Rare earth metal compounds, methods of making, and methods of using the same
View Patent ↗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 rare earth compound selected from the group consisting of crystalline La 2 O 2 CO 3 , crystalline La 2 CO 5 , and crystalline LaCO 3 OH, wherein the rare earth compound has a BET specific surface area of at least about 10 m 2 /g and exhibits a phosphate binding of at least 40% of an initial phosphate content after 10 minutes at an initial pH of about 3 and wherein the rare earth compound is in the form of particles with a porous structure.
2. The rare earth compound of claim 1 wherein the porous structure is made by total evaporation of a lanthanum salt solution followed by calcination.
3. The rare earth compound of claim 2 wherein the evaporation is conducted in a spray dryer.
4. The rare earth compound of claim 2 wherein the evaporation temperature is between about 120° C. and 500° C.
5. The rare earth compound of claim 2 wherein the calcination temperature is between about 400° C. and about 1200° C.
6. The rare earth compound of claim 1 wherein the compound is crystalline La 2 O 2 CO 3 .
7. The rare earth compound of claim 6 wherein the crystalline La 2 O 2 CO 3 is anhydrous.
8. The rare earth compound of claim 1 wherein the compound is crystalline LaCO 3 OH.
9. The rare earth compound of claim 8 wherein the crystalline LaCO 3 OH is anhydrous.
10. The rare earth compound of claim 1 wherein the rare earth compound is crystalline La 2 CO 5 .
11. The rare earth compound of claim 10 wherein the crystalline La 2 CO 5 is anhydrous.
12. The rare earth compound as in any one of claims 1 and 6 - 11 wherein said particles are between about 1 and about 1000 μm in size.
13. The rare earth compound of claim 12 wherein the particles comprise individual crystals.
14. The rare earth compound of claim 7 wherein the crystals are between about 20 nanometers and about 10 microns in size.
15. The rare earth compound of claim 1 wherein the rare earth compound may be delivered to a mammal and used to remove phosphate from the gut or decrease phosphate absorption into the blood stream.
16. A method of treating hyperphosphatemia in a mammal comprising providing an effective amount of the rare earth compound of claim 1 .
17. The method according to claim 16 , wherein the rare earth compound is crystalline La 2 CO 5 .
18. The method according to claim 17 , wherein the crystalline La 2 CO 5 is anhydrous.
19. The method according to claim 16 , wherein the rare earth compound is crystalline LaCO 3 OH.
20. The method according to claim 19 , wherein the crystalline LaCO 3 OH is anhydrous.
21. The method according to claim 16 , wherein the rare earth compound is crystalline La 2 O 2 CO 3 .
22. The method according to claim 21 , wherein the crystalline La 2 O 2 CO 3 is anhydrous.
23. A composition comprising a rare earth compound selected from the group consisting of crystalline La 2 O 2 CO 3 , crystalline La 2 CO 5 , and crystalline LaCO 3 OH, wherein the rare earth compound has a BET specific surface area of at least about 10 m 2 /g and exhibits a phosphate binding of at least 40% of the initial phosphate content after 10 minutes at an initial pH of about 3, and wherein the rare earth compound is in the form of particles with a porous structure.
24. The composition according to claim 23 , wherein the rare earth compound is crystalline La 2 O 2 CO 3 .
25. The composition according to claim 24 , wherein the crystalline La 2 O 2 CO 3 is anhydrous.
26. The composition according to claim 23 , wherein the rare earth compound is crystalline La 2 CO 5 .
27. The composition according to claim 26 , wherein the crystalline La 2 CO 5 is anhydrous.
28. The composition according to claim 23 , wherein the particles comprise individual crystals.
29. The composition of claim 28 wherein the crystals are between about 20 nanometers and about 10 microns in size.
30. The composition of claim 23 wherein said composition may be delivered to a mammal and used to remove phosphate from the gut or decrease phosphate absorption into the blood stream.
