Dual functioning excipient for metal chelate contrast agents
AssigneeBracco International B.V.
InventorsC. Allen Chang, Krishan Kumar, Michael F. Tweedle
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Abstract
A novel dual functioning excipient for metal chelate contrast agents is disclosed. The present excipient, Xm[X′(L′)]n, which is the calcium or zinc salt of the calcium or zinc complex of an organic ligand, enhances safety in that it is able to scavenge both free metal ions and free organic ligand.
Claims46
An excipient for a metal chelate contrast agent, wherein said metal chelate contrast agent, M(L), comprises a metal ion complexed with an organic ligand, which excipient has the formula
- Xm[X′(L′)]n
- wherein X and X′ are each independently selected from calcium or zinc, L′ is an organic ligand which may be L or another organic ligand which has a greater affinity for M than for calcium or zinc, and wherein m and n are each independently 1, 2 or 3.
A contrast agent composition for use in magnetic resonance, x-ray, ultrasound and radio-diagnostic imaging comprising
- a metal ion, M, complexed with an organic ligand, L;
- a complex salt excipient of the formula
- Xm[X′(L′)]n
- wherein X and X′ are each independently selected from calcium or zinc, L′ is an organic ligand which may be L or another organic ligand which has a greater affinity for M than for calcium or zinc, and wherein m and n are each independently 1, 2 or 3;
- and,
- a pharmaceutically acceptable carrier therefor.
A contrast agent composition comprising
- a metal chelate which is gadolinium (III) 1,4,7-tris(carboxymethyl)-10-(2′-hydroxypropyl)-1,4,7,10-tetraazacyclododecane;
- an excipient which is calcium bis[1,4,7-tris(carboxymethyl)-10-(2′-hydroxypropyl)-1,4,7,10-tetraazacyclododecanatocalcium(II)];
- a buffer;
- acidic and/or basic solution sufficient to adjust pH of said composition to a desired value;
- and
- water.
In a method of diagnostic imaging which employs an agent comprising a metal ion, M, complexed with an organic ligand, L, and a pharmaceutically acceptable carrier therefor, the improvement wherein said agent further includes an excipient of the formula
- Xm[X′(L′)]n
- wherein X and X′ are each independently selected from calcium or zinc, L′ is an organic ligand which may be L or another organic ligand which has a greater affinity for M than for calcium or zinc, and wherein m and n are each independently 1, 2 or 3.
Dependencies are inferred from the claim text.