Stress Degradation Products Research Articles

Stability-Indicating HPLC Method for Quantifying Process-Related Impurities in Fedratinib and Identification of Its Forced Degradation Products Using LC-MS/MS

Background: Pharmaceutical industry is characterized by rigorous quality standards to ensure the safety and efficacy of drugs. Despite stringent manufacturing processes, the presence of impurities or generation of degradation products (DPs) in pharmaceutical products remains a concern. This necessitates a comprehensive and systematic approach to analysis impurities and DPs. Objectives: This study deals with the optimization of the stable HPLC method for quantification of fedratinib impurities and its DPs characterization through LC-MS/MS. Method: Method optimization studies were conducted by analyzing standard solutions in various method parameters. The results noticed in every varied method condition were tabulated for finalizing the appropriate conditions for analyzing fedratinib. The mass spectral response of DPs was interpreted carefully for structural conformation of DPs. Results: The method is optimized as HIQSIL C18 (250mm×4.6mm;5µ) column employing 1.0 mL/min flow of phosphate buffer (pH 5.2) and acetonitrile in 45:65 (v/v) and 257 nm. This method elutes 5.4, 2.6, 9.2 and 3.5 min for fedratinib, impurity 1, 2 and 3 respectively. Method sensitivity was verified to be very sensitive that can evaluate up to 0.003, 0.015 and 0.004 µg/mL for impurity 1, 2 and 3 respectively. Well correlated calibration curve achieved in 50-200 µg/mL for fedratinib and 0.05-0.20 µg/mL for impurities. Various stress studies produce four stress DPs and were identified using LC-MS/MS. The molecular mass (g/mol) and formula of DPs were identified as 426 and C21H25N5O3S, 312 and C17H22N5O, 354 and C17H14N4O3S, 215 and C11H11N4O respectively for DP 1 to 4. Conclusion: The method proposed can successfully be helpful for quantifying the pharmaceutical impurities and DPs of fedratinib in bulk batch samples and formulations.

Evaluation of the Genotoxic Impurities of Selpercatinib Through HPLC and LCMS/MS Identification of Selpercatinib Stress Degradation Products

The current investigation entails the characterization of seven degradation products (DPs) formed in different stress conditions of selpercatinib employing liquid chromatography–tandem mass spectrometry (LCMS/MS). Additionally, high-performance liquid chromatographic (HPLC) method for precise quantifying genotoxic impurities of selpercatinib. To explore the stability profile of selpercatinib, it was subjected to forced degradation experiments including acidic, basic, oxidative, photolytic, and thermal stress were conducted. These experiments revealed the degradation of selpercatinib under basic, acidic and photolytic conditions, resulting in the formation of seven distinct DPs. The chromatographic resolution of selpercatinib and its impurities along with DPs was effectively attained on Zorbax C18 (250 mm × 4.6 mm, 5 μm) column using aqueous ammonium acetate and methanol in 70:30 (v/v) at pH 4.5 with 0.1% formic acid as mobile phase, pumped isocratically at 0.9 mL/min and 226 nm wavelength. The approach generates a precise calibration curve that accurately fits within 15-120 μg/mL range for selpercatinib and LOQ (0.015 μg/mL) to 0.12 μg/mL for impurities with acceptable precision, accuracy and recovery. The efficacy of this method was validated through LCMS/MS, which allowed for the verification of the chemical structures of newly generated degradation products of selpercatinib. Hence this approach can appropriate for resolution and quantification of genotoxic impurities of selpercatinib and can also applicable for evaluation stress degradation products.

