METHOD OF PRODUCING NANOSIZED HYDROXYAPATITE Russian patent published in 2020 - IPC C01B25/32 B82B3/00 B82Y30/00 C01F11/18 A61L27/12 

FIELD: chemistry.

SUBSTANCE: method of producing single-phase nanosized biomimetic hydroxyapatite doped with silicate and carbonate anions of formula Ca_10-d(HPO₄)×(PO₄)_6-x-y-z(CO₃)_y(SiO₄)_z(OH)_2+x+y-z-2d. nH₂O, where d is degree of Ca²⁺ deficiency; y is coefficient or degree of substitution of phosphate ions with carbonate anions, z is a coefficient or degree of substitution of phosphate ions with silicate anions and a molar ratio of , involving preparation of a composition from calcium nitrate/citric acid/tetraethoxysilane/ammonium carbonate, for which solution of calcium nitrate is added with stirring solution of citric acid in molar ratio of 10:1 and using solution of ammonium hydroxide of this system is adjusted to 10–11, continuing stirring, performing doping with silicate- and carbonate-anions to obtain finished product with degree of substitution of carbonate and silicon y = z = 1, for which successively adding calculated amounts of first tetraethoxysilane, then ammonium carbonate (NH₄)₂CO₃ and intensely stirred for 5–10 minutes, then in a composition of calcium nitrate/citric acid (TEOS)/ammonium carbonate is added drop-wise at rate of 4÷5 ml/min solution of ammonium hydrophosphate (NH₄)₂HPO₄ to obtain an end product with molar ratio in range of 1.50 to 1.60, while maintaining the pH of the reaction mixture equal to 10–11 using ammonium hydroxide, and stirring for 30 minutes, settling for 24 hours at room temperature, after which the precipitate is separated, washed and dried at 100–120 °C to constant mass with further grinding.

EFFECT: technical result is implementation of the proposed invention ensures production of BMGAP, as close as possible to chemical composition and structure of human and animal bones, doped with silicate- and carbonate anions with controlled solubility, dispersity and bioactivity of formula Ca_10-d(HPO₄)_x(PO₄)_6-x-y-z(CO₃)_y(SiO₄)_z(OH)_2+x+y-z-2d.nH₂O, where d is degree of deficiency of Ca²⁺ ions; y is coefficient or degree of substitution of phosphate ions with carbonate anions, z is coefficient or degree of substitution of phosphate ions with silicate anions.

1 cl, 2 tbl, 5 ex, 5 dwg