Patent US4450150A successfully refreshed from Google Patents.
US4450150A
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US
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Biodegradable, implantable drug delivery depots, and method for preparing and using the same
Assignee: Arthur D Little Inc
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Filing: 1981-05-11
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Granted: 1984-05-22
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Expires: 2001-05-11
Abstract
Abstract An implantable drug deliver depot comprising a hydrophilic poly(glutamic acid-co-ethyl glutamate) structure having one or more substances, e.g., drugs and/or diagnostic agents physically contained therein. The drug or diagnostic agent is released by its permeation of and diffusion through the copolymer structure. The depot may be designed to release the substance or substances at predetermined rates and in predetermined sequence. The copolymer structure ultimately biodegrades to glutamic acid. Among the preferred configurations for the depots are rods and closed-end capsules.
Inventors
- 👤 Kenneth R. Sidman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:26
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/0012; A61K9/0019; A61K9/0024; A61D; A61D7/00; A61K9/20; A61K9/2004; A61K9/2022; A61K9/2031; A61K9/2045; A61M; A61M31/00; A61M31/002; A61K9/0087; A61K9/0092
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
88 words
A depot suitable for implanting within a living host for the controllable release of at least one substance within said host, said depot not in the form of a film or suture, comprising a matrix structure containing said substance in releasable form said matrix being formed of a poly(glutamic acid-co-ethyl glutamate) in which the mole percent of glutamic acid ranges between about 5 and about 50 and having a viscosity average molecular weight of about 80,000 to about 500,000 and which is hydrophilic and of uniform composition throughout.
Claim 2
Dependent Claim
88 words
A depot suitable for implanting within a living host for the controllable release of at least one substance within said host, said depot not in the form of a film or suture, comprising a matrix structure containing said substance in releasable form said matrix being formed of a poly(glutamic acid-co-ethyl glutamate) in which the mole percent of glutamic acid ranges between about 5 and about 50 and having a viscosity average molecular weight of about 80,000 to about 500,000 and which is hydrophilic and of uniform composition throughout.
Claim 3
Dependent Claim
14 words
A depot in accordance with claim 1 wherein said structure is a cylindrical shape.
Claim 4
Dependent Claim
20 words
A depot in accordance with claim 2 wherein said substance amounts up to about 70% by weight of said depot.
Claim 5
Dependent Claim
33 words
A depot in accordance with claim 2 wherein the surface of said rod is treated to control the initial burst of substance release shortly after said depot is implanted within said living host.
Claim 6
Dependent Claim
18 words
A depot in accordance with claim 2 wherein the concentration of said substance is uniform throughout said rod.
Claim 7
Dependent Claim
17 words
A depot in accordance with claim 2 wherein the concentration of said substance varies throughout said rod.
Claim 8
Dependent Claim
20 words
A depot in accordance with claim 2 wherein said depot contains a plurality of said substances for release in sequence.
Claim 9
Dependent Claim
20 words
A depot in accordance with claim 1 wherein said cylindrical-shape is a sealed capsule comprising a casing and a core.
Claim 10
Dependent Claim
20 words
A depot in accordance with claim 8 wherein said substance amounts up to about 98% by weight of said depot.
Claim 11
Dependent Claim
18 words
A depot in accordance with claim 8 wherein said casing is formed only of said poly(glutamic acid-co-ethyl glutamate).
Claim 12
Dependent Claim
15 words
A depot in accordance with claim 8 wherein said core is formed of said substance.
Claim 13
Dependent Claim
25 words
A depot in accordance with claim 8 wherein said core is formed of said substance mixed with a minor proportion of said poly(glutamic acid-co-ethyl glutamate).
Claim 14
Dependent Claim
27 words
A depot in accordance with claim 8 wherein said capsule contains a suspending agent for ensuring contact between said core and the internal wall of said casing.
Claim 15
Dependent Claim
24 words
A depot in accordance with claim 13 wherein said suspending agent comprises water, a physiological saline solution, sesame oil or crystals of sodium chloride.
Claim 16
Dependent Claim
34 words
A depot in accordance with claim 8 wherein the external surface of said casing is treated to control the initial burst of substance release shortly after said depot is implanted with said living host.
Claim 17
Dependent Claim
19 words
A depot in accordance with claim 8 wherein said capsule is of a size to be implanted by trocar.
Claim 18
Dependent Claim
38 words
A depot in accordance with claim 1 wherein said poly(glutamic acid-co-ethyl glutamate) exhibits a moisture regain of at least 15% of its weight within 48 hours when immersed in a buffered physiological saline solution maintained at 37° C.
Claim 19
Dependent Claim
38 words
A depot in accordance with claim 1 wherein said poly(glutamic acid-co-ethyl glutamate) is formed of α and β configurations, the ratio of α to β being adjusted to realize a predetermined drug permeability rate and structure biodegradation rate.
Claim 20
Dependent Claim
22 words
A depot in accordance with claim 1 wherein said poly(glutamic acid-co-ethyl glutamate) has a molecular weight ranging between about 80,000 and 500,000.
Claim 21
Dependent Claim
13 words
A depot in accordance with claim 1 wherein said substance is a drug.
Claim 22
Dependent Claim
15 words
A depot in accordance with claim 21 wherein said drug is a fertility control agent.
Claim 23
Dependent Claim
15 words
A depot in accordance with claim 22 wherein said fertility control agent is a steroid.
Claim 24
Dependent Claim
12 words
A depot in accordance with claim 23 wherein said steroid is progesterone.
Claim 25
Dependent Claim
12 words
A depot in accordance with claim 22 wherein said steroid is d,l-norgestrel.
Claim 26
Dependent Claim
12 words
A depot in accordance with claim 22 wherein said steroid is levonorgestrel.
Claim 27
Dependent Claim
12 words
A depot in accordance with claim 22 wherein said steroid is norethisterone.
Claim 28
Dependent Claim
14 words
A depot in accordance with claim 20 wherein said drug is a narcotic antagonist.
Claim 29
Dependent Claim
14 words
An implant device in accordance with claim 27 wherein said narcotic antagonist is naltrexone.
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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) | 1987-05-22 | 1987-11-21 | 1988-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-22 | 1991-11-21 | 1992-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-22 | 1995-11-21 | 1996-05-22 | $7700.00 | Window Closed / Lapsed |