|Title:|| Pharmaceutical composition containing selected lanthanum carbonate hydrates|
|Abstract:||Selected lanthanum carbonate hydrates may be administered into the gastrointestinal tract, to treat hyperphosphataemia in patients with renal failure.|
|Inventor(s):|| Murrer; Barry A (Berkshire, GB), Powell; Nigel A (Berkshire, GB) |
|Assignee:|| AnorMed Inc. (Langley, CA) |
1. A pharmaceutical composition for the treatment of hyperphosphataemia comprising lanthanum carbonate of the formula
where x has a value from 3 to 6, in admixture with a pharmaceutically acceptable diluent or carrier in a form for administration to the gastrointestinal tract.
2. A composition according to claim 1, wherein x has a value from 3.5 to 5.
3. A composition according to claim 2, wherein x has a value from 3.8 to 4.5.
4. A composition according to any one of claims 1 to 3 in unit dosage form to provide from 0.1 to 20 g/day.
5. A process for the preparation of lanthanum carbonate as defined in any one of claims 1 to 3 which comprises the steps of:
(i) reacting lanthanum oxide with hydrochloric acid to obtain lanthanum chloride;
(ii) reacting a solution of the thus obtained lanthanum chloride with an alkali metal carbonate to produce a wet cake of lanthanum carbonate octahydrate; and
(iii) drying the wet cake of lanthanum carbonate octahydrate so as to obtain a lanthanum carbonate with 3 to 6 molecules of water of crystallisation.
6. A process as claimed in claim 5 wherein the alkali metal carbonate is sodium carbonate.
7. A method to treat hyperphosphataemia in a subject which method comprises administering to said subject an amount of lanthanum carbonate of the formula
wherein x has a value from 3 to 6 effective to treat said hyperphosphataemia.
8. The method of claim 7 wherein x has a value from 3.5 to 5.
9. The method of claim 8 wherein x has a value from 3.8 to 4.5.
10. The method of any of claims 7-9 wherein said administering is by an oral route.