US4134943A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of porous tablets
Assignee: Roche Diagnostics GmbH
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Filing: 1976-12-03
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Granted: 1979-01-16
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Expires: 1996-12-03
Abstract
Abstract Porous tablets are produced by mixing the tablet components with a liquid solvent which is inert towards the components of the tablet and which freezes at a temperature from about -30 to +25° C, the solvent constituting about 5 to 80% by weight of the total mixture, introducing the mixture into an inert cooling medium at a temperature low enough to solidify the solvent, pressing the mixture including the solidified solvent into tablets at a temperature below the freezing point of the solvent, and then evaporating the solvent from the tablets. Advantageously the solvent is water, cyclohexane, benzene and/or tert.-butanol, optionally containing alcohol. The tablets readily disintegrate in liquid.
Inventors
- 👤 Karl-Wolfgang Knitsch
- 👤 Alexander Hagen
- 👤 Eberhard Munz
- 👤 Helmut Determann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:00
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/20; A61K9/2095
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
109 words
A process for the production of porous tablets which are readily soluble in aqueous solutions, comprising mixing the tablet components which are readily soluble in aqueous solutions with a liquid solvent which is inert towards the components of the tablet and which freezes at a temperature from about -30 to +25° C, the solvent constituting about 5 to 80% by weight of the total mixture, introducing the mixture into an inert cooling medium at a temperature low enough to solidify the solvent, pressing the mixture including the solidified solvent into tablets at a temperature below the freezing point of the solvent, and then evaporating the solvent from the tablets.
Claim 2
Dependent Claim
109 words
A process for the production of porous tablets which are readily soluble in aqueous solutions, comprising mixing the tablet components which are readily soluble in aqueous solutions with a liquid solvent which is inert towards the components of the tablet and which freezes at a temperature from about -30 to +25° C, the solvent constituting about 5 to 80% by weight of the total mixture, introducing the mixture into an inert cooling medium at a temperature low enough to solidify the solvent, pressing the mixture including the solidified solvent into tablets at a temperature below the freezing point of the solvent, and then evaporating the solvent from the tablets.
Claim 3
Dependent Claim
20 words
The process according to claim 1, wherein the solvent used comprises at least one of water, cyclohexane, benzene and tert.-butanol.
Claim 4
Dependent Claim
13 words
The process according to claim 2, wherein the solvent includes a lower alcohol.
Claim 5
Dependent Claim
13 words
The process according to claim 1, wherein the solvent is evaporated by lyophilization.
Claim 6
Dependent Claim
23 words
The process according to claim 1, wherein the solvent is evaporated by warming the tablets to ambient temperature and then drying in air.
Claim 7
Dependent Claim
22 words
The process according to claim 1, wherein the tablets are pressed at a pressure of about 500 to 5000 kp/cm 2 .
Claim 8
Dependent Claim
32 words
The process according to claim 1, wherein about 5 to 25% by weight of solvent is used based on the total weight of solvent plus mixture, the resulting tablets being relatively hard.
Claim 9
Dependent Claim
32 words
The process according to claim 1, wherein about 30 to 80% by weight of solvents is used based on the total weight of solvent plus mixture, the resulting tablets being relatively soft.
Claim 10
Dependent Claim
17 words
The process according to claim 8, whereina about 30 to 50% by weight of solvent is used.
Claim 11
Dependent Claim
41 words
The process according to claim 6, wherein the solvent used comprises at least one of water, cyclohexane, benzene and tert.-butanol optionally mixed with a lower alcohol, the solvent being used in about 5 to 80% by weight of solvent plus mixture.
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) | 1982-01-15 | 1982-07-17 | 1983-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-15 | 1986-07-17 | 1987-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-15 | 1990-07-17 | 1991-01-16 | $7700.00 | Window Closed / Lapsed |