Advancing drug safety and mitigating health concerns: High-resolution mass spectrometry in the levothyroxine case study.

Levothyroxine is a drug with a narrow therapeutic index. Changing the drug formulation composition or switching between pharmaceutical brands can alter the bioavailability, which can result in major health problems. However, the increased adverse drug reactions have not been fully explained scientifically yet and a thorough investigation of the formulations is needed. In this study, we used a non-targeted analytical approach to examine the various levothyroxine formulations in detail and to reveal possible chemical changes. Ultra-high-performance liquid chromatography coupled with a data-independent acquisition high-resolution mass spectrometry (UHPLC-DIA-HRMS) was employed. UHPLC-DIA-HRMS allowed not only the detection of levothyroxine degradation products, but also the presence of non-expected components in the formulations. Among these, we identified compounds resulting from reactions between mannitol and other excipients, such as citric acid, stearate, and palmitate, or from reactions between an excipient and an active pharmaceutical ingredient, such as levothyroxine-lactose adduct. In addition to these compounds, undeclared phospholipids were also found in three formulations. This non-targeted approach is not common in pharmaceutical quality control analysis. Revealing the presence of unexpected compounds in drug formulations proved that the current control mechanisms do not have to cover the full complexity of pharmaceutical formulations necessarily.

High-Performance Liquid Chromatography-Tandem Mass Spectrometry Method Development and Validation for Simultaneous Determination of Seven Nitrosamine and Azidomethyl-Biphenyl-Tetrazole Impurities in Losartan.

Nitrosamine-related impurities (N-nitrosomethylamino butyric acid [NMBA], N-nitrosodiethylamine [NDEA], N-nitrosodiisopropylamine [NDIPA], N-nitrosomethylphenylamine [NMPA], N-nitrosodibutylamine [NDBA], N-nitrosodimethylamine [NDMA], and N-nitrosoethylisopropylamine [NEIPA]) and 5-[4'-(azidomethyl)-[1,1'-biphenyl]-2-yl]-2H-tetrazole (AZBT) formed during the manufacture of sartan medicines have been classified into human mutagens and carcinogens after long-term treatment. The study developed a simple, economical but highly sensitive procedure for the simultaneous quantification of seven nitrosamines and AZBT impurities in sartan pharmaceuticals. After extraction with methanol (MeOH) 50%, the compounds were analyzed with a reversed-phase liquid chromatography-tandem mass spectroscopy with atmospheric-pressure chemical ionization (APCI) mode (APCI[+] for nitrosamines and APCI[-] for AZBT), selected reaction monitoring, C18 column, gradient elution with 0.1% formic acid in water and in MeOH, respectively. The validated procedure obtained high extraction efficiency (>90%), wide linear range (0.2-50.0 ng/mL NMBA, NDEA, NDIPA, NMPA, and NDBA; 0.5-50.0 ng/mL NDMA and NEIPA; 2.0-100 ng/mL AZBT), limit of quantification < 10% of the acceptance level, recovery range of 85%-115% with relative standard deviation < 15% and minimum matrix effects for all impurities. The procedure was applied to test 16 commercial losartan samples. As a result, eight samples contained AZBT within the current regulatory limits, but no nitrosamine impurities were detected in all samples.

Characterization of host cell proteins in the downstream process of plant-Based biologics using LC-MS profiling.

Host cell proteins (HCPs) are process-related impurities found in biopharmaceutical products that can impair their safety and efficacy. While ELISA has traditionally been employed to quantify HCPs, LC-MS emerges as a powerful alternative for precise identification of individual HCPs. In this study, we used LC-MS for profiling HCPs from Nicotiana benthamiana-derived biopharmaceuticals. Our approach involved rigorous false discovery rate control to ensure data integrity and reliability. Comprehensive analysis revealed a systematic reduction of HCPs following purification, demonstrating the efficiency of purification processes in removing non-essential proteins. Furthermore, LC-MS enabled the identification of potential contaminants, refining purification strategies and improving product purity and integrity. Our findings highlight the potential of LC-MS as an analytical tool for HCPs analysis in biopharmaceutical development and manufacturing. By providing detailed insights into HCPs profiles and contaminants, LC-MS facilitates informed decision-making in downstream processing steps, benefiting product quality, patient safety, and the biopharmaceutical sector.

