Search

Nimesulide is a widely used drug for the treatment of pain in humans as well as in animals. The presence of trace amounts of drugs in milk or other food supplement affects seriously human health. This study reports a method based on LC-MS detection for the determination of nimesulide and its hydroxy metabolite in cow milk samples. Waters ACQUITY BEH C18 column (100 mm × 2.1 mm, 1.7 µm), with gradient elution using 0.1% formic acid and acetonitrile as mobile phase at a flow rate of 0.3 mL min−1 was used for the chromatographic separation. The ion scans were quantified at m/z 307.0393 for nimesulide, m/z 323.0375 for hydroxy nimesulide metabolite and m/z 434.2198 for IS (valsartan) in negative ESI mode. A double extraction method with protein precipitation by acetonitrile followed by solid-phase extraction was developed to detect nimesulide at 1.30 ng mL−1 and hydroxy nimesulide at 1.03 ng mL−1 in milk. The calibration curve was constructed for nimesulide in the range of 1.30 ng mL−1 to 125.07 ng mL−1 while for hydroxy nimesulide calibration curve was constructed in the range of 1.03 ng mL−1 to 99.70 ng mL−1 in whole cow milk without any treatment. The validation parameters like accuracy, precision, selectivity, stability, matrix effect and dilution integrity were also performed on nimesulide and hydroxy nimesulide. The developed processing and chromatographic method can be used to quantitatively determine nimesulide or its hydroxy nimesulide metabolite in biological matrices, i.e., milk, plasma, faecal, tissue, etc.

The Coamorphous systems (CAM) of lumefantrine (LMF) and alpha-ketoglutaric acid (KGA) were developed using three different methods to address the solubility and bioavailability limitations of LMF. Powder X-ray diffraction spectroscopy (PXRD) and differential scanning calorimetry (DSC) confirmed the complete amorphization of the three CAM by the halo pattern and glass transition temperature (Tg), respectively. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and nuclear magnetic resonance spectroscopy (NMR) results indicated that intermolecular interactions existed in the three CAM. Solid-state molecular dynamics simulations revealed the different intermolecular disordered environments present in all three CAM. Solubility analysis showed 14.73×, 12.8× and 9.81× improvement in the liquid-assisted grinding-based coamorphous system (CAM LAG), solvent evaporation-based coamorphous system (CAM SE) and quench-cool-based coamorphous system (CAM QC), respectively, compared to LMF crystalline (LMF CRY). In the in-vitro dissolution experiment 2.63-, 2.16- and 2.17-times increments were observed in CAM LAG, CAM SE and CAM QC compared to LMF CRY, respectively. In-vivo pharmacokinetics study revealed 10.86-, 9.24- and 8.46- folds increments in C max of CAM LAG, CAM SE and CAM QC, respectively, compared to LMF CRY. All three CAM illustrated anti-cancer activity in the A549 lung cancer cell line. Molecular dynamics simulation of LMF and KGA with Epidermal growth factor receptor (EGFR), a target for lung cancer treatment, revealed good binding affinity and stability. Stability studies performed under accelerated storage (40 °C/75 % RH) and extreme environmental conditions indicated that all three CAM have good stability. Different methods based prepared CAM have shown different physicochemical properties, bioavailability and stability profiles. These findings suggest that LMF-KGA CAM effectively addresses the solubility and bioavailability challenges of LMF, potentially leading to better therapeutic outcomes in lung cancer treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

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 (H 2 O 2 , 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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Rationale: The present study aims to establish structures of the degradation products of an anti-diabetic drug, Imeglimin (IMG) approved for the treatment of type 2 diabetes mellitus in the year 2021. Degradation pathways are proposed along with in silico toxicity assessments of the observed degradation products (DPs) of the drug., Methods: A reversed-phase high-performance liquid chromatography (RP-HPLC), equipped with a photodiode array detector, was used to separate the observed DPs with a Phenomenex Luna PFP (250 × 4.6 mm, 5 μm) column, using 10 mM ammonium formate (pH 4.5) and methanol as mobile phase. Liquid chromatography quadrupole time of flight mass spectrometry (LC-Q-ToF-MS/MS) and nuclear magnetic resonance (NMR) spectroscopy were employed for structural elucidation. Zeneth and Derek suites were used for in silico assessments., Results: A total of four degradation products were observed, which were successfully separated on an RP-HPLC. The structural characterization of three of the four DPs was achieved using LC-Q-TOF-MS/MS by employing electro spray ionization as well as atmospheric pressure chemical ionization. Additionally, DP-3 was isolated using a preparative HPLC and was characterized by NMR. Computationally predicted structures were compared with the experimental observations., Conclusion: An HPLC method, capable of separating the Imeglimin and its four DPs, was developed and validated as per the ICH Q2(R1) guideline. Structure elucidation reveals a variety of products with metformin as one of the identified DPs along with a metabolite. The toxicity potential of DPs was assessed through docking studies., (© 2024 John Wiley & Sons Ltd.)

Ubrogepant is the first oral calcitonin gene-related peptide (CGRP) receptor antagonist which is used for the acute treatment of migraine in adults. The present study employs liquid chromatography-high resolution mass spectrometry (LC-HRMS) and nuclear magnetic resonance spectroscopy (NMR) techniques for the identification and characterization of degradation impurities of ubrogepant. The forced degradation study of ubrogepant was performed as per the International Council for Harmonisation (ICH) Q1A and Q1B guidelines. The in silico degradation profile of ubrogepant was predicted by Zeneth. It was observed that ubrogepant was labile to acidic hydrolysis, basic hydrolysis, and oxidative degradation conditions (H 2 O 2 ), although it was stable in neutral hydrolysis and photolytic (UV light and visible light) conditions. Eight degradation impurities were formed, which were separated on reversed-phase HPLC with a gradient program on an InertSustain C8 column (4.6 × 250 mm, 5 µm) using 10 mM ammonium formate (pH unadjusted) and acetonitrile as the mobile phase. The structures of all the degradation impurities were characterized using the exact masses obtained from the HRMS/MS. Further, NMR studies were conducted on two major degradation impurities (UB-4 and UB-7). A plausible mechanism was proposed to support the structures of all the degradation impurities of UBR. In silico toxicity and mutagenicity assessment were done by DEREK Nexus, SARAH Nexus, and ProTox-II., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Nirmatrelvir (NRV), a 3C-like protease or M pro inhibitor of SARS-CoV-2, is used for the treatment of COVID-19 in adult and paediatric patients. The present study was accomplished to investigate the comprehensive metabolic fate of NRV using in vitro and in vivo models. The in vitro models used for the study were microsomes (human liver microsomes, rat liver microsomes, mouse liver microsomes) and S9 fractions (human liver S9 fractions and rat liver S9 fractions) with the appropriate cofactors, whereas Sprague-Dawley rats were used as the in vivo models. Nirmatrelvir was administered orally to Sprague-Dawley rats, which was followed by the collection of urine, faeces and blood at pre-determined time intervals. Protein precipitation was used as the sample preparation method for all the samples. The samples were then analysed by liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (LC-Q-ToF-MS/MS) using an Acquity BEH C18 column with 0.1% formic acid and acetonitrile as the mobile phase. Four metabolites were found to be novel, which were formed via amide hydrolysis, oxidation and hydroxylation. Furthermore, an in silico analysis was performed using Meteor Nexus software to predict the probable metabolic changes of NRV. The toxicity and mutagenicity of NRV and its metabolites were also determined using DEREK Nexus and SARAH Nexus., (© 2024 John Wiley & Sons Ltd.)

