US4526715A
Expired / Lapsed
US
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Method of preparing highly purified, stroma-free, non-hepatitic human and animal hemoglobin solutions
Assignee: Biotest Pharma GmbH
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Filing: 1984-05-29
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Granted: 1985-07-02
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Expires: 2004-05-29
Abstract
Abstract To provide a method that allows the preparation, not only from human blood but also from animal blood and in quantities large enough for clinical applications, of highly purified hemoglobin solutions that can be employed for the treatment of humans and that are free of plasma proteins and residual stroma lipids (a) a starting material that contains erythrocytes is pumped over a filter unit that has a pore size between 0.1 and 1.2 μm in circulation against an isotonic washing solution, (b) the product of (a) is hemolyzed and pumped over an ultrafiltration unit that has a permeability of 80,000 to 100,000 D in circulation against water, and (c) the ultrafiltrate obtained in stage (b) is pumped and diafiltered over an ultrafiltration unit that has a permeability of 10,000 to 50,000 D in circulation against water, whereby concentration is conducted before and/or after diafiltration.
Inventors
- 👤 Norbert Kothe
- 👤 Bertram Eichentopf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:42
CPC Classifications
C; C07; C07K; C07K14/00; C07K14/795; C07K14/805; A; A61; A61K; A61K38/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
165 words
A method of preparing a highly purified, stroma-free, non-hepatitic human or animal hemoglobin solution, comprising (a) pumping a starting material that contains erythrocytes to overflow a filter unit that has a pore size between 0.1 and 1.2 μm in circulation against an isotonic washing solution, continuously drawing off used washing solution and replenishing it with fresh washing solution, (b) harvesting the washed and concentrated erythrocytes from the filter, hemolyzing the erythrocytes, pumping the hemolysate at almost constant volume to overflow an ultrafiltration unit that has a permeability of 80,000 to 100,000 D in circulation against water, and (c) pumping the dilute hemoglobin solution obtained in step (b) as an ultrafiltrate at almost constant volume to overflow an ultrafiltration unit that has a permeability of 10,000 to 50,000 D in circulation against water thereby to effect diafiltration, and continuing pumping in circulation before and/or after diafiltration through the same ultrafiltration unit but without a countercurrent of water until the hemoglobin is concentrated to a predetermined level.
Claim 2
Independent Claim
165 words
A method of preparing a highly purified, stroma-free, non-hepatitic human or animal hemoglobin solution, comprising (a) pumping a starting material that contains erythrocytes to overflow a filter unit that has a pore size between 0.1 and 1.2 μm in circulation against an isotonic washing solution, continuously drawing off used washing solution and replenishing it with fresh washing solution, (b) harvesting the washed and concentrated erythrocytes from the filter, hemolyzing the erythrocytes, pumping the hemolysate at almost constant volume to overflow an ultrafiltration unit that has a permeability of 80,000 to 100,000 D in circulation against water, and (c) pumping the dilute hemoglobin solution obtained in step (b) as an ultrafiltrate at almost constant volume to overflow an ultrafiltration unit that has a permeability of 10,000 to 50,000 D in circulation against water thereby to effect diafiltration, and continuing pumping in circulation before and/or after diafiltration through the same ultrafiltration unit but without a countercurrent of water until the hemoglobin is concentrated to a predetermined level.
Claim 3
Dependent Claim
49 words
A method according to claim 1 wherein in step (c) pumping in circulation until the hemoglobin is concentrated to the desired level is effected prior to diafiltering in circulation through the same ultrafiltration unit against water, and adjustment of the hemoglobin to the desired final concentration is thereafter effected.
Claim 4
Dependent Claim
21 words
A method according to claim 1, wherein step (a) is carried out at a filtration pressure of 50 to 700 mbar.
Claim 5
Dependent Claim
20 words
A method according to claim 1, wherein an isotonic NaCl solution is employed as the washing solution in step (a).
Claim 6
Dependent Claim
24 words
A method according to claim 1, wherein a filtration unit with a pore size of 0.4 to 0.6 μm is employed in step (a).
Claim 7
Dependent Claim
22 words
A method according to claim 1, wherein a hollow-fiber membrane is employed in all three steps as a filtration or ultrafiltration unit.
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Cited
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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) | 1988-07-01 | 1988-12-31 | 1989-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-01 | 1992-12-31 | 1993-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-01 | 1996-12-31 | 1997-07-02 | $7700.00 | Window Closed / Lapsed |