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Интеллектуальная Система Тематического Исследования НАукометрических данных |
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Cryochemical modification is a powerful method of reducing the size of drug substances particles, changing their form and crystal structure in order to improve their pharmaceutical properties. In many cases cryomodification of the commercial drugs allowed us to obtain nanodispersed substances and the new crystalline modifications, which cannot be obtained by other methods. Previously unknown β- modification of 2,3-bis(hydroxymethyl)chynoxaline-N,N'-dioxide was obtained by means of cryochemical modification using water solution of α-modification of 2,3-bis(hydroxymethyl)chynoxaline-N,N'-dioxide as the initial reagent and freeze drying technique. This new modificaton was carefully studied by different methods of chemical analysis. The data of nuclear magnetic resonance and gas chromatography, confirmed the sameness of the chemical nature of the primary and modified substances. However the data of X-ray phase analysis, differential thermal analysis (DTA) and Fourier transformation infrared spectroscopy (FTIR) showed the differences in crystal packing and phase state of α- and β- modification of 2,3 bis(hydroxymethyl)chynoxaline-N,N'-dioxide. New cryomodified drug substance including 60-250 nm nanoparticles demonstrates higher antibacterial activity against Escherichia coli 52 compared to the original bulk α-modification of 2,3-bis(hydroxymethyl)chynoxaline-N,N'-dioxide.