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Patent US5160726A successfully refreshed from Google Patents.
US5160726A
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US
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Filter sterilization for production of colloidal, superparamagnetic MR contrast agents
Assignee: Amag Pharmaceuticals Inc
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Filing: 1991-02-05
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Granted: 1992-11-03
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Expires: 2011-02-05
Abstract
Abstract An improvement is provided to a method for obtaining an in vivo MR image of an organ or tissue of an animal or human subject, of the type including administering to the subject as a contrast agent to enhance such MR image an effective amount of a colloid including superparamagnetic metal oxide particles dispersed in a physiologically acceptable carrier. In accordance with the improvement, the method includes preparing the colloid in a manner that provides a reduction in toxicity in comparison with that associated with administration of the colloid after terminal sterilization. The improvement may include sterilizing the colloid by filtration. In an additional embodiment, the colloid may be sterilized by filtration and preserved by lyophilization. The colloid may be lyophilized in the presence of a compatible excipient. The excipient utilized may include a dextran or a citrate anion. Other embodiments include related compositions and methods.
Inventors
- 👤 Lee Josephson
- 👤 Ernest V. Groman
- 👤 Stephen Palmacci
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:24
CPC Classifications
A; A61; A61K; A61K49/00; A61K49/06; A61K49/18; A61K49/1818; A61K49/1821; A61K49/1824; A61K49/1827; A61K49/1851; A61K49/1863; A61K49/1806; A61K49/1809; A61L; A61L2/00; A61L2/02; A61L2/022; A61L2/025; A61L2103/00; A61L2103/05; Y; Y10; Y10S; Y10S436/00; Y10S436/806; Y10T; Y10T436/00; Y10T436/24
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
101 words
An improved method, for obtaining an in vivo MR image of an organ or tissue of an animal or human subject, of the type including administering to such subject as a contrast agent to enhance such MR image an effective amount of a colloid including superparamagnetic metal oxide particles dispersed in a physiologically acceptable carrier, in such a manner as to provide a reduction in toxicity in comparison with that associated with administration of the colloid after terminal sterilization, wherein the improvement comprises preparing and sterilizing the colloid in a manner that avoids subjecting the resulting active ingredient to heat stress.
Claim 2
Dependent Claim
101 words
An improved method, for obtaining an in vivo MR image of an organ or tissue of an animal or human subject, of the type including administering to such subject as a contrast agent to enhance such MR image an effective amount of a colloid including superparamagnetic metal oxide particles dispersed in a physiologically acceptable carrier, in such a manner as to provide a reduction in toxicity in comparison with that associated with administration of the colloid after terminal sterilization, wherein the improvement comprises preparing and sterilizing the colloid in a manner that avoids subjecting the resulting active ingredient to heat stress.
Claim 3
Dependent Claim
21 words
A method according to claim 1, wherein preparing and sterilizing the colloid includes the step of sterilizing the colloid by filtration.
Claim 4
Dependent Claim
34 words
A method according to claim 2, wherein the step of sterilizing the colloid by filtration includes the step of removing materials from the colloid that would otherwise clog the filter used to achieve sterilization.
Claim 5
Dependent Claim
37 words
A method according to claim 3, wherein the step of sterilizing the colloid by filtration includes passing the colloid through successively smaller pore size filters, the smallest pore size filter being not greater than approximately 220 nm.
Claim 6
Dependent Claim
25 words
A method according to claim 3, wherein the step of sterilizing the colloid by filtration includes using a magnetic filter to selectively remove larger particles.
Claim 7
Dependent Claim
27 words
A method according to claim 3, wherein the step of sterilizing the colloid by filtration includes using column chromatography to selectively remove larger particles from the colloid.
Claim 8
Dependent Claim
36 words
A method according to claim 3, wherein the step of sterilizing the colloid by filtration includes centrifuging the colloid and passing the supernatant through a filter having a pore size not greater than approximately 220 nm.
Claim 9
Dependent Claim
43 words
A method according to claim 1, wherein the metal oxide particles comprise crystals, each crystal about 10 to about 500 angstroms in diameter and having an overall diameter of about 10 to not more than about 4000 angstroms as measured to light scattering.
Claim 10
Dependent Claim
43 words
A method according to claim 2, wherein the metal oxide particles comprise crystals, each crystal about 10 to about 500 angstroms in diameter and having an overall diameter of about 10 to not more than about 4000 angstroms as measured to light scattering.
Claim 11
Dependent Claim
43 words
A method according to claim 3, wherein the metal oxide particles comprise crystals, each crystal about 10 to about 500 angstroms in diameter and having an overall diameter of about 10 to not more than about 4000 angstroms as measured to light scattering.
Claim 12
Dependent Claim
17 words
A method according to claim 1, wherein the metal oxide particles are associated with a macromolecular substance.
Claim 13
Dependent Claim
17 words
A method according to claim 2, wherein the metal oxide particles are associated with a macromolecular substance.
Claim 14
Dependent Claim
17 words
A method according to claim 3, wherein the metal oxide particles are associated with a macromolecular substance.
Claim 15
Dependent Claim
12 words
A method according to claim 1, wherein the colloid includes dextran magnetite.
Claim 16
Dependent Claim
12 words
A method according to claim 2, wherein the colloid includes dextran magnetite.
Claim 17
Dependent Claim
12 words
A method according to claim 3, wherein the colloid includes dextran magnetite.
Claim 18
Dependent Claim
12 words
A method according to claim 2, further comprising lyophilizing the filter-sterilized colloid.
Claim 19
Dependent Claim
19 words
A method according to claim 17, wherein the filter-sterilized colloid is lyophilized in the presence of a compatible excipient.
Claim 20
Dependent Claim
26 words
A method according to claim 18, wherein the excipient includes one or more compositions selected from the group consisting of a dextran and a citrate anion.
Claim 21
Dependent Claim
16 words
A method according to claim 19, further comprising reconstituting the lyophilized colloid with an aqueous composition.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-11-03 | 1996-05-04 | 1996-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-03 | 2000-05-04 | 2000-11-03 | $3760.00 | Window Closed / Lapsed |
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