US6015546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of further diagnostic agents
Assignee: Quadrant Drug Delivery Ltd
•
Filing: 1995-06-05
•
Granted: 2000-01-18
•
Expires: 2015-06-05
Abstract
Abstract Microcapsules are prepared by a process comprising the steps of (i) spray-drying a solution or dispersion of a wall-forming material in order to obtain intermediate microcapsules and (ii) reducing the water-solubility of at least the outside of the intermediate microcaspsules. Suitable wall-forming materials include proteins such as albumin and gelatin. The microcapsules have walls of 40-500 nm thick and are useful in ultrasonic imaging. The control of median size, size distribution and degree of insolubilization and cross-linking of the wall-forming material allows novel microsphere preparations to be produced.
Inventors
- 👤 Andrew Derek Sutton
- 👤 Richard Alan Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:24
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5005; A61K9/5021; A61K9/5052; A61K47/00; A61K47/30; A61K47/42; A61K49/00; A61K49/22; A61K49/222; A61K49/223; A61K9/14; A61K9/16; A61K9/1605; A61K9/1629; A61K9/1658; A61K9/5031
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
89 words
A process comprising the step of atomizing a solution or dispersion of a proteinaceous wall-forming material in a liquid carrier into a gas in order to obtain gas- or vapor-filled microcapsules by evaporation of the liquid carrier, wherein said microcapsules comprise a poloxamer which, following introduction into the human bloodstream, directs said microcapsules away from the reticulo-endothelial system and/or reduces opsonization of said microcapsules, such that said microcapsules have an in vivo t 1/2 of at least 5 minutes in the blood or in tissue perfused by the blood.
Claim 2
Dependent Claim
89 words
A process comprising the step of atomizing a solution or dispersion of a proteinaceous wall-forming material in a liquid carrier into a gas in order to obtain gas- or vapor-filled microcapsules by evaporation of the liquid carrier, wherein said microcapsules comprise a poloxamer which, following introduction into the human bloodstream, directs said microcapsules away from the reticulo-endothelial system and/or reduces opsonization of said microcapsules, such that said microcapsules have an in vivo t 1/2 of at least 5 minutes in the blood or in tissue perfused by the blood.
Claim 3
Dependent Claim
15 words
A process according to claim 1 wherein said protein is collagen, gelatin or serum albumin.
Claim 4
Dependent Claim
28 words
A process according to claim 2 wherein said protein is human serum albumin, or an analog or fragment thereof, derived from serum or prepared by recombinant DNA techniques.
Claim 5
Dependent Claim
15 words
A process according to claim 2 wherein said protein solution or dispersion comprises 10.0-30.0% protein.
Claim 6
Dependent Claim
13 words
A process according to claim 2 wherein said microcapsules comprise 96-98% monomeric protein.
Claim 7
Dependent Claim
27 words
A process according to claim 1 wherein said microcapsules are subjected to a further step of reducing the water-solubility of at least the outside of said microcapsules.
Claim 8
Dependent Claim
20 words
A process according to claim 6 wherein said steps of forming said microcapsules and reducing their water-solubility are substantially simultaneous.
Claim 9
Dependent Claim
17 words
A process according to claim 6 wherein said water-solubility-reduced microcapsules comprise no more than 5% monomeric protein.
Claim 10
Dependent Claim
15 words
A process according to claim 1 wherein said poloxamer is poloxamer 338, 407, or 908.
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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) | 2003-01-17 | 2003-07-19 | 2004-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-01-17 | 2007-07-19 | 2008-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-01-17 | 2011-07-19 | 2012-01-18 | $7700.00 | Window Closed / Lapsed |