Spectroscopic Characterization of Omeprazole and Its Salts

During drug development, it is important to have a suitable crystalline form of the active pharmaceutical ingredient (API). Mostly, the basic options originate in the form of free base, acid, or salt. Substances that are stable only within a certain pH range are a challenge for the formulation. For the prazoles, which are known to be sensitive to degradation in an acid environment, the formulation is stabilized with alkaline additives or with the application of API formulated as basic salts. Therefore, preparation and characterization of basic salts are needed to monitor any possible salinization of free molecules. We synthesized salts of omeprazole from the group of alkali metals (Li, Na, and K) and alkaline earth metals (Mg, Ca). The purpose of the presented work is to demonstrate the applicability of vibrational spectroscopy to discriminate between the OMP and OMP-salt molecules. For this reason, the physicochemical properties of 5 salts were probed using infrared and Raman spectroscopy, NMR, TG, DSC, and theoretical calculation of vibrational frequencies. We found out that vibrational spectroscopy serves as an applicable spectroscopic tool which enables an accurate, quick, and nondestructive way to determine the characteristic of OMP and its salts.

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Spectroscopic characterization of manganese-doped alkaline earth lead zinc phosphate glasses

Bulletin of Materials Science ◽

10.1007/s12034-015-0863-6 ◽

2015 ◽

Vol 38 (2) ◽

pp. 475-482 ◽

Cited By ~ 9

Author(s):

S SREEHARI SASTRY ◽

B RUPA VENKATESWARA RAO

Keyword(s):

Alkaline Earth ◽

Zinc Phosphate ◽

Spectroscopic Characterization ◽

Phosphate Glasses ◽

Lead Zinc

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Guanine: A Combined Study Using Vibrational Spectroscopy and Theoretical Methods

Spectroscopy An International Journal ◽

10.1155/2012/168286 ◽

2012 ◽

Vol 27 ◽

pp. 273-292 ◽

Cited By ~ 29

Author(s):

R. Pedro Lopes ◽

M. Paula M. Marques ◽

Rosendo Valero ◽

John Tomkinson ◽

Luís A. E. Batista de Carvalho

Keyword(s):

Vibrational Spectroscopy ◽

Significant Contribution ◽

Inelastic Neutron Scattering ◽

Spectroscopic Characterization ◽

Inelastic Neutron ◽

Condensed State ◽

Purine Base ◽

Mechanical Methods ◽

Prevalent Form

The present paper reports a conformational study of solid-state anhydrous guanine, using vibrational spectroscopy techniques—infrared, Raman, and inelastic neutron scattering—coupled to quantum mechanical methods at the DFT level, both for the isolated molecule and the condensed state. In both cases, the 7H-keto-amino tautomer was found to be the prevalent form, contrary to aqueous solutions and hydrated polycrystalline guanine, where the 9H-keto-amino tautomer is the most favoured species. This paper is a significant contribution for the existing spectroscopic characterization of this purine base, by unambiguously assigning its vibrational spectra.

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Spectroscopic Characterization of Cobalt (II) Complexes with Reduced Low-Molar Dextran Derivatives

Acta Facultatis Medicae Naissensis ◽

10.2478/afmnai-2018-0004 ◽

2018 ◽

Vol 35 (1) ◽

pp. 37-48 ◽

Cited By ~ 4

Author(s):

Žarko Mitić ◽

Goran M. Nikolić ◽

Milorad Cakić ◽

Sanja Mitić ◽

Goran S. Nikolić ◽

...

Keyword(s):

Ir Spectra ◽

Ftir Spectroscopy ◽

Cobalt Content ◽

Spectroscopic Characterization ◽

Water Molecules ◽

Glycosidic Bonds ◽

Ph Range ◽

Ir Bands

Summary The formation of Co(II) ion complexes with reduced low-molar dextran (RLMD, Mw 5000 g/mol) was studied at the pH range from 7.0 to 13.5. The cobalt content in synthesized Co(II)-RLMD complexes was ~3–12% (AAS) and it generally increases with pH. Co(II)-RLMD complexes were characterized by UV-Vis spectrophotometry and FTIR spectroscopy. UV-Vis data for synthesized complexes indicate tetragonally distorted Oh coordination of Co(II) ions with O atoms from ligand. The presence of IR bands at 765 cm−1 and 910 cm−1 in Co(II)-RLMD complexes indicates the existence of α-(1→6)O-glycosidic bonds. The similarities in the γ(C–H) range of the IR spectra indicate that there is no difference in the conformation of the glucopyranose units in RLMD and Co(II)-RLMD complexes. The occurrence of water molecules in Co(II)-RLMD complexes was confirmed by FTIR spectroscopy of deuterated samples.

