Details for Patent: 5,874,062

Title:	Methods of computed tomography using perfluorocarbon gaseous filled microspheres as contrast agents
Abstract:	Novel gas filled microspheres useful as computed tomography (CT) contrast agents. The microspheres are prepared from a gas and/or a gaseous precursor, and one or more stabilizing compounds.
Inventor(s):	Unger; Evan C. (Tucson, AZ)
Assignee:	ImaRx Pharmaceutical Corp. (Tucson, AZ)
Filing Date:	May 19, 1995
Application Number:	08/445,299
Claims:	1. A method of providing an image of an internal region of a patient comprising (i) administering to the patient an aqueous composition which comprises gaseous precursor-filled lipid microspheres, (ii) allowing said gaseous precursor to undergo a phase transition from a liquid to a gas, and (iii) scanning the patient using computed tomography to obtain visible images of said region, wherein said gaseous precursor comprises a perfluorocarbon and said microspheres are formulated from one or more phospholipids which contain substantially no disulfide linkages. 2. A method for diagnosing the presence of diseased tissue in a patient comprising (i) administering to the patient an aqueous composition which comprises gaseous precursor-filled lipid microspheres, (ii) allowing said gaseous precursor to undergo a phase transition from a liquid to a gas, and (iii) scanning the patient using computed tomography to obtain visible images of any diseased tissue in the patient, wherein said gaseous precursor comprises a perfluorocarbon and said microspheres are formulated from one or more phospholipids which contain substantially no disulfide linkages. 3. A method according to claim 1 wherein said gaseous precursor undergoes a phase transition from liquid to gaseous states at near the normal body temperature of the patient. 4. A method according to claim 1 wherein said phospholipids are selected from the group consisting of phosphatidylcholine, phosphatidylethanolamine and phosphatidic acid. 5. A method according to claim 4 wherein said phosphatidylcholine is selected from the group consisting of dioleoylphosphatidylcholine, dimyristoylphosphatidylcholine, dipentadecanoylphosphatidylcholine, dilauroylphosphatidylcholine, dipalmitoylphosphatidylcholine and distearoylphosphatidylcholine. 6. A method according to claim 5 wherein said phosphatidylcholine comprises dipalmitoylphosphatidylcholine. 7. A method according to claim 4 wherein said phosphatidylethanolamine is selected from the group consisting of dipalmitoylphosphatidylethanolamine, distearoylphosphatidylethanolamine, dioleoylphosphatidylethanolamine, N-succinyldioleoylphosphatidylethanolamine and 1-hexadecyl-2-palmitoylglycerophosphoethanolamine. 8. A method according to claim 7 wherein said phoshpatidylethanolamine comprises dipalmitoylphosphatidylethanolamine. 9. A method according to claim 4 wherein said phosphatidic acid comprises dipalmitolylphosphatidic acid. 10. A method according to claim 1 wherein said phospholipid further comprises a polymer. 11. A method agent according to claim 10 wherein said polymer comprises a hydrophilic polymer. 12. A method according to claim 11 wherein said hydrophilic polymer comprises polyethylene glycol. 13. A method according to claim 1 wherein said lipid comprises dipalmitoylphosphatidylethanolamine and phosphatidic acid in a combined amount of from about 0.5 to about 30 mole percent. 14. A method according to claim 1 wherein said phospholipid is selected from the group consisting of dipalmitoylphosphatidylcholine and distearoylphosphatidylcholine, in an amount of from about 70 to about 100 mole percent. 15. A method according to claim 1 wherein said phospholipid comprises: (i) a neutral phospholipid, (ii) a negatively charged phospholipid, and (iii) a phospholipid bearing a hydrophilic polymer; wherein the amount of said negatively charged phospholipid is greater than 1 mole percent of the total phospholipid present and the amount of phospholipid bearing a hydrophilic polymer is greater than 1 mole percent of the total phospholipid present. 16. A method according to claim 15 wherein said negatively charged phospholipid is phosphatidic acid and wherein the polymer in said phospholipid bearing a hydrophilic polymer has a weight average molecular weight of from about 400 to about 100,000 and is covalently bound to said phospholipid. 17. A method according to claim 16 wherein said hydrophilic polymer is selected from the group consisting of polyethyleneglycol, polypropyleneglycol, polyvinylalcohol and polyvinylpyrrolidone and copolymers thereof, and wherein said phospholipid of said phospholipid bearing a hydrophilic polymer is selected from the group consisting of dipalmitoylphosphatidylethanolamine and distearoylphosphatidylethanolamine. 