Green Analytical Approach for HPLC Method Development for Quantification of Sorafenib and Its Pharmacopeia Impurities: LC–MS/MS Characterization and Toxicity Prediction of Stress Degradation Products

ABSTRACTThis research presents the development and validation of chromatographic method for analyzing sorafenib and its pharmacopeial impurities, with a focus on stability studies and degradation product (DP) characterization. Initial method optimization involved exploring various column and buffer combinations, ultimately achieving optimal separation and peak symmetry using an ODS‐AQ YMC (150 mm) column with 0.6 mL/min gradient flow of 10 mM ammonium formate buffer adjusted to pH 3.4 with formic acid as solvent A, and ethanol as solvent B as mobile phase and 246 nm wavelength. Method exhibits calibration curve linear in 50–300 µg/mL for sorafenib and 0.050–0.30 µg/mL for impurities with a detection limit of 0.015 µg/mL for impurities. A structural elucidation of DPs was performed using LC–MS/MS, providing valuable insights into their molecular compositions, and was characterized as 4‐[4‐(carboxyamino)phenoxy]pyridine‐2‐carboxylic acid (DP 1) and 4‐(4‐aminophenoxy)pyridine‐2‐carboxamide (DP 2). Using AGREE and GAPI metrics, evaluation highlighted method sustainability through ethanol–water solvents and shorter column to reduce energy consumption. Toxicity assessments revealed differences in environmental impact and toxicological profiles of DPs, emphasizing importance of managing safety considerations for sorafenib and its DPs. This research offers novel insights into sorafenib analysis by addressing pharmacopeial impurities, characterizing DPs, and evaluating method sustainability and safety.

LC-MS/MS characterization of stress degradation products of Gilteritinib and establishment of HPLC method for analysis of process related impurities of Gilteritinib

Background: The current investigation entails the characterization of seven degradation products (DPs) formed in different stress conditions of gilteritinib employing liquid chromatography-tandem mass spectrometry (LC-MS/MS). Methodology: This study developed a stability-indicating reversed-phase high-performance liquid chromatographic (HPLC) method for precisely determining gilteritinib in the presence of its process-related impurities in bulk drug and formulation samples. To explore the stability profile of gilteritinib, it was exposed to forced degradation experiments conducted under various conditions, including acidic, basic, oxidative, photolytic, and thermal stress. These experiments revealed the degradation of gilteritinib under basic, acidic, and photolytic conditions, forming seven distinct DPs. Result: The chromatographic resolution of gilteritinib and its impurities along with DPs was effectively achieved using a Waters Symmetry C18 (250 mm × 4.6 mm, 5 μm) column using equal volumes of solvent A and B (pH 4.5 phosphate buffer and acetonitrile in 25:75 (v/v) as solvent A, acetonitrile and methanol in 75: 25 (v/v) as solvent B) pumped isocratically at 0.7 mL/min and 230 nm wavelength. The method produces an accurate fit calibration curve in 25-175 μg/mL for gilteritinib and LOQ (0.025 μg/mL) – 0.175 μg/mL for its impurities with acceptable precision, accuracy, and recovery. Conclusion: The efficacy of this method was validated through LC-MS/MS, which allowed for the verification of the chemical structures of newly generated degradation products of gilteritinib. Hence, this method is appropriate for the resolution and evaluation of process-related impurities of gilteritinib and can also be applied for evaluating stress degradation products.

Analytical method development, identification, and characterization of stress degradation products of idelalisib by ultrahigh-performance liquid chromatography with photodiode array and ultrahigh-performance liquid chromatography with electrospray ionization quadrupole time-of-flight mass spectrometry studies.

