Process for purification and drying of polymer hydrogels

• US 6,600,011 B2
• Filed: 01/31/2002
• Issued: 07/29/2003
• Est. Priority Date: 10/09/2001
• Status: Expired due to Term

• Current Assignee: Genzyme Corporation (Sanofi )
• Original Assignee: Genzyme Corporation (Sanofi )
• Inventors: McDonnell, Peter D., Thomas, Peter W., Bodmer, Richard V. Jr., Larrousse, Mark F., Rea, Gary S.
• Primary Examiner(s): Boykin, Terressa M.
• Application Number:
  US10/066,411
• Publication Number:
  US 20030078366A1
• Time in Patent Office: 544 Days
• Field of Search: 528/480, 526/96, 526/98, 526/105, 526/106, 526/104, 502/104, 502/105, 502/208, 502/236, 502/414, 502/439, 502/514, 502/235, 502/238, 502/239, 502/242, 502/251, 502/256
• US Class Current: 528/480
• CPC Class Codes: C08F 6/001 Removal of residual monomers by physical means
• CPC Class Codes: C08F 6/008 Treatment of solid polymer wetted by water or organic solvents, e.g. coagulum, filter cakes
• CPC Class Codes: C08F 6/20 Concentration
• CPC Class Codes: C08J 2300/14 Water soluble or water swellable polymers, e.g. aqueous gels
• CPC Class Codes: C08J 3/075 Macromolecular gels
• CPC Class Codes: C08J 3/122 Pulverisation by spraying
• CPC Class Codes: Y10S 502/514 Process applicable either to preparing or to regenerating or to rehabilitating catalyst or sorbent

Abstract

This invention relates to a method for purifying and drying a polymer hydrogel. This invention is based in part upon the discovery that rapid drying of polymer hydrogels can eliminate the problem of unacceptable levels of soluble oligomers caused by prolonged thermal treatment. Rapid drying techniques allow drying hydrogels containing more water than was previously considered possible without a loss in product quality. Furthermore, it was discovered that slurries comprising polymer hydrogels and large quantities of water can be spray dried and that spray drying can be conducted with only minimal oligomer formation.

Claims

1. A method for purifying and drying an organic polymer hydrogel, the method comprising:

a) washing the polymer hydrogel with a water wash medium until the measured conductivity of the resulting slurry comprising the hydrogel and wash water medium is less than about 5 mS/cm; and

b) spray drying the resulting slurry.

2. The method of claim 1 wherein the polymer is washed in a continuous process.

3. The method of claim 2 wherein the polymer is washed counter-currently.

4. The method of claim 2 wherein the temperature of the wash water medium is about 10 to 80°

C.

5. The method of claim 1 wherein the polymer hydrogel is decanted from the wash water medium.

6. The method of claim 5 wherein the polymer hydrogel is decanted from the wash water medium using a belt filter.

7. The method of claim 1 further comprising the step of dispersing the polymer hydrogel in water prior to spray drying.

8. The method of claim 7 wherein a mill device is used to disperse the polymer hydrogel in water.

9. The method of claim 8 wherein the mill device is selected from the group consisting of a disperser, a colloid mill, and a homogenizer.

10. The method of claim 8 wherein the mill device is an inline disperser.

11. The method of claim 1 wherein the slurry is spray dried by distributing the slurry through a nozzle or a rotary dispenser to a drying vessel.

12. The method of claim 11 wherein the slurry has a weight of polymer hydrogel to weight of water ratio of less than about 0.20 before spray drying.

13. The method of claim 12 wherein the slurry is distributed to the drying vessel by a pressure nozzle.

14. The method of claim 12 wherein the slurry is distributed to the drying vessel at a feed pressure of about 18-40 bar (gauge) and at a feed temperature of about 150-350°

C. by an approximately 0.9 mm pressure nozzle.

15. The method of claim 1 wherein the slurry is spray dried into an air atmosphere.

16. The method of claim 1 further comprising the step of adjusting the water content of the spray dried polymer hydrogel with a plate dryer.

17. The method of claim 16 wherein plate drying is accomplished under the following conditions:

relative humidity is greater than about 10%, temperature of the drying medium is about 20-100°

C., and residence time is about 12 to 24 hours.

