Calcium phosphate cement composition and its kit for bone prosthesis

1. A calcium phosphate cement composition comprising (a) 100 parts by mass of calcium phosphate powder, (b) 5-50 parts by mass of a powdery apatite/collagen composite, (c) 15-50 parts by mass of an aqueous blending liquid, and (d) 10-50 parts by mass of a powdery foaming agent comprising carbonate or hydrogen carbonate and a solid organic acid or its salt, per the total amount (100 parts by mass) of the calcium phosphate powder and the powdery apatite/collagen composite; a pasty mixture obtained by their blending being filled in a prosthetic site in a human body to form a hardened calcium phosphate/collagen composite.

2. The calcium phosphate cement composition according to claim 1 , wherein the aqueous blending liquid contains a thickener in a concentration of 2.5-12.5% by mass.

3. The calcium phosphate cement composition according to claim 1 , further comprising 2-10 parts by mass of a hardening accelerator per 100 parts by mass of the calcium phosphate powder.

4. The calcium phosphate cement composition according to claim 1 , wherein the calcium phosphate powder comprises tribasic calcium phosphate as a main component.

5. The calcium phosphate cement composition according to claim 4 , wherein the calcium phosphate powder comprises, in addition to the tribasic calcium phosphate, 2-10% by mass of dibasic calcium phosphate, 10-25% by mass of tetrabasic calcium phosphate, 5% or less by mass of other calcium phosphate compounds than the dibasic to tetrabasic calcium phosphates, and 0.03-2% by mass of magnesium phosphate.

6. The calcium phosphate cement composition according to claim 1 , wherein apatite in the powdery apatite/collagen composite is hydroxyapatite.

7. The calcium phosphate cement composition according to claim 1 , wherein the carbonate is at least one selected from the group consisting of sodium carbonate, potassium carbonate, magnesium carbonate, calcium carbonate and ammonium carbonate, the hydrogen carbonate is at least one selected from the group consisting of sodium hydrogen carbonate, potassium hydrogen carbonate, magnesium hydrogen carbonate, calcium hydrogen carbonate and ammonium hydrogen carbonate, and the solid organic acid is at least one selected from the group consisting of solid aliphatic carboxylic acids, solid aliphatic hydroxycarboxylic acids, ascorbic acid, aspartic acid and glutamic acid.

8. The calcium phosphate cement composition according to claim 2 , wherein the thickener is at least one selected from the group consisting of sodium chondroitin sulfate, sodium hyaluronate and carboxymethylcellulose.

9. The calcium phosphate cement composition according to claim 3 , wherein the hardening accelerator is at least one selected from the group consisting of sodium lactate, disodium succinate, sodium phosphate and sodium chloride.

10. A calcium phosphate cement composition kit comprising (A) a powdery agent comprising 100 parts by mass of calcium phosphate powder, 5-50 parts by mass of a powdery apatite/collagen composite, and a powdery foaming agent comprising carbonate or hydrogen carbonate and a solid organic acid or its salt, in a proportion of 10-50 parts by mass per the total amount (100 parts by mass) of the calcium phosphate powder and the powdery apatite/collagen composite, and (B) an aqueous blending liquid; a paste-like mixture being obtained by blending the powdery agent with the aqueous blending liquid, in such a proportion that the aqueous blending liquid is 15-50 parts by mass per the total amount (100 parts by mass) of the calcium phosphate powder and the powdery apatite/collagen composite, and filled in a predetermined prosthetic site in a human body to form a hardened calcium phosphate/collagen composite.

11. The calcium phosphate cement composition kit according to claim 10 , wherein the aqueous blending liquid contains a thickener in a concentration of 2.5-12.5% by mass.

12. The calcium phosphate cement composition kit according to claim 11 , wherein the aqueous blending liquid further comprises 2-10 parts by mass of a hardening accelerator per 100 parts by mass of the calcium phosphate powder.

13. The calcium phosphate cement composition kit according to claim 10 , wherein the calcium phosphate powder comprises tribasic calcium phosphate as a main component.

14. The calcium phosphate cement composition kit according to claim 13 , wherein the calcium phosphate powder comprises, in addition to the tribasic calcium phosphate, 2-10% by mass of dibasic calcium phosphate, 10-25% by mass of tetrabasic calcium phosphate, 5% or less by mass of other calcium phosphate compounds than the dibasic to tetrabasic calcium phosphates, and 0.03-2% by mass of magnesium phosphate.

15. The calcium phosphate cement composition kit according to claim 10 , wherein apatite in the powdery apatite/collagen composite is hydroxyapatite.

16. The calcium phosphate cement composition kit according to claim 10 , wherein the carbonate is at least one selected from the group consisting of sodium carbonate, potassium carbonate, magnesium carbonate, calcium carbonate and ammonium carbonate, the hydrogen carbonate is at least one selected from the group consisting of sodium hydrogen carbonate, potassium hydrogen carbonate, magnesium hydrogen carbonate, calcium hydrogen carbonate and ammonium hydrogen carbonate, and the solid organic acid is at least one selected from the group consisting of solid aliphatic carboxylic acids, solid aliphatic hydroxycarboxylic acids, ascorbic acid, aspartic acid and glutamic acid.

17. The calcium phosphate cement composition kit according to claim 11 , wherein the thickener is at least one selected from the group consisting of sodium chondroitin sulfate, sodium hyaluronate and carboxymethylcellulose.

18. The calcium phosphate cement composition kit according to claim 12 , wherein the hardening accelerator is at least one selected from the group consisting of sodium lactate, disodium succinate, sodium phosphate and sodium chloride.