US3911137A
Expired / Lapsed
US
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Process for preparing highly concentrated aqueous solution of a dopa compound
Assignee: Sankyo Co Ltd
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Filing: 1973-11-27
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Granted: 1975-10-07
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Expires: 1993-11-27
Abstract
Abstract A highly concentrated aqueous solution of a dopa or tyrosine can be prepared by adding at least one water-soluble high molecular weight substance selected from the group consisting of methyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose or gelatine to a dopa or tyrosine.
Inventors
- 👤 Tomonori Miki
- 👤 Seiji Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:54
CPC Classifications
A; A61; A61K; A61K47/00; A61K47/30; A61K47/36; A61K47/38; A61K31/00; A61K31/185; A61K31/19; A61K31/195; A61K47/42; A61K9/00; A61K9/0012; A61K9/0019
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
43 words
A PROCESS FOR INCREASING THE SOLUBILITY OF DOPA METHYLDOPA OR TYROSINE IN WATER WHICH COMPRISES INCORPORATING IN AN AQUEOUS SOLUTION OF DOPA METHYDOPA OR TYROSINE A HIGH MOLECULAR WEIGHT SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF METHYLCELLULOSE HYDROXYPROPYL CELLULOSE HYDROXYPROPYLMETHYL CELLULOSE AND GELATINE.
Claim 2
Dependent Claim
43 words
A PROCESS FOR INCREASING THE SOLUBILITY OF DOPA METHYLDOPA OR TYROSINE IN WATER WHICH COMPRISES INCORPORATING IN AN AQUEOUS SOLUTION OF DOPA METHYDOPA OR TYROSINE A HIGH MOLECULAR WEIGHT SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF METHYLCELLULOSE HYDROXYPROPYL CELLULOSE HYDROXYPROPYLMETHYL CELLULOSE AND GELATINE.
Claim 3
Dependent Claim
35 words
The process of claim 1, wherein said high molecular weight substance is incorporated in said concentrated aqueous solution in an amount to provide from 0.05 to 1.0 percent of said substance in said stable solution.
Claim 4
Dependent Claim
21 words
The process of claim 1, wherein said dopa, methyldopa or tyrosine is dissolved in water by heating or pH adjustment thereof.
Claim 5
Dependent Claim
15 words
The process of claim 1, wherein dopa is present in said stable concentrated aqueous solution.
Claim 6
Dependent Claim
15 words
The process of claim 1, wherein tyrosine is present in said stable concentrated aqueous solution.
Claim 7
Dependent Claim
38 words
The process of claim 1, wherein the pH of the resulting solution containing said high molecular weight solution is adjusted to about 9 with an aqueous sodium hydroxide solution, and the resulting mixture is heAted at about 80*C.
Claim 8
Dependent Claim
55 words
A process for preparing a stable concentrated aqueous solution of dopa, methyldopa or tyrosine, which comprises dissolving dopa, methyldopa or tyrosine in water to form a concentrated aqueous solution thereof, and incorporating in said concentrated solution a high molecular weight substance selected from the group consisting of methyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose and gelatine.
Claim 9
Dependent Claim
55 words
A process for preparing a stable concentrated aqueous solution of dopa, methyldopa or tyrosine, which comprises dissolving dopa, methyldopa or tyrosine in water to form a concentrated aqueous solution thereof, and incorporating in said concentrated solution a high molecular weight substance selected from the group consisting of methyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose and gelatine.
Claim 10
Dependent Claim
48 words
A stable concentrated aqueous solution of dopa, methyldopa or tyrosine, and a high molecular weight substance selected from the group consisting of methyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose and gelatine, said solution having a concentration of said high molecular weight substance of from 0.05 to 1.0 w/v percent.
Claim 11
Dependent Claim
48 words
A stable concentrated aqueous solution of dopa, methyldopa or tyrosine, and a high molecular weight substance selected from the group consisting of methyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose and gelatine, said solution having a concentration of said high molecular weight substance of from 0.05 to 1.0 w/v percent.
Claim 12
Dependent Claim
22 words
A solution of claim 8, wherein a dopa or tyrosine is present in an amount of 10 mg. per ml. of solution.
Claim 13
Dependent Claim
10 words
A solution of claim 8, wherein dopa is present therein.
Claim 14
Dependent Claim
10 words
A solution of claim 8, wherein tyrosine is present therein.
Claim 15
Dependent Claim
19 words
A solution of claim 8, wherein the high molecular weight substance is gelatine having an isoelectric point of 9.
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) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |