US3946734A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for controlling the release of a drug
Assignee: United States Department of State
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Filing: 1975-02-19
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Granted: 1976-03-30
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Expires: 1995-02-19
Abstract
Abstract The subject invention is directed to an apparatus which selectively contr the rate with which a drug contained therein is released to surrounding tissue. Moreover, the subject invention is directed to process for controlling said release which comprises sealing the end of a suitable vessel with a non-porous material, inserting into said vessel a suitable medicament, and sealing the opposite end thereof with a porous neutral hydrogel through which naturally occuring materials can diffuse and further through which said medicament may diffuse.
Inventors
- 👤 Robert L. Dedrick
- 👤 Robert J. Lutz
- 👤 Daniel S. Zaharko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:54
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/0087; A61K9/0092; A61K9/0012; A61K9/0019; A61K9/0024; A61M; A61M31/00; A61M31/002
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
48 words
A diffusion cell comprising a hollow small diameter capillary tube containing therein a biologically active substance adjacent one end, said one end thereof being sealed with an inert impervious material and the rest of the tube and the other end thereof closed with a neutral hydrophilic polymeric material.
Claim 2
Dependent Claim
48 words
A diffusion cell comprising a hollow small diameter capillary tube containing therein a biologically active substance adjacent one end, said one end thereof being sealed with an inert impervious material and the rest of the tube and the other end thereof closed with a neutral hydrophilic polymeric material.
Claim 3
Dependent Claim
13 words
The apparatus of claim 1, wherein said neutral hydrophilic polymeric material is agarose.
Claim 4
Dependent Claim
21 words
The apparatus of claim 1, wherein said neutral hydrophilic polymeric material has a length of from about 2 to 14 mm.
Claim 5
Dependent Claim
69 words
A process for controlling the release of a biologically active substance in contact with living tissue which comprises implanting a diffusion cell comprising a small capillary tube containing a non-diffusible biologically active substance therein adjacent one end, which capillary tube has said one end thereof sealed with an impervious insoluble material and the rest of the tube and the other end thereof filled with a neutral hydrophilic polymeric gel.
Claim 6
Dependent Claim
69 words
A process for controlling the release of a biologically active substance in contact with living tissue which comprises implanting a diffusion cell comprising a small capillary tube containing a non-diffusible biologically active substance therein adjacent one end, which capillary tube has said one end thereof sealed with an impervious insoluble material and the rest of the tube and the other end thereof filled with a neutral hydrophilic polymeric gel.
Claim 7
Dependent Claim
13 words
The process of claim 4, wherein said neutral hydrophilic polymeric gel is agarose.
Claim 8
Dependent Claim
12 words
The process of claim 4, wherein said biologically active substance is methotrexate.
Claim 9
Dependent Claim
27 words
The process of claim 4, wherein said neutral hydrophilic polymeric material contained in said diffusion cell has a length of from about 2 to about 14 mm.
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) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |