US4772419A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shaped article and processes for its preparation
Assignee: Pharmacia Biosystems AB
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Filing: 1986-02-21
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Granted: 1988-09-20
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Expires: 2006-02-21
Abstract
Abstract A shaped article based upon cross-linked, possibly derivatized hyaluronic acid or a salt thereof is characterized in that it has a dry matter content of at least 65 percent by weight and a tensile strength of at least 2 N/cm2. The shaped article may be prepared by pressure-drying or freeze-drying a corresponding hyaluronic acid gel.
Inventors
- 👤 Tomas Malson
- 👤 Leif G. Ahrgren
- 👤 Anthony N. de Belder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:52
CPC Classifications
C; C08; C08L; C08L5/00; C08L5/08; A; A61; A61L; A61L27/00; A61L27/14; A61L27/20; A61L27/50; A61L27/58; C08B; C08B37/00; C08B37/006; C08B37/0063; C08B37/0072
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
43 words
A shaped article based upon cross-linked, possibly derivatized hyaluronic acid or a salt thereof, which in a substantially unswollen water-swellable state has a dry matter content of at least 65 percent by weight and a tensile strength greater than 100 N/cm 2 .
Claim 2
Dependent Claim
43 words
A shaped article based upon cross-linked, possibly derivatized hyaluronic acid or a salt thereof, which in a substantially unswollen water-swellable state has a dry matter content of at least 65 percent by weight and a tensile strength greater than 100 N/cm 2 .
Claim 3
Dependent Claim
16 words
An article according to claim 1, wherein the dry matter content is 85-98 percent by weight.
Claim 4
Dependent Claim
16 words
An article according to claim 1, having a tensile strength greater than 1000 N/cm 2 .
Claim 5
Dependent Claim
11 words
An article according to claim 1, which is plate- or sheet-shaped.
Claim 6
Dependent Claim
27 words
An article according to claim 1 which is produced by compressing a gel of cross-linked, possibly derivatized hyaluronic acid or a salt thereof between two pressure surfaces.
Claim 7
Dependent Claim
31 words
An article according to claim 5 wherein at least one pressure surface has a sufficient porosity to permit passage of the fluid squeezed out from the gel through the pressure surface.
Claim 8
Dependent Claim
18 words
An article according to claim 5 wherein said compression is effected with a pressure of 10-10 5 kPa.
Claim 9
Dependent Claim
17 words
An article according to claim 7 wherein said compression is effected with a pressure of 200-1000 kPa.
Claim 10
Dependent Claim
27 words
An article according to claim 5 comprising the additional step of heat treating the dried product obtained at a temperature of about 50° to about 150° C.
Claim 11
Dependent Claim
29 words
An article according to claim 1 which is produced by subjecting a gel of cross-linked, possibly derivatized hyaluronic acid or a salt thereof to a vacuum permitting freeze drying.
Claim 12
Dependent Claim
28 words
An article according to claim 10 wherein the gel material is supported on a porous support to be subjected to said vacuum over substantially the entire gel surface.
Claim 13
Dependent Claim
16 words
An article according to claim 10 comprising the additional step of compressing the dried product obtained.
Claim 14
Dependent Claim
19 words
An article according to claim 12 wherein the dried product is compressed at a pressure of 10-10 5 kPa.
Claim 15
Dependent Claim
27 words
An article according to claim 12 comprising the additional step of heat treating the dried product obtained at a temperature of about 50° to about 150° C.
References Cited (Backward Citations)
US2599172A
Cited
US2824092A
Cited
US2926177A
Cited
US3211616A
Cited
US3396081A
Cited
JPS4728090Y1
Cited
US4468334A
Cited
EP0084999A1
Cited
US4613665A
Cited
JPS59145036A
Cited
US4615697A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-20 | 1992-03-21 | 1992-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-20 | 1996-03-21 | 1996-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-20 | 2000-03-21 | 2000-09-20 | $7700.00 | Window Closed / Lapsed |