METHODS FOR MAKING ULTRASOUND CONTRAST AGENTS
Provided herein are improved methods for preparing phospholipid formulations including phospholipid UCA formulations.
1 - 27 . (canceled)
28 . A method of ultrasound contrast imaging a subject comprising
(a) selecting an MPEG5000-DPPE having calcium and/or magnesium divalent metal cation present at a total divalent metal cation concentration of less than 115 parts per million (ppm),
(b) combining the MPEG-5000-DPPE with one or more phospholipids and a non-aqueous solvent, to form a phospholipid solution having calcium and/or magnesium divalent metal cation present at a total divalent metal cation concentration of less than 0.7 ppm,
(c) combining the phospholipid solution with an aqueous solution to form a phospholipid suspension,
(d) activating the phospholipid suspension with a perfluorocarbon gas to form lipid-encapsulated gas microspheres,
(e) administering the lipid-encapsulated gas microspheres to a subject, and
(f) obtaining an ultrasound image of the subject.
29 . The method of claim 28 , wherein the one or more phospholipids comprise DPPC and/or DPPE.
30 . The method of claim 28 , wherein the one or more phospholipids exclude DPPA.
31 . The method of claim 29 , wherein the one or more phospholipids comprise DPPC, and the DPPC has a combined calcium and magnesium concentration of less than 90 ppm.
32 . The method of claim 28 , wherein the non-aqueous solvent comprises propylene glycol.
33 . The method of claim 28 , wherein the non-aqueous solvent has a combined calcium and magnesium concentration of less than 0.7 ppm.
34 . The method of claim 28 , wherein the non-aqueous solvent comprises propylene glycol and glycerol.
35 . The method of claim 29 , wherein the MPEG-5000-DPPE is present in the phospholipid solution in a molar percentage of 5-15%.
36 . The method of claim 29 , wherein the one or more phospholipids comprise DPPC, and the DPPC is present in the phospholipid solution in a molar percentage of 77-90%.
37 . The method of claim 36 , wherein DPPC and MPEG-5000-DPPE are present in the phospholipid solution in a mole % ratio of 82 to 8 (82:8).
38 . The method of claim 28 , wherein the perfluorocarbon gas is perfluoropropane gas.
39 . The method of claim 28 , wherein the one or more phospholipids comprise DPPC, the phospholipid solution comprises DPPC, MPEG5000-DPPE and propylene glycol, the aqueous solution comprises water, propylene glycol and glycerol, and the phospholipid suspension comprises DPPC, MPEG5000-DPPE, propylene glycol, water and glycerol.
40 . The method of claim 28 , wherein the aqueous solution further comprises one or more salts.
41 . The method of claim 28 , wherein the aqueous solution further comprises one or more buffers.
42 . A method of ultrasound contrast imaging a subject comprising
(a) combining one or more solid form phospholipids and a non-aqueous solvent, to form a phospholipid solution having calcium and/or magnesium divalent metal cation present at a total divalent metal cation concentration of less than 0.7 parts per million (ppm), and
(b) combining the phospholipid solution with an aqueous solution to form a phospholipid suspension, and
(c) activating the phospholipid suspension with a perfluorocarbon gas to form lipid-encapsulated gas microspheres,
(d) administering the lipid-encapsulated gas microspheres to a subject, and
(e) obtaining an ultrasound image of the subject.
43 . A composition comprising a phospholipid suspension in contact with a perfluoropropane gas, wherein the phospholipid suspension comprises
(a) a saline solution, and
(b) a phospholipid solution
(i) comprising one or more phospholipids comprising MPEG5000-DPPE,
(ii) having a divalent metal ion concentration of less than 0.7 parts per million (ppm), and
(iii) comprising none, one or two but not all three of methanol, toluene and methyl t-butyl ether (MTBE).
44 . The composition of claim 43 , wherein the one or more phospholipids further comprise DPPA and DPPC.