Comparison of patch testing Brazilian (Green) propolis and Chinese (poplar-type) propolis: Clinical epidemiological study using data from the Information Network of Departments of Dermatology (IVDK).

BACKGROUND: Propolis types differ regarding their chemical composition. OBJECTIVES: To compare patch test results based on Brazilian (Green) propolis with data based on Chinese (poplar-type) propolis, and to evaluate the specifications of raw materials used for the PT preparations. METHODS: In the Information Network of Departments of Dermatology (IVDK), 1290 consecutive patients were patch tested with Brazilian (Green) propolis (NH400, SmartPractice Europe). Patch test reactivity was compared with results obtained with Chinese (poplar-type) propolis (NA71, SmartPractice Europe) by calculating frequencies and corresponding 95% confidence intervals. Data on the specifications of raw materials used for NH400 and NA71 were obtained from the manufacturer. RESULTS: Positive reactions to NH400 were found in 303 (23.5%) patients with unclear clinical relevance in most cases. Patients reacting to NH400 were less often sensitised to fragrances and colophony, but more often to nickel sulphate and cobalt chloride than patients reacting to NA71. The NH400 batch used contained high levels of aerobic bacteria, and was not purified by ethanolic extraction. CONCLUSIONS: Pattern of concomitant reactivity along with raw material properties suggests that the high frequency of positive reactions to NH400 may primarily result from bacterial contamination or impurities in the PT preparation rather than from propolis constituents.

Green Hydrogen Production From Non-Traditional Water Sources: A Sustainable Energy Solution With Hydrogen Storage and Distribution.

Green hydrogen development plays an essential role in creating a sustainable and environmentally conscious society while reducing reliance on traditional fossil fuels. Proton Exchange Membrane Water Electrolysers (PEMWEs), are sensitive to water quality, with various impurities impacting their efficiency, the quality of the hydrogen produced, and the device's lifespan. High-purity water is required for PEM electrolyzers; Type II water, which is required for commercial electrolyzers, must have a resistivity greater than 1 MΩ cm, sodium, and chloride concentrations less than 5 µg/L, and total organic carbon (TOC) content less than 50 parts per billion. The majority of electrolyzers operate on freshwater, or total dissolved solids (TDS) <0.5 g/kg, whereas brackish, rainwater, wastewater, and seawater have TDSs of 1-35 g/kg, 0.01-0.15 g/kg, 0.5-2 g/kg, and 35-45 g/kg, respectively. This critical review offers, for the first time, a comprehensive overview of relevant impurities in operating electrolyzers and their impact. The findings of this study indicate that electrolysis-based H2 processes are promising options that contribute to the H2 production capacity but require improvements to produce larger competitive volumes. In addition, the main challenges and opportunities for generating, storing, transporting, and distributing hydrogen, as well as large-scale adoption are discussed.

Determination of volatile impurities and ethanol content in ethanol-based hand sanitizers: Compliance and toxicity.

This study aimed to assess volatile impurities and ethanol content in ethanol-based hand sanitizers. A total of 31 different brands of hand sanitizers were analyzed using headspace gas chromatography-mass spectrometry to detect impurities and determine alcohol content for compliance. Volatile impurities were identified through Mass Spectrometry database analysis, and regression analysis was employed to ascertain ethanol percentage. Furthermore, a simulated toxicological analysis was conducted to evaluate the potential toxic effects associated with hand sanitizer usage. The detected impurities primarily included ethyl acetate, benzene, acetone, and acetal, along with contaminations such as isobutanol and non-recommended alcohols. In addition, 71 % of samples contained less than the recommended 60 % v/v alcohol concentration, failing to comply with guidelines from the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO). Additionally, the simulation study underscored acute and chronic toxicities primarily linked to benzene contamination. Given that some of the studied products are imported while others are locally produced, it is imperative for consumers worldwide to be informed that certain hand sanitizers may not only be ineffective but also contain harmful residues.