As per International Council for Harmonization (ICH) drug stability test guideline Q1A(R2), inherent stability characteristics of a drug should be studied. This work was designed to investigate inherent degradation characteristics of the drug idelalisib under ICH prescribed stress conditions, identify its degradation products, and postulate their corresponding degradation pathways. Idelalisib was subjected to the ICH prescribed conditions of hydrolytic (neutral, acidic, and alkaline), photolytic, oxidative, and thermal stress according to ICH guideline Q1A(R2). An ultrahigh-performance liquid chromatography with photodiode array (UHPLC-PDA) method was developed to adequately resolve the drug from its degradation products, validated as per the ICH guidelines, and subsequently extended to UHPLC with electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QTOFMS) studies to identify the degradation products. Significant degradation was noted under conditions of acidic/alkaline hydrolysis, acid photolysis, and oxidative stress. The UHPLC/ESI-QTOFMS studies revealed the generation of four degradation products (I-IV), which were satisfactorily resolved from the drug by UHPLC on a Kinetex® C18 (100 × 4.6mm; 2.6μm) column by the developed isocratic elution method. Detection wavelength was selected as 270 nm. All the degradation products (I-IV) could be identified and characterized from their mass spectral data. The degradation pathways for the generation of various products from the drug were postulated. A UHPLC-PDA method was developed and validated for idelalisib. Four degradation products of idelalisib were revealed through UHPLC/ESI-QTOFMS studies, and corresponding degradation pathways were postulated for the same.

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.

Characterization of Degradation Products of Selpercatinib by Mass Spectrometry: Optimization of Stability-Indicating HPLC Method for Separation and Quantification of Process Related Impurities of Selpercatinib

The study aimed to investigate a novel approach by utilizing liquid chromatography in coupled with mass spectrometry (LC-MS) to resolve, analyze and characterize significantly less quantity of stress degradation products (DPs) of selpercatinib along with its process related impurities. The analytes resolved on ZORBAX Eclipse (250 mm) stationary phase that was maintained employing 0.5 M sodium perchlorate at pH 5.4 methanol and acetonitrile in 50:20:30 (v/v) pumped at 0.8 mL/min isocratic flow and 241 nm wavelength. The method produces very high correlate linear curve in 30-240 μg/mL for selpercatinib and 0.03-0.24 μg/mL for its impurities with significantly low detection limit of 0.01 μg/mL for impurities. Selpercatinib pure compound was subjected to stress studies and chromatographic results confirm the formation of four DPs, which were characterized with the interpretation of their mass fragmentation pattern. The DPs were identified as 6-hydroxy-4-(6-(6-((6-methoxypyridin3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (DP 1), 6′-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)-1,2-dihydro-[3,3′-bipyridin]-5-ol (DP 2), (6-hydroxy-4-(6-(6-(pyridin-3-ylmethyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (DP 3), 1-amino-6′-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)-1,2-dihydro-[3,3′-bipyridin]-5-ol (DP 4), 6-(2-hydroxy-2-methyl-propoxy)-4-(6-(3-methylpiperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (DP 5) and 6-(2-hydroxy-2-methyl-propoxy)-4-(6-(3-methylpiperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (DP 6). Based on findings, it was concluded that this method was effectively applied for the regular quantification of impurities of selpercatinib in formulations. Additionally, it demonstrated applicability for the identification of both known and unknown impurities of selpercatinib.

Development of stability-indicating HPLC method for quantification of pharmacopeia impurities of Zuclopenthixol and characterization of its stress degradation products by LCMS/MS

BackgroundThe present study focused to develop a simple and sensitive HPLC method for resolution and estimation process-related impurities of zuclopenthixol and further assessment of forced degradation behavior of zuclopenthixol.ResultsThe chromatographic separation of drug substance, process-related impurities and its degradation products (DPs) was achieved on KNAUER C18 (250 mm × 4.6 mm, 5µ id) column at that was maintained at 35 °C temperature using 0.1 M sodium acetate buffer at pH 4.3 and methanol in 20:80 (v/v) as mobile phase A, 0.1% formic acid and acetonitrile in 75:25 (v/v) as mobile phase B. Equal volume of mobile phase A and B was pumped in isocratic elution at 0.8 mL/min. Detection wavelength was selected as 257 nm. In the proposed conditions, zuclopenthixol is identified at 6.91 and 1.91 min and 2.89 min, respectively, for impurity B and A min with acceptable system suitability and specificity. The method produces LOD at 0.009 for impurities with calibration range of 30–180 µg/mL for zuclopenthixol and 0.03–0.18 µg/mL for impurities. The other validation parameters were notices to be with in the acceptable levels for zuclopenthixol and its impurities. The drug was exposed to different stressed conditions (acid, base, peroxide, thermal and UV light) according to ICH Q1A (R2) guidelines. The DPs formed during the stress study were identified and characterized by LCMS/MS in ESI positive mode.ConclusionThe analysis involved a comparison of collision-induced dissociation mass spectrometry data between the degradation products and zuclopenthixol. As a result, potential structures for six degradation compounds were suggested. The results from additional validation studies were similarly pleasing and demonstrated their suitability for the routine analysis of zuclopenthixol and its associated impurities in both bulk drug and pharmaceutical dosage forms. Additionally, these findings can be extended to assess the mechanism of stress degradation in zuclopenthixol.

