scholarly journals Novel Polymorphic Cocrystals of the Non-Steroidal Anti-Inflammatory Drug Niflumic Acid: Expanding the Pharmaceutical Landscape

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2140
Author(s):  
Francisco Javier Acebedo-Martínez ◽  
Carolina Alarcón-Payer ◽  
Antonio Frontera ◽  
Rafael Barbas ◽  
Rafel Prohens ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Pharmaceutical Industry ◽  
Thermal Analyses ◽  
Active Pharmaceutical Ingredient ◽  
Niflumic Acid ◽  
X Ray Diffraction ◽  
Inflammatory Drug ◽  
X Ray ◽  
Anti Inflammatory

Any time the pharmaceutical industry develops a new drug, potential polymorphic events must be thoroughly described, because in a crystalline pharmaceutical solid, different arrangements of the same active pharmaceutical ingredient can yield to very different physicochemical properties that might be crucial for its efficacy, such as dissolution, solubility, or stability. Polymorphism in cocrystal formulation cannot be neglected, either. In this work, two different cocrystal polymorphs of the non-steroidal anti-inflammatory drug niflumic acid and caffeine are reported. They have been synthesized by mechanochemical methods and thoroughly characterized in solid-state by powder and single crystal X-ray diffraction respectively, as well as other techniques such as thermal analyses, infrared spectroscopy and computational methods. Both theoretical and experimental results are in agreement, confirming a conformational polymorphism. The polymorph NIF–CAF Form I exhibits improved solubility and dissolution rate compared to NIF–CAF Form II, although Form II is significantly more stable than Form I. The conditions needed to obtain these polymorphs and their transition have been carefully characterized, revealing an intricate system.

Synthèse et caractérisation des oxypentafluorouranates(VI) NH4UOF5, KUOF5, RbUOF5 et CsUOF5

1978 ◽  
Vol 56 (14) ◽  
pp. 1874-1880 ◽  
Author(s):  
Philippe Joubert ◽  
Roland Bougon ◽  
Bernard Gaudreau
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Alkali Metal ◽  
Vibrational Spectroscopy ◽  
Uranium Atom ◽  
The Other ◽  
Metal Fluoride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman And Infrared Spectroscopy

The oxypentafluorouranates(VI) MUOF5, where M = NH4, K, Rb, Cs, have been synthetized from reaction of UOF4 with the ammonium or corresponding alkali metal fluoride in liquid SO2. According to X-ray diffraction, Raman and infrared spectroscopy, and from an isomorphism with the corresponding hexafluorouranates(V) MUF6, two different environments around the uranium atom are observed. In CsUOF5 the five fluorine atoms and the oxygen around the uranium result in a pseudo-octahedral surrounding whereas for the other complexes (M = NH4, K, Rb) each uranium is surrounded by eight light atoms forming a dodecahedron. In this structure the dodecahedra are linked together by fluorine atoms to form infinite chains. The UOF5− ion has been characterized by vibrational spectroscopy in the solid state. The proposed assignment, which was made with the assumption of a C4v symmetry of the UOF5− ion, was confirmed by a force constant calculation. From these data and contrary to the values reported for comparable oxypentafluoroanions, the axial fluorine is found to be less ionic than the equatorial ones.

Influence of Molecular Conformation on the Solid State Packing of 1,2-Diglycerides Study of 1,2-Dipalmitin and Some Structural Analogs by Electron Diffraction, X-Ray Diffraction, and Infrared Spectroscopy

1978 ◽  
Vol 33 (1-2) ◽  
pp. 39-49 ◽  
Author(s):  
Douglas L. Dorset ◽  
Walter A. Pangborn ◽  
Anthony J. Hancock ◽  
Iris S. Lee
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Room Temperature ◽  
Molecular Conformation ◽  
Crystalline Solid ◽  
X Ray Diffraction ◽  
Chain Packing ◽  
X Ray ◽  
Monoclinic Form ◽  
Extended Chain

Abstract Diffraction studies on natural 1,2-dipalmitin and on analogs, including those based on the configurational isomers of cyclopentane-1,2,3-triol reveal that the 1,2-diglycerides crystallize from solvent with chain methylene packing identical to the monoclinic form of even-chain alkanes. The chains probably are folded back in “hairpin” fashion as found in phospholipid crystal structures. Acyl shifts are observed to occur in the crystalline solid state at room temperature to give the 1,3-diglyceride. Analogs based on the above-mentioned cyclitols show that isomers with adjacent chains trans to the ring (possibly extended chain packing) or with chains cis to the ring (“hair­ pin”) crystallize readily. Both possibly extended chain configurational isomers have the α-form as well as β′-forms and a β-polymorph. The hairpin isomers each give a β′-polymorph but only the all-cts isomer gives an α-form.

