Identification Of Degradation Products Research Articles

LC and LC-MS/MS Studies for the Separation and Identification of Impurities and Degradation Products of Betaxolol.

Betaxolol (Bx) is a selective β1 receptor blocker used in the treatment of hypertension and glaucoma. The aim of the present work was to demonstrate an approach involving use of liquid chromatography (LC) and liquid chromatography-electrospray ionization mass spectrometry (LC-ESI/MS) for the simultaneous separation, identification and characterization of impurities and of degradation products of betaxolol without their isolation from the reaction mixtures. At optimum condition, and according to ICH guidelines, the limit of detection (LOD) and limit of quantification (LOQ) for Bx are found to be 5.46 and 16.54μgmL-1, respectively. However, the LOD and LOQ for the major degradation product P6 were 2.15 and 6.53μgmL-1. Betaxolol was subjected to hydrolytic (acidic and basic) and oxidative, stress conditions according to International Conference on Harmonization (ICH) guideline Q1A (R2), and as results, the drug was found to be labile in acidic, basic and oxidative stress conditions. Based on LC-ESI/MS analysis, the found results revealed that Bx decomposes in acidic, basic and oxidizing environments. All degradation products were identified with the help of their fragmentation pattern and the masses obtained upon the MS analysis.

Identification of major degradation products of Clorsulon drug substance including its degradation pathways by high resolution mass spectrometry and NMR

Clorsulon is an effective anthelmintic drug substance extensively used in the treatment of parasitic infestations in both cattle and sheep. An in-depth investigation of Clorsulon’s degradation products (DPs) was carried out through forced degradation study to comprehend its degradation path. A total of eight degradation products were separated under various stress degradation conditions. Structural elucidation of these DPs was conducted using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS), and their fragmentation patterns were compared to that of the parent compound. Adequate amount of DP-4 was isolated and purified by semi-preparative high-performance liquid chromatography (HPLC) methods. Subsequently, it was examined in detail using both 1D and 2D NMR (nuclear magnetic resonance spectroscopy). Most probable mechanistic pathways for the formation of degradation products under various stress degradation conditions were proposed to better understand the degradation profile. Based on the results of the stress study, Clorsulon drug substance was found to be unstable under photolytic and oxidative conditions. Understanding Clorsulon's degradation pathway is essential for determining shelf-life prediction of finished product, safety and efficacy assurance, and guiding the development of stable, high-quality formulations.

Synthesis of CuO, ZnO nanoparticles, and CuO-ZnO nanocomposite for enhanced photocatalytic degradation of Rhodamine B: a comparative study

Water pollution, arising from the presence of toxic dyes and chemicals, is a global challenge, urging the need for eco-friendly solutions in water decontamination. This study focused on the synthesis of copper oxide nanoparticles (CuO NPs), zinc oxide nanoparticles (ZnO NPs), and a bimetallic CuO-ZnO nanocomposite (CZ NC) through an environmentally friendly method employing Tragia involucrata L. leaf extract. Comprehensive analysis of structural and optical properties involved using various analytical techniques such as XRD, FT-IR, XPS, UV-DRS, PL, FE-SEM, EDAX, TEM, SAED, zeta potential, TGA, and BET. In comparison to pristine CuO and ZnO NPs, the CZ-NC demonstrated notably enhanced photocatalytic activity in the degradation of Rhodamine B dye (RhB). The optimum conditions for RhB degradation were found to be a pH of 9 and a catalyst dosage of 1 mg/mL for a concentration of 10 ppm. Under these conditions, CuO NPs, ZnO NPs, and CZ-NC demonstrated high efficiencies of 78%, 83%, and 96.1% respectively over 105 min. Through LC-HRMS, the identification of degradation products offered valuable insights into the pathway of photocatalytic degradation. Furthermore, toxicity analysis of intermediates, conducted through ECOSAR software, indicated the formation of non-toxic by-products (ChV/LC50/EC50 > 100) after the completion of the reaction. Furthermore, the recycled catalysts exhibited sustained stability for up to 4 cycles, with only a minor decrease in activity of up to 6.8%. This confirms their catalytic efficacy in purifying polluted water. This research significantly contributes to the progress of environmentally friendly nanocomposites, enhancing their efficacy in the realm of environmental remediation.