Optimization of Stability-Indicating HPLC Method for Analyzing Process Related Impurities of Penfluridol and Structural Elucidation of Stress Degradation Products by LCMS/MSucidation of Stress Degradation Products by LCMS/MS

This study focused on the development of a simple and sensitive HPLC method for resolution and quantification of process-related impurities of penfluridol and further assessment of forced degradation behavior of penfluridol. The chromatographic separation was achieved on XTerra™ C18 (250×4.6 mm, 5.0μm) column and UV detection at 245nm. The mobile phase comprises of methanol and tetrahydrofuran in 55:45 (v/v) as solvent A and acetonitrile and tetrahydrofuran in 80:20 (v/v) as solvent B. The 60:40 (v/v) composition of solvent A and B were pumped isocratically at 1.0mL/min. In the proposed conditions, the retention time identified as 5.29 min for penfluridol, 4.51 min, 9.95 min and 7.64 min respectively for impurity 1, 2 and 3 with acceptable system suitability. The method produces sensitive detection limit of 0.008μg/mL for impurity 1, 2 and 0.004 μg/mL for impurity 3 with calibration range of 25-150 μg/mL for penfluridol and 0.025-0.150 μg/mL for impurities. The drug was exposed to different stressed conditions (acid, base, peroxide, thermal and UV light) according to ICH Q1A (R2) guidelines. The Degradation Products (DPs) formed during the stress study was characterized by LCMS/MS in ESI positive mode and the possible structures of five DPs with possible degradation pathways were proposed. The outcomes of other validation studies were likewise satisfactory and proven adequate for regular analysis of penfluridol and its process-related impurities in bulk drug and pharmaceutical dosage forms and can also applicable for evaluation of stress degradation mechanism of penfluridol.

Identification and Structural Characterization of Forced Degradation Impurities of Sacubitril by HRMS – Development and Validation of a Stability indicating RP-HPLC method

The current work identifies and characterises the stress degradation products of the anti-hypertensive drug sacubitril. The stability profile of sacubitril was evaluated under several stress settings including hydrolytic, oxidative, thermal and photolytic conditions in accordance with ICH recommendations. The degradation products of sacubitril were separated using reverse phase liquid chromatography and structural characterization was carried out using HRMS. The chromatographic separation was carried out by Reverse Phase-High Performance Liquid Chromatography (RP-HPLC) using a Fortis C18 column (150 mm X 4.6 mm; 5μm particle size) with mobile phase A (consisting of 0.1% TFA in Milli-Q water) and mobile phase B (100% Acetonitrile) in gradient mode. With a sample injection volume of 10μL, the mobile phase flow rate was 0.7 mL/min. A quadrupole time-of-flight (Q-TOF) mass spectrometer was used for the LC-MS analysis. Sacubitril is relatively stable in oxidative, thermal and photolytic conditions; however, considerable degradation was observed in acid, base and neutral hydrolysis. Three degradation products were identified and the structural characterization of these impurities was performed using the HRMS data and mass fragmentation. The proposed RP-HPLC method was robust, precise and specific in determining the impurity profile of sacubitril under different stress conditions.

