scholarly journals The mechanism of solvent-mediated desolvation transformation of lenvatinib mesylate from dimethyl sulfoxide solvate to form D

2020 ◽  
Vol 76 (3) ◽  
pp. 343-352
Author(s):  
Zhixin Zheng ◽  
Baohong Hou ◽  
Xiaowei Cheng ◽  
Wanying Liu ◽  
Xin Huang ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Dimethyl Sulfoxide ◽  
Solid Phase ◽  
Polarized Light ◽  
Gravimetric Method ◽  
Solution Concentration ◽  
Water Volume ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Scanning Calorimetry

In this work, the mechanism of solvent-mediated desolvation transformation of lenvatinib mesylate (LM) was investigated. Two new solid forms of LM, a dimethyl sulfoxide (DMSO) solvate and an unsolvated form defined as form D, were discovered and characterized using powder X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, polarized light microscopy and Raman spectroscopy. To investigate the thermodynamic mechanism of solvent-mediated desolvation transformation (SMDT) from LM DMSO solvate to form D, solubilities of LM DMSO solvate and form D in binary solvent mixtures of DMSO and water at different water volume fractions and temperatures (293.15–323.15 K) were measured and correlated by non-random two liquids model. The solubility data were used to evaluate the thermodynamic driving force of the SMDT process from DMSO solvate to form D and the effect of the activities of water and DMSO on the transformation process. Raman spectroscopy was used to monitor in situ the solid phase compositions during the SMDT process from LM DMSO solvate to form D while the solution concentration was measured by the gravimetric method. The overall desolvation transformation experiments demonstrated that the SMDT process was controlled by the nucleation and growth of form D. Moreover, effects of operating factors on the SMDT process were studied and the results illustrated that water activity in solution was the paramount parameter in the SMDT process. Finally, a new SMDT mechanism was suggested and discussed.

scholarly journals Fast real-time monitoring of entacapone crystallization and characterization of polymorphs via Raman spectroscopy, statistics and SWAXS

2014 ◽  
Vol 64 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Tomislav Jednačak ◽  
Aden Hodzic ◽  
Otto Scheibelhofer ◽  
Marijan Marijan ◽  
Johannes G. Khinast ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Optical Probe ◽  
Solvent Mixture ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Starting Point ◽  
Principal Components Method ◽  
Components Method

Abstract Crystallization of the drug entacapone from binary solvent mixtures was monitored in situ using a Raman optical probe. The recorded Raman spectra and statistical analysis, which included the principal components method and indirect hard modeling made it possible to estimate the starting point of crystallization, to assess crystallization temperatures and to provide information on the polymorphic content of the mixture. It was established that crystallization temperatures were proportional to the volume content of the solvent in mixtures. The samples were also evaluated off-line via Raman spectroscopy and SWAXS. The collected data showed the presence of forms b and g in all solvent mixtures. In a toluene/methanol 30:70 mixture, in addition to forms b and g, at least one of the forms A, D or a was also indicated by SWAXS. The results have shown that the presence of a particular polymorph is strongly dependent on the nature and portion of the solvent in the binary solvent mixture.

scholarly journals Harnessing polarity and viscosity to identify green binary solvent mixtures as viable alternatives to DMF in solid-phase peptide synthesis

2021 ◽  
Author(s):  
Vincent Martin ◽  
Sandip Jadhav ◽  
Peter H. G. Egelund ◽  
Raphael Liffert ◽  
Henrik Johansson Castro ◽  
...  
Keyword(s):  
Pharmaceutical Industry ◽  
Peptide Synthesis ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Peptide Sequence ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Binary Solvent Mixtures

Solid-phase peptide synthesis (SPPS) enables routine synthesis of virtually any type of peptide sequence and is the preferred method for peptide synthesis in academia and the pharmaceutical industry alike. Still,...

