Use of polymeric excipients for lyophilization or freezing of particles

1. A method of preparing a lyophilized or frozen preparation of a composition comprising particles comprising a drug, wherein the particles are liposomes or micelles, and wherein the particles are coated with polyethylene glycol (PEG), the method comprising adding polyvinyl alcohol (PVA) to an aqueous composition comprising the particles, and lyophilizing or freezing the aqueous composition.

2. A method of preventing particle aggregation and/or particle size increase upon lyophilization and resuspension or freezing and thawing of an aqueous composition comprising particles comprising a drug, wherein the particles are liposomes or micelles, and wherein the particles are coated with polyethylene glycol (PEG), the method comprising adding polyvinyl alcohol (PVA) to the aqueous particle composition prior to lyophilization or freezing.

3. The method of claim 1 , wherein the concentration of PVA in the aqueous particle composition is between about 0.05% (w/v) to about 1% (w/v).

4. The method of claim 3 , wherein the concentration of PVA in the aqueous particle composition is about 0.1 to about 0.3%.

5. The method of claim 1 , wherein the PVA is about 3K to about 125K.

6. The method of claim 5 , wherein the PVA is about 13K or about 31K.

7. The method of claim 1 , wherein the PVA is at least about 50% hydrolyzed.

8. The method of claim 7 , wherein the PVA is at least about 75% hydrolyzed.

9. The method claim 1 , wherein the weight ratio of the PVA to the particles in the resultant composition is less than about 0.2:1.

10. The method of claim 1 , wherein the concentration of the particles in the aqueous particle composition is about 1% to about 25% (w/v).

11. The method of claim 1 , wherein the particles comprise PLA or PLGA.

12. The method of claim 1 , wherein the average particle size of the particles in the particle composition is no greater than about 200 nm.

13. The method of claim 1 , wherein the average size of the particles does not change by more than about 10% upon lyophilization and resuspension or freezing and thawing.

14. The method of claim 1 , further comprising adding a sugar to the aqueous particle composition prior to lyophilization or freezing.

15. The method of claim 14 , wherein the sugar is sucrose.

16. The method of claim 15 , wherein the concentration of sucrose in the aqueous particle composition is between about 5% to about 20%.

17. The method of claim 14 , wherein the sugar and the PVA are added simultaneously or sequentially into the particle composition.

18. The method of claim 1 , wherein the aqueous particle composition to which the PVA is added is free of PVA.

19. The method of claim 1 , wherein the PEG is covalently attached to the surface of the particles or tethered to the surface of the particles by hydrophobic or charge interactions.

20. The method of claim 1 , wherein the drug is paclitaxel.

21. A pharmaceutical composition comprising particles comprising a drug, wherein the particles are liposomes or micelles, and wherein the particles are coated with polyethylene glycol (PEG), wherein the composition further comprises polyvinyl alcohol (PVA), and wherein less than about 2% of the total PVA in the pharmaceutical composition is associated with the particles.

22. The pharmaceutical composition of claim 21 , wherein the composition is lyophilized or frozen.

23. The pharmaceutical composition of claim 21 , wherein the composition is an aqueous suspension resuspended from a lyophilized or frozen composition.

24. The pharmaceutical composition of claim 21 , wherein the composition is an aqueous suspension.

25. The pharmaceutical composition of claim 21 , wherein the concentration of PVA in the particle composition is between about 0.05% to about 1%.

26. The pharmaceutical composition of claim 25 , wherein the concentration of PVA in the particle composition is about 0.1% to about 0.3%.

27. The pharmaceutical composition of claim 21 , wherein the PVA is about 3K to about 125K.

28. The pharmaceutical composition of claim 27 , wherein the PVA is about 13K or about 31K.

29. The pharmaceutical composition of claim 21 , wherein the PVA is at least about 50% hydrolyzed.

30. The pharmaceutical composition of claim 29 , wherein the PVA is at least about 75% hydrolyzed.

31. The pharmaceutical composition of claim 21 , wherein the particles comprise a polymeric matrix core coated with PEG.

32. The pharmaceutical composition of claim 31 , wherein the particles comprise PLA or PLGA.

33. The pharmaceutical composition of claim 21 , wherein the average particle size of the particles in the particle composition is no greater than about 200 nm.

34. The pharmaceutical composition of claim 21 , further comprising a sugar.

35. The pharmaceutical composition of claim 34 , wherein the sugar is sucrose.

36. The pharmaceutical composition of claim 35 , wherein the concentration of sucrose in the particle composition is between about 5% to about 20%.

37. The pharmaceutical composition of claim 21 , wherein the PEG is covalently attached to the surface of the particles or tethered to the surface of the particles by hydrophobic or charge interactions.

38. The pharmaceutical composition of claim 21 , wherein the weight ratio of the PVA to the particles in the composition is less than about 0.2:1.

39. The pharmaceutical composition of claim 21 , wherein the concentration of the particles in the aqueous particle composition is about 1% to about 25% (w/v).

40. The pharmaceutical composition of claim 21 , wherein the pharmaceutical composition is contained in sealed vial.

41. A pharmaceutical composition produced by the method of claim 1 .

42. The pharmaceutical composition of claim 21 , wherein the drug is paclitaxel.

43. The method of claim 1 , wherein the particles are liposomes.

44. The method of claim 1 , wherein the particles are micelles.

45. The pharmaceutical composition of claim 21 , wherein the particles are liposomes.

46. The pharmaceutical composition of claim 21 , wherein the particles are micelles.