Separation and characterization of related substances of Lurasidone hydrochloride by LC-QTOF-MS techniques

In the present study, a reliable LC-QTOF-MS method was developed and employed for the separation and characterization of process-related substances and forced degradation products of Lurasidone hydrochloride. The chromatographic separation was carried out using an Agilent Poroshell 120 Bonus-RP C18 column (100 mm × 4.6 mm, 2.7 µm) and a mobile phase consisting of a gradient elution of 10 mM ammonium formate solution and methanol. The degradation studies followed the guidelines outlined in ICH Q1A (R2). It was observed that Lurasidone hydrochloride exhibited instability under photolytic, alkaline, and oxidative stress conditions, while remaining relatively stable under acidic and thermal stresses. Through positive ESI-QTOF mass spectrometric analysis, fourteen related compounds in total, including both process-related and stress degradation products, were identified based on the accurate masses of parent and product ions and calculated elemental compositions. Amongst these substances, nine had not been previously reported, and their formation mechanisms were speculated. The process-related substances were further confirmed by NMR spectra determination, and suggestions were proposed to eliminate them. This study highlights the potential for monitoring and controlling related substances during the manufacturing processes, providing valuable insights for process optimization and quality control of Lurasidone hydrochloride.

Development and Application of a Validated HPLC Method for the Determination of Alpelisib and its Process-Related Impurities in Pure Drug and Pharmaceutical Formulations

Impurity analysis plays a significant role in the manufacture of a safe pharmaceutical product that ensures the safety of consumers. Keeping this in consideration, the present study was intended to develop a simple and sensitive HPLC method for the resolution and quantification of 4 process-related impurities namely impurities 1, 2, 3 and 4 in alpelisib pure drug and formulations. The method consumes greener solvents as a mobile phase that resolves the analytes on ProntoSIL ODS-C18 (250×4.6 mm; 5 μ id) column at room temperature as stationary phase, ethanol and 0.1% aqueous acetic acid in 65:35 (V/V) at pH 4.5 as mobile phase at 0.8 mL/min flow rate, UV detection at 246 nm. The method can detect the analytes at retention times of 7.05, 4.52, 6.09, 2.88 and 8.14 min respectively for alpelisib, impurity 1, 2, 3 and 4. The analysis was completed with a run time of 15 min that consume less solvent and the same analysis time. The linearity of the proposed method was perceived in the range of 12.5 to 100 μg/mL for alpelisib and 0.0125 to 0.10 μg/mL for impurities. The method can effectively resolve the unknown stress degradation products generated during the stress exposure of alpelisib along with its known impurities in the study. The outcomes of other validation studies were likewise satisfactory and proven adequate for regular analysis of alpelisib and its process-related impurities in bulk drug and pharmaceutical tablet doses.

LC-PDA-QTof-MS characterization of the stress degradation products of Zanubrutinib: A novel BTK inhibitor

Zanubrutinib (ZAN) is an orally administered anti-cancer medication used for the treatment of Mantle cell lymphoma. Recently, it has also been approved by FDA for the treatment of chronic lymphocytic leukemia. Determination of impurities formed in drug substances/products as a result of manufacturing or storage forms an important aspect of drug life cycle management. The current study concentrated on understanding the stability of ZAN under various stress conditions as per the ICH Q1 (R2) guidelines. In total, ZAN produced thirteen degradation products under various hydrolytic (acid, base and neutral) and thermal stress conditions. The stress degradation products were separated by ultra-performance liquid chromatography, chemical structures of these products were characterized by MS/MS experiments combined with accurate mass measurements conducted on a LC-QTof-MS. The mechanism for the formation of these degradation products was also proposed. This study provides comprehensive information on the inherent stability of ZAN which will be useful in the drug development and manufacturing processes.

