ESR Linewidth and Solution Stability Studies of Dilute Solutions of Cesium in Ethylamine–Ammonia Mixtures

1970 ◽  
Vol 53 (1) ◽  
pp. 119-124 ◽  
Author(s):  
Vincent A. Nicely ◽  
James L. Dye
Keyword(s):  
Solution Stability ◽  
Stability Studies ◽  
Dilute Solutions

Solution stability studies of the subunit components of meningococcal C oligosaccharide‒CRM197 conjugate vaccines

2001 ◽  
Vol 33 (2) ◽  
pp. 91 ◽  
Author(s):  
Mei M. Ho ◽  
Xavier Lemercinier ◽  
Barbara Bolgiano ◽  
Dennis Crane ◽  
Michael J. Corbel
Keyword(s):  
Solution Stability ◽  
Stability Studies ◽  
Conjugate Vaccines

scholarly journals A UPLC-MS/MS METHOD DEVELOPMENT AND VALIDATION FOR THE ESTIMATION OF SOFOSBUVIR FROM HUMAN PLASMA

2016 ◽  
Vol 9 (1) ◽  
pp. 30 ◽  
Author(s):  
Darshan Bhatt ◽  
B. Rajkamal
Keyword(s):  
Chromatographic Separation ◽  
Method Development ◽  
Internal Standard ◽  
Ultra Performance Liquid Chromatography ◽  
Pharmacokinetic Studies ◽  
Solution Stability ◽  
Tandem Mass ◽  
Stability Studies ◽  
Liquid Chromatography Tandem Mass ◽  
Acceptance Limits

Objective: The present work aimed to develop a simple, rapid, specific and precise ultra-performance liquid chromatography-tandem mass spectrophotometric (LC–MS/MS) validated method for quantification of sofosbuvir and internal standard (ISTD) Sofosbuvir-d3 in human plasma.Methods: Samples prepared by employing liquid-liquid extraction (LLE) using 2.5 ml of ethyl acetate. Chromatographic separation was achieved on Gemini 5µ C18, 50 x 4.6 mm column using a mixture of 0.1% (v/v) formic acid in water to methanol at a ratio of 30:70 v/v as the mobile phase. The flow rate was 0.50 ml/min. The LC eluent was split, and approximately 0.1 ml/min was introduced into Tandem mass spectrometer using turbo Ion Spray interface at 325 °C. Quantitation was performed by transitions of 428.35/279.26 (m/z) for sofosbuvir and 431.38/282.37 (m/z) for sofosbuvir-d3.Results: The concentrations of ten working standards showed linearity between 4.063 to 8000.010ng/ml (r2 ≥ 0.9985). Chromatographic separation was achieved within 2 min. The average extraction recoveries of three quality control concentrations were 75.36% for sofosbuvir and were within the acceptance limits. The coefficient of variation was ≤15% for intra-and inter-batch assays. The %CV of ruggedness ranges 0.35% and 3.09%. The % stability of short term and long term stock solution stability studies was found to be 97.25% and 98.81% respectively.Conclusion: The results obtained for specificity, linearity, accuracy, precision, ruggedness and stability studies were within the acceptance limits. Thus the validated economical method was applied for pharmacokinetic studies of sofosbuvir.

scholarly journals A UPLC-MS/MS METHOD DEVELOPMENT AND VALIDATION FOR THE ESTIMATION OF POMALIDOMIDE FROM HUMAN PLASMA

2016 ◽  
Vol 9 (1) ◽  
pp. 37 ◽  
Author(s):  
D. Atul Vasanth ◽  
B. Rajkamal
Keyword(s):  
Formic Acid ◽  
Chromatographic Separation ◽  
Method Development ◽  
Internal Standard ◽  
Pharmacokinetic Studies ◽  
Solution Stability ◽  
Tandem Mass ◽  
Stability Studies ◽  
Liquid Chromatography Tandem Mass ◽  
The Stability