The present study aimed to separate, identify, and characterise the degradation products formed when mavacamten is exposed to stress degradation as well as the stability of the drug in various environments and also to understand its degradation chemistry. Prediction of in silico toxicity and mutagenicity was aimed at the observed degradation products. Stress degradation along with stability studies and degradation kinetics were performed on mavacamten, and separation of degradation products was carried out by high-performance liquid chromatography. Tandem mass spectrometry studies were executed to characterise the structures of degradation products using product ion fragments. Orthogonally, nuclear magnetic resonance experiments were conducted to elucidate the structures having ambiguity in characterising them. Deductive Estimation of Risk from Existing Knowledge and Structure Activity Relationship Analysis using Hypotheses software were used to establish in silico toxicity and mutagenic profiles of mavacamten and its degradation products. Two degradation products of mavacamten found in acidic hydrolytic stress conditions were separated, identified, characterised, and proposed as 1-isopropylpyrimidine-2,4,6(1H,3H,5H)-trione and 1-phenylethanamine. Mavacamten was found to be stable under different pH and gastrointestinal conditions. The degradation kinetics of mavacamten under 1 N acidic condition followed zero-order kinetics, and it was degraded completely within 6 h. In silico toxicity and mutagenicity studies revealed that 1-phenylethanamine can be a skin sensitiser. A high-performance liquid chromatography method was developed for the separation of degradation products of mavacamten and characterised by liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance. During the manufacturing and storage of drug product, precautions need to be taken when dealing with acidic solutions as the drug is prone to hydrolysis in acidic conditions. The formation of 1-phenylethanamine under these conditions is to be monitored as it is a skin sensitiser., (© 2024 John Wiley & Sons Ltd.)

Study aimed to design and development of a supramolecular formulation of sulpiride (SUL) to enhance its solubility, dissolution and permeability by targeting a novel GlyT1 inhibition mechanism. SUL is commonly used to treat gastric and duodenal ulcers, migraine, anti-emetic, anti-depressive and anti-dyspeptic conditions. Additionally, Naringin (NARI) was incorporated as a co-former to enhance the drug's intestinal permeability by targeting P-glycoprotein (P-gp) efflux inhibition. NARI, a flavonoid has diverse biological activities, including anti-apoptotic, anti-oxidant, and anti-inflammatory properties. This study aims to design and develop a supramolecular formulation of SUL with NARI to enhance its solubility, dissolution, and permeability by targeting a novel GlyT1 inhibition mechanism, extensive experimental characterization was performed using solid-state experimental techniques in conjunction with a computational approach. This approach included quantum mechanics-based molecular dynamics (MD) simulation and density functional theory (DFT) studies to investigate intermolecular interactions, phase transformation and various electronic structure-based properties. The findings of the miscibility study, radial distribution function (RDF) analysis, quantitative simulations of hydrogen/π-π bond interactions and geometry optimization aided in comprehending the coamorphization aspects of SUL-NARI Supramolecular systems. Molecular docking and MD simulation were performed for detailed binding affinity assessment and target validation. The solubility, dissolution and ex-vivo permeability studies demonstrated significant improvements with 31.88-fold, 9.13-fold and 1.83-fold increments, respectively. Furthermore, biological assessments revealed superior neuroprotective effects in the SUL-NARI coamorphous system compared to pure SUL. In conclusion, this study highlights the advantages of a drug-nutraceutical supramolecular formulation for improving the solubility and permeability of SUL, targeting novel schizophrenia treatment approaches through combined computational and experimental analyses.Communicated by Ramaswamy H. Sarma.

Aim: Psoriasis is a chronic inflammatory skin disorder characterized by the excessive proliferation of keratinocytes, forming thickened skin plaques due to immune-mediated cytokine responses. Delivering drugs through this barrier to target inflamed tissues remains challenging. Nimbolide (NIM), known for its anti-inflammatory and anticancer properties, shows promise in managing psoriasis. However, its efficacy is limited by its inability to penetrate the thickened horny layer of the skin. To overcome this obstacle, we have developed Nim-loaded niosomal (Nio) formulations (NIM Nio) aimed at improving dermal delivery and achieving localized sustained release at psoriasis-affected sites. Methods: The formulation characteristics were assessed using Zeta sizer, Transmission Electron Microscopy (TEM), and High-performance liquid chromatography (HPLC). The optimized formulation was evaluated for anti-psoriatic potential compared to Nim alone by using molecular techniques such as Confocal Microscopy, Flow cytometry, enzyme-linked immunosorbent assay (ELISA), and Western blotting. Results: NIM Nio showed effective penetration into psoriatic skin, resulting in reductions in keratinocyte hyperproliferation, oxidative stress, splenomegaly, inflammatory cytokines, Psoriasis Area and Severity Index (PASI), and rete ridges compared to NIM alone. Conclusion: Our findings underscore the significant anti-proliferative, antioxidant, and anti-inflammatory properties of NIM Nio in psoriasis, demonstrating its potential as a promising therapeutic option for this challenging condition.

Covalent organic frameworks (COFs) have much potential in the field of analytical separation research due to their distinctive characteristics, including easy modification, low densities, large specific surface areas and permanent porosity. This article provides a historical overview of the synthesis and broad perspectives on the applications of COFs. The use of COF-based membranes in gas separation, water treatment (desalination, heavy metals and dye removal), membrane filtration, photoconduction, sensing and fuel cells is also covered. However, these COFs also demonstrate great promise as solid-phase extraction sorbents and solid-phase microextraction coatings. In addition to various separation applications, this work aims to highlight important advancements in the synthesis of COFs for chiral and isomeric compounds.

Rationale: Baricitinib (BARI), an inhibitor of Janus kinases 1 and 2 (JAK 1/2), is used for the treatment of rheumatoid arthritis and COVID-19. The present study focuses on establishing the forced degradation behavior of BARI under different degradation conditions (hydrolysis, oxidation, and photolysis) following International Council for Harmonization (ICH) guidelines of Q1A (R2)-Stability testing of new drug substances and products and Q1B-Photostability testing of new drug substances and products. This study helps in monitoring the quality and safety of BARI and its product development., Methods: Prior to conducting the study, the in silico degradation profile of BARI was predicted by Zeneth. Reversed-phase high-performance liquid chromatography employing a gradient program was used for the identification and separation of degradation impurities with an InertSustain C8 column (4.6 × 250 mm, 5 μm). The mobile phases used were 10 mM ammonium formate (pH 2.89) and acetonitrile. High-resolution mass spectrometry (HRMS) was used for the structural elucidation of the degradation impurities., Results: BARI was labile to hydrolytic (acidic, basic, and neutral) and photolytic degradation conditions which yielded 10 new degradation impurities and it was stable under oxidative (H 2 O 2 ) conditions. The separated degradation impurities were characterized by HRMS and the respective degradation pathways were proposed. The generated information helped to propose a mechanism for the formation of the degradation impurities. Additionally, one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy were used for the characterization of two major degradation impurities., Conclusion: The forced degradation study of BARI was carried out in accordance with ICH Q1A and Q1B guidelines, which resulted in the formation of 10 new degradation impurities. In our analysis, three degradation impurities were matching with the Zeneth predictions. In silico tools, DEREK Nexus® and SARAH Nexus®, were used for predicting the toxicity and mutagenicity of BARI and its degradation impurities. Overall, this study sheds light on BARI's safety monitoring and storage circumstances., (© 2023 John Wiley & Sons Ltd.)

Roxadustat is the first drug approved for anemia due to chronic kidney disease. Drug degradation profile is very crucial for assessing the quality and safety of the drug substances and their formulations. Forced degradation studies are conducted for quick prediction of drug degradation products. Forced degradation of roxadustat was carried out as per ICH guidelines, and nine degradation products (DPs) were observed. These DPs (DP-1 to DP-9) were separated using the reverse phase HPLC gradient method with an XBridge column (250 mm × 4.6 mm, 5 µm). The mobile phase consisted of 0.1% formic acid (solvent A) and acetonitrile (solvent B) at a flow rate of 1.0 ml/min. The chemical structures of all the DPs were proposed by using LC-Q-TOF/MS. DP-4 and DP-5, the two major degradation impurities, were isolated, and NMR was used to confirm their chemical structures. Based on our experiments, the roxadustat was found stable to thermal degradation in solid state and oxidative conditions. However, it was unstable in acidic, basic, and photolytic conditions. A very remarkable observation was made about DP-4 impurity. DP-4 was generated as a common degradation impurity in alkaline hydrolysis, neutral hydrolysis as well as photolysis conditions. DP-4 has a similar molecular mass to roxadustat but is structurally different. DP-4 is chemically, (1a-methyl-6-oxo-3-phenoxy-1,1a,6,6a-tetrahydroindeno [1,2-b] aziridine-6a-carbonyl) glycine. In silico toxicity study was conducted using Dereck software to gain the best knowledge of the drug and its degradation products towards carcinogenicity, mutagenicity, teratogenicity, and skin sensitivity. A further study using molecular docking confirmed the potential interaction of DPs with proteins responsible for toxicity. DP-4 shows a toxicity alert due to the presence of aziridine moiety., Competing Interests: Declaration of competing interest All the authors declare no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Repeated mild traumatic brain injury (rmTBI) poses adversity in the form of neurological deficits. The ignition of long-term neurological aberrations post-TBI is appended with the microbiota gut-brain axis perturbation. Herein, we examined whether quercetin, which is anti-inflammatory and antioxidant flavonoid, serves as a prebiotic and modifies the compromised microbiome gut-brain axis in rmTBI mouse model. Male C57BL/6 mice were subjected to rmTBI for 7 times. The quercetin (50 mg/kg) was administered peroral from the day1 of first injury till 7 days post-injury. The neurobehavioral assessments were performed using return of righting reflex (ROR), rotarod, forced swimming test (FST), elevated zero maze (EZM), novel object recognition test (NORT), and Y-maze. Mice fecal samples, brains, and intestines were collected for molecular studies. Mice underwent rmTBI showed significant neurological deficits in ROR and rotarod test and also exhibited long-term neuropsychiatric aberrations like anxiety- and depression-like phenotypes, and cognitive deficits in EZM, FST, and Y-maze assays, respectively. Repeated peroral administration of quercetin ameliorated these neuropsychiatric problems. Quercetin treatment also restored the increased expression of GFAP and decreased expression of occludin and doublecortin in the frontal cortex and hippocampus of rmTBI mice. The altered levels of acetate and propionate, and microbial phylum abundance in fecal samples were also normalized in the quercetin-treated group. We also noted an improved intestinal permeability indicated by reduced villi rupture, blunting, and mucosal thinning in quercetin-treated mice. We suggest that the neuroprotective effect of quercetin may be mediated via remodeling of the microbiome gut-brain axis in rmTBI mouse model., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

This review aims to collate information about the analytical methodologies, bioanalytical methodologies, pharmaceutical formulations, solid-state studies, and the current and future market scenario for a relatively new class of drugs, Roxadustat. Roxadustat is a hypoxia-inducible factor propyl hydroxylase inhibitor that significantly increases blood hemoglobin via the action of transcriptional activator HIF. As the molecule has a promising role in stimulating erythropoiesis, it is considered an ideal therapeutic agent for patients with anemia. In the current review, an attempt has been made to compile the pharmacological, pharmacokinetic, and pharmacodynamic characteristics of Roxadustat and systematically present product development data. This drug has several polymorphs of cocrystal, co-former, and salt, which have been explained in detail in the current work. The comprehensive review summarizes all the chromatographic methods and is presented in table form. This review has extensively covered Liquid chromatography-tandem mass spectrometry methods used to analyze Roxadustat in the biological matrix. The literature needs more data on forced degradation study, impurity profiling, gas chromatography, analytical methods for assay, dissolution, and different formulation aspects of Roxadustat., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (© 2023 Published by Elsevier Ltd.)

The degradation profile of ponatinib was established during the present study by exposing it to various stress conditions. In-silico degradation pattern of ponatinib was outlined by using Zeneth software. Five degradation impurities were formed during the stress testing of ponatinib. High performance liquid chromatographic method was developed to separate these degradation impurities which includes ammonium acetate of pH 4.75 (A) and methanol (B) as mobile phase in gradient elution mode and Waters Reliant C18 (4.6 × 250 mm, 5 µm) column as stationary phase. Optimised flow rate, injection volume and detection wavelength of the HPLC method were 1.0 mL/min, 10 µL and 254 nm, respectively. Chemical structures of degradation impurities were proposed by high resolution mass spectrometry further, major degradation products were isolated, enriched and investigated thoroughly with the aid of nuclear magnetic resonance spectroscopy studies. The degradation impurities were identified as 4-aminophthalaldehyde (DP 1), 4-((4-methylpiperazin-1-yl)methyl)- 3-(trifluoromethyl) benzenamine (DP 2), 3-(2-(imidazo[1,2-b]pyridazin-3-yl)acetyl)- 4-methylbenzoic acid (DP 3), 3-(2-(imidazo[1,2-b]pyridazin-3-yl)ethynyl)- 4-methylbenzoic acid (DP 4) and N-oxide impurity (DP 5) which are new and were not reported in the literature till date. Additionally, toxicity and mutagenicity profiles of ponatinib and its degradation impurities were predicted in-silico by using DEREK and SARAH software. This whole study gives meaningful insights about chemical stability of ponatinib which is useful in its drug development lifecycle., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Osimertinib mesylate is a third-generation epidermal growth factor receptor tyrosine kinase inhibitor used to treat nonsmall-cell lung cancer. The objective was to understand in silico prediction and chemical-based stress testing of the osimertinib mesylate. A total of eight degradation products (DPs) were formed under chemical stress testing. An in silico tool viz., Zeneth predicted a higher percentage of DPs. The separation of all the DPs was achieved using reversed phase high-performance liquid chromatography, employing X-Bridge C18 column with ammonium acetate (pH adjusted to 7.50 with ammonia) and acetonitrile as mobile phase. The overall results showed it underwent significant degradation in acidic, alkaline, and oxidative conditions. In rest of the conditions, osimertinib mesylate was found to be stable or slight degradation was observed in photolytic condition. The structure of DPs was elucidated with a comparison of data generated from high-resolution mass spectrometry (HRMS) of osimertinib mesylate and its degradation products. To confirm the unambiguous regioisomers, one-dimensional (1D) and two-dimentional (2D) nuclear magnetic resonance studies were performed. Furthermore, the N-oxide position was assigned for the first time using the Meisenheimer rearrangement reaction in atmospheric pressure chemical ionization mode. Interestingly, an unusual reaction of DP2 formation was observed at alkaline conditions. In silico tools such as DEREK and Sarah predicted osimertinib mesylate and most of the DPs found to be structural alert for mutagenicity.

Background: Due to the rising cases of treatment-refractory affective disorders, the discovery of newer therapeutic approaches is needed. In recent times, probiotics have garnered notable attention in managing stress-related disorders. Herein, we examined the effect of Bacillus coagulans Unique IS-2® probiotic on anxiety- and depression-like phenotypes employing maternal separation (MS) and chronic-unpredictable mild stress (CUMS) model in rats., Methods: Both male and female Sprague-Dawley rats were subjected to MS + CUMS. Probiotic treatment was provided for 6 weeks via drinking water. Anxiety- and depression-like phenotypes were assessed using sucrose-preference test (SPT), forced-swimming test (FST), elevated-plus maze test (EPM), and open-field test (OFT). Blood, brain, intestine, and fecal samples were obtained for biochemical and molecular studies., Results: Stress-exposed rats drank less sucrose solution, showed increased passivity, and explored less in open-arms in SPT, FST, and EPM, respectively. These stress-generated neurobehavioral aberrations were alleviated by 6-week of Bacillus coagulans Unique IS-2 treatment. The overall locomotor activity in OFT remained unchanged. The decreased levels of BDNF and serotonin and increased levels of C-reactive protein, TNF-α, IL-1β, and dopamine, in the hippocampus and/or frontal cortex of stress-exposed rats were reversed following probiotic treatment. Administration of probiotic also restored the systemic levels of L-tryptophan, L-kynurenine, kynurenic-acid, and 3-hydroxyanthranilic acid, villi/crypt ratio, goblet-cell count, Firmicutes to Bacteroides ratio, and levels of acetate, propionate, and butyrate in fecal samples. These results indicate remodeling of the microbiome gut-brain axis in Bacillus coagulans Unique IS-2 recipient rats. However, protein levels of doublecortin, GFAP, and zona occludens in the hippocampus and occludin-immunoreactivity in the intestine remained unchanged. No prominent sex-specific changes were noted., Conclusion: Anxiolytic- and antidepressant-like effects of Bacillus coagulans Unique IS-2 in MS + CUMS rat model may be mediated via reshaping the microbiome gut-brain axis., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Rationale: Brexpiprazole (BRZ) was subjected to hydrolytic (acid, base and neutral), oxidative, photolytic and thermal stress degradation in solutions prepared in a mixture of acetonitrile-water (70:30 v/v). The oxidative study was additionally done in methanol-buffer mixture at pH 3, 7 and 11. Also, compatibility of the drug with selected excipients was investigated in the solid state. Additionally, physicochemical and ADMET properties of BRZ and its degradation products (DPs) were predicted using ADMET Predictor™ software. It provides the conditions for quality control of BRZ and its derivatives during manufacturing, processing and storage conditions., Methods: The formed DPs were separated from the drug and among themselves on a C-18 column utilizing mobile phase composed of methanol and ammonium formate buffer (10mM, pH 4.0), which was run in a gradient mode. Characterization of DPs was carried out by first establishing the mass fragmentation pathway of the drug based on its liquid chromatography/quadrupole-time-of-flight mass spectrometry (LC/Q-TOF-MS) data, followed by LC/Q-TOF-MS studies of DPs. Three DPs were isolated and, along with the drug, they were subjected to 1D ( 1 H, 13 C and DEPT-135) and 2D (COSY and HSQC) NMR studies for confirmation of their structures., Results: BRZ was observed to be susceptible to hydrolytic (neutral, acid and alkali), photolytic and oxidative degradation conditions; it was stable on thermal exposure. A total of 12 DPs (BRZ-1 to BRZ-12) were formed in solution state. Mechanisms of BRZ degradation were postulated., Conclusions: The extent of degradation of BRZ in different stress conditions highlights that stability of BRZ in drug formulations can be improved (i) by using excipients that can impart a low-pH microenvironment, (ii) by addition of antioxidants and (iii) through protection from light., (© 2022 John Wiley & Sons Ltd.)

