US4427647A
Expired / Lapsed
US
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Method and reagent for making a radiopharmaceutical composition based on pertechnetate
Assignee: GE Healthcare Ltd
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Filing: 1981-07-27
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Granted: 1984-01-24
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Expires: 2001-07-27
Abstract
Abstract A method of making a radiopharmaceutical composition by mixing an aqueous solution of pertechnetate with a reducing agent comprising tin metal or stannous ion to reduce the pertechnetate and a complexing agent to form a complex with the reduced technetium, is characterized by incorporating nitrate and/or nitrite in an amount to diminish oxidation of Sn2+to Sn4+, and hence to prevent re-oxidation of technetium to pertechnetate, during preparation and storage of the complex. Nitrate and nitrite are superior to organic antioxidants previously proposed. A reagent for the purpose comprises the reducing agent, the complexing agent and the nitrate and/or nitrite usually in a sterile freeze-dried state.
Inventors
- 👤 Anthony Brockas
- 👤 Roy Abrahams
- 👤 James D. Kelly
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; A61K51/0474; A61K51/0478; A61K2123/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
81 words
In a method of making a radiopharmaceutical composition by mixing an aqueous solution of pertechnetate with a reducing agent comprising tin as metal or Sn ++ to reduce the pertechnetate and a complexing agent to form a complex with the reduced technetium, the improvement which comprises incorporating in the composition a nitrate or nitrite or a mixture of said nitrate and nitrite in an amount to diminish oxidation of Sn 2+ to Sn 4+ during preparation and storage of the complex.
Claim 2
Dependent Claim
81 words
In a method of making a radiopharmaceutical composition by mixing an aqueous solution of pertechnetate with a reducing agent comprising tin as metal or Sn ++ to reduce the pertechnetate and a complexing agent to form a complex with the reduced technetium, the improvement which comprises incorporating in the composition a nitrate or nitrite or a mixture of said nitrate and nitrite in an amount to diminish oxidation of Sn 2+ to Sn 4+ during preparation and storage of the complex.
Claim 3
Dependent Claim
47 words
The method as claimed in claim 1, wherein there is provided a first-formed mixture of the reducing agent comprising tin, the complexing agent and the nitrate, nitrite or mixture of said nitrate and nitrite, and the aqueous solution of pertechnetate is subsequently added to this first-formed mixture.
Claim 4
Dependent Claim
35 words
The method as claimed in claim 2, wherein the first-formed mixture is formed by dispensing and freeze-drying solutions of stannous ion, the complexing agent and the nitrate, nitrite or mixture of said nitrate and nitrite.
Claim 5
Dependent Claim
40 words
The method as claimed in claim 2, wherein the first-formed mixture is formed by providing a piece of metallic tin and dispensing and freeze-drying solutions of the complexing agent and the nitrate, nitrite or mixture of said nitrate and nitrite.
Claim 6
Dependent Claim
14 words
The method as claimed in claim 2, wherein the first-formed mixture is made sterile.
Claim 7
Dependent Claim
57 words
The method as claimed in claim 1, wherein, the solution of pertechnetate has an activity of up to about 500 mCi, there is used from 0.01 mg to 5.0 mg of nitrite, expressed as sodium nitrate, or from 0.1 mg to 50 mg of nitrate, expressed as sodium nitrate, or a mixture of said nitrite and nitrate.
Claim 8
Dependent Claim
77 words
A reagent which forms, on addition of an aqueous solution of pertechnetate, a radiopharmaceutical composition, which reagent comprises in a sterile state a stannous tin reducing agent for the pertechnetate, a complexing agent to form a complex with the reduced technetium, and nitrate or nitrite ion or a mixture of nitrate and nitrite ions in an amount to diminish oxidation of Sn 2+ to Sn 4+ during preparation and storage of the reagent and of the complex.
Claim 9
Dependent Claim
77 words
A reagent which forms, on addition of an aqueous solution of pertechnetate, a radiopharmaceutical composition, which reagent comprises in a sterile state a stannous tin reducing agent for the pertechnetate, a complexing agent to form a complex with the reduced technetium, and nitrate or nitrite ion or a mixture of nitrate and nitrite ions in an amount to diminish oxidation of Sn 2+ to Sn 4+ during preparation and storage of the reagent and of the complex.
Claim 10
Dependent Claim
73 words
A reagent which forms, on addition of an aqueous solution of pertechnetate, a radiopharmaceutical composition, which reagent comprises in a sterile state a tin metal reducing agent for the pertechnetate, a complexing agent to form a complex with the reduced technetium, and nitrate or nitrite ion or a mixture of nitrate and nitrite ions in an amount to diminish oxidation of Sn 2+ to Sn 4+ during preparation and storage of the complex.
Claim 11
Dependent Claim
73 words
A reagent which forms, on addition of an aqueous solution of pertechnetate, a radiopharmaceutical composition, which reagent comprises in a sterile state a tin metal reducing agent for the pertechnetate, a complexing agent to form a complex with the reduced technetium, and nitrate or nitrite ion or a mixture of nitrate and nitrite ions in an amount to diminish oxidation of Sn 2+ to Sn 4+ during preparation and storage of the complex.
Claim 12
Dependent Claim
47 words
The reagent as claimed in claim 7 or claim 8, wherein there is present from 0.01 mg to 5.0 mg of nitrite, expressed as sodium nitrite, or from 0.1 mg to 50 mg of nitrate, expressed as sodium nitrate or a mixture of said nitrate and nitrite.
References Cited (Backward Citations)
US3962412A
Cited
US4075314A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-23 | 1987-07-25 | 1988-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-23 | 1991-07-25 | 1992-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-23 | 1995-07-25 | 1996-01-24 | $7700.00 | Window Closed / Lapsed |