Rare earth metal compositions for treating hyperphosphatemia and related methods

Abstract

Rare earth metal compounds, particularly lanthanum, cerium, and yttrium, are formed as porous particles and are effective in binding metals, metal ions, and phosphate. A method of making the particles and a method of using the particles is disclosed. The particles may be used in the gastrointestinal tract or the bloodstream to remove phosphate or to treat hyperphosphatemia in mammals. The particles may also be used to remove metals from fluids such as water.

1 . A method of treating hyperphosphatemia in a mammal, wherein the method comprises administering an effective amount of a composition comprising a rare earth metal compound to the mammal, and wherein the rare earth metal compound exhibits an X-Ray diffraction scan as shown in  FIG. 16 , and wherein the rare earth metal compound has a phosphate binding capacity of at least 50 mg PO 4 /g of rare earth metal compound. 
     
     
         2 . The method according to  claim 1 , wherein the rare earth metal compound comprises particles, and wherein the particles are between 1 and 1000 μm in size. 
     
     
         3 . The method according to  claim 1 , wherein the rare earth metal compound has a phosphate binding capacity of at least 75 mg PO 4 /g of rare earth metal compound. 
     
     
         4 . The method according to  claim 1 , wherein the rare earth metal compound has a BET specific surface area of at least about 10 m 2 /g. 
     
     
         5 . The method according to  claim 1 , wherein the rare earth metal compound is hydrated. 
     
     
         6 . The method according to  claim 2 , wherein the particles comprise individual crystals. 
     
     
         7 . The method according to  claim 6 , wherein the rare earth metal compound has a phosphate binding capacity of at least 75 mg PO 4 /g of rare earth metal compound. 
     
     
         8 . The method according to  claim 7 , wherein the rare earth metal compound has a BET specific surface area of at least about 10 m 2 /g. 
     
     
         9 . The method according to  claim 8 , wherein the rare earth metal compound has a phosphate binding capacity of at least 100 mg PO 4 /g of rare earth metal compound. 
     
     
         10 . The method according to  claim 8 , wherein the individual crystals are between 20 nm and 10 μm in size.