The present study describes forced degradation of benidipine (BEN) as per  Q1A (R2) and Q1B guidelines of the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. BEN degraded under hydrolysis (neutral, acidic, and alkaline), hydrogen peroxide induced oxidation, and UV light mediated photolytic degradation. A total of 14 degradation products (DPs) were found in all degradation studies, comprising 4 hydrolytic DPs, 8 oxidative DPs, and 4 photolytic DPs. A selective stability-indicating method was developed using an XBridge BEH C18 column with gradient elution program consisting of ammonium acetate (10 mM, 4.8 pH, acetic acid) and acetonitrile. The flow rate was maintained at 1 ml min -1 . All DPs were separated well using the developed HPLC method and were characterized using LC-MS/MS data. As this method is effective in identifying and separating BEN and its DPs with sufficient resolution, it can be used in laboratories for quality control of drugs in daily routine analysis and stability studies., (© 2022 John Wiley & Sons Ltd.)

In silico tool is the flourishing pathway for Researchers and budding chemists to strain the analytical data in a snapshot. Traditionally, drug research has heavily relied on labor-intensive experiments, often limited by time, cost, and ethical constraints. In silico tools have paved the way for more efficient and cost-effective drug development processes. By employing advanced computational algorithms, these tools can screen large libraries of compounds, identifying potential toxicities and prioritizing safer drug candidates for further investigation. Integrating in silico tools into the drug research pipeline has significantly accelerated the drug discovery process, facilitating early-stage decision-making and reducing the reliance on resource-intensive experimentation. Moreover, these tools can potentially minimize the need for animal testing, promoting the principles of the 3Rs (reduction, refinement, and replacement) in animal research. This paper highlights the immense potential of in silico tools in revolutionizing drug research. By leveraging computational models to predict drug metabolism, pharmacokinetics, and toxicity. Researchers can make informed decisions and prioritize the most promising drug candidates for further investigation. The synchronicity of In silico tools in this article on trending topics is insightful and will play an increasingly integral role in expediting drug development., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

The drug substance, acalabrutinib was subjected to hydrolytic (acid, base and neutral) and oxidative stress degradation as per ICH recommendations. Degradation products (DPs) generated from the drug substance were separated on a Shimadzu Shim-pak C-8 column utilizing a mobile phase composed of methanol: acetonitrile (90:10 v/v) and ammonium acetate buffer (10 mM, pH 3.80) in a gradient elution mode. Acalabrutinib was found to be labile under acid, basic, neutral and oxidative conditions. A total of eighteen DPs of drug substance were formed in hydrolytic (fourteen DPs) and oxidative degradation conditions (four DPs). All the DPs were characterized by comparing the LC-Q-TOF mass spectrometric fragmentation pathway of the drug substance with DPs. Further, hydrogen/deuterium (H/D) exchange studies were also carried out on the DPs to confirm the presence of labile hydrogens in their structures. Four DPs (H-12, O-2, O-3 and O-4) were isolated for chemical structural elucidation by NMR. Probable mechanisms involved in degradation of acalabrutinib were also postulated., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Entrectinib is a potent inhibitor of receptor tyrosine kinases and anaplastic lymphoma kinase. It is designated as an orphan drug. There exists no report of comprehensive degradation profiling of the drug in the literature. Therefore, the present study focused on establishment of its stress degradation chemistry under hydrolytic (acidic, alkaline, neutral), oxidative (H 2 O 2 ), photolytic and thermal conditions. For the purpose, the stressed solutions were subjected to HPLC studies on a C8 column by employing a gradient elution method, in which acetonitrile and 10 mM ammonium acetate were used as the mobile phase components. The results showed that entrectinib was labile to alkaline, H 2 O 2, and photoneutral conditions in the solution state. The drug proved to be stable under acidic, solid-state photolytic, and thermal conditions. A total of sixteen degradation products were formed, which were characterized with the help of high resolution mass spectrometry, and in one case additional help was taken of 1D and -2D NMR data. The knowledge of the structures of the degradation products helped in establishment of degradation pathway of the drug and the involved mechanisms. Also, the toxicity profile of the drug and its degradation products was predicted using ADMET Predictor™ software, which indicated mutagenic potential of atleast five degradation products., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A Ru(II)-catalyzed regioselective direct ortho -amidation of 2-aryl benzo[ d ]thiazoles employing acyl azides as a nitrogen source has been accomplished. This approach utilizes the efficiency of benzothiazole as a directing group and the role of acyl azide as an effective amidating agent toward C-N bond formation, thereby evading the general Curtius rearrangement. The protocol highlights significant functional group tolerance, single-step, and external oxidant-free conditions, with the release of only innocuous molecular nitrogen as the byproduct. The reaction mechanism and the intermediates associated with this selective Ru-catalyzed reaction have been investigated using ESI-MS. The protocol also aided in the construction of ortho -amidated β-carbolines, unveiling another class of fluorescent molecules., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Assessment of drug candidate's potential to inhibit cytochrome P450 (CYP) enzymes remains crucial in pharmaceutical drug discovery and development. Both direct and time-dependent inhibition of drug metabolizing CYP enzymes by the concomitant administered drug is the leading cause of drug-drug interactions (DDIs), resulting in the increased toxicity of the victim drug. In this context, pharmaceutical companies have grown increasingly diligent in limiting CYP inhibition liabilities of drug candidates in the early stages and examining risk assessments throughout the drug development process. This review discusses different strategies and decision-making processes for assessing the drug-drug interaction risks by enzyme inhibition and lays particular emphasis on in vitro study designs and interpretation of CYP inhibition data in a stage-appropriate context.

Rationale: Linagliptin is a drug used for the management of type 2 diabetes, which is a leading cause of global ill health and mortality. Impurities can affect the quality and safety of drug products and eventually may affect human health. A robust, sensitive and reliable analytical method is required to detect, characterize, quantify and control the presence of impurities in finished pharmaceutical products such as linagliptin., Methods: Linagliptin was stressed under harsh conditions as in the ICH Q1A (R2) guidelines to generate degradation products. The degradation products and process-related impurities were separated using an InertSustain C8 column (4.6 mm × 150 mm, 5 μm) and characterized by tandem quadrupole time-of-flight mass spectrometry in positive mode electrospray ionization. The developed method was validated according to the ICH Q2 (R1) guidelines., Results: Upon forced degradation, 12 degradation products were obtained (6 in oxidative stress and 3 in each of acid and alkaline hydrolysis). The special finding here was the presence of a pair of isomeric degradation products in acid hydrolysis and the formation of degradation products in base hydrolysis and oxidative degradation caused by the use of acetonitrile as a diluent. The 12 degradation products and 6 process-related substances were successfully identified using liquid chromatography/tandem mass spectrometry., Conclusions: A reversed-phase high-performance liquid chromatography method was developed and validated for the separation of the 12 degradation products and 6 process-related impurities. Structural characterization of all impurities was carried out using fragmentation pathways obtained from tandem mass spectrometry. The method was sufficiently sensitive and reproducible for quality control of linagliptin and for further research studies., (© 2020 John Wiley & Sons, Ltd.)

Olaparib (OLA) is a poly ADP ribose polymerase (PARP) inhibitor approved for germline BRCA-mutated (gBRCAm) advanced ovarian cancer and breast cancer. Low oral bioavailability of this drug requires increase in the dose and frequency causing haematological toxicity in the patients. The purpose of this study is to prepare different nano-formulations of OLA lipospheres (LP) by melt dispersion and nano-suspensions (NSP) by solvent evaporation (SE) and wet milling (WM) techniques and compare oral bioavailability of these formulations. Size of the nano-formulations OLA-LP, OLA-NSP SE and OLA-NSP WM were found to be 126.71 ± 4.54, 128.6 ± 2.34 and 531.1 ± 5.34 nm with polydispersity index below 0.3. In vitro release studies were performed by dialysis bag method where the sustained drug release was observed from nano-formulations until 9 h with Higuchi for OLA suspended in 2.5% w/v sodium carboxy methyl cellulose (OLA-SP), OLA-LP and OLA-NSP WM and Peppas for OLA-NSP SE -based drug release kinetics. In vivo pharmacokinetic studies, haematological toxicity and distribution studies were performed on rats. Results showed that there was an improvement in C max , AUC total , t 1/2 and MRT by OLA nano-formulations when compared with OLA-SP. OLA-SP has shown reduction in WBC, platelets and lymphocytes at 12 and 36 h time points; however, no reduction in cell count was observed with OLA nano-formulations. Distribution studies proved FITC nano-formulations were most rapidly absorbed and distributed when compared with FITC-loaded suspension. From the above results, it was concluded that OLA nano-formulations can be an alternative to enhance the oral bioavailability and to reduce the haematological toxicity of OLA.

Curcumin (cur) is a well known plant flavonoid with pleiotropic pharmacological activities. However, due to its poor bioavailability those therapeutic benefits are still out of reach for patient community. The main aim of our study was to prepare sustained release cur microparticles (CuMPs) with Poly (lactic-co-glycolic acid) (PLGA), an FDA approved biodegradable polymer and to assess their pharmacological potential in multiple low doses streptozotocin (MLD-STZ) induced type 1 diabetes mellitus (T1DM). CuMPs were formulated and characterized for size (12.71 ± 4.20 μm) and encapsulation efficiency (85.10 ± 2.33%) with 28% drug loading. In vitro release and in vivo pharmacokinetics studies showed promising results of sustained release of cur from CuMPs. With this here we report a strategy that single administration of CuMPs may fill the therapeutic window that is missing from free drug repeated administration and low bioavailability of cur. Moving forward with this concept, we compared the therapeutic effects of CuMPs (equivalent to 7.5 mg/kg cur with free cur orally (100 mg/kg) and intraperitoneally (7.5 mg/kg) administered daily in MLD-STZ challenged animals). CuMPs exhibited superior effects compared to daily administration free drug given either orally or i.p. in terms of lowering the blood glucose levels, improved glucose clearance as evident from results of i.p. glucose tolerance test (IPGTT). Interestingly, we observed a remarkable reduction in diabetes incidence in CuMPs groups (only one out of six animals i.e. 16.6%). Moreover, plasma and tissue levels of insulin indicated superior effect of CuMPs. In addition, immunohistochemical analysis of insulin in pancreatic β-cells further confirmed the improved therapeutic benefit with significant increase in insulin signal with CuMPs. Amelioration of oxidative stress and inflammation of CuMPs was observed as the molecular mechanism behind the observed superior pharmacological effects with CuMPs. Cumulatively, our sustained release CuMPs formulation may serve as a bridge in overcoming the poor pharmacokinetics issues associated with cur and may hasten the clinical translation of cur., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Acute pancreatitis (AP) is a serious inflammatory disorder of the pancreas with considerable mortality. The clinical therapy is hampered due to lack of any approved drug for AP. In this study, we developed curcumin (cur)-loaded poly (lactic-co-glycolic acid) cur microparticles (CuMPs) for sustained release. CuMPs were prepared by emulsion solvent evaporation method and characterized for shape, size, compatibility, and entrapment efficiency. The in vitro drug release and in vivo pharmacokinetic studies confirmed sustained release pattern of cur from CuMPs. The pharmacodynamic study was conducted in cerulein induced AP model. Prophylactic treatment was planned with single dose of CuMPs (equivalent to 7.5 mg/kg of cur) and compared with free cur given orally (100 mg/kg) and intraperitoneally (7.5 mg/kg) daily for 7 days. Interestingly, the effects of CuMPs were superior compared to the free drug administered either orally or intraperitoneally through repeated administrations. CuMPs showed significant decrease of serum amylase and lipase levels, oxidative and nitrosative stress was also significantly decreased. Moreover, CuMPs impressively decreased inflammatory cytokines. Our results may pave a way to propose similar strategy for many of promising natural products to combat several oxidative stress-mediated disorders via sustained release microparticle approaches., (Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.)

