US4351938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anticoagulant substance
Assignee: Riker Laboratories Inc
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Filing: 1980-05-19
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Granted: 1982-09-28
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Expires: 2000-05-19
Abstract
Abstract Partially depolymerized heparin products having particular analyzable reducing end groups, a process for their preparation and their use as anticoagulants and antithrombotics.
Inventors
- 👤 William E. Barnett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:48
CPC Classifications
A; A61; A61K; A61K31/00; A61K31/70; A61K31/715; C; C08; C08B; C08B37/00; C08B37/006; C08B37/0063; C08B37/0075
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
147 words
A process which comprises reacting a heparin salt with from about 5 to 100 milliliters of an aqueous nitrous acid solution per gram of the heparin salt, the aqueous solution containing from about 5 to 80 milligrams of nitrous acid per gram of the heparin salt under controlled conditions of temperature in the range of about 0° C. to 30° C. and pH in the range of from about 1.5 to 4 until the heparin has partially depolymerized to a product which has (1) a weight average molecular weight of from about 2,000 to 7,000 daltons, when determined by HPLC using 1.5 molar aqueous sodium chloride as the mobile phase and dextrans as the standard, (2) a polydispersity (D) of less than about 2.5, and (3) analyzable reducing end groups of which the majority are anhydromannose groups, terminating the depolymerization reaction and recovering the partially depolymerized product.
Claim 2
Dependent Claim
147 words
A process which comprises reacting a heparin salt with from about 5 to 100 milliliters of an aqueous nitrous acid solution per gram of the heparin salt, the aqueous solution containing from about 5 to 80 milligrams of nitrous acid per gram of the heparin salt under controlled conditions of temperature in the range of about 0° C. to 30° C. and pH in the range of from about 1.5 to 4 until the heparin has partially depolymerized to a product which has (1) a weight average molecular weight of from about 2,000 to 7,000 daltons, when determined by HPLC using 1.5 molar aqueous sodium chloride as the mobile phase and dextrans as the standard, (2) a polydispersity (D) of less than about 2.5, and (3) analyzable reducing end groups of which the majority are anhydromannose groups, terminating the depolymerization reaction and recovering the partially depolymerized product.
Claim 3
Dependent Claim
40 words
A process according to claim 1 wherein the proportion of nitrous acid charged is just sufficient to bring the depolymerization reaction to the desired point and the reaction is terminated upon disappearance of the nitrous acid from the reaction mixture.
Claim 4
Dependent Claim
43 words
A process according to claim 1 wherein the proportion of nitrous acid charged is in excess of the quantity required to bring the depolymerization reaction to the desired point and the reaction is terminated when the desired degree of depolymerization has been achieved.
Claim 5
Dependent Claim
20 words
A process according to claim 1 wherein the depolymerization is carried out in the presence of a lower alkanoic acid.
Claim 6
Dependent Claim
27 words
A process according to claim 2 wherein the depolymerization is carried out in the presence of from about 0.5 to 10 percent by volume of acetic acid.
Claim 7
Dependent Claim
28 words
A process according to claim 1 wherein the depolymerization is carried out in an aqueous system in which the pH is adjusted by means of a mineral acid.
Claim 8
Dependent Claim
54 words
A depolymerization process according to claim 3 wherein the depolymerization reaction is terminated when the peak retention time molecular weight of the heparin reaches a desired value in the range of 2,500 to 8,000 daltons, when determined by HPLC, using 1.5 molar aqueous sodium chloride as the mobile phase and dextrans as the standard.
References Cited (Backward Citations)
US3766167A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-09-27 | 1986-03-29 | 1986-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-27 | 1990-03-29 | 1990-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-27 | 1994-03-29 | 1994-09-28 | $7700.00 | Window Closed / Lapsed |