31. The composition according to claim 23 wherein the rare earth compound is crystalline LaCO 3 OH.
32. The composition according to claim 31 wherein the crystalline LaCO 3 OH is anhydrous.
33. The composition of claim 23 wherein said composition comprises a vehicle and an effective amount of said rare earth compound and wherein the composition is an orally ingestible form selected from the group consisting of liquid solutions, liquid suspensions, tablets, capsules, and gelcaps.
34. The composition of claim 33 , wherein the rare earth compound is crystalline La 2 O 2 CO 3 .
35. The composition of claim 34 , wherein the crystalline La 2 O 2 CO 3 is anhydrous.
36. The composition of claim 33 , wherein the rare earth compound is crystalline La 2 CO 5 .
37. The composition of claim 36 , wherein the crystalline La 2 CO 5 is anhydrous.
38. The composition of claim 33 wherein the rare earth compound is crystalline LaCO 3 OH.
39. The composition of claim 38 wherein the crystalline LaCO 3 OH is anhydrous.
40. The composition of claim 33 , wherein the particles comprise individual crystals.
41. The composition of claim 40 wherein the crystals are between about 20 nanometers and about 10 microns in size.
42. The composition of claim 33 wherein said orally ingestible form may be delivered to a mammal and used to remove phosphate from the gut or decrease phosphate absorption into the blood stream.
43. A method of treating hyperphosphatemia in a mammal comprising administering an effective amount of a composition comprising the rare earth compound of claim 1 .
44. The method according to claim 43 , wherein the rare earth compound is crystalline La 2 O 2 CO 3 .
45. The method according to claim 44 , wherein the crystalline La 2 O 2 CO 3 is anhydrous.
46. The method according to claim 43 , wherein the rare earth compound is crystalline La 2 CO 5 .
47. The method according to claim 46 , wherein the crystalline La 2 CO 5 is anhydrous.
48. The method according to claim 43 , wherein the particles comprise individual crystals.
49. The method of claim 48 wherein the crystals are between about 20 nanometers and about 10 microns in size.
50. The method according to claim 43 , wherein the rare earth compound is crystalline LaCO 3 OH.
51. The method according to claim 50 , wherein the crystalline LaCO 3 OH is anhydrous.
52. The method according to claim 43 , wherein the composition is administered in the form of an orally ingestible form selected from the group consisting of liquid solutions, liquid suspensions, tablets, capsules, and gelcaps.
53. A method of binding a phosphate comprising reacting a composition comprising the rare earth compound of claim 1 .
54. The method according to claim 53 , wherein the rare earth compound is crystalline La 2 O 2 CO 3 .
55. The method according to claim 54 , wherein the crystalline La 2 O 2 CO 3 is anhydrous.
56. The method according to claim 53 , wherein the rare earth compound is crystalline La 2 CO 5 .
57. The method according to claim 56 , wherein the crystalline La 2 CO 5 is anhydrous.
58. The method according to claim 53 , wherein the particles comprise individual crystals.
59. The method of claim 58 wherein the crystals are between about 20 nanometers and about 10 microns in size.
60. The method according to claim 53 , wherein the rare earth compound is crystalline LaCO 3 OH.
61. The method according to claim 60 , wherein the crystalline LaCO 3 OH is anhydrous.
62. A device for removing phosphate from blood, wherein the device comprises a filter fluidically connected to a dialysis machine through which blood flows, and wherein the filter comprises the rare earth compound of claim 1 .
63. The device according to claim 62 , wherein the rare earth compound is anhydrous.
64. The device according to claim 63 , wherein the rare earth compound is La 2 O 2 CO 3 , and wherein the La 2 O 2 CO 3 has a crystal structure as shown in FIG. 19 .
65. The device according to claim 62 , wherein the particles comprise individual crystals.
66. The device according to claim 65 , wherein the individual crystals are between about 20 nm and about 10 μm in size.
67. A method for removing phosphate from the bloodstream, the method comprising:
positioning a device in the bloodstream, wherein the device comprises a filter and wherein the filter comprises the rare earth compound of claim 1 .
68. The method of claim 67 wherein the particles comprise individual crystals.
69. The method of claim 68 wherein the individual crystals are between about 20 nm and about 10 μm in size.
70. The method according to claim 67 , wherein the rare earth compound is anhydrous.