US3824997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of alginic material
Assignee: Medical Alginates Ltd
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Filing: 1971-11-29
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Granted: 1974-07-23
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Expires: 1991-11-29
Abstract
Abstract Partially soluble alginic material in the form of gauze or wool, suitable for the preparation of surgical dressings, based on alginic acid and containing calcium, sodium and acid forms e.g. in the ratio 4 : 5 : 1 and characterised by a calcium content of 2 to 6 percent and a reaction pH of 4 to 7 and a method of manufacture by treatment of the insoluble calcium form of the material with a predetermined quantity of acid and, thereafter, alcoholic alkali.
Inventors
- 👤 K Franklin
- 👤 K Bates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:21
CPC Classifications
C; C08; C08B; C08B37/00; C08B37/006; C08B37/0084; A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
24 words
The product of claim 1 having a reaction pH of 5 to 6 and a calcium content of 3 to 5 percent by weight.
Claim 2
Dependent Claim
12 words
A surgical dressing including the product of claim 1 in sterile form.
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) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |