A novel stability-indicating HPLC method for the determination of enantiomeric purity of eluxadoline drug: Amylose tris(3,5-dichlorophenyl carbamate) stationary phase Sudhakar Yerra, Hemantkumar Sharma, Sreenivasulu B, Mohana Naidu K, Venkateswara Rao B Biomedical Chromatography, 2022 A simple and sensitive stability indicating chiral HPLC method has been developed and validated as per ICH guidelines for the determination of enantiomeric purity of Eluxadoline drug substance. The impact of different mobile phase compositions and CSP's on the separation of Eluxadoline enantiomer along with process and degradation related impurities have been studied. Homogeneity of Eluxadoline and stable results of Eluxadoline enantiomer in all degraded samples reveals the fact that the proposed method was specific (stability indicating). Amylose tris (3,5-dichlorophenyl carbamate) stationary phase column Chiralpak IE-3(150mm x 4.6mm), 3μm give better resolution with polar organic solvents than cellulose derivative, crown ether and zwitterion stationary phases and non-polar solvents. Mobile phase consisted of acetonitrile, tetrahydrofuran, methanol, butylamine and acetic acid in the ratio of 500:500:20:2:1.5 v/v/v/v/v. Isocratic elution was performedat a flow rate of 1.0 mL/min, 35°C column temperature, 10 μl injection volume and 240 nm UV detection. The USP resolution of Eluxadoline enantiomers was found to be more than 4.0 within 65mins run time. Eluxadoline enantiomer detector response linearity over the concentration range of 0.859-4.524 μg/mL was found to be R2 =0.9985. LOD and LOQ and average %recovery values were established as 0.283 μg/mL, 0.859μg/mL and 96.0, respectively.
A novel reverse phase hplc method for the quantification of potential genotoxic impurities in doripenem monohydrate: A broad-spectrum carbapenem antibiotic drug Sudhakar Yerra, P.N. Kishore Babu, B. Sreenivasulu, Hemant Kumar Sharma, K. Mohana Naidu, et al. Asian Journal of Chemistry, 2021 A novel sensitive gradient reverse phase high performance liquid chromatographic (RP-HPLC) method has been developed and validated for the quantification of potential genotoxic impurities in doripenem monohydrate (DORIBAX) drug substance, namely mono-p-nitrobenzyl malonate, 1β-methyl bicyclic ketoester, desilylated β-keto ester, 1β-methyldiazoazetidinone, deprotected doripenem side chain, N-protected mercapto alcohol, protected doripenem and doripenem side chain. The analysis performed on Alliance Waters e2695 separation module on C18 (250 × 4.6) mm, 5 μm (make: Inertsil) column, oven temperature maintained at 40 ºC and UV detection at 270 nm. The separation was accomplished using buffer (pH 6.0 ± 0.05) and acetonitrile in the ratio of 98:2 v/v as mobile phase-A and acetonitrile as mobile phase-B, flow rate: 1.0 mL/min and injection volume: 50 μL. The proposed method was validated as per ICH guidelines in terms of limit of detection (LOD), limit of quantification (LOQ), linearity, precision, accuracy and specificity.
A novel approach for the synthesis of functionalized hydroxylamino derivative of dihydroquinazolinones Chikkanti Jaganmohan, Vinay Kumar K. P., Venkateshwarlu R., Sandeep Mohanty, Jaydeep Kumar, et al. Synthetic Communications, 2020 A new metal-free and modular approach for the synthesis of various functionalized dihydroquinazolinones has been developed from isatoic anhydride, amines, 4-chloro-N-hydroxybenzimidoylchloride to yield up to 71%. The reaction has been screened in various bases, solvents at different temperatures. The substrate scope of the reaction has been studied with various amines and the possible reaction mechanism for this reaction has also been proposed. Graphical Abstract
In situ FTIR spectroscopic monitoring of the formation of the arene diazonium salts and its applications to the heck-matsuda reaction K. Sateesh Reddy, Bandi Siva, S. Divya Reddy, N. Reddy Naresh, T. V. Pratap, et al. Molecules, 2020 This study depicts the use of a fiber-optic coupled Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) probe for the in-depth study of arene diazonium salt formation and their utilization in the Heck–Matsuda reaction. The combination of these chemical reactions and in situ IR spectroscopy enabled us to recognize the optimum parameters for arene diazonium salt formation and to track the concentrations of reactants, products and intermediates under actual reaction conditions without time consuming HPLC analysis and the necessity of collecting the sample amid the reaction. Overall advantages of the proposed methodology include precise reaction times as well as identification of keto enol tautomerization in allylic alcohols supporting the ‘path a’ elimination mechanism in the Heck–Matsuda reaction.
Synthesis of 1-((5-oxo-4,5-Dihydro-1,3,4-oxadiazol-2-yl)methyl)-1H-1,2,4-triazole-3-carboxylic Acid-Application of Antibacterial activity Manuri Brahmayya, Dasi Samsonu, Alaparthi Venkateswara Rao, Nelli Srinivasa Rao, Battula Venkateswara Rao, et al. Proceedings of the National Academy of Sciences India Section A Physical Sciences, 2019 Synthesis of 1-((5-oxo-4,5-dihydro-1,3,4-oxadiazol-2-yl) methyl)-1H-1,2,4-triazole-3-carboxylic acid was accomplished starting with the commercially available 1,2,4-triazole-3-carboxylic acid. The conversion of hydrazide and carbon dioxide to 1,3,4-oxadiazole has been explained. Antibacterial activity also studied for some synthesized compounds.
A novel stability indicating RP-HPLC method development and validation for the determination of valsartan and hydrochlorothiazide in bulk and pharmaceutical formulations Indian Drugs, 2017
Evaluation of in-vivo anti-diarrheal and cytotoxic activity of ethanolic extract of Alsotinia scholoris leaves International Journal of Pharmaceutical Sciences Review and Research, 2016
A novel stability indicating RP-HPLC method development and validation for the determination of nebivolol and indapamide in bulk and pharmaceutical formulations Indian Drugs, 2016
A modified liquid chromatographic method development and validation for simultaneous estimation of atazanavir and ritonavir in bulk and tablet dosage form Der Pharmacia Lettre, 2016
