US4615879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Particulate NMR contrast agents for gastrointestinal application
Assignee: Vanderbilt University
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Filing: 1983-11-14
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Granted: 1986-10-07
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Expires: 2003-11-14
Abstract
Abstract Contrast media compositions for nuclear magnetic resonance (NMR) imaging of the gastrointestinal system are provided for oral or rectal administration. The compositions comprise aqueous suspensions of particles of an NMR contrast agent, the particles being very finely-divided and providing in their outer surfaces a substantially water-insoluble paramagnetic compound. Suspending and/or wetting agents may be included to maintain the contrast agent particles in a dispersed, suspended condition for the oral or rectal administration. Buffering agents may also be included to maintain the pH of the suspension in a pH range protecting the insolubility of the paramagnetic compound.
Inventors
- 👤 Val M. Runge
- 👤 Jeffrey A. Clanton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:53
CPC Classifications
A; A61; A61K; A61K49/00; A61K49/06; A61K49/18; A61K49/1806; Y; Y10; Y10S; Y10S436/00; Y10S436/806; Y10T; Y10T436/00; Y10T436/24
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
79 words
A contrast medium composition for nuclear magnetic resonance (NMR) imaging of the gastrointestinal system, comprising an orally or rectally administrable aqueous suspension of particles of an NMR contrast agent said suspension containing wetting and/or suspending agents to maintain said contrast agent particles in a dispersed suspended condition, said particles comprising a substantially water-insoluble compound of a paramagnetic metal, said particles being sized below 10 microns diameter and being capable of passing through the stomach while remaining in particulate form.
Claim 2
Dependent Claim
79 words
A contrast medium composition for nuclear magnetic resonance (NMR) imaging of the gastrointestinal system, comprising an orally or rectally administrable aqueous suspension of particles of an NMR contrast agent said suspension containing wetting and/or suspending agents to maintain said contrast agent particles in a dispersed suspended condition, said particles comprising a substantially water-insoluble compound of a paramagnetic metal, said particles being sized below 10 microns diameter and being capable of passing through the stomach while remaining in particulate form.
Claim 3
Dependent Claim
64 words
The composition of claim 1 in which said particles are composed of a compound of a paramagnetic metal selected from the group consisting of gadolinium, chromium, copper, manganese, and iron, said particles being insoluble to the extent that less than 1% by weight dissolves in 30 minutes at a temperature of 37° C. in water adjusted to a pH of 1.2 with hydrochloric acid.
Claim 4
Dependent Claim
34 words
The composition of claim 1 in which the suspension contains a buffering agent to maintain the pH of the suspension at a pH of 6.0 to 8.5 for protecting the insolubility of said particles.
Claim 5
Dependent Claim
21 words
The composition of claim 1 in which said paramagnetic metal is selected from the group consisting of gadolinium, chromium, and iron.
Claim 6
Dependent Claim
120 words
A contrast medium composition for nuclear magnetic resonance (NMR) imaging of the gastrointestinal system, comprising an orally or rectally administrable aqueous suspension of particles of an NMR contrast agent, said suspension containing of wetting and/or suspending agents to maintain said contrast agent particles in a dispersed suspended condition for the administration, said particles being sized in the range below 3 microns diameter and being composed of a compound of a paramagnetic metal, said particles being insoluble to the extent that less than 1% by weight dissolves in 30 minutes at a temperature of 37° C. in water adjusted to a pH of 1.2 with hydrochloric acid so that said particles are capable of passing through the stomach in particulate form.
Claim 7
Dependent Claim
120 words
A contrast medium composition for nuclear magnetic resonance (NMR) imaging of the gastrointestinal system, comprising an orally or rectally administrable aqueous suspension of particles of an NMR contrast agent, said suspension containing of wetting and/or suspending agents to maintain said contrast agent particles in a dispersed suspended condition for the administration, said particles being sized in the range below 3 microns diameter and being composed of a compound of a paramagnetic metal, said particles being insoluble to the extent that less than 1% by weight dissolves in 30 minutes at a temperature of 37° C. in water adjusted to a pH of 1.2 with hydrochloric acid so that said particles are capable of passing through the stomach in particulate form.
Claim 8
Dependent Claim
139 words
A contrast medium composition for nuclear magnetic resonance (NMR) imaging of the gastrointestinal system, comprising an orally or rectally adminstrable aqueous suspension of finely-divided particles of an NRM contrast agent, said suspension containing wetting and/or suspending agents to maintain said contrast agent particles in a dispersed suspended condition for the administration, said suspension also containing a buffering agent for maintaining the pH of the suspension in a pH range of 6.0 to 8.5 for protecting the insolubility of the contrast agent, said particles being sized below 3 microns diameter and being composed of a compound of a paramagnetic metal, said particles being insoluble in the suspension to the extent that less than 1% by weight dissolves in 30 minutes at a temperature of 37° C. so that said particles are capable of passing through the stomach in particulate form.
Claim 9
Dependent Claim
139 words
A contrast medium composition for nuclear magnetic resonance (NMR) imaging of the gastrointestinal system, comprising an orally or rectally adminstrable aqueous suspension of finely-divided particles of an NRM contrast agent, said suspension containing wetting and/or suspending agents to maintain said contrast agent particles in a dispersed suspended condition for the administration, said suspension also containing a buffering agent for maintaining the pH of the suspension in a pH range of 6.0 to 8.5 for protecting the insolubility of the contrast agent, said particles being sized below 3 microns diameter and being composed of a compound of a paramagnetic metal, said particles being insoluble in the suspension to the extent that less than 1% by weight dissolves in 30 minutes at a temperature of 37° C. so that said particles are capable of passing through the stomach in particulate form.
Claim 10
Dependent Claim
12 words
The composition of claim 6 in which said paramagnetic metal is gadolinium.
Claim 11
Dependent Claim
12 words
The composition of claim 6 in which said paramagnetic metal is chromium.
Claim 12
Dependent Claim
12 words
The composition of claim 6 in which said paramagnetic metal is iron.
Claim 13
Dependent Claim
53 words
The method of nuclear magnetic resonance (NMR) imaging of the gastrointestinal which includes the step of orally or rectally administering to a human subject the contrast medium composition of claim 1 and obtaining an NMR image of a portion of the gastrointestinal tract in which said paramagnetic compound is present in particulate form.
Claim 14
Dependent Claim
54 words
The method of nuclear magnetic resonance (NMR) imaging of the gastrointestinal system which includes the step of orally or rectally administering to a human subject the contrast medium composition of claim 6, and obtaining an NMR image of a portion of the gastrointestinal tract in which said paramagnetic compound is present in particulate form.
Claim 15
Dependent Claim
12 words
The method of claim 11 in which said paramagnetic metal is iron.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-06 | 1990-04-07 | 1990-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-06 | 1994-04-07 | 1994-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-06 | 1998-04-07 | 1998-10-07 | $7700.00 | Window Closed / Lapsed |