Identification and structural characterization of potential degradation products of baricitinib using liquid chromatography combined with quadrupole time-of-flight mass spectrometry

AbstractBaricitinib (BRT) is a drug substance with potent anti-inflammatory activity indicated in rheumatoid arthritis, atopic dermatitis, severe alopecia areata and recently for the treatment of Covid-19. Process impurities of the drug during its formulation are quite known, however studies regarding its degradation products (DPs) under stress conditions are limited. In this study, the drug was subjected to forced degradation under various degradation conditions, including acidic hydrolysis, alkaline hydrolysis, oxidative and thermal, to determine its inherent stability. To this purpose, a novel HPLC method was developed for the determination of degradation impurities of BRT. Alkaline hydrolysis test showed a selectivity towards breaking C–C bonds. This resulted to five DPs formed by chain scission reactions occurred at the pyrrolo-pyrimidine group between C6–C10 and C8–C9. Also, the ethylsulfonyl-azetidin-ylidene group was subjected to C–C bond cleavage at C12–C15 and C16–C18. Degradation products were further characterized with the use of liquid chromatography quadrupole time of flight tandem mass spectrometry (LC-Q-TOF-MS/MS).

Novel polyurethane-degrading cutinase BaCut1 from Blastobotrys sp. G-9 with potential role in plastic bio-recycling

Environmental pollution caused by plastic waste has become global problem that needs to be considered urgently. In the pursuit of a circular plastic economy, biodegradation provides an attractive strategy for managing plastic wastes, whereas effective plastic-degrading microbes and enzymes are required. In this study, we report that Blastobotrys sp. G-9 isolated from discarded plastic in landfills is capable of depolymerizing polyurethanes (PU) and poly (butylene adipate-co-terephthalate) (PBAT). Strain G-9 degrades up to 60% of PU foam after 21 days of incubation at 28 ℃ by breaking down carbonyl groups via secretory hydrolase as confirmed by structural characterization of plastics and degradation products identification. Within the supernatant of strain G-9, we identify a novel cutinase BaCut1, belonging to the esterase family, that can reproduce the same effect. BaCut1 demonstrates efficient degradation toward commercial polyester plastics PU foam (0.5 mg enzyme/25 mg plastic) and agricultural film PBAT (0.5 mg enzyme/10 mg plastic) with 50% and 18% weight loss at 37 ℃ for 48 h, respectively. BaCut1 hydrolyzes PU into adipic acid as a major end-product with 42.9% recovery via ester bond cleavage, and visible biodegradation is also identified from PBAT, which is a beneficial feature for future recycling economy. Molecular docking, along with products distribution, elucidates a special substrate-binding modes of BaCut1 with plastic substrate analogue. BaCut1-mediated polyester plastic degradation offers an alternative approach for managing PU plastic wastes through possible bio-recycling.

Integrated transcriptomics and metabolomics analyses reveal the aerobic biodegradation and molecular mechanisms of 2,3′,4,4′,5-pentachlorodiphenyl (PCB 118) in Methylorubrum sp. ZY-1

2,3′,4,4′,5-pentachlorodiphenyl (PCB 118), a highly representative PCB congener, has been frequently detected in various environments, garnering much attention across the scientific community. The degradation of highly chlorinated PCBs by aerobic microorganisms is challenging due to their hydrophobicity and persistence. Herein, the biodegradation and adaptation mechanisms of Methylorubrum sp. ZY-1 to PCB 118 were comprehensively investigated using an integrative approach that combined degradation performance, product identification, metabolomic and transcriptomic analyses. The results indicated that the highest degradation efficiency of 0.5 mg L−1 PCB 118 reached 75.66% after seven days of inoculation when the bacteria dosage was 1.0 g L−1 at pH 7.0. A total of eleven products were identified during the degradation process, including low chlorinated PCBs, hydroxylated PCBs, and ring-opening products, suggesting that strain ZY-1 degraded PCB 118 through dechlorination, hydroxylation, and ring-opening pathways. Metabolomic analysis demonstrated that the energy supply and redox metabolism of strain ZY-1 was disturbed with exposure to PCB 118. To counteract this environmental stress, strain ZY-1 adjusted both the fatty acid synthesis and purine metabolism. The analysis of transcriptomics disclosed that multiple intracellular and extracellular oxidoreductases (e.g., monooxygenase, alpha/beta hydrolase and cytochrome P450) participated in the degradation of PCB 118. Besides, active efflux of PCB 118 and its degradation intermediates mediated by multiple transporters (e.g., MFS transporter and ABC transporter ATP-binding protein) might enhance bacterial resistance against these substances. These discoveries provided the inaugural insights into the biotransformation of strain ZY-1 to PCB 118 stress, illustrating its potential in the remediation of contaminated environments.