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Crystal structures and spectroscopic characterization of galactitol complexes of trivalent lanthanide and divalent alkaline earth chlorides

Carbohydrate Research ◽

10.1016/j.carres.2005.07.025 ◽

2006 ◽

Vol 341 (1) ◽

pp. 75-83 ◽

Cited By ~ 10

Author(s):

Yunlan Su ◽

Limin Yang ◽

Zheming Wang ◽

Xianglin Jin ◽

Shifu Weng ◽

...

Keyword(s):

Crystal Structures ◽

Alkaline Earth ◽

Spectroscopic Characterization ◽

Trivalent Lanthanide ◽

Alkaline Earth Chlorides

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Observation of alkaline earth complexes M(CO)8 (M = Ca, Sr, or Ba) that mimic transition metals

Science ◽

10.1126/science.aau0839 ◽

2018 ◽

Vol 361 (6405) ◽

pp. 912-916 ◽

Cited By ~ 89

Author(s):

Xuan Wu ◽

Lili Zhao ◽

Jiaye Jin ◽

Sudip Pan ◽

Wei Li ◽

...

Keyword(s):

Gas Phase ◽

Alkaline Earth ◽

Principal Quantum Number ◽

Spectroscopic Characterization ◽

Alkaline Earth Metals ◽

Matrix Analysis ◽

Carbonyl Complexes ◽

Metal Chemistry ◽

Cation Complexes

The alkaline earth metals calcium (Ca), strontium (Sr), and barium (Ba) typically engage in chemical bonding as classical main-group elements through their ns and np valence orbitals, where n is the principal quantum number. Here we report the isolation and spectroscopic characterization of eight-coordinate carbonyl complexes M(CO)8 (where M = Ca, Sr, or Ba) in a low-temperature neon matrix. Analysis of the electronic structure of these cubic Oh-symmetric complexes reveals that the metal–carbon monoxide (CO) bonds arise mainly from [M(dπ)] → (CO)8 π backdonation, which explains the strong observed red shift of the C-O stretching frequencies. The corresponding radical cation complexes were also prepared in gas phase and characterized by mass-selected infrared photodissociation spectroscopy, confirming adherence to the 18-electron rule more conventionally associated with transition metal chemistry.

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Spectroscopic characterization of alkaline earth uranyl carbonates

Journal of Solid State Chemistry ◽

10.1016/j.jssc.2004.07.050 ◽

2005 ◽

Vol 178 (2) ◽

pp. 567-577 ◽

Cited By ~ 40

Author(s):

Samer Amayri ◽

Tobias Reich ◽

Thuro Arnold ◽

Gerhard Geipel ◽

Gert Bernhard

Keyword(s):

Alkaline Earth ◽

Spectroscopic Characterization

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Isolation and Characterization of Plasminogen Activator from Pig Leucocytes

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649147 ◽

1974 ◽

Vol 31 (01) ◽

pp. 072-085 ◽

Cited By ~ 5

Author(s):

M Kopitar ◽

M Stegnar ◽

B Accetto ◽

D Lebez

Keyword(s):

Molecular Weight ◽

Plasminogen Activator ◽

Gel Electrophoresis ◽

Gel Filtration ◽

Ph Optimum ◽

Isolation And Characterization ◽

Ph Range ◽

Inhibition Studies ◽

Final Purification

SummaryPlasminogen activator was isolated from disrupted pig leucocytes by the aid of DEAE chromatography, gel filtration on Sephadex G-100 and final purification on CM cellulose, or by preparative gel electrophoresis.Isolated plasminogen activator corresponds No. 3 band of the starting sample of leucocyte cells (that is composed from 10 gel electrophoretic bands).pH optimum was found to be in pH range 8.0–8.5 and the highest pH stability is between pH range 5.0–8.0.Inhibition studies of isolated plasminogen activator were performed with EACA, AMCHA, PAMBA and Trasylol, using Anson and Astrup method. By Astrup method 100% inhibition was found with EACA and Trasylol and 30% with AMCHA. PAMBA gave 60% inhibition already at concentration 10–3 M/ml. Molecular weight of plasminogen activator was determined by gel filtration on Sephadex G-100. The value obtained from 4 different samples was found to be 28000–30500.

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