US4486410A
Expired / Lapsed
US
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Heat defibrinogenation of AHF preparation
Assignee: Armour Pharmaceutical Co
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Filing: 1984-02-09
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Granted: 1984-12-04
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Expires: 2004-02-09
Abstract
Abstract Antihemophilic factor (AHF), a blood component necessary for clotting of normal whole blood, is extracted from cryoprecipitate containing AHF and fibrinogen as its principal components by: rapidly raising and thereafter lowering the temperature of the cryoprecipitate suspension to selectively denature the fibrinogen in the suspension; and separating the AHF-rich supernatant from the denatured fibrinogen.
Inventors
- 👤 Joseph D. Fisher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:18
CPC Classifications
C; C07; C07K; C07K14/00; C07K14/435; C07K14/745; C07K14/755; A; A61; A61K; A61K38/00; Y; Y10; Y10S; Y10S530/00; Y10S530/827; Y10S530/829; Y10S530/83
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
88 words
A method for producing a substantially fibrinogen-free AHF product from a cryoprecipitate containing as its primary components AHF and fibrinogen comprising: a., suspending thawed cryoprecipitate in a low molar buffer solution; b., rapidly raising the temperature of the suspension to 50° to 55° C.; c., maintaining the temperature of the suspension for 1.5±0.5 minutes to obtain a two-phase suspension; d., rapidly cooling the two-phase suspension to a temperature of about 10°-15° C.; e., centrifuging the two-phase suspension at about 10°-15° C.; and f., decanting the supernatant containing AHF.
Claim 2
Independent Claim
88 words
A method for producing a substantially fibrinogen-free AHF product from a cryoprecipitate containing as its primary components AHF and fibrinogen comprising: a., suspending thawed cryoprecipitate in a low molar buffer solution; b., rapidly raising the temperature of the suspension to 50° to 55° C.; c., maintaining the temperature of the suspension for 1.5±0.5 minutes to obtain a two-phase suspension; d., rapidly cooling the two-phase suspension to a temperature of about 10°-15° C.; e., centrifuging the two-phase suspension at about 10°-15° C.; and f., decanting the supernatant containing AHF.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the pH of the thawed cryoprecipitate in the low molar buffer is adjusted to 6.4-7.5.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein said low molar buffer is a glycine solution.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein said low molar buffer is a tris solution.
Claim 6
Dependent Claim
14 words
The method of claim 1 wherein said low molar buffer further comprises sodium chloride.
Claim 7
Dependent Claim
14 words
The method of claim 1 wherein said low molar buffer further comprises sodium citrate.
Claim 8
Dependent Claim
25 words
The method of claim 1 wherein said suspension of cryoprecipitate in the low molar buffer is agitated during the heating steps of b and c.
Claim 9
Dependent Claim
20 words
The method of claim 1 wherein said two-phase suspension of step c is cooled to 40° C. within one minute.
Claim 10
Dependent Claim
23 words
The method of claim 1 wherein said cooling of the two-phase suspension to about 10°-15° C. is accomplished in less than 10 minutes.
Claim 11
Dependent Claim
21 words
The method of claim 1 wherein said centrifuging of the two-phase suspension is at about 12,000 gravities for about 20 minutes.
Claim 12
Dependent Claim
15 words
The method of claim 1 further comprising the step of lyophilizing said supernatant containing AHF.
Claim 13
Dependent Claim
13 words
The method of claim 1 further comprising the step of ultrafiltering the supernatant.
Claim 14
Dependent Claim
14 words
The method of claim 12 further comprising the step of lyophilizing the ultrafiltered supernatant.
Claim 15
Independent Claim
144 words
A method for producing a substantially fibrinogen-free AHF product for a cryoprecipitate containing as its primary components AHF and fibrinogen comprising: a., thawing a frozen cryoprecipitate and suspending it in a low molar buffer solution selected from the group consisting of imidazole, sodium phosphate, hepes, ammonium bicarbonate, glycine, and tris; b., adjusting the pH of said cryoprecipitate-containing buffer solution to 6.4-7.5; c., rapidly raising the temperature of said suspension to 50° to 55° C.; d., maintaining the temperature of the suspension for 1.5±0.5 minutes to obtain a two-phase suspension; e., rapidly cooling the two-phase suspension to a temperature of 10°-15° C.; f., centrifuging the two-phase suspension at 10°-15° C. at 10,000 rpm to separate a precipitate containing fibrinogen; g., decanting the supernatant containing AHF; h., ultrafiltering said supernatant through an XM300 membrane; i. and lyophilizing the ultrafiltered supernatant at -70° C. for 15 hours.
Claim 16
Independent Claim
144 words
A method for producing a substantially fibrinogen-free AHF product for a cryoprecipitate containing as its primary components AHF and fibrinogen comprising: a., thawing a frozen cryoprecipitate and suspending it in a low molar buffer solution selected from the group consisting of imidazole, sodium phosphate, hepes, ammonium bicarbonate, glycine, and tris; b., adjusting the pH of said cryoprecipitate-containing buffer solution to 6.4-7.5; c., rapidly raising the temperature of said suspension to 50° to 55° C.; d., maintaining the temperature of the suspension for 1.5±0.5 minutes to obtain a two-phase suspension; e., rapidly cooling the two-phase suspension to a temperature of 10°-15° C.; f., centrifuging the two-phase suspension at 10°-15° C. at 10,000 rpm to separate a precipitate containing fibrinogen; g., decanting the supernatant containing AHF; h., ultrafiltering said supernatant through an XM300 membrane; i. and lyophilizing the ultrafiltered supernatant at -70° C. for 15 hours.
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) | 1987-12-04 | 1988-06-04 | 1988-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-04 | 1992-06-04 | 1992-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-04 | 1996-06-04 | 1996-12-04 | $7700.00 | Window Closed / Lapsed |