Olaparib (OLA) is a poly ADP ribose polymerase (PARP) enzyme inhibitor used to treat prostate, ovarian and breast cancer. The drug substance OLA was subjected to forced degradation as per ICH prescribed guidelines. It was degraded in hydrolytic (acidic and basic) and oxidative stress conditions and yielded four degradation products (DPs) while it remained stable in neutral hydrolytic, dry heat and photolytic stress conditions. A stability indicating assay method was developed to separate OLA and its DPs using InertSustain C18 column (250 × 4.6 mm, 5 μm) with a gradient mobile phase of 10 mM ammonium acetate (pH 4.5) and acetonitrile (ACN) at a flow rate of 1 mL min -1 . The characterization of DPs was carried out by using liquid chromatography-electrospray ionization-quadrupole-time of flight tandem mass spectrometry (LC-ESI-Q-TOF-MS/MS). Major degradation products (DP-1 and DP-2) were isolated by using preparative HPLC and structures were further confirmed by using NMR spectroscopy. All the obtained DPs were new and not reported previously. The developed chromatographic method was validated as per ICH Q2 (R1) guideline and USP general chapter on method validation., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Rationale: The presence of impurities and degradation products will affect the pharmacokinetic, pharmacodynamic properties and alter the safety of a drug. Hence, the development of a stability-indicating assay method is an integral part of quality product development and is crucial for the regulatory approval of drug products., Methods: Acotiamide was subjected to stress degradation under hydrolytic, oxidative, photo and thermal stress conditions. The resulted degradation products (DPs), as well as a process-related impurity (IMP), were selectively separated from the drug on a Waters Acquity HSS cyano column (100 × 2.1 mm, 1.8 μm) with a mobile phase containing a gradient mixture of 0.1% formic acid and acetonitrile (ACN) at a flow rate of 0.25 mL min -1 ., Results: The drug was found to degrade under hydrolytic (acidic and basic), oxidative and photolytic stress while it remained stable under neutral hydrolytic and thermal stress conditions. The seven degradation products (DPs) and one process-related impurity (IMP) were observed. All the DPs and process-related IMP were well separated by the developed ultra-high-performance liquid chromatography (UHPLC) method and subsequently characterized by UHPLC/electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI-QTOF-MS/MS). The proposed UHPLC method was validated with respect to specificity, linearity, accuracy, precision and robustness as per ICH guideline, Q2 (R1)., Conclusions: All the observed DPs were new and formed by hydrolysis of an amide bond, phenyl ring hydroxylation and hydrolysis of the methoxy group of the phenyl ring. The despropyl process-related impurity was observed and well separated from the drug. The proposed UHPLC mass spectrometric method has greater utility in the identification of DPs in much less time with excellent selectivity., (Copyright © 2017 John Wiley & Sons, Ltd.)

Rationale: Saquinavir mesylate (SQM) is an antiviral drug used for the treatment of HIV infections. The identification and characterization of all degradation products are essential for achieving the quality in pharmaceutical product development and also for patient safety., Methods: The drug was subjected to hydrolytic (HCl, NaOH and water), oxidative (H 2 O 2 ), photolytic (UV and fluorescence light) and thermal (dry heat) forced degradation conditions as per ICH guidelines. The best chromatographic separation of the drug and all degradation products (DPs) was achieved on a CSH-Phenyl Hexyl column (100 × 2.1 mm, 1.7 μm) with ammonium acetate (10 mM, pH 5.0) and methanol as mobile phase in gradient mode at a flow rate of 0.28 mL/min., Results: Nine DPs were obtained under various forced degradation conditions. All the DPs were characterized by using ultra-high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/ESI-QTOF MS/MS) and the degradation pathway of the drug was justified by mechanistic explanations. The main DPs were formed by amide hydrolysis, conversion into diastereomers, an N-oxide and dehydration as well as oxidation of the alcohol from the drug. The method was validated and can be used in a quality control (QC) laboratory to assure the quality of SQM in bulk and finished formulations., Conclusions: A simple UHPLC/photodiode array (PDA) method was developed and successfully transferred to UHPLC/ESI-Q-TOF MS/MS for the identification and characterization of DPs. Very interestingly, diastereomeric DPs were obtained and successfully resolved by the chromatographic method. Copyright © 2017 John Wiley & Sons, Ltd., (Copyright © 2017 John Wiley & Sons, Ltd.)

Ledipasvir, a novel NS5A inhibitor is used in the management of hepatitis C virus infections. The drug was subjected to forced degradation studies as per the conditions prescribed in ICH Q1 (R2) guideline. Ledipasvir degraded in hydrolytic (acid, alkaline and neutral) and oxidative stress conditions. The drug was found to be stable in thermal and photolytic conditions. Eight novel degradation products were obtained and were well separated using an HPLC C18 stationary phase (150×4.6mm, 5μm) and mobile phase composed of formic acid/acetonitrile in gradient elution mode. All the degradation products were characterised using tandem mass spectrometry with a time-of-flight analyser and the major degradation products of hydrolytic and oxidative stress were isolated and their structural confirmation was studied using 1 H and 13 C NMR. A well resolved chromatographic method proposed in this study suggests that the proposed analytical method finds its application as a stability indicating assay method for the drug and can be used in routine analysis., (Copyright © 2017. Published by Elsevier B.V.)