Syntheses and crystal structures of trigonal rare-earth dioxymonocyanamides, Ln2O2CN2 (Ln=Dy, Ho, Er, Tm, Yb)

2007 ◽  
Vol 22 (1) ◽  
pp. 59-63 ◽  
Author(s):  
Min Li ◽  
Wenxia Yuan ◽  
Jingfang Wang ◽  
Cong Gu ◽  
Huaizhou Zhao
Keyword(s):  
Rare Earth ◽  
Infrared Spectroscopy ◽  
Solid State ◽  
Rietveld Method ◽  
Reaction Pathways ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Trigonal System ◽  
Xrd Patterns

Trigonal rare-earth dioxymonocyanamides Ln2O2CN2 (Ln=Dy, Ho, Er, Tm, Yb) were synthesized by the modified solid-state metathesis (SSM) method, in which Ln2O3 and melamine C3N6H6 were mixed and heated at 850 °C in vacuumed silica ampoules. Possible chemical reaction pathways are proposed. X-ray diffraction (XRD) patterns of Ln2O2CN2 were refined using the Rietveld method. Compounds Ln2O2CN2 crystallize in the trigonal system with space group P3m1, Z=1, and cell parameters of a and c varying from 3.7267(1) to 3.6407(1) Å and from 8.1848(3) to 8.1152(3) Å, respectively, as Ln atoms change from Dy to Yb. These compounds have stacking structures of Ln2O22+ and CN22− layers, similar to those of previously reported compounds Ln2O2CN2 (Ln=Ce, Pr, Nd, Sm, Eu, Gd). The presence of CN22− ions has been confirmed by infrared spectroscopy, with two characteristic peaks in the vicinity of 651 and 2075 cm−1.

In Situ Characterization of Waters of Hydration in a Variable-Hydrate Active Pharmaceutical Ingredient Using 35Cl Solid-State NMR and X-ray Diffraction

2019 ◽  
Vol 19 (12) ◽  
pp. 7349-7362 ◽  
Author(s):  
David A. Hirsh ◽  
Sean T. Holmes ◽  
Paroma Chakravarty ◽  
Austin A. Peach ◽  
Antonio G. DiPasquale ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Active Pharmaceutical Ingredient ◽  
X Ray Diffraction ◽  
In Situ Characterization ◽  
X Ray

Quantification of solid-state impurity with powder X-ray diffraction using laboratory source

2020 ◽  
Vol 35 (4) ◽  
pp. 226-232
Author(s):  
Meenakshi Sundaram ◽  
Saravanan Natarajan ◽  
Amol G. Dikundwar ◽  
Hemant Bhutani
Keyword(s):  
Solid State ◽  
High Performance ◽  
Method Development ◽  
Active Pharmaceutical Ingredient ◽  
X Ray Diffraction ◽  
Limit Of Quantification ◽  
X Ray ◽  
Laboratory Source ◽  
State Chemical ◽  
Low Levels

The application of powder X-ray diffraction (PXRD) for the detection and quantification of low levels of a solid-state chemical impurity, BrettPhos oxide, in an active pharmaceutical ingredient is discussed. It is demonstrated that with appropriate methodology and experimentation, the impurity levels of as low as 0.07% w/w could be detected reliably and limit of quantification of 0.10% w/w could be achieved by PXRD, using a laboratory X-ray source. Method development, validation, and benchmarking using conventional high-performance liquid chromatography are presented in the manuscript highlighting the robustness and reproducibility of such measurements.

Anisole at 100 K: the first crystal structure determination

2015 ◽  
Vol 71 (8) ◽  
pp. 664-666 ◽  
Author(s):  
Rüdiger W. Seidel ◽  
Richard Goddard
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Pharmaceutical Industry ◽  
Close Packing ◽  
Asymmetric Unit ◽  
Aryl Ether ◽  
X Ray Diffraction ◽  
Alkyl Aryl ◽  
X Ray ◽  
Face To Face

The simplest alkyl aryl ether, anisole (methoxybenzene), C7H8O, is a feedstock chemical and is widely used in the pharmaceutical industry. The structure of anisole at 100 K, as determined by single-crystal X-ray analysis, is reported. A crystal (m.p. 236 K) suitable for X-ray diffraction was obtained from the melt. The title compound crystallizes in the centrosymmetric space groupP21/cwith two molecules in the asymmetric unit (Z′ = 2). Both crystallographically distinct molecules adopt a virtually flat (Cs-symmetric) conformation. The arrangement of the molecules in the solid state appears to be governed by close packing. No face-to-face π–π stacking of the molecules is observed, but rather edge-to-face interactions result in a herringbone packing motif.

Characterization and Physicochemical Evaluation of Molecular Complexes Formed Between Umifenovir and Dicarboxylic Acids

2014 ◽  
Vol 52 (1-2) ◽  
pp. 28-40 ◽  
Author(s):  
A. Kons ◽  
A. Bērziņš ◽  
K. Krūkle-Bērziņa ◽  
A. Actiņš
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Thermal Properties ◽  
Infrared Spectroscopy ◽  
Solid State ◽  
Dicarboxylic Acids ◽  
Molecular Complexes ◽  
Resonance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Physicochemical Evaluation

Abstract The paper reports the investigation of three umifenovir molecular complexes with dicarboxylic acids, prepared to improve the bioavailability of this drug. All three molecular complexes were investigated by powder X-ray diffraction, infrared spectroscopy, and solid-state nuclear magnetic resonance spectroscopy. The solubility and thermal properties were determined as well. Polymorph and solvate screening of umifenovir molecular complexes were performed by recrystallization from various solvents, as well as neat and solvent-drop grinding

Solid-State Polymerization of 2,5-Dibromothiophene Derivatives and Properties of Corresponding Conducting Polymers

2011 ◽  
Vol 239-242 ◽  
pp. 924-929 ◽  
Author(s):  
Shu Ai Chen ◽  
Jing Kun Xu ◽  
Bao Yang Lu ◽  
Xue Min Duan ◽  
Fang Fang Kong
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Solid State ◽  
Conducting Polymers ◽  
Thermal Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Monomer Structure ◽  
Solid State Polymerization ◽  
Scanning Electron

Conducting polymers poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-ethylenedithiathiophene) (PEDTT) have been synthesized by solid-state polymerization of 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) and 2,5-dibromo-3,4-ethylenedithiathiophene (DBEDTT) respectively in air and under vacuum. Both polymers were completely insoluble in common organic solvents and retained partial crystal structure of monomers as indicated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. Thermoelectric tests showed that PEDTT exhibited Seebeck coefficient about 120 µV K−1at 170 K, which is higher than PEDOT, while the later exhibited higher electrical conductivity (0.1S cm-1at 298 K) and better thermal stability indicated by the thermal analyses. These results showed that replacement of oxygen by sulfur in the monomer structure played an important role on the properties of polymers.

scholarly journals Efficient Molybdenum Hydrazonato Epoxidation Catalysts Operating under Green Chemistry Conditions: Water vs. Decane Competition

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 756
Author(s):  
Silvija Mrkonja ◽  
Edi Topić ◽  
Mirna Mandarić ◽  
Dominique Agustin ◽  
Jana Pisk
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Theoretical Calculations ◽  
Catalyst Activity ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tert Butylhydroperoxide ◽  
Solid State Structures

Molybdenum compounds containing benzaldehyde-based hydrazones were obtained. The reaction in MeOH resulted with monomeric Mo complexes, [MoO2(L)(MeOH)], while the reaction in dichloromethane (DCM) provided oligomeric complexes, [MoO2(L)]n. The solid-state structures of the obtained compounds were investigated through Infrared Spectroscopy - Attenuated Total Reflection (IR-ATR), Thermogravimetric analysis (TGA), and via X-ray diffraction. The prepared molybdenum species were employed as cyclooctene epoxidation catalysts. TBHP (tert-butylhydroperoxide) in water and TBHP in decane were employed and compared as oxidants, with 0.25 mol% [Mo]. The catalyst activity and selectivity towards epoxide is >90% for all the reactions. The results have been linked to theoretical calculations, showing the importance of the first step, i.e., the transformation of [MoO2(L)(MeOH)] into the pentacoordinate [MoO2(L)].

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