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US4101435A Expired / Lapsed US ⏱️ 0.0 years remaining

Magnetic iron oxide-dextran complex and process for its production

Assignee: Meito Sangyo KK
•
Filing: 1976-06-14
•
Granted: 1978-07-18
•
Expires: 1996-06-14
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Abstract

Abstract A magnetic iron oxide-dextran complex. This novel compound can be produced by reacting an aqueous sol of magnetic iron oxide with dextran having an intrinsic viscosity of about 0.02 to about 0.5 at an elevated temperature in an aqueous medium, and is useful not only in pharmaceutical and medical fields as a hematinic medium, a radiopaque medium, a blood measuring agent, or a carrier for a medicinal substance, but also in wide range of other technological fields where its magnetic property can be utilized.

Inventors

  • 👤 Masakatsu Hasegawa
  • 👤 Syusaburo Hokkoku

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 03:47
CPC Classifications
C; C08; C08B; C08B37/00; C08B37/0006; C08B37/0009; C08B37/0021; A; A61; A61K; A61K31/00; A61K31/70; A61K31/715; A61K33/00; A61K33/24; A61K33/26; A61K49/00; A61K49/04; A61K49/0409; A61K9/00; A61K9/48; A61K9/50; A61K9/5094; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54313; G01N33/54326; G01N33/5434; H; H01; H01F; H01F1/00; H01F1/44; H01F1/445; G01N2400/00; G01N2400/10; G01N2400/12; G01N2400/14; G01N2400/22; G01N2446/00; G01N2446/20; G01N2446/30; Y; Y10; Y10S; Y10S428/00; Y10S428/90

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 36 words
A water dispersable magnetic iron oxide-dextran complex wherein the proportion of the dextran, calculated as its anhydrous glucose unit, is about 0.1 to about 1 mole per mole of iron oxide, calculated as an iron atom.
Claim 2
Dependent Claim 36 words
A water dispersable magnetic iron oxide-dextran complex wherein the proportion of the dextran, calculated as its anhydrous glucose unit, is about 0.1 to about 1 mole per mole of iron oxide, calculated as an iron atom.
Claim 3
Dependent Claim 27 words
An aqueous sol of the complex of claim 1 which is stable to the addition of an equal amount of a 20% aqueous solution of sodium chloride.
Claim 4
Dependent Claim 23 words
The complex of claim 1 which has a saturation magnetic flux density of more than 0 but not more than amount 90 emu/g.
Claim 5
Dependent Claim 19 words
The complex of claim 3 having a saturation magnetic flux density of from about 5 to about 80 emu/g.
Claim 6
Dependent Claim 22 words
The complex of claim 1 which shows in its X-ray diffraction a pattern having a diffraction intensity corresponding to a spinel structure.
Claim 7
Dependent Claim 34 words
The complex of claim 1 in the form of a solid powder having a saturation magnetic flux density of from 15 emu to 50 emu/g and an iron content of 30 to 45.5 w/w%.
Claim 8
Dependent Claim 45 words
A process for producing a magnetic iron oxide-dextran complex, which comprises reacting an aqueous sol of magnetic iron oxide with dextran having an intrinsic viscosity of about 0.02 to about 0.5 at a temperature of from about 50° to 120° C in an aqueous medium.
Claim 9
Dependent Claim 45 words
A process for producing a magnetic iron oxide-dextran complex, which comprises reacting an aqueous sol of magnetic iron oxide with dextran having an intrinsic viscosity of about 0.02 to about 0.5 at a temperature of from about 50° to 120° C in an aqueous medium.
Claim 10
Dependent Claim 44 words
The process of claim 7 wherein the molar ratio of the aqueous sol of magnetic iron oxide to the dextran is 1 : about 1-5 calculated as the ratio of the iron atom of the oxide to the anhydrous glucose unit of the dextran.
Claim 11
Dependent Claim 26 words
The process of claim 8 wherein the molar ratio of the aqueous sol of magnetic iron oxide to the dextran is 1: about 1.5 to 3.
Claim 12
Dependent Claim 19 words
The process of claim 7 wherein the dextran has an intrinsic viscosity of from about 0.04 to about 0.1.
Claim 13
Dependent Claim 25 words
The process of claim 7 wherein the reaction is carried out at a temperature of from about 70° to about 110° C and under reflux.
Claim 14
Dependent Claim 18 words
The process of claim 7 wherein the magnetic iron oxide sol has a pH of 2.5 to 4.5.
Claim 15
Dependent Claim 39 words
The process of claim 7 wherein prior to the reaction, the dextran is modified by heating in an aqueous medium in the presence of a base selected from the group consisting of sodium hydroxide, potassium hydroxide and calcium hydroxide.
Claim 16
Dependent Claim 22 words
The process of claim 7 wherein the dextran is glucan having mainly an α-1,6-linkage formed by reacting a leuconostoc mesenteroide with sucrose.

References Cited (Backward Citations)

US2360327A Cited
US2978414A Cited
US2856366A Cited
US2971916A Cited
US3041289A Cited
US3100202A Cited
US3776987A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-07-17 1982-01-16 1982-07-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-07-17 1986-01-16 1986-07-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-07-17 1990-01-16 1990-07-18 $7700.00 Window Closed / Lapsed

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