US5569449A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gaseous microparticles as ultrasound contrast agents
Assignee: GE Healthcare AS
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Filing: 1995-06-05
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Granted: 1996-10-29
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Expires: 2015-06-05
Abstract
Abstract This invention relates to ultrasound contrast agents in the form of microparticles comprising a biotolerable matrix (e.g. of a carbohydrate or an X-ray contrast agent) in association with a gas or a precursor therefor. The contrast agents are stabilized to enhance their in vivo stability and/or echogenicity by covalently modifying the structure of the matrix, e.g. to introduce crosslinking groups or to attach lipophilic groups and/or molecules. The covalent moieties may include biodegradable linkages to assist rapid subsequent elimination of the contrast agents from the system.
Inventors
- 👤 Jo Klaveness
- 👤 Pål Rongved
- 👤 Per Strande
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:30
CPC Classifications
A; A61; A61K; A61K49/00; A61K49/22; A61K49/222; A61K49/223
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
49 words
Ultrasound contrast agents in the form of microparticles comprising a biotolerable matrix in association with a gas or precursor therefore, the gas comprising SF 6 or a fluorinated low molecular weight hydrocarbon, in which the microparticles are stabilised by the presence of cross-linking groupings covalently attached to the matrix.
Claim 2
Dependent Claim
49 words
Ultrasound contrast agents in the form of microparticles comprising a biotolerable matrix in association with a gas or precursor therefore, the gas comprising SF 6 or a fluorinated low molecular weight hydrocarbon, in which the microparticles are stabilised by the presence of cross-linking groupings covalently attached to the matrix.
Claim 3
Dependent Claim
16 words
Ultrasound contrast agents as claimed in claim 1 in which the biotolerable matrix is a carbohydrate.
Claim 4
Dependent Claim
14 words
Ultrasound contrast agents as claimed in claim 2 in which the carbohydrate is galactose.
Claim 5
Dependent Claim
18 words
Ultrasound contrast agents as claimed in claim 1 in which the biotolerable matrix is an X-ray contrast agent.
Claim 6
Dependent Claim
35 words
Ultrasound contrast agents as claimed in claim 1 in which the microparticles are present in the form of aggregates having an aggregate size of 30-50 micrometres of microparticles having a particle size of 5-10 micrometres.
Claim 7
Dependent Claim
18 words
Ultrasound contrast agents as claimed in claim 5 in which the said aggregates have been prepared by ball-milling.
Claim 8
Dependent Claim
42 words
Ultrasound contrast agents as claimed in claim 1 in which the crosslinking groupings contain linkages which are biodegradable in vivo, and which are selected from the group consisting of amide, imide, imine, ester, anhydride, acetal, carbamate, carbonate, carbonate ester and disulphide groups.
Claim 9
Dependent Claim
166 words
Ultrasound contrast agents as claimed in claim 1 in which the crosslinking groups contain linkages which are biodegradable in vivo and are of the formula (I) ##STR12## wherein each X, which may be the same or different, is selected from the group consisting of --O--, --S-- and --NR--, where R represents a hydrogen atom or an organic group; each Y, which may be the same or different, represents carbonyl, thiocarbonyl, sulphonyl, phosphoryl or a similar acid-forming group; each Z, which may be the same or different, is selected from the group consisting of --O--, --S-- and --NR--, where R is as defined above; m and n, which may be the same or different are each zero or 1, and R 1 and R 2 , which may be the same or different, are each selected from the group consisting of hydrogen atoms, monovalent organic groups and groups of formula -X.Y.(Z) m as hereinbefore defined, or R 1 and R 2 together form a divalent organic group.
Claim 10
Dependent Claim
73 words
Ultrasound contrast agents as claimed in claim 7 in which the crosslinking groupings contain linkages which are biodegradable in vivo and which are of formula (Ia): ##STR13## where m and n are each 0 or 1; R 1 and R 2 are each selected from the group consisting of hydrogen atoms, monovalent organic groups and groups of formula --O.CO.(O) m ; or R 1 and R 2 together form a divalent organic group.
Claim 11
Dependent Claim
13 words
Ultrasound contrast agents as claimed in claim 1 wherein the hydrocarbon is perfluorinated.
Claim 12
Dependent Claim
13 words
Ultrasound contrast agents as claimed in claim 7 wherein the hydrocarbon is perfluorinated.
Claim 13
Dependent Claim
13 words
Ultrasound contrast agents as claimed in claim 8 wherein the hydrocarbon is perfluorinated.
Claim 14
Dependent Claim
13 words
Ultrasound contrast agents as claimed in claim 9 wherein the hydrocarbon is perfluorinated.
References Cited (Backward Citations)
EP0160266A2
Cited
US4985233A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-10-29 | 2000-04-29 | 2000-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-29 | 2004-04-29 | 2004-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-29 | 2008-04-29 | 2008-10-29 | $7700.00 | Window Closed / Lapsed |