Characterization of stress degradation products of bedaquiline fumarate and bedaquiline by LC-PDA and LC-MS

Bedaquiline fumarate was a first-in-class diarylquinoline drug used for the treatment of M. tuberculosis and its main biologically active form was bedaquiline. This paper studied and compared the degradation products of bedaquiline fumarate and bedaquiline using LC-PDA, LC-MS, and NMR techniques under thermal, alkaline, acidic, oxidative, and photolytic conditions respectively. A LC method was established and optimized to separate all analytes of bedaquiline fumarate and bedaquiline. All degradation products were identified by LC-HRMS/MS and LC-MSn. Bedaquiline fumarate formed three degradation products (DP1, DP2, and DP3) related to fumarate under photolytic condition and formed demethylation product DP4 under acid condition. Bedaquiline formed four degradation products (IM1, IM2, IM3, and IM4) related to the side chains of tertiary alcohol and tertiary amine groups under photolytic condition and formed DP4 under acid condition. The two compounds were stable under thermal, alkaline, and oxidative conditions. DP1 and DP2 indicate that the fumarate could take cis-trans isomerization under light condition. DP3, IM3 and IM4 were first reported degradation products of bedaquiline fumarate and bedaquiline. Compared the degradation behavior of bedaquiline fumarate with bedaquiline, the fumarate form can make the side chain of bedaquiline more stable. It is better to avoid acid and light contact during their storage and manufacturing process.

Identification and characterization of stress degradation products of ibrutinib by LC-UV/PDA and LC-Q/TOF-MS studies.

The anticancer drug ibrutinib was subjected to stress degradation studies under the ICH-prescribed hydrolytic, photolytic, oxidative and thermal stress conditions, and its degradation behavior was studied. A significant degradation was noted for the drug under acidic/alkaline hydrolytic, acid/alkaline photolytic, and oxidative conditions. The UPLC-UV/PDA studies revealed the generation of six degradation products (I-VI), and these were adequately resolved from the drug under the developed chromatographic conditions over a Kinetex® C18 (100 mm×4.6 mm; 2.6 μm) column employing isocratic elution method. Detection wavelength was selected as 289 nm. The UPLC-UV/PDA method conditions were extrapolated to UPLC-MS/TOF studies. All the six degradation products were found to be ionized in the total ion chromatogram, and the products could be identified and characterized from their mass spectral data. The possible degradation route of ibrutinib leading to generation of various products was also postulated.

Method validation and characterization of stress degradation products of gefitinib through UPLC-UV/PDA and LC–MS/TOF studies

Gefitinib was subjected to stress degradation conditions of hydrolysis (neutral, acidic and alkaline), oxidation, photolysis and thermal stress, as per the ICH guideline Q1A(R2). A UPLC-UV/PDA based stability-indicating method was developed for the drug and validated as per ICH guidelines. The drug showed significant degradation under acidic/alkaline/neutral hydrolytic, acidic/alkaline/neutral photolytic, thermal and oxidative stress conditions. In total, seven degradation products (I-VII) were formed, which could be separated from the drug by UPLC on a Kinetex® C18 (100 mm × 4.6 mm; 2.6 μ) column using isocratic elution method. Detection wavelength was selected as 257 nm. The developed method was extended to UPLC-MS/TOF studies and accurate mass spectral data was used to identify and characterize the degradation products. Out of the seven degradation products, five products (I-II; V-VII) could be characterized through their MS/TOF spectral data. The degradation pathway of the drug leading to generation of various products was postulated and this has not been reported so far.

Eco friendly stability indicating HPTLC method for simultaneous determination of sofosbuvir and ledipasvir in pharmaceutical tablets and HPTLC-MS characterization of their degradation products