Identification of Degradation Products and Components in Shellfish Purple by Ultrahigh Performance Liquid Chromatography Coupled with Tandem Mass Spectrometry

Ultrahigh performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was used to analyze a colorant and silk, which were prepared and dyed using shellfish (Hexaplex trunculus L.) purple. Solutions of colorant and silk extracts were analyzed immediately after preparation (fresh samples) and after storing them in the dark for thirty days (aged sample I). Moreover, a silk sample was subjected to artificially accelerated ageing under UV radiation (aged sample II). The application of the UHPLC-MS/MS method leads to the detection of (i) the major coloring components of shellfish purple, which are indigotin, indirubin, 6-bromoindigotin, 6′-bromoindirubin, 6-bromoindirubin, 6,6′-dibromoindigotin, 6,6′-dibromoindirubin; (ii) four minor indigoid components in shellfish purple (compounds A, B, C and D), which belong to the same structural class as indirubin, and whose identification has been reported only once in the past; and (iii) eight degradation products (isatin, degradation products DP3, DP4, DP5, DP6, DP7, DP9 and DP10). The latter were also detected in stored indigotin solution, except for DP 6, which was used as reference sample. The method development was assisted by a new solution preparation approach for investigating compound fragmentation, using a solvent system compatible with direct infusion ESI. This system replaceddimethyl sulfoxide, which inhibits detection through electrospray ionization.

Recent Approaches of Impurity Profiling in Pharmaceutical Analysis: A Concise Review

Purity profiling is the process of gathering and analyzing information to determine the biological safety of a specific impurity, hence highlighting its importance and range in pharmaceutical research. In the field of pharmaceuticals, impurity has no precise meaning. Identification, structural elucidation, and quantitative determination of impurities and degradation products in bulk medicinal materials and pharmaceutical formulations are all included in impurity profiling. Since unrecognized, possibly poisonous impurities are dangerous to health and should be found and determined by selective procedures in order to increase the safety of drug therapy, impurity profiling has become more significant in contemporary pharmaceutical analysis. Impurities are typically described using words like residual solvents, byproducts, transformation products, degradation products, interaction products, and related products. Impurity identification is carried out using different chromatographic methods in addition to passing the CGMP, QC, QA, and water activity tests, a pharmaceutical ingredient also needs to satisfy the requirements for a new impurity. It is important to separate and characterize impurities in order to collect and evaluate data that determines biological safety, which emphasizes the need for and promise of drug impurity profiling in pharmaceutical research. To separate and measure the pollutants, a range of instrumental analytical techniques have been consistently used. The detection and regulatory evaluation of organic impurities is a very challenging task because to the numerous sources of organic impurities, including microbiological contamination, API breakdown products, and traces of intermediates.

