METHOD FOR PRODUCING MAGNETITE CRYSTALS Russian patent published in 2018 - IPC C30B29/16 C30B29/60 A61K33/26 A61K49/06 B82B3/00 B82Y5/00 B82Y40/00 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to the technology for producing magnetite crystals (Fe₃O₄), which can be used as contrast agents, drug delivery agents, in magnetic hyperthermia. Method for producing magnetite crystals comprises mixing octadecene with iron (III) oleate or iron (III) acetylacetonate in a concentration range of 0.02–0.10 mol/l and oleic acid and sodium oleate in a concentration range of 0.02–0.10 mol/l and 0.06–0.20 mol/l, respectively, heating the mixture to 70 °C and holding at this temperature for 30 minutes, reheating the mixture in an inert gas atmosphere from 70 °C to 320 °C at a speed of 2 to 6 °C/min, holding at this temperature for 25–60 minutes and cooling the mixture to room temperature for 30–120 minutes, in an inert gas atmosphere, introducing isopropanol in volume of 200–400 % of volume of the reaction mixture into the system and separating magnetite crystals, further separating magnetite crystals, dispersing magnetite crystals in a non-polar high boiling organic solvent selected from the group consisting of dibenzyl ether, octadecene and trioctylamine, to a concentration of 3.20–15.5 mg/ml in magnetite in the presence of oleic acid and sodium oleate with concentrations in the range of 0.02–0.10 mol/l and 0.06–0.30 mol/l, respectively, heating the resultant dispersion to a temperature of 290–350 °C in an inert gas atmosphere at a rate of 2–6 °C/min, followed by introducing a solution of iron (III) oleate dropwise into the heated dispersion in a non-polar high boiling organic solvent with a concentration of 0.04–0.50 mol/l for 1–10 h and cooling the dispersion to room temperature for 30–120 minutes in an inert gas atmosphere, re-introducing isopropanol into the system and separating magnetite crystals.

EFFECT: invention in comparison with the known analogs increases by 5½ times the saturation magnetization of crystals of Fe₃O₄ and increases by 3,7 times the speed of their r₂-relaxivity.

1 cl, 3 ex