scholarly journals Identification and Structural Characterization of Unidentified Impurity in Bisoprolol Film-Coated Tablets

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Ivana Mitrevska ◽  
Ema Kikovska-Stojanovska ◽  
Gjorgji Petrusevski ◽  
Marina Chachorovska ◽  
Suzan Memed-Sejfulah ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Structural Characterization ◽  
Drug Product ◽  
Parent Compound ◽  
Relative Molecular Mass ◽  
Full Characterization ◽  
Depth Analysis ◽  
Structural Alerts ◽  
Ionization Mode

The aim of this study is the identification, structural characterization, and qualification of a degradation impurity of bisoprolol labeled as Impurity RRT 0.95. This degradation product is considered as a principal thermal degradation impurity identified in bisoprolol film-coated tablets. The impurity has been observed in the stress thermal degradation study of the drug product. Using HPLC/DAD/ESI-MS method, a tentative structure was assigned and afterwards confirmed by detailed structural characterization using NMR spectroscopy. The structure of the target Impurity RRT 0.95 was elucidated as phosphomonoester of bisoprolol, having relative molecular mass of 406 (positive ionization mode). The structural characterization was followed by qualification of Impurity RRT 0.95 using several different in silico methodologies. From the results obtained, it can be concluded that no new structural alerts have been generated for Impurity RRT 0.95 relative to the parent compound bisoprolol. The current study presents an in-depth analysis of the full characterization and qualification of an unidentified impurity in a drug product with the purpose of properly defining the quality specification of the product.

scholarly journals Isolation and structural characterization of novel thermal degradation impurity of nafcillin sodium using spectrosocpic and computational techniques

ARKIVOC ◽  
2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Prasad Yaragorla ◽  
Yesudas Kada ◽  
Krishnam Raju Ch ◽  
Arunima Pola ◽  
Rabin Bera ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Structural Characterization ◽  
Computational Techniques

scholarly journals A study on electrospray mass spectrometry of fullerenol C60(OH)24

2013 ◽  
Vol 9 ◽  
pp. 1285-1295 ◽  
Author(s):  
Mihaela Silion ◽  
Andrei Dascalu ◽  
Mariana Pinteala ◽  
Bogdan C Simionescu ◽  
Cezar Ungurenasu
Keyword(s):  
Full Characterization ◽  
Signal Stability ◽  
Multiply Charged ◽  
Negative Ionization Mode ◽  
Positive Mode ◽  
Ionization Mode ◽  
Negative Ionization ◽  
Good Signal ◽  
Capillary Voltage

Full characterization of fullerenol C60(OH)24 by HPLC ESI-MS in negative and positive ionization modes was achieved. Fragmentor voltage and capillary voltage were optimized in order to obtain a good signal stability and the best peak intensity distribution for the fullerenol C60(OH)24 in both negative and positive modes. While the predominant base peak observed for C60(OH)24 in the negative ionization mode was [M − H]− at m/z 1127, those observed in the positive mode were multiply charged [M − H2O + 4H]4+ at m/z 279 and [M − 12H2O + 2NH3 + 6H]6+ at m/z 158.

Synthesis and Structural Characterization of the Dinuclear Beryllium Species [Be2Cl2(μ-Cl)2(PCy3)2]

2011 ◽  
Vol 66 (1) ◽  
pp. 55-57 ◽  
Author(s):  
Holger Braunschweig ◽  
Katrin Gruß
Keyword(s):  
Structural Characterization ◽  
Full Characterization

The synthesis and full characterization of [Be2Cl2(μ-Cl)2(PCy3)2], which results from the reaction of [Pd(PCy3)2] and BeCl2 with concomitant precipitation of elemental palladium, is reported

New ultrastructural findings about Borrelia burgdorferi by cryofixation, negative staining, thin sectioning and scanning techniques

1990 ◽  
Vol 48 (3) ◽  
pp. 582-583
Author(s):  
S. F. Hayes ◽  
M. D. Corwin ◽  
T. G. Schwan ◽  
D. W. Dorward ◽  
W. Burgdorfer
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Structural Characterization ◽  
Negative Staining ◽  
Low Speed ◽  
Thin Sectioning ◽  
Ultrastructural Findings

Characterization of Borrelia burgdorferi strains by means of negative staining EM has become an integral part of many studies related to the biology of the Lyme disease organism. However, relying solely upon negative staining to compare new isolates with prototype B31 or other borreliae is often unsatisfactory. To obtain more satisfactory results, we have relied upon a correlative approach encompassing a variety EM techniques, i.e., scanning for topographical features and cryotomy, negative staining and thin sectioning to provide a more complete structural characterization of B. burgdorferi.For characterization, isolates of B. burgdorferi were cultured in BSK II media from which they were removed by low speed centrifugation. The sedimented borrelia were carefully resuspended in stabilizing buffer so as to preserve their features for scanning and negative staining. Alternatively, others were prepared for conventional thin sectioning and for cryotomy using modified procedures. For thin sectioning, the fixative described by Ito, et al.

Structural characterization of the PPIase domain of FKBP51, a cochaperone of human Hsp90

2011 ◽  
Vol 44 (06) ◽  
Author(s):  
A Bracher ◽  
C Kozany ◽  
AK Thost ◽  
F Hausch
Keyword(s):  
Structural Characterization ◽  
Ppiase Domain
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