US3689634A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protracted activity oral hydrogel bead
Assignee: Czech Academy of Sciences
•
Filing: 1970-09-23
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Granted: 1972-09-05
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Expires: 1990-09-23
Abstract
Abstract Drugs are released gradually to a living organism after oral ingestion, through a layer of non-ionogenic, neutral hydrogel of a polymer of ethylene glycol methacrylate or similar monomer cross-linked sufficiently to make the polymer insoluble in all gastro intestinal liquids.
Inventors
- 👤 Karel Kliment
- 👤 Jiri Vacik
- 👤 Zdenek Ott
- 👤 Vladimir Majkus
- 👤 Miroslav Stol
- 👤 Vladimir Stoy
- 👤 Otto Wichterle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:30
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/20; A61K9/2004; A61K9/2022; A61K9/2027; C; C08; C08F; C08F36/00; C08F36/02; C08F36/20
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
46 words
The carriers according to claim 1 wherein said particles comprise a core consisting of said beads as a macroporous hydrogel containing the saturated biologically active oral therapeutic substance, and an outer inert acid resistant coating layer, said carriers intended for treating diseases of the gastro-intestinal tract.
Claim 2
Dependent Claim
27 words
The carrier according to claim 1 wherein said thickness and diffusion rates are predetermined and predefined to provide a controlled delivery for tetracyline hydrochloride from each particle.
Claim 3
Dependent Claim
21 words
The carrier according to claim 3 wherein said tetracyline hydrochloride as the biological substance comprises about 1 percent of said mixture.
Claim 4
Dependent Claim
41 words
The carrier according to claim 1 wherein said mixture comprises fractions of one part 0.1 - 0.5 parts of 0.5 - 1 mm and three parts of 1 - 2 mm beads prepared in bead form 0.1 -2.0 mm in size.
References Cited (Backward Citations)
US3551556A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |