Purpose: The purpose of this work was to investigate the mechanisms of cocrystal formation during cogrinding and storage of solid reactants, and to establish the effects of water by cogrinding with hydrated form of reactants and varying RH conditions during storage.
Methods: The hydrogen bonded 1:1 carbamazepine-saccharin cocrystal (CBZ-SAC) was used as a model compound. Cogrinding of solid reactants was studied under ambient and cryogenic conditions. The anhydrous, CBZ (III), and dihydrate forms of CBZ were studied. Coground samples were stored at room temperature at 0% and 75% RH. Samples were analyzed by XRPD, FTIR and DSC.
Results: Cocrystals prepared by cogrinding and during storage were similar to those prepared by solvent methods. The rate of cocrystallization was increased by cogrinding the hydrated form of CBZ and by increasing RH during storage. Cryogenic cogrinding led to higher levels of amorphization than room temperature cogrinding. The amorphous phase exhibited a T (g) around 41 degrees C and transformed to cocrystal during storage.
Conclusions: Amorphous phases generated by pharmaceutical processes lead to cocrystal formation under conditions where there is increased molecular mobility and complementarity. Water, a potent plasticizer, enhances the rate of cocrystallization. This has powerful implications to control process induced transformations.
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http://dx.doi.org/10.1007/s11095-006-9110-6 | DOI Listing |
J Chem Phys
January 2025
Department of Chemistry and Paula M. Trienens Institute for Sustainability and Energy Northwestern University, Evanston, Illinois 60208-3113, USA.
Organic donor-acceptor (D-A) cocrystals are gaining attention for their potential applications in optoelectronic devices. This study explores the dynamics of charge transfer (CT) and triplet exciton formation in various D-A cocrystals. By examining a series of D-A cocrystals composed of coronene (COR), peri-xanthenoxanthene (PXX), and perylene (PER) donors paired with N,N-bis(3'-pentyl)perylene-3,4:9,10-bis(dicarboximide) (PDI), naphthalene-1,4:5,8-tetracarboxy-dianhydride (NDA), or pyrene-4,5,9,10-tetraone (PTO) acceptors, using transient absorption microscopy and time-resolved electron paramagnetic resonance spectroscopy, we find that the strength of the CT interaction influences the nature and yield of triplet excitons produced by CT state recombination.
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October 2024
Supramolecular Compounds Division, Institute of General and Inorganic Chemistry, Uzbekistan Academy of Sciences, Tashkent, Uzbekistan.
The cocrystal (or supramolecular complex) between the Cu(II) complex of salicylic acid and uncoordinated piracetam has been synthesized. Its structure is characterized by elemental analysis, FT-IR, UV-Vis spectroscopy, and X-ray crystallography. Spectroscopic methods confirm the formation of the metal complex, while X-ray crystallography establishes the molecular and crystal structure of the obtained compound.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Scientific Platforms, Southern Research, 2000 9th Avenue South, Birmingham, AL 35205, USA.
As a transcription factor, GLI1 plays an important role in cell cycle regulation, DNA replication, and DNA damage responses. The aberrant activation of GLI1 has been associated with cancers such as glioma, osteosarcoma, and rhabdomyosarcoma. The binding of GLI1 to a specific DNA sequence was achieved by five tandem zinc finger motifs (Zif motifs) on the N-terminal part of the molecule.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Department of Physiology, "Iuliu Haţieganu" University of Medicine and Pharmacy, 400006 Cluj-Napoca, Romania.
Development of cocrystals through crystal engineering is a viable strategy to formulate poorly water-soluble active pharmaceutical ingredients as stable crystalline solid forms with enhanced bioavailability. This study presents a controlled cocrystallization process by cooling for the 1:1 cocrystal of Ketoconazole, an antifungal class II drug with the Fumaric acid coformer. This was successfully set up following the meta-stable zone width determination in acetone-water 4:6 (/) and pure ethanol.
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