METHOD OF OBTAINING BISMUTH-POTASSIUM AMMONIUM CITRATE Russian patent published in 2018 - IPC C01G29/00 C01D13/00 C07C59/265 C07C51/41 C01C1/28 A61K31/29 A61P1/00 

FIELD: technological processes.

SUBSTANCE: invention can be used in the preparation of solid compounds used in the manufacture of drugs with increased therapeutic activity for the treatment of diseases of the gastrointestinal tract. To obtain bismuth-potassium-ammonium citrate, metallic bismuth is oxidized by introducing into its dispersed melt at 300–400 °C with stirring, 15–25 wt.% Bismuth oxide, followed by treatment of the obtained powder with a solution of ammonium nitrate with a molar ratio of ammonium nitrate to bismuth, equal to 1.0–1.6. Resulting paste is dried at a temperature of 180–300 °C. Dissolve the resulting oxide in nitric acid with precipitation of bismuth in the form of basic nitrate, which is converted to bismuth oxide as a result of sequential treatment with an aqueous solution of ammonia at pH 7–8, solution of potassium hydroxide at pH 11.5–13 and temperature 15–40 °C. Solution of bismuth-potassium-ammonium citrate is obtained by treating the obtained bismuth oxide with a solution of potassium hydroxide in the presence of citric acid and an aqueous solution of ammonia with pH of 7–10. After that, drying is carried out by evaporation.

EFFECT: invention allows to increase the purity of the product according to the content of nitrate ions, to reduce the consumption of citric acid, to eliminate the emission of nitrogen oxides into the atmosphere at the stage of obtaining a solution of bismuth nitrate from metallic bismuth.

3 cl, 3 tbl, 2 ex