US4451451A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiopharmaceutical composition based on technetium-99m and reagent for making it
Assignee: GE Healthcare Ltd
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Filing: 1982-10-26
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Granted: 1984-05-29
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Expires: 2002-10-26
Abstract
Abstract Radiopharmaceutical compositions containing complexes of technetium-99m with a complexing agent are prone to time and activity-related decomposition and formation of pertechnetate. Stabilizing agents for such complexes are organic compounds having an amine group and a carboxylic acid group attached to an aromatic ring. A preferred stabilizing agent is the sodium salt of 4-aminobenzoic acid. There are claims to a composition comprising a technetium 99-m complex stabilized by means of the said stabilizing agent; and to a reagent which forms, on addition of an aqueous solution of pertechnetate, a radiopharmaceutical composition, which reagent comprises a tin metal or stannous reducing agent for the pertechnetate, a complexing agent for the reduced technetium, for example a phosphorus-containing bone scanning agent, and a stabilizing agent as defined.
Inventors
- 👤 John Rimmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:39
CPC Classifications
A; A61; A61K; A61K51/00; A61K51/02; A61K51/04; A61K51/0489; A61K51/0474; A61K51/0478; A61K2123/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
65 words
A composition comprising technetium-99m present in a valency state greater than 0 and less than 7, stabilized by means of a stabilizing agent having the general formula: ##STR2## where is C1-C6 alkyl or hydrogen, X is C1-C6 alkyl or OH, m is 0, 1 or 2, Y is OH or --NH.CH 2 .COOH, n is 1 or 2 or a salt, ester or amide thereof.
Claim 2
Dependent Claim
65 words
A composition comprising technetium-99m present in a valency state greater than 0 and less than 7, stabilized by means of a stabilizing agent having the general formula: ##STR2## where is C1-C6 alkyl or hydrogen, X is C1-C6 alkyl or OH, m is 0, 1 or 2, Y is OH or --NH.CH 2 .COOH, n is 1 or 2 or a salt, ester or amide thereof.
Claim 3
Dependent Claim
20 words
A composition as claimed in claim 1, in the form of a radiopharmaceutical composition suitable for administration to a mammal.
Claim 4
Dependent Claim
32 words
A composition as claimed in claim 1, wherein the stabilizing agent is selected from 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, 4-methylaminobenzoic acid, 3,5-diaminobenzoic acid, 4-aminosalicylic acid, and 4-aminohippuric acid and salts thereof.
Claim 5
Dependent Claim
19 words
A composition as claimed in claim 3, where in the stabilizing agent is the sodium salt of 4-aminobenzoic acid.
Claim 6
Dependent Claim
36 words
A composition as claimed in claim 1, wherein the technetium is present as a complex in a scanning agent selected from phosphorus-containing bone scanning agents, kidney visualisation agents, brain and kidney function agents, and hepatobiliary agents.
Claim 7
Dependent Claim
33 words
A composition as claimed in claim 5, wherein the technetium is present as a complex with a complexing agent selected from methylene diphosphonate, pyrophosphate, hydroxymethane diphosphonate, hydroxyethane diphosphonate, aminoethane diphosphonates, and 2,3-dicarboxypropane-1,1diphosphonic acid.
Claim 8
Dependent Claim
23 words
A composition as claimed in claim 5, wherein the technetium is present as a complex with diethylenetriamine pentaacetic acid or a salt thereof.
Claim 9
Dependent Claim
84 words
A reagent which forms, on addition of an aqueous solution of pertechnetate, a radiopharmaceutical composition according to claim 2, which reagent comprises a tin metal or stannous reducing agent for the pertechnetate, a complexing agent for the reduced technetium, and a stabilizing agent having the general formula: ##STR3## where R is C1-C6 alkyl or hydrogen, X is C1-C6 alkyl or OH, m is 0, 1 or 2, Y is OH or --NH.CH.COOH, n is 1 or 2 or a salt, ester or amide thereof.
Claim 10
Dependent Claim
16 words
A reagent as claimed in claim 8, containing from 0.1 to 10 mg of stabilizing agent.
Claim 11
Dependent Claim
48 words
A reagent as claimed in claim 8, intended for reaction with an aqueous solution of pertechnetate having an activity of up to 500 mCi, including from 0.1 to 1.0 mg of a stannous reducing agent for the pertechnetate and from 0.5 to 6 mg of the stabilizing agent.
Claim 12
Dependent Claim
23 words
A reagent as claimed in claim 8, wherein the complexing agent is selected from methylene diphosphonate and diethylenetriamine pentaacetic acid and salts thereof.
Claim 13
Dependent Claim
18 words
A reagent as claimed in claim 8, wherein the stabilizing agent is the sodium salt of 4-aminobenzoic acid.
References Cited (Backward Citations)
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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) | 1987-05-29 | 1987-11-28 | 1988-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-29 | 1991-11-28 | 1992-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-29 | 1995-11-28 | 1996-05-29 | $7700.00 | Window Closed / Lapsed |