METHOD OF PRODUCING SPHERICAL HYDROXYLAPATITE WITH CONTROLLED GRANULOMETRIC COMPOSITION Russian patent published in 2020 - IPC C01B25/32 C01F11/00 A61L27/12 A61L27/32 

FIELD: medicine.

SUBSTANCE: invention can be used in additive technologies for bone tissue implant formation. Method of producing spherical granules of hydroxylapatite with controlled granulometric composition involves preparing mixture containing 11–15 wt % calcium nitrate, 5–9 wt % ammonium hydrophosphate and water – the rest. Addition of aqueous ammonium hydroxide solution is used to adjust the pH of mixture to 10–12. Mixture is held in autoclave at pressure 150–200 atm and temperature 200–250 °C for 1–1.5 hours. Precipitate is washed to neutral pH. Residue is dried in a rarefied atmosphere at pressure of not more than 10^-5 mm Hg and temperature not more than -55 °C. Suspension consisting of 25–27 wt % of ethyl alcohol, 68–70 wt % of water and dry residue is the rest. Suspension is treated with ultrasound for at least 5 minutes at power not less than 200 W. Granulation is carried out using spray drying at a temperature in working chamber of 200–220 °C and suspension feed rate of 13–15 ml/minute with subsequent collection of spherical granules from complex of cyclone filters.

EFFECT: invention enables to obtain spherical granules of hydroxylapatite with size from 5 to 25 mcm.

1 cl, 6 dwg, 2 tbl, 3 ex