FIELD: medicine, pharmaceutics.
SUBSTANCE: present invention refers to a new crystalline modification A of hydrochloride (-)-(1R, 2R)-3-(3-dimethylamino-1-ethyl-2-methylpropiyl)phenol having at least characteristic lines in X-ray powder diffractogram presented with using Cu Kα-radiation with the values of a 2-teta angle making 15.1±0.2, 16.0±0.2, 18.9±0.2, 20.4±0.2, 22.5+0.2, 27.3±0.2, 29.3±0.2 and 30.4±0.2. An elementary cell of said modification usually has a monoclinic structure. According to the present invention, the crystalline modification A of said compound is produced, e.g. by dissolving hydrochloride (-)-(1R, 2R)-3 (3-dimethylamino-1-ethyl-2-methylpropyl)phenol in the form of the crystalline modification B in acetone or acetonitrile at temperature more than +40°C or in isopropanol at temperature more than +65°C, but not exceeding 80°C, keeping a crystallisation solution and recovering the crystals of hydrochloride (-)-(1R, 2R)-3 (3-dimethylamino-1-ethyl-2-methylpropyl)phenol in the form of the crystalline modification A.
EFFECT: preparation of a drug for pain management or enuresis treatment.
15 cl, 4 tbl, 15 ex