Comprehensive Stress Degradation Studies of Fipronil: Identification and Characterization of Major Degradation Products of Fipronil Including Their Degradation Pathways Using High Resolution-LCMS

Comprehensive Stress Degradation Studies of Fipronil: Identification and Characterization of Major Degradation Products of Fipronil Including Their Degradation Pathways Using High Resolution-LCMS

GC–MS identification of DR31 textile dye degradation products during its efficient electrochemical removal from wastewater media

DR31 dye is widely used in cotton, silk, polyamide fiber, cellulose fiber, and viscose/silk blended fabric dyeing. Electrochemical oxidation with graphite electrodes was used to successfully degrade Direct Red 31 (DR31) textile dye in its synthetic and actual industrial effluents samples, degradation is confirmed by cyclic voltammetry. The change in concentration of the dyes was followed by UV–Visible spectroscopy and the acquired degradation products were confirmed by GC–MS analysis. Under optimal conditions (dye conc. = 200 mg/L, pH = 2, 300 mg NaCl, and current intensity = 50 mA), the dye was decolorized and degraded with a percent of 98.17 % in 10 min. GC–MS analysis was applied to determine the degradation products, where the large dye molecule is broken down into different products of smaller size. On the other hand, cyclic voltammetry measurements under optimum conditions confirmed the successful degradation of DR31 dye, and are in good agreement with the electrochemical oxidation results. A hypothesized mechanism for DR31 degradation by electrochemical oxidation/reduction using graphite electrodes is depicted.

Identification and Mechanistic Analysis of Toxic Degradation Products in the Advanced Oxidation Pathways of Fluoroquinolone Antibiotics.

The degradation of fluoroquinolones (FQs) via advanced oxidation processes (AOPs) is a promising avenue, yet the complete mineralization of certain FQ molecules remains elusive, raising concerns about the formation of toxic by-products. This study delineates five primary AOP degradation pathways for 16 commercially available FQ molecules, inferred from existing literature. Density functional theory (DFT) was employed to calculate the bond dissociation energies within these pathways to elucidate the correlation between bond strength and molecular architecture. Subsequently, Comparative Molecular Similarity Index Analysis (CoMSIA) models were constructed for various degradation reactions, including piperazine ring cleavage, defluorination, hydroxylation, and piperazine ring hydroxylation. Three-dimensional contour maps generated from these models provide a deeper understanding of the interplay between FQ molecular structure and bond dissociation energy. Furthermore, toxicity predictions for 16 FQ molecules and their advanced oxidation intermediates, conducted using VEGA 1.2.3 software, indicate that degradation products from pathways P2 and P5 pose a heightened health risk relative to their parent compounds. Furthermore, the application of the Multwfn program to compute the Fukui function for FQ molecules discerns the disparity in degradation propensities, highlighting that N atoms with higher f0 values can augment the likelihood of piperazine ring cleavage. HOMO-LUMO distribution diagrams further confirm that methoxy substitution at the 1-position leads to a dilution of HOMOs on the piperazine ring and an increased energy gap for free radical reactions, diminishing the reactivity with hydroxyl radicals. This study elucidates the pivotal role of structural characteristics in FQ antibiotics for their degradation efficiency within AOPs and unveils the underlying mechanisms of bond dissociation energy disparities. The toxicity parameter predictions for FQ molecules and their intermediates offer unique perspectives and theoretical underpinnings for mitigating the use of high-risk FQs and for devising targeted degradation strategies to circumvent the generation of toxic intermediates in AOPs through molecular structure optimization.

Phytic acid pre-modulated and Fe/N co-doped biochar derived from ramie fiber to active persulfate for efficient degradation of tetracycline via radical and non-radical pathways

Biochar-driven advanced oxidation processes (AOPs) have been widely applied in water decontamination from recalcitrant organic pollutants, yet its performance is restricted due to the complex functional groups of precursors and the obstacles of regulating the active sites. Herein, we prepared a phytic acid (PA) pre-modulated and Fe/N co-doped biochar derived from ramie fiber (Fe/N-PABC) to activate peroxydisulfate (PDS) for tetracycline hydrochloride (TCH) removal. The pre-treatment by PA facilitates the formation of pore structure and provide abundant loading sites for subsequent iron and nitrogen (Fe, N) doping. The main forms of Fe, N present in Fe/N-PABC are Fe0, Fe (II), pyridine N, and graphite N, respectively. In the presence of Fe/N-PABC, 80 % of TCH were degraded by PDS in 20 min at pH 5.0, whereas only 16.3 % of TCH was removed by single PDS. The oxidation of TCH was affected in the presence of Cl-, NO3–, SO42-, H2PO4- and HCO3–. Meanwhile, the performance was also validated in authentic waters in terms of degradation efficiency of TCH. The synergistic effects of radical and 1O2 dominated non-radical pathways were confirmed with the introduction of Fe, N in the system. Electrochemical oxidation experiments and density functional theory (DFT) calculations unveiled the electron transfer pathway and the key role of Fe/N-PABC/PDS* as an intermediate oxide. The possible degradation pathways were proposed based on the identification of degradation products. This study sheds light on the innovative concepts for modulating functional biochar and offering fundamental mechanisms of antibiotic degradation in wastewater treatment.

