US4059681A
Expired / Lapsed
US
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Stable dried aluminum hydroxide gel
Assignee: Purdue Research Foundation
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Filing: 1975-04-09
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Granted: 1977-11-22
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Expires: 1995-04-09
Abstract
Abstract Stable dried aluminum hydroxide gels possessing the high acid reactivity of liquid aluminum hydroxide gel are prepared by drying the gel from non-aqueous solvents.
Inventors
- 👤 Stanley L. Hem
- 👤 Joe L. White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:07
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; A; A61; A61K; A61K33/00; A61K33/06; A61K33/08; B; B01; B01J; B01J13/00; B01J13/0052; B01J13/0069; C01P; C01P2002/00; C01P2002/80; C01P2002/88
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
123 words
A process for drying an aqueous aluminum hydroxide gel to form a stable dried aluminum hydroxide gel meeting the United States Pharmacopeia, Eighteenth Revision specification, said process comprising: replacing the aqueous liquid in the aluminum hydroxide gel with a water miscible, non-aqueous solvent, said non-aqueous solvent being selected from a group consisting of lower alkanols having 1 to 5 carbon atoms, mixtures of lower alkanols having 1 to 5 carbon atoms and no more than 50% of benzene and toluene mixed therewith, and ketones having 2 to 4 carbon atoms; and drying the gel of aluminum hydroxide removing the non-aqueous solvent and producing a stable, acid-reactant dried amorphous powder comprising not less than 50% and not more than about 56.8% of aluminum oxide.
Claim 2
Dependent Claim
123 words
A process for drying an aqueous aluminum hydroxide gel to form a stable dried aluminum hydroxide gel meeting the United States Pharmacopeia, Eighteenth Revision specification, said process comprising: replacing the aqueous liquid in the aluminum hydroxide gel with a water miscible, non-aqueous solvent, said non-aqueous solvent being selected from a group consisting of lower alkanols having 1 to 5 carbon atoms, mixtures of lower alkanols having 1 to 5 carbon atoms and no more than 50% of benzene and toluene mixed therewith, and ketones having 2 to 4 carbon atoms; and drying the gel of aluminum hydroxide removing the non-aqueous solvent and producing a stable, acid-reactant dried amorphous powder comprising not less than 50% and not more than about 56.8% of aluminum oxide.
Claim 3
Dependent Claim
22 words
A process as set forth in claim 1 in which the non-aqueous solvent is ethanol admixed with between 0% and 50% benzene.
Claim 4
Dependent Claim
63 words
A process as set forth in claim 1 in which the aqueous aluminum hydroxide gel is prepared by adding an aqueous solution of 0.5 to 1.0 moles of aluminum chloride to a solution containing 0.4 to 1.0 moles of sodium carbonate and 1.0 to 2.5 moles of sodium bicarbonate to precipitate the aluminum hydroxide gel within a pH range of 6.0 to 8.0.
Claim 5
Dependent Claim
63 words
A process as set forth in claim 3 in which the aqueous aluminum hydroxide gel is precipitated at a pH of 6.5 by adding 11.4% aqueous solution containing 0.755 moles of aluminum chloride hexahydrate to a solution containing 0.56 moles of sodium carbonate at a concentration of 2.8% by weight and 1.336 moles of sodium bicarbonate at a concentration of 4.5% by weight.
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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) | 1980-11-21 | 1981-05-23 | 1981-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-21 | 1985-05-23 | 1985-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-21 | 1989-05-23 | 1989-11-22 | $7700.00 | Window Closed / Lapsed |