Granted Patent B2

US 8,685,441 · App. 13/949,105 · Granted Apr 1, 2014

Abstract

Claims (53)

1. A method comprising

(a) formulating a lipid suspension with a perfluorocarbon gas to form an ultrasound contrast agent, and

(b) using the ultrasound contrast agent in an imaging application in a subject, wherein the lipid suspension is made by

(i) contacting phospholipids 1,2-dipalmitoyl-sn-glycero-3-phosphatidic acid, mono sodium salt (DPPA), 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), and N-(methoxypolyethylene glycol 5000 carbamoyl)-1,2-dipalmitoyl-sn-glycero-3-phosphatidylethanolamine, mono sodium salt (MPEG5000-DPPE) with a first non-aqueous solvent to form a lipid solution, wherein contacting comprises

(1) sequential addition of the individual phospholipids to the first non-aqueous solvent or

(2) combining the individual phospholipids with each other prior to their addition to the first non-aqueous solvent;

(ii) contacting the lipid solution of (i) with a second non-aqueous solvent which causes the phospholipids to precipitate out as a solid lipid blend;

(iii) collecting the solid lipid blend;

(iv) contacting the solid lipid blend with a third non-aqueous solvent which causes the lipid blend to dissolve to form a lipid blend solution; and

(v) contacting the lipid blend solution with an aqueous solution to yield the lipid suspension.

2. The method of claim 1 , wherein the first non-aqueous solvent is a mixture of methanol and toluene.

3. The method of claim 1 , wherein the second non-aqueous solvent is methyl t-butyl ether.

4. The method of claim 1 , wherein the third non-aqueous solvent is propylene glycol.

5. The method of claim 1 , wherein the aqueous solution comprises sodium chloride, glycerin, and propylene glycol.

6. The method of claim 1 , wherein

(i) the first non-aqueous solvent is a mixture of methanol and toluene;

(ii) the second non-aqueous solvent is methyl t-butyl ether;

(iii) the third non-aqueous solvent is propylene glycol; and

(iv) the aqueous solution comprises sodium chloride, glycerin and propylene glycol.

7. The method of claim 1 , wherein about 0.75 to 1.0 mg of the lipid blend is present per mL of the lipid suspension.

8. The method of claim 1 , wherein about 0.75 mg of the lipid blend is present per mL of the lipid suspension.

9. The method of claim 1 , wherein the third non-aqueous solvent is heated to a temperature of about 30 to 70° C. prior to contacting with the solid lipid blend.

10. The method of claim 1 , wherein the third non-aqueous solvent is heated to a temperature of about 50 to 55° C. prior to contacting with the solid lipid blend.

11. The method of claim 1 , wherein the ratio of solid lipid blend to third non-aqueous solvent is from about 5-15 mg of solid lipid blend per mL of third non-aqueous solvent.

12. The method of claim 1 , wherein the ratio of solid lipid blend to third non-aqueous solvent is about 15 mg of solid lipid blend per mL of third non-aqueous solvent.

13. The method of claim 1 , wherein the aqueous solution is heated to a temperature of about 45 to 60° C. prior to contacting with the lipid blend solution.

14. The method of claim 1 , wherein the aqueous solution is heated to a temperature of about 50 to 55° C. prior to contacting with the lipid blend solution.

15. The method of claim 1 , further comprising filtering the lipid suspension through one or two sterilizing filters to form a filtered lipid suspension, prior to formulating with the perfluorocarbon gas.

16. The method of claim 15 , wherein the one or two sterilizing filters are 0.2 μm filters.

17. The method of claim 15 , further comprising dispensing the filtered lipid suspension into a vial, prior to formulating with the perfluorocarbon gas.

18. The method of claim 1 , wherein formulating the lipid suspension with the perfluorocarbon gas comprises dispensing the lipid suspension into a vial and exchanging headspace gas of the vial with the perfluorocarbon gas, wherein the lipid suspension is a filtered lipid suspension.

19. The method of claim 1 , wherein the perfluorocarbon gas is perfluoropropane.

20. The method of claim 18 , wherein the perfluorocarbon gas is perfluoropropane.

21. The method of claim 18 , further comprising sterilizing the vial.

22. The method of claim 21 , wherein the vial is sterilized at about 126-130° C. for 1 to 10 minutes.

23. The method of claim 1 , wherein

(i) the third non-aqueous solvent is heated to a temperature of about 50-55° C. prior to contacting with the solid lipid blend; and

(ii) the aqueous solution is heated to a temperature of about 50-55° C. prior to contacting with the lipid blend solution.

24. The method of claim 6 , wherein the lipid suspension comprises about 0.75-1.0 mg of the lipid blend per mL of the lipid suspension.

25. The method of claim 1 , wherein the lipid suspension comprises MPEG5000-DPPE, DPPA and DPPC in a mole % ratio of 8 to 10 to 82.

26. The method of claim 7 , wherein the lipid suspension comprises MPEG5000-DPPE, DPPA and DPPC in a mole % ratio of 8 to 10 to 82.

27. The method of claim 24 , wherein the lipid suspension comprises MPEG5000-DPPE, DPPA and DPPC in a mole % ratio of 8 to 10 to 82.

28. A method comprising:

(a) contacting phospholipids with a first non-aqueous solvent which causes the phospholipids to dissolve and form a lipid solution, wherein the contacting comprises

(i) sequential addition of the individual phospholipids to the first non-aqueous solvent, or

(ii) combining the individual phospholipids with each other prior to their addition to the first non-aqueous solvent, and

wherein the phospholipids are 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), 1, 2-dipalmitoyl-sn-glycero-3-phosphatidic acid, mono sodium salt (DPPA) and N-(methoxypolyethylene glycol 5000 carbamoyl)-1,2-dipalmitoyl-sn-glycero-3-phosphatidylethanolamine, mono sodium salt (MPEG5000-DPPE);

(b) contacting the non-aqueous lipid solution of (a) with a second non-aqueous solvent which causes the phospholipids to precipitate out as a solid lipid blend;

(c) collecting the solid lipid blend;

(d) contacting the solid lipid blend with a third non-aqueous solvent which causes the lipid blend to dissolve to form a lipid blend solution;

(e) contacting the lipid blend solution with an aqueous solution to yield a lipid suspension;

(f) formulating the lipid suspension with a perfluorocarbon gas to form an ultrasound contrast agent; and

(g) using the ultrasound contrast agent in an imaging application in a subject.

Assignments (10)