Aspects of complexity in quality and safety assessment of peptide therapeutics and peptide-related impurities. A regulatory perspective.

In recent years, a number of therapeutic peptides have been authorized in the EU market, and several others are in the clinical development phase or under assessment for full dossier or generic applications. Quality and safety guidelines specific to peptides are limited, and some aspects have to be considered. In particular, concerns relate to the analytical investigation for impurities and the toxicological assessment of these substances. The guidelines and the compendial pharmacopoeias provide certain references but that may be questionable if interpreted according to whether therapeutic peptides are considered chemical or biological entities, large or small. The characterization of peptide-related impurities cannot follow the small molecule approach but should consider aspects closely linked to the complex mechanisms of action that these large molecules can exert in the human body. Although direct genotoxic mechanisms cannot be excluded, hazardous interactions on biological systems cannot be ruled out, as in the case of natural peptide toxins and their specific interactions with cellular or membrane targets. From a regulatory perspective, only after specific risk identification and characterization should an equally specific safety threshold in relation to potential toxicity be defined.

NDSRIs Crisis in Pharmaceuticals; Insights on Formation Pathways, Root Causes, Risk Management, and Novel Analytical Techniques.

The discovery of a new class of nitrosamine impurities called N-nitroso drug substance related impurities (NDSRIs) in pharmaceuticals has emerged as a significant challenge for the pharmaceutical sector due to their significant genotoxic and mutagenic effects. Regulatory bodies globally in active collaboration with all the concerned stake holders, are taking effective measures to prevent and control NDSRIs. This comprehensive review on NDSRIs discusses formation pathways, root cause analysis, acceptable intake limits, case studies, control strategies and regulatory responses pertaining to recent NDSRI incidents. This review discusses the novel liquid chromatographic techniques (LC- MS/MS, GC-MS/MS) used to identify and quantify of NDSRIs. This review would aid pharmaceutical professionals, R&D analytical and formulation scientists, and regulatory bodies in gaining deeper insights into the NDSRIs crisis, facilitating formulation of NDSRI-free drug products, and ensuring their sensitive detection with accurate risk evaluation.

Investigation of the Influence of Copovidone Properties and Hot-Melt Extrusion Process on Level of Impurities, In Vitro Release, and Stability of an Amorphous Solid Dispersion Product.

Hot-melt extrusion (HME) is a widely used method for creating amorphous solid dispersions (ASDs) of poorly soluble drug substances, where the drug is molecularly dispersed in a solid polymer matrix. This study examines the impact of three different copovidone excipients, their reactive impurity levels, HME barrel temperature, and the distribution of colloidal silicon dioxide (SiO2) on impurity levels, stability, and drug release of ASDs and their tablets. Initial peroxide levels were higher in Kollidon VA 64 (KVA64) and Plasdone S630 (PS630) compared to Plasdone S630 Ultra (PS630U), leading to greater oxidative degradation of the drug in fresh ASD tablets. However, stability testing (50 °C, closed container, 50 °C/30% RH, open conditions) showed lower oxidative degradation impurities in ASD tablets prepared at higher barrel temperatures, likely due to greater peroxide degradation. Plasdone S630 is suitable for ASDs with drugs prone to oxidative degradation, while standard purity grades may benefit drugs susceptible to free radical degradation, as they generate fewer free radicals post-HME. ASD tablets exhibited greater physical stability than milled extrudate samples, likely due to reduced exposure to stability conditions within the tablet matrix. Including SiO2 in the extrudate composition resulted in greater physical stability of the ASD system in the tablet; however, it negatively affected chemical stability, promoting greater oxidative degradation and hydroxylation of the drug substance. No impact of the distribution of SiO2 on drug release was observed. The study also confirmed the congruent release of copovidone, the drug substance, and Tween 80 using flow NMR coupled with in-line UV/vis. This research highlights the critical roles of peroxide levels and SiO2 in influencing the dissolution and physical and chemical stability of ASDs. The findings provide valuable insights for developing stable and effective pharmaceutical formulations, emphasizing the importance of controlling reactive impurities and excipient characteristics in ASD products prepared by using HME.

