Patent US4523591A successfully refreshed from Google Patents.
US4523591A
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Polymers for injection molding of absorbable surgical devices
Assignee: United States Surgical Corp
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Filing: 1982-10-22
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Granted: 1985-06-18
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Expires: 2002-10-22
Abstract
Abstract Absorbable, substantially amorphous surgical fasteners having good in vivo strength-retaining and absorption characteristics may be made of copolymers of lactide and glycolide made from 70-85% m lactide and 15-30% m glycolide provided the inherent viscosity and glass transition temperature of the copolymers have at least certain minimum values.
Inventors
- 👤 Donald S. Kaplan
- 👤 Ross R. Muth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:53
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/06; C08G63/08; A; A61; A61L; A61L31/00; A61L31/04; A61L31/06
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
133 words
A method for making an absorbable surgical fastener of a copolymer made from 70-85% m lactide and 15-30% glycolide, said fastener retaining its strength in vivo for a sufficient amount of time and having a crystallinity of not more than about 5%, said method comprising the steps: (a) copolymerizing lactide and glycolide; (b) purifying the resulting crude product by removing the unreacted monomers sufficiently to raise the glass transition temperature to at least 56° C. when measured by differential scanning calorimetry at 20° C./min and maintaining the inherent viscosity at at least 1.3 when measured in chloroform at 30° C. at a concentration of 0.25 g/dl; (c) drying the copolymer; (d) forming the fastener from the purified dry copolymer; and (e) maintaining the crystallinity of the fastener at not more than about 5%.
Claim 2
Independent Claim
133 words
A method for making an absorbable surgical fastener of a copolymer made from 70-85% m lactide and 15-30% glycolide, said fastener retaining its strength in vivo for a sufficient amount of time and having a crystallinity of not more than about 5%, said method comprising the steps: (a) copolymerizing lactide and glycolide; (b) purifying the resulting crude product by removing the unreacted monomers sufficiently to raise the glass transition temperature to at least 56° C. when measured by differential scanning calorimetry at 20° C./min and maintaining the inherent viscosity at at least 1.3 when measured in chloroform at 30° C. at a concentration of 0.25 g/dl; (c) drying the copolymer; (d) forming the fastener from the purified dry copolymer; and (e) maintaining the crystallinity of the fastener at not more than about 5%.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein the fastener is a surgical clip.
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein the fastener is a surgical staple.
Claim 5
Dependent Claim
16 words
The method of claim 1 wherein step (b) comprises extracting the unreacted monomers with a solvent.
Claim 6
Dependent Claim
25 words
The method of claim 1 wherein step (b) comprises extracting the unreacted monomers with ethyl ether and removing residual solvent from the relatively monomerfree copolymer.
Claim 7
Dependent Claim
12 words
The method of claim 5 wherein the fastener is a surgical clip.
Claim 8
Dependent Claim
12 words
The method of claim 5 wherein the fastener is a surgical staple.
Claim 9
Dependent Claim
18 words
The method of claim 1 wherein step (d) is carried out in the presence of dry inert gas.
Claim 10
Dependent Claim
12 words
The method of claim 8 wherein the fastener is a surgical clip.
Claim 11
Dependent Claim
12 words
The method of claim 8 wherein the fastener is a surgical staple.
Claim 12
Dependent Claim
14 words
The method of claim 1 wherein step (d) is carried out by injection molding.
Claim 13
Dependent Claim
12 words
The method of claim 11 wherein the fastener is a surgical clip.
Claim 14
Dependent Claim
12 words
The method of claim 11 wherein the fastener is a surgical staple.
Claim 15
Dependent Claim
76 words
An absorbable surgical fastener that retains in vivo strength for a sufficient period of time comprising a copolymer made from 70-85% m lactide and 15-30% m glycolide, said fastener having a glass transition temperature of at least 54° C. when measured by differential scanning calorimetry at 20° C./min, an inherent viscosity of at least 0.9 when measured in chloroform at 30° C. at a concentration of 0.25 g/dl, and a crystallinity of not more than 5%.
Claim 16
Dependent Claim
76 words
An absorbable surgical fastener that retains in vivo strength for a sufficient period of time comprising a copolymer made from 70-85% m lactide and 15-30% m glycolide, said fastener having a glass transition temperature of at least 54° C. when measured by differential scanning calorimetry at 20° C./min, an inherent viscosity of at least 0.9 when measured in chloroform at 30° C. at a concentration of 0.25 g/dl, and a crystallinity of not more than 5%.
Claim 17
Dependent Claim
13 words
The surgical fastener of claim 14 wherein the fastener is a surgical clip.
Claim 18
Dependent Claim
13 words
The surgical fastener of claim 14 wherein the fastener is a surgical staple.
Claim 19
Dependent Claim
14 words
The surgical fastener of claim 14 wherein the crystallinity is not more than 1.5%.
Claim 20
Dependent Claim
13 words
The surgical fastener of claim 17 wherein the fastener is a surgical clip.
Claim 21
Dependent Claim
13 words
The surgical fastener of claim 17 wherein the fastener is a surgical staple.
Claim 22
Dependent Claim
16 words
The surgical fastener of claim 14 wherein the glass transition temperature is at least 56° C.
Claim 23
Dependent Claim
14 words
The surgical fastener of claim 20 wherein the crystallinity is not more than 1.5%.
Claim 24
Dependent Claim
13 words
The surgical fastener of claim 21 wherein the fastener is a surgical clip.
Claim 25
Dependent Claim
13 words
The surgical fastener of claim 21 wherein the fastener is a surgical staple.
Claim 26
Dependent Claim
19 words
The surgical fastener of claim 14 wherein the copolymer is made from 75-80% m lactide and 20-25% m glycolide.
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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) | 1988-06-17 | 1988-12-17 | 1989-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-17 | 1992-12-17 | 1993-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-17 | 1996-12-17 | 1997-06-18 | $7700.00 | Window Closed / Lapsed |