Patent JPS62237093A successfully refreshed from Google Patents.
US4379138A
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US
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Biodegradable polymers of lactones
Assignee: RTI International
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Filing: 1981-12-28
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Granted: 1983-04-05
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Expires: 2001-12-28
Abstract
Abstract Homopolymers and copolymers of lactones are prepared by ring-opening polymerization of a mixture of lactones which includes a monolactone, such as epsilon -caprolactone, and a dilactone, such as bis-2,2-( epsilon -caprolacton-4-yl)propane, which is capable of forming crosslinks. The resulting polymers range from tough and partially crystalline to amorphous, elastomeric materials, depending on the monomer composition and proportions. Additionally, these polymers may be designed to achieve different degrees of permeability and rates of biodegradation. As such, they are useful for the controlled delivery of medicinal agents and as surgical aids and temporary artificial biomaterials such as skin substitutes and burn dressings.
Inventors
- 👤 Colin G. Pitt
- 👤 Anton E. Schindler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:47
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/06; C08G63/08; A; A61; A61K; A61K9/00; A61K9/20; A61K9/2004; A61K9/2022; A61K9/2031; A61K9/204; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/26; A61L27/00; A61L27/14; A61L27/18; A61L27/50; A61L27/60
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
39 words
An elastomeric, biodegradable polymer formed by the opening polymerization of at least one monocyclic lactone and at least one polycyclic dilactone containing two lactone groups, each of which may be polymerized by ring opening to form a two-dimensional polymer.
Claim 2
Dependent Claim
39 words
An elastomeric, biodegradable polymer formed by the opening polymerization of at least one monocyclic lactone and at least one polycyclic dilactone containing two lactone groups, each of which may be polymerized by ring opening to form a two-dimensional polymer.
Claim 3
Dependent Claim
31 words
The polymer of claim 1 wherein said monocyclic lactone is selected from the group consisting of glycolide, DL-lactide, L-lactide, δ-valerolactone, ε-caprolactone, ω-dodecalactone and the C 1-8 alkyl and aryl derivatives thereof.
Claim 4
Dependent Claim
41 words
The polymer of claim 1 or 2 wherein said dilactone is of the formula: ##STR2## wherein R 1 and R 2 , each of which may be the same or different, is an alkyl group of 1 to 8 carbon atoms.
Claim 5
Dependent Claim
10 words
The polymer of claim 3 wherein said dilactone is 2,2-bis(ε-caprolacton-4-yl)propane.
Claim 6
Dependent Claim
16 words
The polymer of claim 4 wherein the monocyclic lactone is a mixture of δ-valerolactone and ε-caprolactone.
Claim 7
Dependent Claim
17 words
The polymer of claim 1 containing from about 0.5 to about 20 mole percent of said dilactone.
Claim 8
Dependent Claim
22 words
The polymer of claim 6 wherein said dilactone is present in an amount ranging from about 3 to about 10 mole percent.
Claim 9
Dependent Claim
63 words
A process for the preparation of the elastomeric biodegradable polymer of claim 1 which comprises the steps of: (a) mixing at least one monocyclic lactone, and at least one polycyclic dilactone containing two lactone groups, together with a polymerization catalyst; (b) degassing the mixture obtained in step (a); and (c) heating the degassed mixture for a period of time sufficient to polymerize same.
Claim 10
Dependent Claim
23 words
A process according to claim 8 wherein said degassed mixture is heated at a temperature ranging from about 80° to about 180° C.
Claim 11
Dependent Claim
18 words
A process according to claim 9 wherein the degassed mixture is heated from about 125° to 150° C.
Claim 12
Dependent Claim
22 words
A process according to claim 9 wherein said degassed mixture is heated for a period of from 10 to about 50 hours.
Claim 13
Dependent Claim
23 words
A pharmaceutical preparation comprising a pharmaceutically acceptable medicinal agent as an active ingredient dissolved or dispersed in the biodegradable polymer of claim 1.
Claim 14
Dependent Claim
9 words
A prosthesis formed from the polymer of claim 1.
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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) | 1986-04-04 | 1986-10-04 | 1987-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-04 | 1990-10-04 | 1991-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-04 | 1994-10-04 | 1995-04-05 | $7700.00 | Window Closed / Lapsed |