Troglitazone containing two asymmetric carbons has four isomers. Crystalline troglitazone consists of two crystalline diastereomer-pairs, RR/SS and RS/SR, which have different melting points. Using a closed melting method, troglitazone-polyvinylpyrrolidone solid dispersions with various crystallinities were prepared. Raman spectroscopy and its mapping technique were applied to discriminate between the crystalline RR/SS, crystalline RS/SR and amorphous form of troglitazone in solid dispersions. The results of the Raman mapping of solid dispersions showed the co-existence of crystal and amorphous forms, and which diastereomer-pairs remained as crystals, in addition to the distribution of the drug. Moreover, the distribution of PVP could be illustrated from the Raman mapping data. Thus, Raman spectroscopy and its mapping technique are useful tools to evaluate crystal and amorphous states, including discrimination of crystalline diastereomer-pairs in solid dispersions. In addition, by describing the distribution of the drug and the carrier, it could be guessed how drug crystals become amorphous during preparation from the point of view of the distribution of the amorphous form of the drug substance and the carrier.
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http://dx.doi.org/10.1016/j.ijpharm.2008.05.009 | DOI Listing |
Food Chem
December 2024
Poznan University of Technology, Faculty of Chemical Technology, Berdychowo 4, 60-965 Poznań, Poland.. Electronic address:
The determination of iodine after the enrichment on solid sorbent ZrO in the combination with molecular absorption spectrometric (MAS) detection is presented. The detection limit and enrichment factor obtained were 0.009 μg mL and 9, respectively.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China. Electronic address:
Enhancing the decomposition rate of ammonium perchlorate (AP), the most common oxidizer in solid propellants, is important for improving propellant performance. Metal organic frameworks (MOFs) have been developed as key materials for catalyzing AP decomposition, as they can achieve good dispersion of active sites through in-situ decomposition. Despite having considerable potential, the structural transformation process and catalytic performance of MOFs in AP decomposition are still unclear, which seriously hinders their application in the field of AP decomposition.
View Article and Find Full Text PDFNat Mater
January 2025
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.
High thermoelectric performance is generally achieved by synergistically optimizing two or even three of the contradictorily coupled thermoelectric parameters. Here we demonstrate magneto-thermoelectric correlation as a strategy to achieve simultaneous gain in an enhanced Seebeck coefficient and reduced thermal conductivity in topological materials. We report a large magneto-Seebeck effect and high magneto-thermoelectric figure of merit of 1.
View Article and Find Full Text PDFJ Food Drug Anal
December 2024
Department of Pharmacy, School of Health Sciences, Frederick University, Nicosia, 1036, Cyprus.
Pharmaceutical nanosuspensions, also called nanocrystals, are heterogeneous mainly aqueous dispersions of insoluble drug particles stabilised by surfactants and/or polymers. Nanosuspensions as liquid formulations suffer from instability. Solidification of nanosuspensions to solid dosage forms is a way to combine the advantages of nanocrystals with the advantages of the solid state.
View Article and Find Full Text PDFNanoscale
January 2025
Department of Chemistry, Federal University of São Paulo (UNIFESP), Diadema, SP, Brazil.
This study aims to use superparamagnetic iron oxide nanoparticles (SPIONs), specifically magnetite (FeO), to deliver deflazacort (DFZ) and ibuprofen (IBU) to Duchenne muscular dystrophy-affected (DMD) mouse muscles using an external magnetic field. The SPIONs are synthesized by the co-precipitation method, and their surfaces are functionalized with L-cysteine to anchor the drugs, considering that the cysteine on the surface of the SPIONs in the solid state dimerizes to form the cystine molecule, creating the FeO-(Cys)-DFZ and FeO-(Cys)-IBU systems for tests. The FeO nanoparticles (NPs) were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and magnetic measurements.
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