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US4204992A
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Method for preparing pyrogen free collagen
Assignee: Alcon Puerto Rico Inc
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Filing: 1979-01-11
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Granted: 1980-05-27
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Expires: 1999-01-11
Abstract
Abstract Collagen, such as, corium, is freed of pyrogenetic substances by processing green corium with aqueous solutions of alkalie or alkaline earth metal hypochlorites, washing with aqueous ethanol and subsequently washing with pyrogen free water.
Inventors
- 👤 Mamerto M. Cruz, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:25
CPC Classifications
C; C07; C07K; C07K14/00; C07K14/435; C07K14/78; A; A61; A61K; A61K38/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
51 words
The method for producing pyrogen free collagen which comprises removing mechanically foreign substances from the surfaces of the collagen while in contact with an aqueous solution of an alkalie or alkaline earth metal hypochlorite, washing the collagen with an aqueous ethanol solution and thereafter washing the collagen with pyrogen free water.
Claim 2
Independent Claim
51 words
The method for producing pyrogen free collagen which comprises removing mechanically foreign substances from the surfaces of the collagen while in contact with an aqueous solution of an alkalie or alkaline earth metal hypochlorite, washing the collagen with an aqueous ethanol solution and thereafter washing the collagen with pyrogen free water.
Claim 3
Dependent Claim
19 words
The method as defined in claim 1 wherein the aqueous hypochlorite solution is an aqueous solution of sodium hypochlorite.
Claim 4
Dependent Claim
21 words
The method as defined in claim 2 wherein the aqueous solution contains from about 50 to 250 ppm of sodium hypochlorite.
Claim 5
Dependent Claim
25 words
The method as defined in claim 1 wherein the aqueous ethanol solution contains about 30 to 90% ethanol by volume and 70-10% water by volume.
Claim 6
Dependent Claim
48 words
The method as defined in claim 1 wherein the aqueous hypochlorite solution is an aqueous solution of sodium hypochlorite containing from about 50 to 250 ppm sodium hypochlorite and the aqueous ethanol solution contains about 30 to 90% ethanol by volume and 70 to 30% water by volume.
Claim 7
Dependent Claim
12 words
The method as defined in claim 1 wherein the collagen is corium.
Claim 8
Dependent Claim
33 words
The method as defined in claim 6 wherein the foreign substances are removed from the corium surfaces by brush washing the corium surfaces while in contact with an aqueous solution of sodium hypochlorite.
Claim 9
Dependent Claim
45 words
The method as defined in claim 6 wherein the corium is derived from hides washed with an aqueous solution of sodium hypochlorite containing from 50 to 250 ppm sodium hypochlorite and the flesh and graid sides of the hide are removed to recover the corium.
Claim 10
Dependent Claim
63 words
The method as defined in claim 8 wherein foreign substances are removed from the corium surfaces by brush washing the surfaces while in contact with an aqueous solution containing from about 50 to 100 ppm sodium hypochlorite and the aqueous ethanol solution contains about 70% ethanol by volume and 30% water by volume, the solutions having a temperature not exceeding about 40° C.
Claim 11
Dependent Claim
21 words
The method as defined in claim 9 wherein the temperature of the solutions is between the freezing point and 25° C.
Claim 12
Dependent Claim
17 words
As an article of manufacture, pyrogen free collagen prepared by the method as defined in claim 1.
Claim 13
Dependent Claim
14 words
An article of manufacture as defined in claim 11 wherein the collagen is corium.
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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) | 1983-05-27 | 1983-11-26 | 1984-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-05-27 | 1987-11-26 | 1988-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-05-27 | 1991-11-26 | 1992-05-27 | $7700.00 | Window Closed / Lapsed |