Separation and characterization of degradation impurities of upadacitinib by liquid chromatography and high resolution mass spectrometry.

Upadacitinib is an oral Janus Kinase inhibitor used for the treatment of rheumatoid arthritis. This research focuses on the forced degradation study of upadacitinib and the characterization of its degradation impurities. Upadacitinib was subjected to various degradation conditions such as hydrolysis (acid, base, neutral), oxidation, thermal, and photolysis according to International Council for Harmonisation guidelines. Twelve degradation impurities of upadacitinib were observed under oxidation (H2O2, AIBN, Fenton's reagent) and photolysis (UV light). Zeneth software was used to predict the in silico degradation profile. High-performance liquid chromatography was used to separate the observed degradation impurities with ammonium formate (pH 3.63) and acetonitrile as mobile phases on an Agilent Zorbax Eclipse plus C18 column (4.6 × 250 mm, 5 µm). The separated degradation impurities were characterized by using high resolution mass spectrometry. The accurate masses obtained from LC-HRMS/MS were used to determine the structures of all the degradation impurities. A suitable mechanism for the formation of degradation impurities was proposed. DEREK Nexus and SARAH Nexus were used for the in silico toxicity and mutagenicity assessments.

Separation and identification of oligonucleotides impurities and degradation products by reversed phase ultra-high performance liquid chromatography using phenyl-bonded stationary phases without ion pairs - A step towards sustainability.

This manuscript discusses the development of a reversed-phase ultra high-performance liquid chromatography (RP UHPLC) method based on phenyl-bonded stationary phases without ion-pairs for the separation and identification of oligonucleotides. The elimination of ion-pair reagents makes the proposed protocol as more compliant to the principles of green chemistry, compared to the traditional ion-pair reversed-phase liquid chromatography methods (IP RP LC). In detail, three phenyl-based stationary phases were tested, namely a C18/AR (a C18 stationary phase with the addition of aromatic groups), a Phenyl-hexyl, and a Diphenyl. Generally, the retention of oligonucleotides increases with the increase of salt concentration and the decrease of the pH, thus confirming the significant impact of van der Waals interactions, salting-out effect, and π-electrons interactions in the retention mechanism. The highest retention and best peak symmetry were observed for the C18/AR stationary phase, while the lowest retention for the Phenyl-hexyl, with retention influenced by the type of salt in the mobile phase. The obtained methods using C18/AR stationary phases allow for the effective separations of positional isomers and for identifying impurities and degradation products using RP UHPLC Q-TOF-MS in a comparatively short time. The application of RP UHPLC Q-TOF-MS provides reasonable selectivity for the resolution of 33 impurities and two degradation products. Both groups of compounds are mainly 3'N and 5'N-shortmers, but in the case of impurities, modifications of cyclic phosphate and phosphate groups were also identified. Nevertheless, Diphenyl and Phenyl-Hexyl may be applied to separate modified oligonucleotides with higher salt concentrations. The proposed separation methods without ion-pair reagents contribute to a more sustainable approach in oligonucleotide analysis.

Research on wheat impurity identification method based on terahertz imaging technology.

The traditional detection of impurities in wheat has difficulties such as low precision, time-consuming, and cumbersome, therefore, it is important to study the method of rapid and accurate detection of impurities in wheat for correctly assessing the quality grade of wheat. Terahertz (THz) technology has many superior properties such as transient, broadband, low-energy, and penetrating, which can realize rapid and nondestructive detection of wheat quality. In this study, a classification and recognition algorithm AHA-RetinaNet-X for wheat impurity terahertz images based on RetinaNet and Artificial hummingbird algorithm (AHA) is proposed.A THz three-dimensional tomography imaging system is used to image wheat and its impurities, and two THz image datasets, respectively the wheat and impurity dataset for verifying the classification effect of wheat and impurities and the impurity dataset for verifying the classification effect of impurities. The experimental results show that the AHA-RetinaNet-X model outperforms other detection and classification models in terms of accuracy, F1-score, precision, recall, and specificity, and is able to achieve 96.1%, 94.9%, 95.2%, 95.8%, 95.5%, 95.3%, and 93.3% for the wheat and impurity dataset and the impurity dataset, respectively, 95.6%, 96.3%, and 95.2%, and the mAP value of AHA-RetinaNet-X is also higher than the other models and can reach 92.1%. The combination of THz imaging technology and AHA-RetinaNet-X can realize the classification and identification of wheat and impurities, which provides a new method for the non-contact rapid nondestructive detection and identification of wheat and impurities, and also provides a reference for the research of the identification and detection methods of other substances.