Sofosbuvir is a direct acting antiviral medication used to treat Hepatitis C viral infection. The present study focuses on the degradation behavior of the drug under various stress conditions (hydrolysis, oxidative, thermal and photolytic) as per International Conference on Harmonization (ICH Q1A (R2)) guidelines. A high performance liquid chromatographic system (HPLC) was used to develop a selective, precise and accurate method for separating all the degradation products. The separation was achieved on a Sunfire™ C18 (150mm×4.6mm×5μm) stationary phase with a mobile phase of 10mM ammonium acetate (pH 5.0) buffer and acetonitrile in gradient elution mode. A quadrupole-time of flight mass analyzer equipped with an electrospray ionization technique was used to propose the structural information based on the MS/MS and accurate mass measurements. Seven degradation products were identified and characterised by LC-ESI-QTOF-MS/MS. In silico toxicity of the drug and its degradation products was determined using TOPKAT and DEREK toxicity prediction softwares. The proposed method was validated as per the ICH Q2 guidelines., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Quality-by-design-based methods hold greater level of confidence for variations and greater success in method transfer. A quality-by-design-based ultra high performance liquid chromatography method was developed for the simultaneous assay of sumatriptan and naproxen along with their related substances. The first screening was performed by fractional factorial design comprising 44 experiments for reversed-phase stationary phases, pH, and organic modifiers. The results of screening design experiments suggested phenyl hexyl column and acetonitrile were the best combination. The method was further optimized for flow rate, temperature, and gradient time by experimental design of 20 experiments and the knowledge space was generated for effect of variable on response (number of peaks ≥ 1.50 - resolution). Proficient design space was generated from knowledge space by applying Monte Carlo simulation to successfully integrate quantitative robustness metrics during optimization stage itself. The final method provided the robust performance which was verified and validated. Final conditions comprised Waters® Acquity phenyl hexyl column with gradient elution using ammonium acetate (pH 4.12, 0.02 M) buffer and acetonitrile at 0.355 mL/min flow rate and 30°C. The developed method separates all 13 analytes within a 15 min run time with fewer experiments compared to the traditional quality-by-testing approach., (©2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Rationale: Azilsartan medoxomil potassium (AZM) is a new antihypertensive drug introduced in the year 2011. The presence of degradation products not only affects the quality, but also the safety aspects of the drug. Thus, it is essential to develop an efficient analytical method which could be useful to selectively separate and identify the degradation products of azilsartan medoxomil potassium., Methods: AZM was subjected to forced degradation under hydrolytic (acid, base and neutral), oxidative, photolytic and thermal stress conditions. Separation of the drug and degradation products was achieved by a liquid chromatography (LC) method using an Acquity UPLC(®) C18 CSH column with mobile phase consisting of 0.02% trifluoroacetic acid and acetonitrile using a gradient method. Identification and characterization of the degradation products was carried out using LC/electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QTOFMS)., Results: A total of five degradation products (DP 1 to DP 5) were formed under various stress conditions and their structures were proposed with the help of tandem mass spectrometry (MS/MS) experiments and accurate mass data. A common degradation product (DP 4) was observed under all the degradation conditions. DP 1, DP 2 and DP 5 were observed under acid hydrolytic conditions whereas DP 3 was observed under alkaline conditions., Conclusions: AZM was found to degrade under hydrolytic, oxidative and photolytic stress conditions. The structures of all the degradation products were proposed. The degradation pathway for the formation of degradation products was also hypothesized. A selective method was developed to quantify the drug in the presence of degradation products which is useful to monitor the quality of AZM., (Copyright © 2015 John Wiley & Sons, Ltd.)

A validated stability-indicating HPLC method was established, and comprehensive stress testing of ivabradine, a cardiotonic drug, was carried out as per ICH guidelines. Ivabradine was subjected to acidic, basic and neutral hydrolysis, oxidation, photolysis and thermal stress conditions, and the resulting degradation products were investigated by LC-PDA and LC-HR-MS/MS. The drug was found to degrade in acid and base hydrolysis. An efficient and selective stability assay method was developed on Phenomenex Luna C18 (250 × 4.6 mm, 5.0 µm) column using ammonium formate (10 mM, pH 3.0) and acetonitrile as mobile phase at 30 °C in gradient elution mode. The flow rate was 0.7 ml/min and detection wavelength was 286 nm. A total of five degradation products (I-1 to I-5) were identified and characterized by LC-HR-MS/MS in combination with accurate mass measurements. The drug exhibited different degradation behaviour in HCl and H2SO4 hydrolysis conditions. It is a unique example where two of the five degradation products in HCl hydrolysis were absent in H2SO4 acid hydrolysis. The present study provides guidance to revise the stress test for the determination of inherent stability of drugs containing lactam moiety under hydrolytic conditions. Most probable mechanisms for the formation of degradation products have been proposed on the basis of a comparison of the fragmentation pattern of the drug and its degradation products. In silico toxicity revealed that the degradation products (I-2 to I-5) were found to be severe irritants in case of ocular irritancy. The analytical assay method was validated with respect to specificity, linearity, range, precision, accuracy and robustness., (Copyright © 2015 John Wiley & Sons, Ltd.)

An isocratic, stability-indicating, reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed for the quantitative determination of doxofylline and terbutaline sulphate, used for the treatment of respiratory problems. The chromatographic separation was achieved on a Zorbax-SB Phenyl 250 × 4.6mm × 5 μm column with the mobile phase consisting of a mixture of 25 mM ammonium acetate (pH 5.0) : acetonitrile (85:15 %v/v) at a flow rate of 1.0 ml/min. The eluate was monitored at 274 nm using a PDA detector. Forced degradation studies were performed on the bulk sample of doxofylline and terbutaline sulphate using acid (0.1N HCl), base (0.1N NaOH), oxidation (10% hydrogen peroxide), photolytic, and thermal degradation conditions. Good resolution was observed between the degradants and analytes. Degradation products resulting from the stress studies did not interfere with the detection of doxofylline and terbutaline sulphate, thus the assay is stability-indicating. The method has the requisite accuracy, selectivity, sensitivity, and precision for the simultaneous estimation of doxofylline and terbutaline sulphate in bulk and pharmaceutical dosage forms. The limit of quantitation and limit of detection were found to be 1.16 μg/ml and 0.38 μg/ml for doxofylline, 2.08 μg/ml and 0.62 μg/ml for terbutaline sulphate, respectively.