Method for the preparation of carbonated hydroxyapatite compositions

Abstract

A process for the preparation of a single phase carbonate-substituted hydroxyapatite composition, which process comprises the steps of (i) preparing an aqueous solution containing Co32− and PO43− ions in the substantial absence of cations other than H+ ions: (ii) mixing the solution from step (i) with an aqueous solution or suspension of a calcium compound; and (iii) collecting and drying the precipitate formed in step (ii); the ratio of Ca/P in the calcium-containing solution or suspension and the phosphorus-containing solution, when mixed together, being maintained above 1.67. The product of the process is novel with a Ca/P molar ratio of greater than 1.67 and comprises up to 5% by weight of CO32− ions substituted in the B site or the B and A sites of the hydroxyapatite structure, with at least 50% of the CO32− ions being substituted on the B site. This product does not contain Na+ or NH4+ ions.

Dependencies are inferred from the claim text.