The Effect of Electrolyte pH and Impurities on the Stability of Electrolytic Bicarbonate Conversion.

Electrolytic bicarbonate conversion holds the promise to integrate carbon capture directly with electrochemical conversion. Most research has focused on improving the faradaic efficiencies of the system, however, the stability of the system has not been thoroughly addressed. Here, we find that the bulk electrolyte pH has a large effect on the selectivity, where a higher pH results in a lower selectivity. However, the bulk electrolyte pH has no effect on the stability of the system. A decrease in CO selectivity of 30% was observed within the first three hours of operation in an optimized system with 3 M KHCO3 and gap between the membrane and electrode. Single-pass electrolyte experiments at various constant pH values (8.5, 9.0, 9.5, and 10.0), show that only at a pH of 10 the CO selectivity was stable during three hours, reaching a faradaic efficiency toward CO of only 18% as compared to an initial 55% at pH 8.5. Trace metal impurities present in the electrolyte were found to be the cause of the decrease in stability as these deposit on the electrode surface. By complexing the trace metal ions with ethylenediaminetetraacetic acid (EDTA), the metal deposition was avoided and a stable CO selectivity was obtained.

Elemental impurities (heavy metals) in kratom products: an assessment of published individual product analyses.

INTRODUCTION: Kratom is commonly used by consumers, and the elemental impurity exposure that consumers would have at different kratom ingestion doses has been determined. METHODS: This assessment used original data from independent third-party laboratory testing of kratom products to identify the percentage of products that exceeded permissible daily exposure limits for lead (5 µg/day), nickel (200 µg/day), arsenic (15 µg/day), and cadmium (5 µg/day), the interim reference level for lead in adults (12.5 µg/day), and the tolerable upper intake level for manganese (11 mg/day) and nickel (1 mg/day). We assessed all products regardless of type and then evaluated non-extract products, extract products, and a soda preparation separately for elemental impurities. RESULTS: Three assessments of elemental impurities in kratom products have been published, totaling 68 products. Assessing all products and assuming a 3 g daily dose of kratom, 7.4% would exceed the permissible daily exposure limits for lead, 0% for nickel, 3.1% for arsenic, and 0% for cadmium. At a kratom dose of 25 g daily, 70.6% would exceed the permissible daily exposure limits for lead, 20.6% for nickel, 9.4% for arsenic, and 0% for cadmium. The interim reference level for lead would be exceeded by 1.5% of products at a kratom daily dose of 3 g and 33.8% of products at 25 g. The tolerable upper intake level for manganese would be exceeded by 12.5% of products at a kratom daily dose of 3 g and 41.7% of products at 25 g. Non-extract products generally contain greater concentrations of elemental impurities than extract products or the soda preparation. DISCUSSION: Apart from their concentrations in a gram of product, assessing the amount of exposure to elemental impurities at different kratom ingestion doses is also important. Elemental impurities exceeding regulatory permissible concentrations for many products, especially with greater daily kratom ingestion doses, may impact human health. CONCLUSIONS: Some kratom products contain excessive concentrations of elemental impurities of toxicological concern, such as lead and arsenic. Non-extract products (powders, capsules, tablets) generally contain greater concentrations of elemental impurities than extract products or the soda preparation. Daily use of these products can result in exposures exceeding regulatory thresholds and adverse health effects.

Optimizing the detection of N-nitrosamine mutagenicity in the Ames test.

