Patent CA1242394A successfully refreshed from Google Patents.
CA1242394A
Expired / Lapsed
CA
⏱️ 0.0 years remaining
Controlled release device
Assignee: National Research Development Corp UK
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Filing: 1985-03-07
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Granted: 1988-09-27
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Expires: 2005-03-07
Abstract
Abstract ABSTRACT OF THE DISCLOSURE A controlled release device is provided herein. The device includes (i) a hydrogel, and incorporated therewith (ii), an active substance. At least part of at least one surface of the device comprises (iii) a layer which is impermeable to aqueous media. Such device is an improved so-called "zero order" release device in which the release is sustained over a prolonged period of time.
Inventors
- 👤 Neil B. Graham
- 👤 Marion E. McNeill
- 👤 David A. Wood
Bibliographic Details
Application Number
—
Jurisdiction
CA
Data Source
google_patents
Last Synchronized
2026-11-03 14:25
CPC Classifications
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Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
56 words
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS: 1. A controlled release device which comprises: (i) a hydrogel; and incorporated therewith (ii) an active substance; at least part of at least one surface of said device comprising: (iii) a layer which is impermeable to aqueous media.
Claim 2
Dependent Claim
97 words
A controlled release device according to claim 1 wherein said hydrogel (i) comprises a hydrophilic homo- or copolymer comprising residues derivable from at least one of the following monomer classes: (a) (meth)acrylic acid, (meth)acrylamide, an unsubstituted or hydroxy-substituted alkyl (meth)acrylate, or a poly(oxyethylene) (meth)- acrylate; or (b) a substituted or unsubstituted cyclic mono- or poly ether having from 3 to 6 ring atoms, or a cyclic imine having 3 ring atoms; or (c) a substituted or unsubstituted vinyl alcohol, aldehyde, ether, acetal, ketone, ester, anhydride or substituted or unsubstituted N - or C - vinyl heterocyclic compound.
Claim 3
Dependent Claim
18 words
A controlled release device according to claim 1 wherein said hydrogel (i) comprises a mono- or copoly(alkylene oxide).
Claim 4
Dependent Claim
17 words
A controlled release device according to claim 3 wherein said hydrogel (i) comprises a poly(ethylene oxide). 24
Claim 5
Dependent Claim
23 words
A controlled release device according to claim 3 wherein said poly(alkylene oxide) is cross-linked through reaction with isocyanate or unsaturated cyclic ether groups.
Claim 6
Dependent Claim
17 words
A controlled release device according to claim 1 wherein said active substance (ii) comprises a lithium salt.
Claim 7
Dependent Claim
16 words
A controlled release device according to claim 1 wherein said active substance (ii) comprises a prostaglandin.
Claim 8
Dependent Claim
22 words
A controlled release device according to claim 1 wherein said active substance (ii) is homogeneously or inhomogeneously dispersed throughout the hydrogel (i).
Claim 9
Dependent Claim
22 words
A controlled release device according to claim 1 wherein said active substance (ii) is contained in a reservoir within said hydrogel (i).
Claim 10
Dependent Claim
25 words
A controlled release device according to claim 1 which is formed as a rod, slab, or film hemisphere and is of hollow or sinusoidal profile.
Claim 11
Dependent Claim
15 words
A controlled release device according to claim 1 which is of hollow or sinusoidal profile.
Claim 12
Dependent Claim
15 words
A controlled release device according to claim 1 wherein said impermeable layer (iii) is hydrophobic.
Claim 13
Dependent Claim
21 words
A controlled release device according to claim 1 wherein said impermeable layer (iii) is also impermeable to said active substance (ii).
Claim 14
Dependent Claim
40 words
A controlled release device according to claim 1 wherein said impermeable layer (iii) covers all of at least one surface of said device, thereby defining at least one orifice thereon through which the hydrogel (i) is contactable by aqueous media.
Claim 15
Dependent Claim
34 words
A controlled release device according to claim 1 which comprises a rod, slab or film of hydrogel (i), wherein said impermeable layer (iii) covers all of the surfaces except one or both end profiles.
Claim 16
Dependent Claim
27 words
A controlled release device according to claim 1 wherein said rod or slab of hydrogel (i), is formed with a single or bis-sinusoidal profile along its length.
Claim 17
Dependent Claim
29 words
A controlled release device according to claim 1 which comprises a hemisphere of hydrogel (i). wherein said impermeable layer (iii) covers all of the surfaces except a polar orifice.
Claim 18
Dependent Claim
26 words
A controlled release device according to claim 1 which comprises a ring of hydrogel (i), wherein said impermeable layer (iii? covers all of the external surfaces.
Claim 19
Dependent Claim
15 words
A controlled release device according to claim 1 which comprises a plurality of orifices. 26
References Cited (Backward Citations)
No citation records indexed.
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