Solid−Solid Phase Transitions indl-Norvaline Studied by Differential Scanning Calorimetry and Raman Spectroscopy

2010 ◽  
Vol 114 (3) ◽  
pp. 1294-1300 ◽  
Author(s):  
Petros Chatzigeorgiou ◽  
Nikos Papakonstantopoulos ◽  
Nikolitsa Tagaroulia ◽  
Evangelos Pollatos ◽  
Pantelis Xynogalas ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Phase Transitions ◽  
Solid Phase ◽  
Scanning Calorimetry

Cryogenic mechanical milling of high density polyethylene

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Ana Paula Cysne Barbosa ◽  
Michael Stranz ◽  
Frank Katzenberg ◽  
Uwe Köster
Keyword(s):  
Mechanical Milling ◽  
Solid Phase ◽  
Polarized Light ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Monoclinic Modification ◽  
X Ray ◽  
Responsible Mechanism ◽  
Solid Phase Transition ◽  
Melting And Crystallization

AbstractHDPE was analyzed after being submitted to cryogenic mechanical milling (CMM) by X-ray diffraction (WAXS), polarized light microscopy and differential scanning calorimetry (DSC). After CMM, besides the known phase transformation of the orthorhombic PE crystals into the monoclinic modification, slight changes in the melting and crystallization behavior as well as an unexpected increase in crystallinity were observed. The observed results can be explained by assuming a solid/solid phase transition as the responsible mechanism.

scholarly journals Dielectric Properties of Binary Solvent Mixtures of Dimethyl Sulfoxide with Water

2009 ◽  
Vol 10 (3) ◽  
pp. 1261-1270 ◽  
Author(s):  
Li-Jun Yang ◽  
Xiao-Qing Yang ◽  
Ka-Ma Huang ◽  
Guo-Zhu Jia ◽  
Hui Shang
Keyword(s):  
Dielectric Properties ◽  
Dimethyl Sulfoxide ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Binary Solvent Mixtures

scholarly journals Replacing DMF in solid-phase peptide synthesis: Varying the composition of green binary solvent mixtures as a tool to mitigate common side-reactions

2021 ◽  
Author(s):  
Sandip Jadhav ◽  
Vincent Martin ◽  
Peter H. G. Egelund ◽  
Henrik Johansson Castro ◽  
Tobias Krüeger ◽  
...  
Keyword(s):  
Peptide Synthesis ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Environmentally Benign ◽  
Side Reactions ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Binary Solvent Mixtures ◽  
Made In

Significant efforts have been made in recent years to identify more environmentally benign and less hazardous alternatives to N,N-dimethylformamide (DMF) in solid-phase peptide synthesis (SPPS). Several greener solvents have been...

Application of mixed solvents for elution of organophosphate pesticides extracted from raw propolis by matrix solid-phase dispersion and analysis by GC-MS

2014 ◽  
Vol 68 (11) ◽  
Author(s):  
Kati Medina-Dzul ◽  
David Muñoz-Rodríguez ◽  
Yolanda Moguel-Ordoñez ◽  
Cristian Carrera-Figueiras
Keyword(s):  
Solid Phase ◽  
Mixed Solvents ◽  
Solvent Mixture ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Organophosphate Pesticides ◽  
Experimental Conditions ◽  
Matrix Solid Phase Dispersion ◽  
Phase Dispersion ◽  
Relative Standard

AbstractThe excessive application of organophosphate pesticides (OPPs) in crop fields close to hives and its application in beekeeping practices are potential sources of contamination of propolis. Pesticides were extracted from raw propolis by matrix solid-phase dispersion. Because of the complex chemical composition of propolis, binary solvent mixtures based on acetonitrile and a relatively non-polar solvent in different proportions were tested for the selective elution of OPPs. The effect of mixed solvents on clean-up was evaluated by GC-MS and the main interfering compounds co-eluted with pesticides were identified. In addition, three volumes of the solvent mixture and the volume of the sample were evaluated in an experimental factorial design. The final experimental conditions were 1 mL of dissolved propolis and 8 mL of acetonitrile/dichloromethane (g4 r = 25: 75). Mean recoveries ranged from 55 % to 96 % (relative standard deviation < 8 %) with an inter-day precision lower than 24 %. The proposed method was applied to the analysis of real samples obtained from local beekeepers.

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