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Information × Registration Number 0223U005749, 0123U103072 , R & D reports Title Study of polymorphism of biologically active substances by X-ray diffraction methods popup.stage_title Head Shaposhnyk Anna M., к.х.н. Registration Date 30-12-2023 Organization State Scientific Institution Scientific and Technological Complex" Institute of Single Crystals "of the National Academy of Sciences of Ukraine popup.description2  Report for the RW: 18 pages, 4 figures, 3 tables, 18 reference sources. The object of the study: polymorphic modifications of active pharmaceutical ingredients and biologically active substances. The purpose of the work: the search for new polymorphic modifications of biologically active substances and APIs and establishing their structure by X-ray diffraction methods. The main methods of research: X-ray structural studies by the method of single crystal and powder diffractions. Use of the Rietveld method for quantitative analysis of powder diffraction patterns and refinement of profile characteristics of powder patterns. Main results: 1. Desloratadine API has three polymorphic modifications I-III. Polymorph II is metastable and is formed only during the synthesis of desloratadine officinal in production, and any further processing of the resulting desloratadine substance leads to its partial transition into polymorphs I and/or III; 2. During the recrystallization of the desloratadine substance from various solvents, as well as the melt, it leads to the complete disappearance of polymorphic modification II in the composition of the sample; 3. The ratio of polymorphs I and III in the recrystallized product depends on the type of solvent used for recrystallization; 4. The maximum content of polymorph I was obtained during recrystallization from chloroform (77 wt.%), polymorph III - during recrystallization from water (86 wt.%) and from melt (90 wt.%); Based on the results of the work, the material was submitted to the editorial board of the journal. Key words: biologically active substance, crystal structure, polymorphism, X-ray diffraction, Rietveld method. Product Description popup.authors popup.nrat_date 2023-12-30 Close