18. A method according to claim 1 wherein said phospholipid comprises about 77.5 mole percent of dipalmitoylphosphatidylcholine, about 12.5 mole percent of dipalmitoylphosphatidic acid, and about 10 mole percent of dipalmitoylphosphatidylethanolamine-polyethyleneglycol 5000. 19. A method according to claim 1 wherein said phospholipid comprises about 82 mole percent of dipalmitoylphosphatidylcholine, about 10 mole percent of dipalmitoylphosphatidic acid, and about 8 mole percent of dipalmitoylphosphatidylethanolamine-polyethyleneglycol 5000. 20. A method according to claim 1 wherein said composition further comprises compounds selected from the group consisting of ingestible oils; mixed micelle systems compounds; viscosity modifiers; emulsifying and/or solubilizing agents; suspending or viscosity-increasing agents; synthetic suspending agents; and tonicity-raising agents. 21. A method according to claim 1 wherein said microspheres are prepared from a composition comprising dipalmitoylphosphatidylcholine, glycerol and propylene glycol. 22. A method according to claim 1 wherein said perfluorocarbon is selected from the group consisting of perfluoropropane, perfluorobutane, perfluorocyclobutane, perfluoropentane, perfluorohexane and perfluoroheptane. 23. A method according to claim 1 wherein said microspheres are selected from the group consisting of unilamellar microspheres, oligolamellar microspheres and multilamellar microspheres. 24. A method according to claim 23 wherein said microspheres comprise unilamellar microspheres. 25. A method according to claim 23 wherein said microspheres comprise a monolayer. 26. A method according to claim 25 wherein said gaseous precursor comprises a perfluorocarbon. 27. A method according to claim 26 wherein said perfluorocarbon is perfluoropropane. 28. A method according to claim 27 wherein said perfluorocarbon is perfluoropentane. 29. A method according to claim 23 wherein said microspheres comprise a bilayer. 30. A method according to claim 29 wherein said gaseous precursor comprises a perfluorocarbon. 31. A method according to claim 30 wherein said perfluorocarbon is perfluoropropane. 32. A method according to claim 30 wherein said perfluorocarbon is perfluoropentane. 33. A method according to claim 23 wherein said microspheres are selected from the group consisting of oligolamellar microspheres and multilamellar microspheres. 34. A method according to claim 33 wherein said microspheres comprise a monolayer. 35. A method according to claim 34 wherein said gaseous precursor comprises a perfluorocarbon. 36. A method according to claim 35 wherein said perfluorocarbon is perfluoropropane. 37. A method according to claim 35 wherein said perfluorocarbon is perfluoropentane. 38. A method according to claim 33 wherein said microspheres comprise a bilayer. 39. A method according to claim 38 wherein said gaseous precursor comprises a perfluorocarbon. 40. A method according to claim 39 wherein said perfluorocarbon is perfluoropropane. 41. A method according to claim 39 wherein said perfluorocarbon is perfluoropentane. 42. A method according to claim 1 wherein the region comprises the vasculature. 43. A method according to claim 1 wherein the region comprises the cardiovascular region. 44. A method according to claim 1 wherein the region comprises the gastrointestinal region. 45. A method according to claim 1 wherein said scanning is of a region of a patient selected from the group consisting of the intranasal tract, the auditory canal, the intraocular region, the intraperitoneal region, the kidneys, the urethra and the genitourinary tract. 46. A method according to claim 1 wherein said microspheres are rehydrated from lyophilized microspheres. 47. A method according to claim 22 wherein said gaseous precursor filled microspheres further comprise nitrogen. 48. A method according to claim 2 wherein said microspheres are rehydrated from lyophilized microspheres. 49. A method according to claim 2 wherein said gaseous precursor filled microspheres further comprise nitrogen in combination with said perfluorocarbon, wherein said perfluorocarbon is selected from the group consisting of perfluoromethane, perfluoroethane, perfluoropropane, perfluorobutane, perfluorocyclobutane, perfluoropentane, perfluorohexane, and perfluoroheptane. 50. A method according to claim 49 wherein said perfluorocarbon is perfluoropropane. 51. A method according to claim 49 wherein said perfluorocarbon is perfluorohexane.