Accurately determining the mutagenicity of small-molecule N-nitrosamine drug impurities and nitrosamine drug substance-related impurities (NDSRIs) is critical to identifying mutagenic and cancer hazards. In the current study we have evaluated several approaches for enhancing assay sensitivity for evaluating the mutagenicity of N-nitrosamines in the bacterial reverse mutagenicity (Ames) test. Preincubation assays were conducted using five activation conditions: no exogenous metabolic activation and metabolic activation mixes employing both 10% and 30% liver S9 from hamsters and rats pretreated with inducers of enzymatic activity. In addition, preincubations were conducted for both 60 min and 30 min. These test variables were evaluated by testing 12 small-molecule N-nitrosamines and 17 NDSRIs for mutagenicity in Salmonella typhimurium tester strains TA98, TA100, TA1535, and TA1537, and Escherichia coli strain WP2 uvrA (pKM101). Eighteen of the 29 N-nitrosamine test substances tested positive under one or more of the testing conditions and all 18 positives could be detected by using tester strains TA1535 and WP2 uvrA (pKM101), preincubations of 30 min, and S9 mixes containing 30% hamster liver S9. In general, the conditions under which NDSRIs were mutagenic were similar to those found for small-molecule N-nitrosamines.

Identification and quantitative analysis of genotoxic impurities in rifampicin: Development and validation of a targeted LC-MS/MS method for 1-amino-4-methylpiperazine.

Rifampicin, essential for long-term tuberculosis treatment, requires rigorous control of non-therapeutic impurities due to their potential adverse, including mutagenic effects. Reports on control strategies for genotoxic impurities in rifampicin have been limited. This study introduced an analytical method to identify potential genotoxic impurities from the synthesis of raw materials. The structure of the 25-deacetyl-23-acetyl-rifampicin genotoxic impurity was confirmed using nuclear magnetic resonance, high-resolution mass spectrometry (HRMS), and high-performance liquid chromatography (HPLC). An HPLC-HRMS method was established and validated for detecting another genotoxic impurity, 1-amino-4-methylpiperazine, adhering to the International Council on Harmonization guidelines, which include specificity, linearity, detection and quantification limits, accuracy, precision, and robustness. These developments improve the quality control strategy for genotoxic impurities in rifampicin, ensuring product safety.

A practical HPLC-MS method for the analysis of nitrosamine drug substance related impurities using an inexpensive single quadrupole mass spectrometer.

Nitrosamine drug substance related impurities (NDSRIs) are often analyzed using high performance liquid chromatography (HPLC) with mass spectrometry (MS) detection. Due to high sensitivity requirements, high resolution MS or MS/MS is commonly used. However, it is difficult to implement this type of method for routine analysis at a supply site. Herein, we report a systematic approach to develop and validate a practical, robust, and user-friendly method for the analysis of NDSRIs using an inexpensive single quadrupole MS instrument such as QDa. We used 7-nitroso-3-(trifluoromethyl)-5,6,7,8-tetrahydro- [1,2,4] triazolo [4,3-a] pyrazine (NTTP) as an example to demonstrate the method development process. By optimizing the HPLC and MS parameters, we were able to develop a simple HPLC-MS method that provides the desired specificity and sensitivity for the analysis of NTTP and can be easily implemented in an analytical lab. The limit of quantitation is 0.5 ng/mL, corresponding to 0.1 ppm with respect to 5 mg/mL sitagliptin. The method has been successfully validated per ICH guidelines.

Identification and characterization of two new oxidation degradation impurities in cinnarizine through LC-HRMS/MS and 1H NMR, along with in silico toxicity predictions of its degradation products.