Analysis and identification of degradation products in gas, particle, and liquid phases of polypropylene and polyethyleneterephthalate microplastics aging through non-thermal plasma simulation.

Plastic aging can cause alterations in the physical and chemical characteristics of plastics, as well as their behavior in the environment. Due to the extremely slow natural aging process, laboratory simulated aging methods have to be used. In this study, non-thermal plasma (NTP) was adopted to investigate the aging process of polypropylene (PP) and polyethylene terephthalate (PET) microplastics. Various analytical instruments, including proton transfer reaction mass spectrometry and single-particle aerosol mass spectrometry, were employed to examine and identify the organic constituents of the gas, liquid, and particle phase degradation products, as well as to monitor the degradation process. The results showed that after 90min of aging, both PP and PET surfaces showed yellowing, and the carbonyl index of PP increased while that of PET decreased, with an increase in crystallinity. The organic components of reaction products, such as ketones, esters, acids, and alcohols, increased with longer aging times. Gas products mainly contain aromatic hydrocarbons, while particles from aged PET contain compounds with benzene rings and metal elements. Liquid products from aged PP show a significant presence of branched alkanes. Based on this analysis, degradation mechanisms of PP and PET by NTP were proposed. This investigation represents the initial systematically exploration of the release of organic substances during the degradation of microplastics mediated by NTP. It provides significant insights into the detrimental organic compounds emitted during this process, thereby offering valuable information for understanding the environmental and human health implications of natural microplastic degradation. Furthermore, it addressed the requirements for increased attention to the potential environmental risks associated with these harmful components.

Identification and Structural Characterization of Degradation Products of Linagliptin by Mass Spectrometry Techniques.

As part of the development and production of pharmaceuticals, the purity of Active Pharmaceutical Ingredients stands as a fundamental parameter that significantly influences the quality, safety, and efficacy of the final drug product. Impurities in Active Pharmaceutical Ingredients are various unwanted substances that can appear during the whole manufacturing process, from raw materials to the final product. These impurities can stem from multiple sources, including starting materials, intermediates, reagents, solvents, and even degradation products resulting from exposure to environmental factors such as heat, light, or moisture. Their presence can potentially compromise the therapeutic effect of the drug, introduce unexpected side effects, or even pose safety risks to patients. This study aims to conduct the forced degradation of linagliptin and subsequently attempt to identify the resulting degradants. The degradation procedures were carried out in accordance with the guidelines of the International Committee for Harmonization. The degradation profile of linagliptin was investigated under various conditions, including acid hydrolysis, alkaline hydrolysis, oxidation, heat, and light exposure, utilizing ultra-performance liquid chromatography connected to a photo array detector. Identification and characterization of the degradation products were achieved using an ultra-performance liquid chromatography coupled with a single quadrupole detector mass spectrometer and also a liquid chromatography coupled with a high-resolution mass spectrometry. The identified degradation products demonstrate that linagliptin is particularly susceptible to degradation when exposed to acid and peroxide. Whereas, no significant degradation effects were observed under alkali, thermolytic, and photolytic conditions.

Compound Similarity Network as a Novel Data Mining Strategy for High-Throughput Investigation of Degradation Pathways of Organic Pollutants in Industrial Wastewater Treatment.

