US5228446A
Expired / Lapsed
US
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Gas filled liposomes and their use as ultrasonic contrast agents
Assignee: Bristol Myers Squibb Pharma Co
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Filing: 1991-06-18
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Granted: 1993-07-20
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Expires: 2011-06-18
Abstract
Abstract Contrast agents for ultrasonic imaging comprising gas filled liposomes prepared using vacuum drying gas instillation methods, and gas filled liposomes substantially devoid of liquid in the interior thereof, are described. Methods of and apparatus for preparing such liposomes and methods for employing such liposomes in ultrasonic imaging applications are also disclosed. Also described are diagnostic kits for ultrasonic imaging which include the subject contrast agents.
Inventors
- 👤 Evan C. Unger
- 👤 Guanli Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:37
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/10; A61K9/127; A61K41/00; A61K41/0028; A61K41/0052; A61K47/00; A61K47/50; A61K47/69; A61K47/6905; A61K47/6911; A61K47/6921; A61K47/6925; A61K49/00; A61K49/06; A61K49/18; A61K49/1806; A61K49/1815; A61K49/22; A61K49/222; A61K49/223; A61K49/227; A61K9/1277; A61K9/1278
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
19 words
A contrast agent for ultrasonic imaging comprising a gas filled liposome prepared by a vacuum drying gas instillation method.
Claim 2
Dependent Claim
19 words
A contrast agent for ultrasonic imaging comprising a gas filled liposome prepared by a vacuum drying gas instillation method.
Claim 3
Dependent Claim
51 words
A contrast agent of claim 1 wherein said liposomes are comprised of lipid materials selected from the group consisting of fatty acids, lysolipids, dipalmitoylphosphatidylcholine, phosphatidylcholine, phosphatidic acid, sphingomyelin, cholesterol, cholesterol hemisuccinate, tocopherol hemisuccinate, phosphatidylethanolamine, phosphatidylinositol, lysolipids, sphingomyelin, glycosphingolipids, glucolipids, glycolipids, sulphatides, lipids with ether and ester-linked fatty acids, and polymerized lipids.
Claim 4
Dependent Claim
13 words
A contrast agent of claim 2 wherein said liposomes are comprised of dipalmitoylphosphatidylcholine.
Claim 5
Dependent Claim
30 words
A contrast agent of claim 1 wherein said liposomes are filled with a gas selected from the group consisting of air, nitrogen, carbon dioxide, oxygen, argon, xenon, helium, and neon.
Claim 6
Dependent Claim
14 words
A contrast agent of claim 4 wherein said liposomes are filled with nitrogen gas.
Claim 7
Dependent Claim
16 words
A contrast agent of claim 1 wherein said liposomes are stored suspended in an aqueous medium.
Claim 8
Dependent Claim
12 words
A contrast agent of claim 1 wherein said liposomes are stored dry.
Claim 9
Dependent Claim
18 words
A contrast agent of claim 1 wherein said liposomes have a stability of greater than about three weeks.
Claim 10
Dependent Claim
18 words
A contrast agent of claim 1 wherein said liposomes have a reflectivity of greater than about 2 dB.
Claim 11
Dependent Claim
21 words
A contrast agent of claim 9 wherein said liposomes have a reflectivity of between about 2 dB and about 20 dB.
Claim 12
Dependent Claim
19 words
A contrast agent for ultrasonic imaging comprising a gas filled liposome substantially devoid of liquid in the interior thereof.
Claim 13
Dependent Claim
19 words
A contrast agent for ultrasonic imaging comprising a gas filled liposome substantially devoid of liquid in the interior thereof.
Claim 14
Dependent Claim
51 words
A contrast agent of claim 11 wherein said liposomes are comprised of lipid materials selected from the group consisting of fatty acids, lysolipids, dipalmitoylphosphatidylcholine, phosphatidylcholine, phosphatidic acid, sphingomyelin, cholesterol, cholesterol hemisuccinate, tocopherol hemisuccinate, phosphatidylethanolamine, phosphatidylinositol, lysolipids, sphingomyelin, glycosphingolipids, glucolipids, glycolipids, sulphatides, lipids with ether and ester-linked fatty acids, and polymerized lipids.
Claim 15
Dependent Claim
13 words
A contrast agent of claim 12 wherein said liposomes are comprised of dipalmitoylphosphatidylcholine.
Claim 16
Dependent Claim
30 words
A contrast agent of claim 11 wherein said liposomes are filled with a gas selected from the group consisting of air, nitrogen, carbon dioxide, oxygen, argon, xenon, helium, and neon.
Claim 17
Dependent Claim
14 words
A contrast agent of claim 14 wherein said liposomes are filled with nitrogen gas.
Claim 18
Dependent Claim
16 words
A contrast agent of claim 11 wherein said liposomes are stored suspended in an aqueous medium.
Claim 19
Dependent Claim
12 words
A contrast agent of claim 11 wherein said liposomes are stored dry.
Claim 20
Dependent Claim
20 words
A contrast agent of claim 11 wherein said liposomes have a shelf life stability of greater than about three weeks.
Claim 21
Dependent Claim
18 words
A contrast agent of claim 11 wherein said liposomes have a reflectivity of greater than about 2 dB.
Claim 22
Dependent Claim
21 words
A contrast agent of claim 19 wherein said liposomes have a reflectivity of between about 2 dB and about 20 dB.
Claim 23
Dependent Claim
17 words
A kit for ultrasonic imaging comprising gas filled liposomes prepared by a vacuum drying gas instillation method.
Claim 24
Dependent Claim
17 words
A kit for ultrasonic imaging comprising gas filled liposomes prepared by a vacuum drying gas instillation method.
Claim 25
Dependent Claim
13 words
A kit in accordance with claim 21 further comprising conventional ultrasonic imaging components.
Claim 26
Dependent Claim
17 words
A kit for ultrasonic imaging comprising gas filled liposomes, substantially devoid of liquid in the interior thereof.
Claim 27
Dependent Claim
17 words
A kit for ultrasonic imaging comprising gas filled liposomes, substantially devoid of liquid in the interior thereof.
Claim 28
Dependent Claim
13 words
A kit in accordance with claim 23 further comprising conventional ultrasonic imaging components.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-07-19 | 1997-01-18 | 1997-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-19 | 2001-01-18 | 2001-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-19 | 2005-01-18 | 2005-07-20 | $7700.00 | Window Closed / Lapsed |