Rebamipide is marketed as a peptic ulcer agent under the trade name Mucosta(R). The objective of this work was to investigate the existence of polymorphs and pseudopolymorphs of rebamipide. Two crystal forms of rebamipide were isolated by recrystallization and characterized by differential thermal analysis (DTA), thermogravimetric analysis (TG), powder X-ray diffractometry, infrared spectrometry, and nuclear magnetic resonance. The DTA curve of Form 1 showed one endothermic peak at 305.2 °C, and that of Form 2 showed one endothermic peak at 307.3 °C. The TG curve of Form 1 showed a single weight loss at 305.2 °C, which corresponded to melting. The TG curve of Form 2 also showed a single weight loss at 307.3 °C, which corresponded to melting. The melting point of Form 2 was higher than that of Form 1. In the dissolution studies in pH 6.8 buffer at 37 ± 0.5 °C, the two crystal forms showed no significant differences in dissolution. After 3 months of storage at 0, 52, and 95% RH, the two crystal forms were not transformed. After milling with a Specamill for 2 h, the two crystal forms were not transformed.
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http://dx.doi.org/10.1007/s12272-016-0723-y | DOI Listing |
J Am Chem Soc
January 2025
Key Laboratory of Green Printing, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
Colloidal crystal engineering enables the precise construction of structures with remarkable properties. However, the flexible and synergistic regulation of multiple properties of colloidal crystals remains a significant challenge. Here, we inspire from Brazilian opals to self-assemble polymer nanoparticles in the gaps of a single-layer opal substrate to fabricate large-scale binary colloidal crystals (BCCs).
View Article and Find Full Text PDFChemistry
January 2025
Universite Claude Bernard Lyon 1, ICBMS, Bâtiment Lederer, 1 Rue Victor Grignard, F-69622, Villeurbanne, FRANCE.
In this article we describe research on the synthesis and characterization of a family of "Janus" amphiphiles composed of disaccharide head groups and alkaloid units joined together via a methylene linker, and bearing a lateral aliphatic chain of varying length. The condensed phases formed by self-organization of the products as a function of temperature were characterized by differential scanning calorimetry, thermal polarized light microscopy, and small angle X-ray scattering, allied with computational modelling and simulations. Structural studies on heating specimens from the solid showed that some homologues exhibited lamellar, columnar and bicontinuous mesophases, whereas the same homologues revealed different phase sequences on cooling from the amorphous liquid.
View Article and Find Full Text PDFSmall
January 2025
Dept. of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel.
Transient amorphous phases are known as functional precursors in the formation of crystalline materials, both in vivo and in vitro. A common route to regulate amorphous calcium carbonate (ACC) crystallization is via direct interactions with negatively charged macromolecules. However, a less explored phenomenon that can influence such systems is the electrostatically driven formation of Ca-macromolecule dense phases.
View Article and Find Full Text PDFSmall
January 2025
Department of Applied Physics, Nagoya University, Nagoya, 464-8603, Japan.
Moiré superlattices formed in van der Waals (vdW) bilayers of 2D materials provide an ideal platform for studying previously undescribed physics, including correlated electronic states and moiré excitons, owing to the wide-range tunability of their lattice constants. However, their crystal symmetry is fixed by the monolayer structure, and the lack of a straightforward technique for modulating the symmetry of moiré superlattices has impeded progress in this field. Herein, a simple, room-temperature, ambient method for controlling superlattice symmetry is reported.
View Article and Find Full Text PDFOrganic cocrystals have garnered significant research attention owing to their distinctive properties and promising applications. However, challenges in molecular structure design and control of intermolecular interactions continue to impede further advancements. In this study, two novel cocrystals were successfully formed from a series of synthesized benzotriazole derivatives.
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