Patent US4865849A successfully refreshed from Google Patents.
US4865849A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tablet for pharmaceutical use able to release active substances at successive times
Assignee: PHARMIDEA Srl
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Filing: 1987-12-30
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Granted: 1989-09-12
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Expires: 2007-12-30
Abstract
Abstract A tablet for pharmaceutical use able to release active substances at successive times, comprising at least; a first layer containing a portion of the active substance with suitable excipients, a barrier layer of polymer material gellable and/or soluble in water and/or aqueous liquids, which is interposed between said first layer and a third layer containing the remaining portion of active substance with suitable excipients, said barrier layer and said third layer being housed in a casing consisting of polymer material impermeable and insoluble in water or soluble in an alkaline environment. That part of the active substance not inserted in the casing is immediately available for dissolving, whereas the part inserted in the casing is available only after dissolution or rupture of the barrier layer and/or after solubilization of the casing.
Inventors
- 👤 Ubaldo Conte
- 👤 Aldo La Manna
- 👤 Paolo Colombo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:51
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/20; A61K9/2072; A61K9/2086; A61K9/209
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
156 words
A tablet for pharmaceutical use able to release an active substance at successive times, comprising: a first layer containing a first portion of an active substance, a disintegrant substance which on contact with water or aqueous liquids is able to develop a disintegrating force, and at least one excipient; a third layer containing a second portion of said active substance, a disintegrant substance, which on contact with water or aqueous liquid is able to develop a disintegrating force, and at least one excipient; a second layer comprising at least one polymeric material selected from the group consisting of cellulosic derivatives and polyvinyl alcohols, gellable or soluble on contact with water or an aqueous liquid, said second layer being interposed between the first and third layer; a casing comprising a film-forming polymeric material which is impermeable and insoluble in water having a pH of 7 or less which partially encapsulates the second layer and the third layer.
Claim 2
Dependent Claim
156 words
A tablet for pharmaceutical use able to release an active substance at successive times, comprising: a first layer containing a first portion of an active substance, a disintegrant substance which on contact with water or aqueous liquids is able to develop a disintegrating force, and at least one excipient; a third layer containing a second portion of said active substance, a disintegrant substance, which on contact with water or aqueous liquid is able to develop a disintegrating force, and at least one excipient; a second layer comprising at least one polymeric material selected from the group consisting of cellulosic derivatives and polyvinyl alcohols, gellable or soluble on contact with water or an aqueous liquid, said second layer being interposed between the first and third layer; a casing comprising a film-forming polymeric material which is impermeable and insoluble in water having a pH of 7 or less which partially encapsulates the second layer and the third layer.
Claim 3
Dependent Claim
37 words
A tablet according to claim 1, wherein in the first layer the disintegrant substance is selected from the group consisting of carboxymethylamide, cross-linked sodium carboxymethylcellulose, cross-linked polyvinylpyrrolidone, cross-linked hydroxypropylmethyl cellulose, sodium bicarbonate, sodium carbonate and magnesium oxide.
Claim 4
Dependent Claim
46 words
A tablet according to claim 1, wherein the polymeric material of the second layer is selected from the group consisting of hydroxy propylcellulose methylcellulose and polyvinyl alcohols, and additionally contains at least one excipient selected from the group consisting of mannitol, talc, polyvinylpyrrolidone and magnesium stearate.
Claim 5
Dependent Claim
31 words
A tablet according to claim 1, wherein the casing comprises at least one polymeric substance selected from the group consisting of ethylcellulose, cellulose-acetatepropionate, methacrylate polymers, acrylic and methacrylic copolymers, and polyvinylalcohols.
Claim 6
Dependent Claim
24 words
A tablet according to claim 1, wherein said first and third layers each contain from 1% to 95% by weight of said disintegrant substance.
Claim 7
Dependent Claim
65 words
A tablet as claimed in claim 1, wherein at least one additional layer containing an active substance is present, and said additional layer is separated from said third layer by a barrier layer comprising at least one polymeric material selected from the group consisting of cellulosic derivatives and polyvinyl alcohols, said barrier layer being gellable or soluble on contact with water or an aqueous liquid.
Claim 8
Dependent Claim
26 words
A tablet as claimed in claim 1, wherein the active substance in the first layer is the same as the active substance in the third layer.
Claim 9
Dependent Claim
25 words
A tablet as claimed in claim 1, wherein the active substance in the first layer is different from the active substance in the third layers.
Claim 10
Dependent Claim
28 words
A tablet as claimed in claim 1, wherein said active substance is present in at least one of said first layer and said third layer in microencapsulated form.
Claim 11
Dependent Claim
31 words
A process for preparing the tablet of claim 1, comprising pressing said first, second, and third layer together to prepare a multilayer tablet, and applying said casing to said multilayer tablet.
Claim 12
Dependent Claim
36 words
A process as claimed in claim 10, wherein said casing is applied to said multilayer tablet by at least one method selected from the group consisting of spraying, compression, immersion, and inserting into a preformed casing.
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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) | 1992-09-11 | 1993-03-13 | 1993-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-11 | 1997-03-13 | 1997-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-11 | 2001-03-13 | 2001-09-12 | $7700.00 | Window Closed / Lapsed |