18. The method of claim 1 wherein the polymer hydrogel is an organic polymer hydrogel used as an active pharmaceutical ingredient.

19. The method of claim 18 wherein the polymer hydrogel is a cross-linked poly(allylamine).

20. The method of claim 19 wherein the cross-linked poly(allylamine) is spray dried in an inert gas atmosphere.

21. The method of claim 20 wherein the cross-linked poly(allylamine) is spray dried in an atmosphere free of carbon dioxide.

22. The method of claim 21 wherein the cross-linked poly(allylamine) is spray dried in a nitrogen gas atmosphere.

23. The method of claim 19 wherein the cross-linked poly(allylamine) is spray dried in an air atmosphere.

24. The method of claim 18 wherein the polymer hydrogel is cross-linked poly(allylamine hydrochloride).

25. The method of claim 24 wherein the cross-linked poly(allylamine hydrochloride) is spray dried in an inert gas atmosphere.

26. The method of claim 24 wherein the cross-linked poly(allylamine hydrochloride) is spray dried in an air atmosphere.

27. A method for purifying and drying an amine polymer hydrogel, the method comprising:

a) washing the polymer hydrogel with a water wash medium until the resulting slurry comprising the hydrogel and wash water medium is in the substantial absence of monomer, oligomer, and other contaminants; and

b) spray drying the resulting slurry.

28. The method of claim 27 wherein the polymer is washed in a continuous process.

29. The method of claim 28 wherein the polymer is washed counter-currently.

30. The method of claim 28 wherein the temperature of the wash water medium is about 10 to 80°

C.

31. The method of claim 27 wherein the polymer hydrogel is decanted from the wash water medium.

32. The method of claim 31 wherein the polymer hydrogel is decanted from the wash water medium using a belt filter.

33. The method of claim 27 further comprising the step of dispersing the polymer hydrogel in water prior to spray drying.

34. The method of claim 33 wherein a mill device is used to disperse the polymer hydrogel in water.

35. The method of claim 34 wherein the mill device is selected from the group consisting of a disperser, a colloid mill, and a homogenizer.

36. The method of claim 34 wherein the mill device is an inline disperser.

37. The method of claim 27 wherein the slurry is spray dried by distributing the slurry through a nozzle or a rotary dispenser to a drying vessel.

38. The method of claim 37 wherein the slurry has a weight of polymer hydrogel to weight of water ratio of less than about 0.20 before spray drying.

39. The method of claim 38 wherein the slurry is distributed to the drying vessel by a pressure nozzle.

40. The method of claim 38 wherein the slurry is distributed to the drying vessel at a feed pressure of about 18-40 bar (gauge) and at a feed temperature of about 150-350°

C. by an approximately 0.9 mm pressure nozzle.

41. The method of claim 27 wherein the slurry is spray dried into an air atmosphere.

42. The method of claim 27 further comprising the step of adjusting the water content of the spray dried polymer hydrogel with a plate dryer.

43. The method of claim 42 wherein plate drying is accomplished under the following conditions:

relative humidity is greater than about 10%, temperature of the drying medium is about 20-100°

C., and residence time is about 12 to 24 hours.

44. The method of claim 27 wherein the polymer hydrogel is used as an active pharmaceutical ingredient.

45. The method of claim 44 wherein the polymer hydrogel is a cross-linked poly(allylamine).

46. The method of claim 45 wherein the cross-linked poly(allylamine) is spray dried in an inert gas atmosphere.

47. The method of claim 46 wherein the cross-linked poly(allylamine) is spray dried in an atmosphere free of carbon dioxide.

48. The method of claim 47 wherein the cross-linked poly(allylamine) is spray dried in a nitrogen gas atmosphere.

49. The method of claim 45 wherein the cross-linked poly(allylamine) is spray dried in an air atmosphere.

50. The method of claim 44 wherein the polymer hydrogel is cross-linked poly(allylamine hydrochloride).

51. The method of claim 50 wherein the cross-linked poly(allylamine hydrochloride) is spray dried in an inert gas atmosphere.

52. The method of claim 50 wherein the cross-linked poly(allylamine hydrochloride) is spray dried in an air atmosphere.