Recently, the analytical community has shown increasing interest in developing more environment-friendly practices by eliminating or reducing the use of hazardous chemicals and solvents which are extremely dangerous to human health and the environment. Thus in this study, a simple, rapid, inexpensive and eco-friendly HPTLC method with densitometric detection was designed, optimized and validated for the simultaneous quantitation of the antiviral drugs sofosbuvir (SOF) and ledipasvir (LED) in pure powder, synthetic mixtures, combined pharmaceutical formulation and in the presence of their stressed degradation products with high sensitivity and no interference. The separation was carried out on silica gel F254 plates, using green mobile phase ethyl acetate: water: ethanol (94:5:1v/v/v) for development followed by densitometric detection of SOF and LED at 250 and 320 nm, respectively. Both drugs had second order polynomial calibration curves within ranges 100–5000 ng/spot and 100–3000 ng/spot for SOF and LED, respectively, with correlation coefficients >0.9998 and the limits of detection were 30 and 29 ng/spot and the limits of quantification were 90 and 88 ng/spot for SOF and LED, respectively. The method was validated in terms of linearity, accuracy, precision, selectivity, and robustness. The drugs were subjected to acidic and basic hydrolysis, oxidation and photolytic conditions as per ICH guidelines, followed by detection of the degradation products and structure elucidation of their fragments with the aid of the HPTLC-ESI- MS technique. The greenness of the proposed method was assessed using the analytical Eco-Scale as an assessment tool with a 93-point score. So, it is considered excellent green.

Identification, Isolation, and Structural Characterization of Novel Forced Degradation Products of Darunavir Using Advanced Analytical Techniques Like UPLC-MS, Prep-HPLC, HRMS, NMR, and FT-IR Spectroscopy.

The online version contains supplementary material available at 10.1007/s10337-022-04226-z.

Identification and characterization of stress degradation products of febuxostat employing ultra-performance liquid chromatography-ultraviolet/photodiode array and liquid chromatography-mass spectrometry/time-of-flight studies.

Febuxostat (FEB) is a xanthine oxidase inhibitor approved by the U.S. Food and Drug Administration for long-term treatment of gout and hyperuricemia. There were no reports on identification and characterization of stress degradation products of the drug. FEB was subjected to forced decomposition conditions such as hydrolysis (neutral, acidic, and alkaline), oxidation, photolysis, and thermal stress, per the ICH guideline Q1A(R2). The degradation products formed were subjected to ultra-performance liquid chromatography (UPLC) on a C18 Kinetex column (100 × 4.6mm, 2.6μm) using isocratic elution method. Detection wavelength was 317 nm. The developed method was extended to UPLC-mass spectrometry/time of flight (MS/TOF) studies to identify and characterize the degradation products. The drug exhibited significant degradation under alkaline/neutral hydrolytic, alkaline/acidic photolytic, and oxidative conditions, whereas it remained stable under acid hydrolytic, neutral photolytic, and thermal conditions. In total, eight degradation products (I-VIII) were formed, which could be adequately determined from the drug using the developed UPLC method. Of the eight degradation products identified from the liquid chromatography-ultraviolet (LC-UV) chromatogram, five (III and IV and VI-VIII) could be characterized using their MS/TOF spectral data. The degradation pathway leading to the formation of the products was postulated, and this is not reported so far. Forced degradation studies were conducted on FEB, and the degradation products produced were identified by their mass spectral data obtained using LC-MS studies.

SEPARATION AND IDENTIFICATION OF FORCED DEGRADATION PRODUCTS OF LOFEXIDINE BY USING LC-MS/MS

Objectives: A rapid and reliable isocratic LC-MS/MS method was developed and validated for the separation and identification of stress degradation products (DPs) of lofexidine. Methods: Lofexidine, a non-opioid centrally acting alpha2-adrenergic receptor agonist, was subjected to hydrolysis (acidic, alkaline, and neutral), oxidation, photolysis, and thermal stress as per International Council on Harmonization specified conditions. The drug showed extensive degradation under alkaline, acidic, oxidation, and photolytic stress condition. Results: A total of 14 DPs were observed and the chromatographic separation of the drug and its DPs were achieved on waters symmetry C18 (150 × 4.6 mm, 3.5 μm) column using water and acetonitrile (75:25 v/v) as mobile phase. The DPs were separated and identified using LC-MS/MS. The LC-MS/MS method was validated with respect to specificity, linearity, accuracy, and precision. Conclusion: The proposed method was used for impurity profiling and routine quality control tests of lofixidine.