Identification of degradation products and pathways is crucial for investigating emerging pollutants and evaluation of wastewater treatment methods. Nontargeted analysis is a powerful tool to comprehensively investigate the degradation pathways of organic pollutants in real-world wastewater samples but often generates large data sets, making it difficult to effectively locate the exact information on interests. Herein, to efficiently establish the linkages among compounds in the same degradation pathways, we introduce a compound similarity network (CSN) as a novel data mining strategy for LC-MS-based nontargeted analysis of complex wastewater samples. Different from molecular networks that cluster compounds based on MS/MS spectra similarity, our CSN strategy harnesses molecular fingerprints to establish linkages among compounds and thus is spectra-independent. The effectiveness of CSN was demonstrated by nontargeted identification of degradation pathways and products of organic pollutants in leather industrial wastewater that underwent laboratory-scale activated carbon adsorption (ACD) and ozonation treatments. Utilizing CSN in interpreting nontargeted data, we tentatively annotated 4324 compounds in the untreated leather industrial wastewater, 3246 after ACD, and 3777 after ACD/ozonation. We located 145 potential degradation pathways of organic pollutants in the ACD/ozonation process using CSN and validated 7 pathways with 15 chemical standards. CSN also revealed 5 clusters of emerging pollutants, from which 3 compounds were selected for in vitro cytotoxicity study to evaluate their potential biohazards as new pollutants. As CSN offers an efficient way to connect massive compounds and to find multiple degradation pathways in a high-throughput manner, we anticipate that it will find wide applications in nontargeted analysis of diverse environmental samples.

Isolation and identification of forced degradation products of Febuxostat

AbstractThe current study explains the degradation behavior of Febuxostat API, a non‐purine xanthine oxidase inhibitor used to treat hyperuricemia. A degradation study was carried out as per the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines, and the study confirms that the Febuxostat is largely stable in thermal, photolytic, oxidative, and basic hydrolytic conditions and labile in acid hydrolysis conditions. There were four different degradation products (DPs) found during acid hydrolysis; of these, DPs 2, 3, and 4 are new and have never been reported before, while DP 1 is known and has already been published. All these DPs were identified using ultra‐high‐performance liquid chromatography‐mass spectrometry (UHPLC‐MS) analysis, purified by using preparative HPLC, and characterized using high‐resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) spectroscopy techniques. The formed DPs are by the hydrolysis of the cyano functional group of Febuxostat and the esterification of DP‐1 under acidic conditions. All DP's structural characterization was carried out using NMR spectroscopy and HRMS. The present study describes concrete confirmation of DP structures and it explains the stability behavior of the Febuxostat. The current method is also used to identify DPs with shorter runtime in the future.

Method validation and characterization of stress degradation products of azelastine hydrochloride using LC-UV/PDA and LC-Q/TOF-MS studies.

Azelastine HCl is a second-generation H1 -receptor antagonist approved by the US Food and Drug Administration (US FDA) for treating seasonal allergic rhinitis and non-allergic vasomotor rhinitis. This study encompasses the validation of a liquid chromatography-ultra violet photo diode array (LC-UV/PDA) method for the drug and its extension to liquid chromatography/quadrupole time-of-flightmassspectrometry (LC-Q/TOF-MS) studies for identification and characterization of various stress degradation products of the drug. Stress degradation of azelastine HCl was undertaken under the International Council for Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) prescribed conditions of hydrolytic, photolytic, oxidative, and thermal stress. The degraded drug solutions were analyzed using Ultra Performance Liquid Chromatography (UPLC) employing a C18 (100 × 4.6mm; 2.6μ, Kinetex) column by isocratic elution. Detection wavelength was 241 nm. The degradation products were identified and characterized using UPLC-MS/TOF studies, and an attempt was made to isolate one of the degradation products by solvent extraction. The drug was found to significantly degrade under acidic/alkaline/neutral photolytic, oxidative, and alkaline hydrolytic conditions. Six degradation products (I-VI) were identified through LC-Q/TOF-MS studies that were adequately resolved from the drug with the developed UPLC method. All degradation products (I-VI) were ionized in the total ion chromatogram (TIC) in the LC-MS studies, and these were identified and characterized, and the degradation pathway of the drug was postulated. One of the oxidation products isolated from the degraded drug solution was characterized through differential scanning calorimetry, Fourier-transform infrared spectroscopy, and nuclear magnetic resonance spectral data. Six degradation products generated from stress degradation studies on azelastine HCl were adequately resolved through LC-UV/PDA studies followed by method validation. These were successfully identified and characterized through LC-Q/TOF-MS studies, and the degradation pathways for the generation of these products from the drug have been postulated.

