Patent US4882168A successfully refreshed from Google Patents.
US4882168A
Expired / Lapsed
US
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Polyesters containing alkylene oxide blocks as drug delivery systems
Assignee: Wyeth Holdings LLC
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Filing: 1986-09-05
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Granted: 1989-11-21
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Expires: 2006-09-05
Abstract
Abstract The invention is a slow release drug delivery system comprising a drug and an ABA or AB block copolymer wherein one block (B) is a poly(alkylene oxide) and the other blocks (A) are comprised of degradable random copolymers of (1) the cyclic ester of an alpha-hydroxy acid and (2) a second cyclic ester monomer is with the proviso that the second cyclic ester monomer not the same as the first cyclic ester.
Inventors
- 👤 Donald J. Casey
- 👤 Louis Rosati
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:47
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/70; A61K9/20; A61K9/2004; A61K9/2022; A61K9/2031; A61K9/204
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
76 words
A slow release drug delivery system comprising a drug and an ABA or AB block polymer wherein the (B) block is a poly(alkylene oxide) having an average molecular weight in a range of about 5,000 to about 20,000 and the blocks (A) are comprised of degradable random copolymers of (1) the cyclic ester of an alpha-hydroxy acid and (2) trimethylene carbonate; wherein said block polymer has a glass transition temperature at or less than 16° C.
Claim 2
Dependent Claim
76 words
A slow release drug delivery system comprising a drug and an ABA or AB block polymer wherein the (B) block is a poly(alkylene oxide) having an average molecular weight in a range of about 5,000 to about 20,000 and the blocks (A) are comprised of degradable random copolymers of (1) the cyclic ester of an alpha-hydroxy acid and (2) trimethylene carbonate; wherein said block polymer has a glass transition temperature at or less than 16° C.
Claim 3
Dependent Claim
23 words
A drug delivery system according to claim 1 wherein the polymer is an ABA block polymer, and the first cyclic ester is glycolide.
Claim 4
Dependent Claim
19 words
A drug delivery system according to claim 2 wherein the B block is polyethylene oxide or polyethylene oxide-co-propylene oxide.
Claim 5
Dependent Claim
60 words
A drug delivery system according to claim 2 wherein the poly(ethylene oxide) comprises from about 4 to about 54 weight % of the ABA polymer and the ratio of glycolide to trimethylene carbonate components is within a range of 45 weight % glycolide and 55 weight % trimethylene carbonate to 68% weight % glycolide and 32 weight % trimethylene carbonate.
Claim 6
Dependent Claim
31 words
A drug delivery system according to claim 4 wherein the drug is bovine somatotropin and the poly(ethylene oxide) comprises from about 4 to about 30 weight % of the ABA polymer.
Claim 7
Dependent Claim
22 words
A drug delivery system according to claim 4 wherein average molecular weight of the poly(ethylene oxide) is within a range of 6,000-20,000.
Claim 8
Dependent Claim
24 words
A drug delivery system according to claim 6 wherein the bovine somatotropin comprises from about 10 to about 40 weight % of the system.
Claim 9
Dependent Claim
20 words
A drug delivery system according to claim 7 wherein the bovine somatotropin comprises about 25 weight % of the system.
Claim 10
Dependent Claim
19 words
A drug delivery system according to claim 8 wherein the average molecular weight of the poly(ethylene oxide) is 8000.
Claim 11
Dependent Claim
19 words
A drug delivery system according to claim 8 wherein the average molecular weight of the poly(ethylene oxide) is 14,000.
Claim 12
Dependent Claim
19 words
A drug delivery system according to claim 8 wherein the average molecular weight of the poly(ethylene oxide) is 20,000.
Claim 13
Dependent Claim
30 words
A drug delivery system according to claim 4 wherein the drug is theophylline and the poly(ethylene oxide) comprises from about 4 to about 30 weight % of the ABA polymer.
Claim 14
Dependent Claim
19 words
A slow release drug delivery system according to claim 1 suspended in a pharmaceutically or pharmacologically acceptable liquid vehicle.
Claim 15
Dependent Claim
23 words
A drug delivery system according to claim 1 wherein the polymer is an AB block polymer and the first cyclic ester is glycolide.
Claim 16
Dependent Claim
22 words
A drug delivery system according to claim 14 wherein the B block is a monomethyl ether of a hydroxyl ended polyethylene oxide.
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) | 1992-11-20 | 1993-05-22 | 1993-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-20 | 1997-05-22 | 1997-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-20 | 2001-05-22 | 2001-11-21 | $7700.00 | Window Closed / Lapsed |