US4871548A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled release dosage form comprising different cellulose ethers
Assignee: Alza Corp
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Filing: 1987-04-17
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Granted: 1989-10-03
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Expires: 2007-04-17
Abstract
Abstract A dosage form is disclosed comprising a low number average molecular weight hydroxypropylmethylcellulose, a high number average molecular weight hydroxypropylmethylcellulose, and a beneficial drug.
Inventors
- 👤 David E. Edgren
- 👤 Judy A. Magruder
- 👤 Gurdish K. Bhatti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:17
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/20; A61K9/2004; A61K9/2022; A61K9/205; A61K9/2054; A61K9/2072; A61K9/2086; A61K9/209
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
107 words
A dosage form for delivering a beneficial drug to an environment of use, which dosage form comprises: a matrix adapted for entrance into the environment of use, said matrix comprising from 30 to 99.9% of a cellulosic ether formulation, which formulation comprises from 10 to 99% of at least one hydroxypropylmethylcellulose comprising a high number average molecular weight of from 30,000 to 350,000, from 5 to 80% of at least one hydroxypropylmethylcellulose comprising a low number average molecular weight of from 9,000 to 30,000, from 2 to 30% of a hydroxypropylcellulose comprising a hydroxypropoxy content of 7 to 16%, and a dosage amount of the beneficial drug.
Claim 2
Dependent Claim
107 words
A dosage form for delivering a beneficial drug to an environment of use, which dosage form comprises: a matrix adapted for entrance into the environment of use, said matrix comprising from 30 to 99.9% of a cellulosic ether formulation, which formulation comprises from 10 to 99% of at least one hydroxypropylmethylcellulose comprising a high number average molecular weight of from 30,000 to 350,000, from 5 to 80% of at least one hydroxypropylmethylcellulose comprising a low number average molecular weight of from 9,000 to 30,000, from 2 to 30% of a hydroxypropylcellulose comprising a hydroxypropoxy content of 7 to 16%, and a dosage amount of the beneficial drug.
Claim 3
Dependent Claim
31 words
The dosage form for delivering the beneficial drug to the environment of use, according to claim 1, wherein the environment of use is the fluidic gastrointestinal tract of a warm-blooded animal.
Claim 4
Dependent Claim
26 words
The dosage form for delivering the beneficial drug to the environment of use, according to claim 1, wherein the environmemt of use is the human stomach.
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) | 1992-10-02 | 1993-04-03 | 1993-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-02 | 1997-04-03 | 1997-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-02 | 2001-04-03 | 2001-10-03 | $7700.00 | Window Closed / Lapsed |