LC/Q-TOF-MS-based structural characterization of enasidenib degradation products and establishment of a stability-indicating assay method: Insights into chemical stability.

Enasidenib (EDB) is an orally active selective mutant isocitrate dehydrogenase-2 enzyme inhibitor approved by the U.S. Food and Drug Administration to treat acute myeloid leukemia. It lacks a reported forced degradation study and a stability-indicating assay method (SIAM). This study addresses this gap by establishing a degradation profile in accordance with the International Council for Harmonisation Q1A and Q1B (R2) guidelines and developing a validated SIAM for EDB. EDB was exposed to forced degradation under various conditions (hydrolytic, photolytic, oxidative, and thermal stress). Degradation samples were analyzed using high-performance liquid chromatography on an Agilent ZORBAX Eclipse Plus C18 column with a mobile phase consisting of 0.1% formic acid in Milli-Q water and acetonitrile at a flow rate of 1mL/min and detection at 270 nm. Liquid chromatography-quadrupole time-of-flight-high-resolution mass spectrometry (LC/Q-TOF HRMS) was used for the identification and characterization of degradation products. Nitrosamine risk assessment was conducted using a modified nitrosation assay procedure (NAP) test due to the presence of a secondary amine group in the drug, which is liable to forming nitrosamine drug substance-related impurities (NDSRI). The drug exhibited significant degradation under acidic, basic, photolytic, and oxidative conditions in the solution state. A total of nine degradation products (DP) were formed (DP-I, DP-III, and DP-IV: acidic conditions; DP-I and DP-III: basic conditions; DP-II, DP-V, DP-VI, and DP-VII: oxidative stress; and DP-VII, DP-VIII, and DP-IX: photolytic conditions), which were separated and identified using reversed-phase high-performance liquid chromatography and characterized using liquid chromatography-tandem mass spectrometry. The mechanism behind the formation of EDB degradation products has been discussed, and this study was the first to develop a degradation pathway for EDB. In addition, the possibilities of NDSRI formation for EDB were studied using a modified NAP test, which can contribute to the risk assessment of the drug. Forced degradation studies were conducted by establishing a SIAM for EDB. All the degradation products were characterized by mass spectral data obtained using LC/Q-TOF-HRMS.

Isolation, identification and structural characterization of forced degradation products of mobocertinib using LC-MS/MS and NMR

The main objective of this study is to develop and validate an LC-MS/MS stability-indicating method for the isolation, identification, and characterization of forced degradation products of mobocertinib under various stress conditions, utilizing LC-MS/MS and NMR techniques. Four degradation products (DP1, DP2, DP3 and DP4) were isolated. Degradation under acidic and oxidative conditions provides DP1 and DP4, respectively. Both DP2 and DP3 were obtained under basic conditions. Chromatographic development and separation were achieved using an ODS C18 column (Chemsil) with a constant flow rate of 1.0 ml/min. The mobile phase consisted of 40 % water containing 0.1 % formic acid in methanol, and detection was performed at a wavelength of 225 nm. The application of LC-MS/MS technology was utilized to separate the above degradation products. The LC-MS/MS method has validated which includes specificity, linearity, LOD and LOQ, precision, accuracy and robustness. The chemical structure of the degradation products were characterized by 1H NMR and mass spectroscopy. The above listed degradation impurities are novel and not listed in the literature. In conclusion, this study provides vital information about mobocertinib’s chemical stability and helpful in further drug development process.

Identification and Toxicity Profiling of Degradation Products of Haloperidol by Using Tandem Mass Spectrometry and In Silico Studies

Identification and Toxicity Profiling of Degradation Products of Haloperidol by Using Tandem Mass Spectrometry and In Silico Studies