Patent US4244931A successfully refreshed from Google Patents.
US4244931A
Expired / Lapsed
US
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Dicalcium phosphate dihydrate with improved stability
Assignee: Solutia Inc
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Filing: 1979-05-29
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Granted: 1981-01-13
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Expires: 1999-05-29
Abstract
Abstract Dicalcium phosphate dihydrate containing a sufficient amount of trimagnesium phosphate and/or tetrasodium pyrophosphate to inhibit spontaneous hydrolysis and/or decomposition of the dicalcium phosphate dihydrate is widely used as a dental polishing agent with and without added fluoride. Now it has been found that dicalcium phosphate dihydrate containing a sufficient amount of pyrophosphate to provide hydrolytic stability to the dicalcium phosphate can have improved soluble fluoride stability when at least 0.1 weight percent of trimagnesium phosphate and a pharmaceutically acceptable polyphosphate salt are each added to the formulation. In the preferred embodiment, less than 2 percent pentasodium tripolyphosphate provides satisfactory results.
Inventors
- 👤 William M. Jarvis
- 👤 Keun Y. Kim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:58
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/32; C01B25/327; A; A61; A61K; A61K8/00; A61K8/18; A61K8/19; A61K8/24; A61Q; A61Q11/00; A61K2800/00; A61K2800/40; A61K2800/59
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
67 words
A composition which comprises dicalcium phosphate dihydrate and (a) from about 0.1 weight percent to about 5 weight percent P 2 O 5 equivalent of pyrophosphate complex; (b) from about 0.1 weight percent to about 5 weight percent trimagnesium phosphate; and (c) from about 0.1 weight percent to about 3 weight percent of a pharmaceutically acceptable polyphosphate salt; based on the weight of the dicalcium phosphate dihydrate.
Claim 2
Dependent Claim
67 words
A composition which comprises dicalcium phosphate dihydrate and (a) from about 0.1 weight percent to about 5 weight percent P 2 O 5 equivalent of pyrophosphate complex; (b) from about 0.1 weight percent to about 5 weight percent trimagnesium phosphate; and (c) from about 0.1 weight percent to about 3 weight percent of a pharmaceutically acceptable polyphosphate salt; based on the weight of the dicalcium phosphate dihydrate.
Claim 3
Dependent Claim
27 words
A composition of claim 1 wherein the amount of pyrophosphate complex is from about 0.5 weight percent to about 2.5 weight percent P 2 O 5 equivalent.
Claim 4
Dependent Claim
22 words
A composition of claim 1 wherein the amount of trimagnesium phosphate is from about 0.5 weight percent to about 2.5 weight percent.
Claim 5
Dependent Claim
25 words
A composition of claim 1 wherein the amount of the pharmaceutically acceptable polyphosphate salt is from about 0.3 weight percent to about 2 weight percent.
Claim 6
Dependent Claim
44 words
A composition of claim 4 wherein the amount of pyrophosphate complex is from about 0.5 weight percent to about 2.5 weight percent P 2 O 5 equivalent, and the amount of trimagnesium phosphate is from about 0.5 weight percent to about 2.5 weight percent.
Claim 7
Dependent Claim
13 words
A composition of claim 5 wherein the pharmaceutically acceptable polyphosphate is pentasodium tripolyphosphate.
Claim 8
Dependent Claim
38 words
A composition of claim 5 or 6 wherein there is added to the composition from about 0.1 weight percent to about 3 weight percent, based on the weight of the dicalcium phosphate dihydrate, of an alkali metal orthophosphate.
Claim 9
Dependent Claim
38 words
A composition of claim 5 or 6 wherein there is added to the composition from about 0.3 weight percent to about 1 weight percent, based on the weight of the dicalcium phosphate dihydrate, of an alkali metal orthophosphate.
Claim 10
Dependent Claim
35 words
A composition of claim 6 wherein there is added to the composition from about 0.3 weight percent to about 1 weight percent, based on the weight of the dicalcium phosphate dihydrate, of monosodium dihydrogen phosphate.
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) | 1984-01-13 | 1984-07-14 | 1985-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-13 | 1988-07-14 | 1989-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-13 | 1992-07-14 | 1993-01-13 | $7700.00 | Window Closed / Lapsed |