Search

Your search keyword '"Umeda, Daiki"' showing total 24 results
Start Over Author "Umeda, Daiki"
24 results on '"Umeda, Daiki"'

2. Capturing a new hydrate polymorph of amodiaquine dihydrochloride dihydrate via heterogeneous crystallisation

Author

Putra, Okky Dwichandra, Pettersen, Anna, Nilsson Lill, Sten O., Umeda, Daiki, Yonemochi, Etsuo, Nugraha, Yuda Prasetya, and UEKUSA, hidehiro

Subjects
Materials science, 02 engineering and technology, General Chemistry, Amodiaquine, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, law.invention, Crystal, Crystallography, Chain structure, Similarity (network science), law, Metastability, medicine, Sheet structure, General Materials Science, Crystallization, 0210 nano-technology, Hydrate, medicine.drug, amodiaquinium dichloride dihydrate crystal structure hydrogen bond thermal stability
Abstract

Herein, we report a new polymorph of amodiaquine dihydrochloride dihydrate obtained via heterogeneous crystallisation. This new polymorph exhibits similarity in molecular conformation as well as in its one-dimensional chain structure with a previously known polymorph, however with a difference in its two-dimensional sheet structure. Although crystal DFT-calculations predict the new form to be thermodynamically less stable compared to the previously known polymorph, the preparation method applied opened up the access to its metastable zone.

Published
2018

6. Simultaneous Improvement of Epalrestat Photostability and Solubility via Cocrystallization: A Case Study

Author

Putra, Okky Dwichandra, Umeda, Daiki, Nugraha, Yuda Prasetya, Nango, Kazuya, Yonemochi, Etsuo, and UEKUSA, hidehiro

Subjects
Photoisomerization, Chemistry, Hydrogen bond, epalrestat betaine cocrystal cocrystn photostability soly, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Photochemistry, 01 natural sciences, 0104 chemical sciences, Layered structure, chemistry.chemical_compound, Betaine, Molecule, General Materials Science, Solubility, 0210 nano-technology, Dissolution, Epalrestat
Abstract

In this study, we attempt to simultaneously improve the photostability and solubility of epalrestat (a drug used for neuropathy treatment) by preparing epalrestat–betaine zwitterionic cocrystals and characterize the physicochemical property alterations accompanying their formation. Notably, we reveal that the strong hydrogen bonds between epalrestat and betaine molecules in the above cocrystals and the reduced size of the reaction cavity around epalrestat molecules prevent the E,Z to Z,Z photoisomerization of the latter, resulting in improved photostability. Furthermore, the prepared cocrystals exhibit a higher solubility and larger dissolution rate than pure epalrestat crystals due to featuring a layered structure with alternately arranged epalrestat and betaine coformer molecules.

Published
2017
Full Text
View/download PDF

8. Solubility improvement of benexate through salt formation using artificial sweetener

Author

Putra, Okky Dwichandra, Umeda, Daiki, Fujita, Eriko, Haraguchi, Tamami, Uchida, Takahiro, Yonemochi, Etsuo, and UEKUSA, hidehiro

Subjects
artificial sweetener benexate soly, Structure analysis, sweetener, Pharmaceutical Science, Salt (chemistry), dissolution, lcsh:RS1-441, 02 engineering and technology, 010402 general chemistry, Crystal engineering, 01 natural sciences, Article, lcsh:Pharmacy and materia medica, chemistry.chemical_compound, Organic chemistry, Solubility, Dissolution, chemistry.chemical_classification, solubility, benexate, 021001 nanoscience & nanotechnology, Artificial Sweetener, Benexate, 0104 chemical sciences, chemistry, crystal engineering, 0210 nano-technology, Salt formation
Abstract

Benexate, a drug used clinically as a defensive type anti-ulcer agent, has poor solubility and a bitter taste. To improve its solubility, a crystal engineering approach was proposed with the formation of novel salts using an artificial sweetener as a salt co-former. This was also expected to address the bitter taste of the drug. In this work, we report on the preparation and evaluation of the physicochemical properties of the novel salts benexate saccharinate monohydrate and benexate cyclamate whose crystal structures were determined by single-crystal X-ray structure analysis. These novel salts showed higher solubility and faster dissolution profiles that were associated with the occurrence of local layered-like structures. They also showed better moisture uptake profiles and were classified as non-hygroscopic materials. Therefore, benexate saccharinate monohydrate and benexate cyclamate expedited the development of sweet pharmaceutical salts of benexate with improved performances.

