Pharmaceutical compositions comprising phosphate-binding polymer

1. In a pharmaceutical composition consisting essentially of sevelamer combined with pharmaceutically acceptable additive, the improvement comprising: use of pharmaceutically acceptable additive consisting essentially of pharmaceutically acceptable additive which does not provide a source of metal ion or monovalent anion.

2. The composition as claimed in claim 1 , wherein the composition comprises wet granulated sevelamer.

3. The composition as claimed in claim 1 , wherein the metal ions are monovalent, divalent or trivalent and are selected from the group consisting of sodium, potassium, calcium, magnesium and aluminium and the added monovalent anion source is a metal salt of monovalent anion.

4. A pharmaceutical composition comprising wet granulated sevelamer and at least one polyol, said composition having at least one of the following characteristics:

(a) less than about 0.05% (w/w) of monovalent anion other than bicarbonate anion;

(b) free of added metal ions and/or added monovalent anion source;

(c) said composition is a solid dosage form having sevelamer particles, at most about 90% of said sevelamer particles with a particle size not more than about 400 microns but not less than about 45 microns and having a disintegration time of less than 30 minutes;

(d) free of reducing sugars;

(e) free of agents which compete with sevelamer for phosphate binding activity; wherein

(f) said composition comprises sevelamer in an amount of less than about 95% by weight of total composition.

5. The composition as claimed in claim 4 , wherein the polyol is selected from the group consisting of inositol, sorbitol, mannitol, isomalt, xylitol, lactitol, erythritol and maltitol.

6. A pharmaceutical composition consisting essentially of sevelamer carbonate substantially free of monovalent anion other than bicarbonate anion.

7. The composition as claimed in claim 6 , wherein said composition comprises less than about 0.05% (w/w) of monovalent anion.

8. The composition as claimed in claim 6 , wherein said composition comprises less than about 0.05% (w/w) of halides.

9. The composition as claimed in claim 1 , wherein the sevelamer carbonate is present in an amount from about 60% to 90% by weight of total composition.

10. The composition as claimed in claim 1 , wherein the composition comprises hydrated sevelamer in an amount of about 70% to 90% by weight of total composition.

11. The composition as claimed in claim 9 , wherein the unit dose strength of said sevelamer is from about 0.4 gram to about 3.0 gram.

12. The composition as claimed in claim 1 , wherein said composition has a Phosphate Binding Capacity of about 3 mMole/gm to about 7 mMole/gm.

13. The composition as claimed in claim 1 , wherein the particles of the active ingredient sevelamer are spherical or globular/oval in shape.

14. The composition as claimed in claim 1 , wherein the composition is free of reducing sugars.

15. The composition as claimed in claim 1 , wherein the composition is free of agents which compete with sevelamer for phosphate binding activity.

16. The composition as claimed in claim 14 , wherein the composition is safe for administration to patients with Chronic Kidney Disease and diabetic patients.

17. A process for preparing wet granulated sevelamer as defined in claim 4 , the process comprising the steps of:

(a) providing sevelamer;

(b) preparing a mixture of said sevelamer carbonate and at least one polyol;

(c) granulating said mixture with a granulation liquid comprising at least 60% (w/w) of organic solvent to produce granulated sevelamer.

18. The process as claimed in claim 17 , wherein the organic solvent is an alcohol, preferably C 1 to C 4 alcohol.

19. The process as claimed in claim 17 , wherein the mixture is pre-wetted with water or aqueous solution of polyethylene glycol prior to granulation.