US4046858A
Expired / Lapsed
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Synthesis for crystalline hydroxyapatite
Assignee: Individual
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Filing: 1974-07-24
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Granted: 1977-09-06
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Expires: 1994-07-24
Abstract
Abstract A new synthesis is disclosed which produces synthetic crystalline hydroxyapatite. The process comprises reacting anhydrous trisodium phosphate wih calcium chloride in a formamide/water solution. Good yields of hydroxyapatite are obtained quickly, simply, and at low temperatures.
Inventors
- 👤 John J. Barsa
- 👤 Edward T. Farris
- 👤 Richard J. Lagow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:19
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/32; C01B25/325; A; A61; A61K; A61K6/00; A61K6/80; A61K6/831; A61K6/838
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
58 words
A process for preparing crystalline hydroxyapatite comprising contacting a source of calcium ions with about a stoichiometric amount of anhydrous trisodium phosphate in a combination solvent comprising from about 10 to about 75 weight percent of a polar, aprotic organic solvent and from about 25 to about 90 weight percent of water and thereafter recovering said crystalline hydroxyapatite.
Claim 2
Dependent Claim
58 words
A process for preparing crystalline hydroxyapatite comprising contacting a source of calcium ions with about a stoichiometric amount of anhydrous trisodium phosphate in a combination solvent comprising from about 10 to about 75 weight percent of a polar, aprotic organic solvent and from about 25 to about 90 weight percent of water and thereafter recovering said crystalline hydroxyapatite.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein said polar, aprotic, organic solvent consists essentially of formamide.
Claim 4
Dependent Claim
16 words
The process of claim 2 wherein said source of calcium ions consists essentially of calcium chloride.
Claim 5
Dependent Claim
23 words
The process of claim 3 wherein said combination solvent consists essentially of about 50 weight percent formamide and about 50 weight percent water.
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) | 1980-09-05 | 1981-03-07 | 1981-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-05 | 1985-03-07 | 1985-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-05 | 1989-03-07 | 1989-09-06 | $7700.00 | Window Closed / Lapsed |