Cinnarizine (CIN) drug substance is a US FDA and EMA approved antihistaminic drug, There is no report available on CIN for the identification of degradation products and their degradation pathway. Herein, we report a stability-indicating assay method for CIN, the formation and characterization of its major degradation products using LC-HRMS/MS and 1H-NMR techniques. CIN was subjected to oxidation, acid, base, thermal and photolytic degradation conditions. Two unknown degradation products (DP-1 and DP-2) of CIN were formed under oxidative conditions. We successfully separated these degradants using gradient elution on an Inertsil ODS 3 V column (150 × 4.6 mm, 5 µm) using mobile phase A consisting of 0.1% formic acid and the mobile phase B consisting of 0.1% formic acid/acetonitrile (20/80, v/v). CIN was labile to oxidative conditions and stable to acidic, alkaline hydrolytic, photolytic and thermal conditions. The degradation pathways were derived from the nature of the product formed under oxidative degradation conditions and available reports for confirmation of the mechanism. Since the stability-indicating assay method can be utilized for stability studies and routine quality control of CIN in both the pharmaceutical industry and research laboratories. This method has been validated in compliance with the guidelines set forth by the ICH.

Exposure to Valsartan Products Containing Nitrosamine Impurities in the United States, Canada, and Denmark.

BACKGROUND: Following the mass recall of valsartan products with nitrosamine impurities in July 2018, the number of patients exposed to these products, the duration of exposure, and the potential for cancer remains unknown. Therefore, we assessed the extent and duration of use of valsartan products with a nitrosamine impurity in the United States, Canada, and Denmark. METHODS: We conducted a retrospective cohort study using administrative healthcare data from the US FDA Sentinel System, four Canadian provinces that contribute to the Canadian Network for Observational Drug Effect Studies (CNODES), and the Danish National Prescription Registry. Patients, 18 years and older between May 2012 and December 2020 with a valsartan dispensing were identified in each database. Patients were followed from the date of valsartan dispensing until discontinuation. We defined four valsartan exposure categories based on nitrosamine impurity status; recalled generic products with confirmed NDMA/NDEA levels (recalled-tested); recalled generic products that were not tested (recalled); non-recalled generic and non-recalled branded products. In Denmark, the recalled-tested category was not included due to absence of testing data. The proportion and duration of use of valsartan episodes stratified by nitrosamine-impurity status was calculated. RESULTS: We identified 3.3 and 2.8 million (United States) and 51.3 and 229 thousand (Canada) recalled-tested and recalled valsartan exposures. In Denmark, where valsartan exposure was generally low, there were 10 747 recalled exposures. Immediately after the recall notices were issued, there was increased rates of switching to a non-valsartan ARB. The mean duration of use of the recalled-tested products was 167 (±223.1) and 146 (±255.8) days in the United States and Canada respectively. For the recalled products, mean cumulative duration of use was 178 (±249.6), 269 (±397.3) and 166 (±251.0) days in the United States, Canada, and Denmark, respectively. CONCLUSION: In this cohort study, despite widespread use of recalled generic valsartan between 2012 and 2018, the duration of use was relatively short and probably did not pose an elevated risk of nitrosamine-induced cancer. However, since products with nitrosamine impurity could have been on the market over a 6-year period, patients exposed to these products for longer durations could have a potentially different risk of cancer.

Clear insight into complex multimodal resins and impurities to overcome recombinant protein purification challenges: A review.

Increasing attention has been paid to the purity of therapeutic proteins imposing extensive costs and challenges to the downstream processing of biopharmaceuticals. One of the efforts, that has been exerted to overcome such limitations, was developing multimodal or mixed-mode chromatography (MMC) resins for launching selective, orthogonal, non-affinity purification platforms. Despite relatively extensive usage of MMC resins, their real potential and fulfillment have not been extensively reviewed yet. In this work, the explanation of practical and key aspects of downstream processing of recombinant proteins with or without MMC resins was debated, as being useful for further purification process development. This review has been written as a step-by-step guide to deconvolute both inherent protein purification and MMC complexities. Here, after complete elucidation of the potential of MMC resins, the effects of frequently used additives (mobile phase modifiers) and their possible interactions during the purification process, the critical characteristics of common product-related impurities (e.g., aggregates, charge variants, fragments), host-related impurities (e.g., host cell protein and DNA) and process related impurities (e.g., endotoxin, and viruses) with solved or unsolved challenges of traditional and MMC resins have been discussed. Such collective experiences which are reported in this study could be considered as an applied guide for developing successful downstream processing in challenging conditions by providing a clear insight into complex MMC resins and impurities.