentrations (2, 5, and 8 ng/mL) in water samples, and the relative standard deviations were between 1.96 and 8.38%. This proposed method not only showed high sensitivity and good reusability but also provided a new adsorbent for enriching trace N-nitrosoamines in environmental water samples.

Recent Advances in Sample Preparation for Cosmetics and Personal Care Products Analysis

The use of cosmetics and personal care products is increasing worldwide. Their high matrix complexity, together with the wide range of products currently marketed under different forms imply a challenge for their analysis, most of them requiring a sample pre-treatment step before analysis. Classical sample preparation methodologies involve large amounts of organic solvents as well as multiple steps resulting in large time consumption. Therefore, in recent years, the trends have been moved towards the development of simple, sustainable, and environmentally friendly methodologies in two ways: (i) the miniaturization of conventional procedures allowing a reduction in the consumption of solvents and reagents; and (ii) the development and application of sorbent- and liquid-based microextraction technologies to obtain a high analyte enrichment, avoiding or significantly reducing the use of organic solvents. This review provides an overview of analytical methodology during the last ten years, placing special emphasis on sample preparation to analyse cosmetics and personal care products. The use of liquid–liquid and solid–liquid extraction (LLE, SLE), ultrasound-assisted extraction (UAE), solid-phase extraction (SPE), pressurized liquid extraction (PLE), matrix solid-phase extraction (MSPD), and liquid- and sorbent-based microextraction techniques will be reviewed. The most recent advances and future trends including the development of new materials and green solvents will be also addressed.

On-line solid phase extraction-ultra-high performance liquid chromatography coupled to tandem mass spectrometry for the determination of N-nitrosodiethanolamine in baby shampoo

N-nitrosodiethanolamine (NDELA) is a carcinogenic contaminant of concern in the cosmetics industry. Contaminated raw material, degradation, reactions of ingredients of the formulation, or migration of packaging material can be responsible for the presence of NDELA in the final product. Liquid chromatography coupled to tandem mass spectrometry is the most widely accepted technique for the quantitation of NDELA in cosmetic products. Still, there is no consensus regarding the sample preparation procedure. The aim of this work was to evaluate the performance of two-dimensional liquid chromatography coupled with tandem mass spectrometry for the determination of NDELA in shampoo. In the first dimension an Oasis HLB SPE-column was used and in the second dimension a CSH C18 column. NDELA-d₈ was used as an internal standard. The 2D-LC parameters were optimized by a central composite multivariate design. However, before quantitation, a sample preparation step using solid-phase extraction was necessary to eliminate compounds present in the formulation, especially surfactants that were not compatible with the chromatographic columns. Moreover, the complex matrices and singular compositions of shampoo from different manufacturers required adjustments of the sample preparation procedure for each sample. The limit of quantitation of the method for the determination of NDELA in shampoo was in the range of 5-10 ng g^-1. The accuracy of the method at the LOQ (10 ng g^-1) was 114 % and the inter-day precision of 15.3 % (n = 9). One sample out of 12 presented an NDELA concentration of 54 ng g^-1.

Progress in the pretreatment and analysis of N-nitrosamines: an update since 2010

As highly toxic substances, N-nitrosamines (NAs) have been proved to cause carcinogenesis and mutagenesis in humans. Therefore, to carefully monitor safety and preserve human health, the development of rapid, accurate, and high-sensitivity determination methods of NAs is of substantial importance. This review provides a current-status comprehensive summary of the pretreatment and determination methods of NAs in various samples since 2010. Common pretreatment methods that have been used to extract and purify targets include solid-phase extraction, liquid-liquid extraction and various microextraction methods, such as solid-phase microextraction and liquid-phase microextraction, among others. Determination methods include liquid chromatography, gas chromatography, supercritical fluid chromatography and electrochemical methods, among others. In addition, we discuss and compare the advantages and disadvantages of various pretreatment and analytical methods and examine the prospects in this area.