Objective: The present work aimed to develop a simple, rapid, specific and precise liquid chromatography-tandem mass spectrophotometric (LC–MS/MS) validated method for quantification of pomalidomide and internal standard (ISTD) Fluconazole in human plasma.Methods: 50 µl of 0.1% formic acid was added to plasma samples prior to liquid-liquid extraction (LLE) using 2.5 ml of ethyl acetate. Chromatographic separation was achieved on Xterra, RP18, 5 µ (50 x 4.6 mm) column using a mixture of 0.1% (v/v) formic acid in water to methanol at a ratio of 12:88, v/v as the mobile phase. The flow rate was 0.50 ml/min. The LC eluent was split, and approximately 0.1 ml/min was introduced into Tandem mass spectrometer using turbo Ion Spray interface at 325 °C. Quantitation was performed by transitions of m/z 260.1 precursor ion to the m/z 148.8 for pomalidomide and m/z 307.1/238.0 for fluconazole.Results: The concentrations of nine working standards showed linearity between 9.998 to 1009.650 ng/ml (r2 ≥ 0.9968). Chromatographic separation was achieved within 2 min. The average extraction recoveries of three quality control concentrations were 53.86% for pomalidomide and were within the acceptance limits. The coefficient of variation was ≤15% for intra-and inter-batch assays. The %CV of ruggedness ranges 1.32 to 4.03. The % stability of short term and long term stock solution stability studies was found to be 99.01% and 98.49% respectively.Conclusion: The results obtained for specificity, linearity, accuracy, precision, ruggedness and stability studies were within limits. Thus the validated economical method was applied for pharmacokinetic studies of pomalidomide.

scholarly journals A Simple Complex on the Verge of Breakdown: Isolation of the Elusive Cyanoformate Ion

Science ◽  
2014 ◽  
Vol 344 (6179) ◽  
pp. 75-78 ◽  
Author(s):  
Luke J. Murphy ◽  
Katherine N. Robertson ◽  
Scott G. Harroun ◽  
Christa L. Brosseau ◽  
Ulrike Werner-Zwanziger ◽  
...  
Keyword(s):  
Active Site ◽  
Theoretical Calculations ◽  
Acc Oxidase ◽  
Dielectric Medium ◽  
Solution Stability ◽  
Stability Studies ◽  
Simple Complex ◽  
Low Dielectric ◽  
Dielectric Media ◽  
Iron Center

Why does cyanide not react destructively with the proximal iron center at the active site of 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase, an enzyme central to the biosynthesis of ethylene in plants? It has long been postulated that the cyanoformate anion, [NCCO2]–, forms and then decomposes to carbon dioxide and cyanide during this process. We have now isolated and crystallographically characterized this elusive anion as its tetraphenylphosphonium salt. Theoretical calculations show that cyanoformate has a very weak C–C bond and that it is thermodynamically stable only in low dielectric media. Solution stability studies have substantiated the latter result. We propose that cyanoformate shuttles the potentially toxic cyanide away from the low dielectric active site of ACC oxidase before breaking down in the higher dielectric medium of the cell.

Transition metal–saccharide chemistry: synthesis, characterization and solution stability studies of cis-dioxomolybdenum saccharide complexes

1998 ◽  
Vol 311 (3) ◽  
pp. 147-154 ◽  
Author(s):  
Anindita Mukhopadhyay ◽  
Abhijeet Karkamkar ◽  
Erkki Kolehmainen ◽  
Chebrolu P. Rao
Keyword(s):  
Transition Metal ◽  
Solution Stability ◽  
Stability Studies

scholarly journals Thermoanalytical and solution stability studies of hexamethylenedithiocarbamates

2006 ◽  
Vol 17 (4) ◽  
pp. 680-688 ◽  
Author(s):  
Valéria D. Benedini ◽  
Patrícia A. Antunes ◽  
Éder T. G. Cavalheiro ◽  
Gilberto O. Chierice
Keyword(s):  
Solution Stability ◽  
Stability Studies
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