Patent ID: 7381428

Claim:
In a method for treating hyperphosphatemia comprising administering a therapeutically effective amount of a lanthanum carbonate composition comprising lanthanum carbonate having the formula: La 2 (CO 3 ) 3 .xH 2 O wherein x has a value from 0 to 10, in an amount effective to treat hyperphosphatemia, the improvement comprising: stabilizing the lanthanum carbonate against substantial decarboxylation to lanthanum hydroxycarbonate before administration by admixing the lanthanum carbonate in an amount of from 13.4-13.9% to 32.2-33.3% by weight of the composition as elemental lanthanum with a monosaccharide or disaccharide in an amount from 20 to 80% by weight of the composition, wherein the monosaccharide or disaccharide is dextrates, mannitol, sorbitol, or a mixture thereof and the amount of the monosaccharide or disaccharide is such that lanthanum hydroxycarbonate is not observed in an x-ray powder diffraction (XRPD) pattern of the lanthanum carbonate composition after it has been exposed to 60° C. and 95% relative humidity for at least 7 days.