EP0156077A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Controlled absorption pharmaceutical formulation
Assignee: Elan Corp PLC
•
Filing: 1984-12-20
•
Granted: —
•
Expires: 2004-12-20
Abstract
Abstract A controlled absorption methyldopa formulation for oral administration comprises a pellet having a core of methyldopa or a pharmaceutically acceptable salt thereof in association with an organic acid, and an outer membrane which permits release of methyldopa in an aqueous medium at a controlled rate which is substantially pH independent. The pellet has a dissolution rate in vitro, which when measured in a Basket Assembly according to U.S. Pharmacopoeia XX at 37 DEG C. and 75 r.p.m., is not more than 50% of the total methyldopa after one hour of measurement. Not more than 80% of the total methyldopa is released after a total of 3 hours of measurement and 100% release is achieved after a total of 7 hours.
Inventors
- 👤 Donald Eugene Panoz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 17:33
CPC Classifications
A; A61; A61K; A61K31/00; A61K31/185; A61K31/19; A61K31/195; A61K9/00; A61K9/48; A61K9/50; A61K9/5073; A61K9/5078; A61P; A61P9/00; A61P9/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
170 words
A controlled absorption methyldopa formulation for oral administration, characterised in that it comprises a pellet having a core of methyldopa or a pharmaceutically acceptable salt thereof in association with an organic acid, and an outer membrane which permits release of methyldopa in an aqueous medium, said pellet having a dissolution rate which is substantially pH independent and which when measured in a Basket Assembly according to U.S. Pharmacopoeia XX at 37 0 C and 75 r.p.m. has the following characteristics: a) between 25 and 50% of the total methyldopa is released after a total of 1 hour of measurement in said assembly; b) between 50 and 80% of the total methyldopa is released after a total of 3 hours of measurement in said assembly; c) between 80 and 100% of the total methyldopa is , released after a total of 5 hours of measurement in said assembly; and d) between 90 and 100% of the total methyldopa is released after a total of 7 hours of measurement in said assembly.
Claim 2
Dependent Claim
170 words
A controlled absorption methyldopa formulation for oral administration, characterised in that it comprises a pellet having a core of methyldopa or a pharmaceutically acceptable salt thereof in association with an organic acid, and an outer membrane which permits release of methyldopa in an aqueous medium, said pellet having a dissolution rate which is substantially pH independent and which when measured in a Basket Assembly according to U.S. Pharmacopoeia XX at 37 0 C and 75 r.p.m. has the following characteristics: a) between 25 and 50% of the total methyldopa is released after a total of 1 hour of measurement in said assembly; b) between 50 and 80% of the total methyldopa is released after a total of 3 hours of measurement in said assembly; c) between 80 and 100% of the total methyldopa is , released after a total of 5 hours of measurement in said assembly; and d) between 90 and 100% of the total methyldopa is released after a total of 7 hours of measurement in said assembly.
Claim 3
Dependent Claim
46 words
A formulation according to Claim 1, characterised in that the core comprises methyldopa or a pharmaceutically acceptable salt thereof and the associated organic acid embedded in a polymeric material in a multi-layer arrangement and in that it is built up in a manner known per se.
Claim 4
Dependent Claim
36 words
A formulation according to Claim 2, characterised in that the polymeric material in which the methyldopa is embedded is rapidly soluble in water, the water soluble polymer preferably being selected from hydroxypropylmethylcellulose, polyvinylpyrrolidone and Eudragit RL.
Claim 5
Dependent Claim
25 words
A formulation according to Claim 2, characterised in that the polymeric material in which the methyldopa is embedded is readily permeable to methyldopa and water.
Claim 6
Dependent Claim
36 words
A formulation according to Claim 2, characterised in that the polymeric material includes a minor proportion of a water insoluble polymer; the water insoluble polymer preferably being selected from methylcellulose, ethylcellulose, propylcellulose, Shellac and Eudragit RS.
Claim 7
Dependent Claim
51 words
A formulation according to any preceding Claim, characterised in that the outer membrane has a major proportion of a water insoluble polymer and a minor portion of a water soluble polymer, the ratio of water insoluble to water soluble polymer being determined by the inherent solubility characteristics of the respective polymers.
Claim 8
Dependent Claim
42 words
A formulation according to Claim 6, characterised in that the water insoluble polymer of the outer membrane is selected from Shellac, ethylcellulose and Eudragit RS and the water soluble polymer of the outer membrane is selected from polyvinylpyrrolidone, hydroxypropylcellulose and Eudragit RL.
Claim 9
Dependent Claim
53 words
A formulation according to any one of Claims 1 to 5 characterised in that the outer membrane is composed of a major proportion of a non-porous polymer and a minor proportion of a porous polymer, the ratio of non-porous polymer to porous polymer being determined by the inherent porosity of the respective polymers.
Claim 10
Dependent Claim
13 words
A capsule comprising pellets according to any one of Claims 1 to 8.
Claim 11
Dependent Claim
55 words
a process for the production of a formulation according to any one of Claims 1 to 8, comprising forming a core of methyldopa or a pharmaceutically acceptable salt thereof and an organic acid and enclosing the core in an outer membrane which permits release of the methyldopa in the manner set out in Claim 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.