US4786506A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the preparation of granulates suited for the production of sustained release coated tablets for oral use
Assignee: Istituto Gentili SpA
•
Filing: 1987-03-02
•
Granted: 1988-11-22
•
Expires: 2007-03-02
Abstract
Abstract A method for the preparation of tablets slowly releasing the active principle, characterized in that (I) during the granulation step a solution in organic solvents of a polymer insoluble in biological juices is sprayed on a mixture containing an active principle, slightly swelling polymers and usual excipients; (II) the granulated obtained in this way is added with a highly hydroswelling colloidal polymer; (III) a solution, in organic solvents, of an entero-soluble polymer, is sprayed on the granulate; (IV) the resulting granulate is submitted to compression; (V) the obtained tablets are hardened by washing with organic solvents; and (VI) they are then optionally coated.
Inventors
- 👤 Luciano Fontanelli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:29
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/20; A61K9/2004; A61K9/2022; A61K9/2027; A61K9/2072; A61K9/2077; A61K9/2081
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
120 words
A process for the preparation of tablets slowly releasing an active principle which consists essentially of preparing a mixture containing said active principle, a slightly swelling polymer and an excipient, then spraying onto said mixture in step (I) a solution in an organic solvent of a polymer insoluble in physiological fluids granulating said thus sprayed mixture to obtain a granulate; in step (II) adding to said granulate a hydroswelling colloidal polymer to obtain a granulate with increased swelling properties; in step (III) spraying a solution, in an organic solvent, of an entero-soluble polymer onto said granulate from step (II); in step (IV) compressing said granulate to obtain tablets; in step (V) hardening said tablets by washing with an organic solvent.
Claim 2
Dependent Claim
120 words
A process for the preparation of tablets slowly releasing an active principle which consists essentially of preparing a mixture containing said active principle, a slightly swelling polymer and an excipient, then spraying onto said mixture in step (I) a solution in an organic solvent of a polymer insoluble in physiological fluids granulating said thus sprayed mixture to obtain a granulate; in step (II) adding to said granulate a hydroswelling colloidal polymer to obtain a granulate with increased swelling properties; in step (III) spraying a solution, in an organic solvent, of an entero-soluble polymer onto said granulate from step (II); in step (IV) compressing said granulate to obtain tablets; in step (V) hardening said tablets by washing with an organic solvent.
Claim 3
Dependent Claim
17 words
The process according to claim 1 wherein said tablets from step (V) are coated in step (VI).
Claim 4
Dependent Claim
14 words
The process according to claim 1, wherein after step (III), step (I) is repeated.
Claim 5
Dependent Claim
23 words
The process according to claim 1, wherein the solution sprayed in step (I) is an acetone solution of polyvinyl chloride and/or polyvinyl acetate.
Claim 6
Dependent Claim
29 words
The process according to claim 1, wherein the colloidal polymer of step (II) is a member selected from the group consisting of gelatine, arabic gum, sodium carboxymethylcellulose and hydroxypropylcellulose.
Claim 7
Dependent Claim
27 words
The process according to claim 1, wherein the entero-soluble polymer of step (III) is a member selected from the group consisting of shellac, cellulose acetophthalate and stearylmyristate.
Claim 8
Dependent Claim
23 words
The process according to claim 1, wherein said organic solvent in step (IV) is the same as the solvent used in step (III).
Claim 9
Dependent Claim
34 words
The process according to claim 1, wherein the ratio of said active principle, said polymer of step (II), said insoluble polymer of step (I), said entero-soluble polymer of step (III) is 1:0.5:0.10:0.10 to 1:1.5:0.20:0.25.
Claim 10
Dependent Claim
12 words
A pharmaceutical sustained release tablet obtained by the process of claim 1.
References Cited (Backward Citations)
US4132753A
Cited
US3400185A
Cited
US3453360A
Cited
US3487138A
Cited
US3864469A
Cited
US3692896A
Cited
US3608030A
Cited
US3629393A
Cited
US3906086A
Cited
US3836618A
Cited
US4113816A
Cited
US3922339A
Cited
US4088798A
Cited
US4415547A
Cited
US4684516A
Cited
US4591496A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-22 | 1992-05-23 | 1992-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-22 | 1996-05-23 | 1996-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-22 | 2000-05-23 | 2000-11-22 | $7700.00 | Window Closed / Lapsed |