Published
2018

16. Capturing a new hydrate polymorph of amodiaquine dihydrochloride dihydrate via heterogeneous crystallisation.

Author

Putra, Okky Dwichandra, Pettersen, Anna, Nilsson Lill, Sten O., Umeda, Daiki, Yonemochi, Etsuo, Nugraha, Yuda Prasetya, and Uekusa, Hidehiro

Subjects
CRYSTALLIZATION, MOLECULAR conformation, HYDRATES, CELL sheets (Biology)
Abstract

Herein, we report a new polymorph of amodiaquine dihydrochloride dihydrate obtained via heterogeneous crystallisation. This new polymorph exhibits similarity in molecular conformation as well as in its one-dimensional chain structure with a previously known polymorph, however with a difference in its two-dimensional sheet structure. Although crystal DFT-calculations predict the new form to be thermodynamically less stable compared to the previously known polymorph, the preparation method applied opened up the access to its metastable zone. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

20. Simultaneous Improvement of Epalrestat Photostability and Solubility via Cocrystallization: A Case Study

Author

Putra, Okky Dwichandra, Umeda, Daiki, Nugraha, Yuda Prasetya, Nango, Kazuya, Yonemochi, Etsuo, and Uekusa, Hidehiro

Abstract

In this study, we attempt to simultaneously improve the photostability and solubility of epalrestat (a drug used for neuropathy treatment) by preparing epalrestat–betaine zwitterionic cocrystals and characterize the physicochemical property alterations accompanying their formation. Notably, we reveal that the strong hydrogen bonds between epalrestat and betaine molecules in the above cocrystals and the reduced size of the reaction cavity around epalrestat molecules prevent the E,Zto Z,Zphotoisomerization of the latter, resulting in improved photostability. Furthermore, the prepared cocrystals exhibit a higher solubility and larger dissolution rate than pure epalrestat crystals due to featuring a layered structure with alternately arranged epalrestat and betaine coformer molecules.

Published
2024
Full Text
View/download PDF

24. Epalrestat tetra-hydro-furan monosolvate: crystal structure and phase transition.

Author

Umeda D, Putra OD, Gunji M, Fukuzawa K, and Yonemochi E

Abstract

The title compound, epalrestat {systematic name: (5 Z )-5-[(2 E )-2-methyl-3-phenyl-prop-2-en-1-yl-idene]-4-oxo-2-sulfanyl-idene-1,3-thia-zolidine-3-acetic acid}, crystallized as a tetra-hydro-furan monosolvate, C 15 H 13 NO 3 S 2 ·C 4 H 8 O. Epalrestat, an important drug for diabetic neuropathy, has been reported to exist in polymphic, solvated and co-crystal forms. In the mol-ecule reported here, the phenyl ring is inclined to the rhodamine ring by 22.31 (9)°, and the acetic acid group is almost normal to the rhodamine ring, making a dihedral angle of 88.66 (11)°. In the crystal, pairs of O-H⋯O hydrogen bonds are observed between the carb-oxy-lic acid groups of epalerstat mol-ecules, forming inversion dimers with an R 2 2 (8) loop. The dimers are linked by pairs of C-H⋯O hydrogen bonds, forming chains along [101]. The solvate mol-ecules are linked to the chain by a C-H⋯O(tetra-hydro-furan) hydrogen bond. A combination of thermal analysis and powder X-ray diffraction revealed that title compound desolvated into epalerstat Form II. One C atom of the tetra-hydro-furan solvate mol-ecule is positionally disordered and has a refined occupancy ratio of 0.527 (18):0.473 (18).

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results