Composition comprising mixed metal compounds and xanthan gum
The present invention provides a composition comprising (i) a mixed metal compound containing at least one trivalent metal selected from iron (lll) and aluminum and at least one divalent metal selected from of magnesium, iron, zinc, calcium, lanthanum and cerium, (ii) xanthan gum (iii) at least one of (a) polyvinyl pyrrolidone (b) locust bean gum (c) methyl cellulose wherein the composition has been irradiated with ionizing radiation in an amount of at least 4 kGy.
1. A composition comprising an aqueous suspension comprising:
(i) an insoluble mixed metal compound capable of binding phosphate containing at least one trivalent metal selected from iron (III) and aluminium and at least one divalent metal selected from of magnesium, iron, zinc, calcium, lanthanum and cerium, wherein the component (i) is present in an amount up to 12% by weight, based on the total weight of the composition,
(ii) xanthan gum present in the composition in an amount of no greater than about 2% by weight, based on the total weight of the composition;
(iii) at least one of
(a) polyvinyl pyrrolidone
(b) locust bean gum
(c) methyl cellulose
wherein the composition has been irradiated with ionising radiation in an amount of at least 4 kGy.
2. A composition according to claim 1 where in the compound is of formula I
M II 1-x M III x (OH) 2 A n− y .m H 2 O (I)
wherein M II is one or more bivalent metals and is at least Mg 2+ ;
M III is one or more trivalent metals and is at least Fe 3+ ;
A n− is one or more n-valent anions and is at least CO 3 2− ;
(Σyn)/x is from 0.5 to 1.5
0<x≦0.4,
0<y≦1 and
0<m≦10.
3. A composition according to claim 1 wherein the compound has an aluminium content of less than 10000 ppm.
4. A composition according to claim 1 wherein the composition has been irradiated with ionising radiation in an amount of at least 6 kGy.
5. A composition according to claim 1 wherein the composition has been irradiated with ionising radiation in an amount of at least 8 kGy.
6. A composition according to claim 1 wherein the composition has been irradiated with ionising radiation in an amount of at least 10 kGy.
7. A composition according to claim 1 wherein component (iii) is present in an amount of no greater than 2 wt % based on weight of the composition.
8. A composition according to claim 1 wherein the xanthan gum and component (iii) are present in a ratio of 2:1 to 1:2.
9. A composition according to claim 1 wherein the xanthan gum and component (iii) are present in a ratio of approximately 1:1.
10. A composition according to claim 1 wherein the composition comprises at least polyvinyl pyrrolidone.
11. A composition according to claim 10 wherein the composition comprises (ii) xanthan gum and (iii) polyvinyl pyrrolidone, wherein the xanthan gum and polyvinyl pyrrolidone are present in a ratio of approximately 2:1.
12. A composition according to claim 10 wherein the composition has been irradiated with ionising radiation in an amount of at least 8 kGy.
13. A composition according to claim 1 wherein the composition comprises at least locust bean gum.
14. A composition according to claim 13 wherein the composition comprises (ii) xanthan gum and (iii) locust bean gum, wherein the xanthan gum and locust bean gum are present in a ratio of approximately 1:1.
15. A composition according to claim 13 wherein the composition has been irradiated with ionising radiation in an amount of at least 6 kGy.
16. A composition according to claim 1 wherein the composition comprises at least methyl cellulose.
17. A composition according to claim 16 wherein the composition comprises (ii) xanthan gum and (iii) methyl cellulose, wherein the xanthan gum and methyl cellulose are present in a ratio of approximately 1:1.
18. A composition according to claim 16 wherein the composition has been irradiated with ionising radiation in an amount of at least 10 kGy.
19. A composition according to claim 1 wherein the composition is a pharmaceutical composition and optionally further comprises (iv) one or more pharmaceutically acceptable adjuvants, excipients, diluents or carriers.
20. A composition according to claim 1 for use as a medicament.
21. A pharmaceutical composition according to claim 1 for binding phosphate.
22. A pharmaceutical composition according to claim 1 for use in the treatment of hyperphosphataemia.
23. A composition comprising an aqueous suspension comprising:
(i) an insoluble mixed metal compound capable of binding phosphate containing at least one trivalent metal selected from iron (iii) and aluminum and at least one divalent metal selected from magnesium, iron, zinc, calcium, lanthanum, and cerium, wherein component (i) is present in the composition in an amount of about 8% to 12% by weight, based on the total weight of the composition,
(ii) xanthan gum, wherein component (ii) is present in the composition in an amount of no greater than about 2% by weight, based on the total weight of the composition, and
(iii) at least one of (a) polyvinyl pyrrolidone, (b) locust bean gum, and (c) methyl cellulose, wherein component (iii) is present in an amount no greater than about 2% by weight based on the total weight of the composition, wherein the composition has been irradiated with ionizing radiation in an amount of at least 4 kGy.
24. An aqueous suspension comprising:
(i) an insoluble mixed metal compound capable of binding phosphate containing at least one trivalent metal selected from iron (III) and aluminium and at least one divalent metal selected from magnesium, iron, zinc, calcium, lanthanum and cerium,
(ii) xanthan gum;
(iii) at least one of
(a) polyvinyl pyrrolidone
(b) locust bean gum
(c) methyl cellulose
wherein the xanthan gum and component (iii) are provided in a ratio of 2:1 to 1:2, the suspension has been irradiated with ionising radiation in an amount of at least 4 kGy, and the suspension has a yield stress of greater than about 2.6 Pa to about 19 Pa.
25. The aqueous suspension of claim 24 , wherein the xanthan gum is present in the suspension in an amount of no greater than about 2% by weight, based on the total weight of the suspension.
26. The aqueous suspension of claim 25 , wherein the mixed metal compound is present in the suspension in an amount up to about 12 wt %.