Patent US202769A successfully refreshed from Google Patents.
EP0092060A1
Expired / Lapsed
EP
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Pharmaceutical products in sustained-release form, and their preparation process
Assignee: LABORATORI PROPHIN Industria Chimica Farmaceutica SpA
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Filing: 1983-03-21
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Granted: —
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Expires: 2003-03-21
Abstract
Abstract A new sustained-release form is described for the oral administration of drugs which produce a pH value of less than or equal to 5 when in aqueous solution. The new sustained-release form can also be used for drugs which do not produce an acid pH when in solution but which can be formulated with excipients of acid pH. The formulation comprises essentially: a) a nucleus constituted by a continuous rigid polymer matrix which incorporates the drug, this polymer matrix being insoluble at acid pH values but biodegradable at pH values exceeding 5. b) a first film which is applied over the nucleus and is arranged to regulate the diffusion of the drug by means of a membrane effect; c) a second film which does not obstruct the diffusion of the drug, which protects the preceding film and which possibly carries a quantity of drug to compensate for the release time lag.
Inventors
- 👤 Paolo Colombo
- 👤 Ubaldo Conte
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 14:19
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/20; A61K9/28; A61K9/2886; A61K9/2004; A61K9/2022; A61K9/205; A61K9/2054
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
80 words
A pharmaceutical product in sustained-release form for oral administration, characterised by comprising: a) a nucleus constituted by a continuous rigid polymer matrix which incorporates the drug and is biodegradable at pH values exceeding 5, b) a first film applied over the nucleus and constituted by a filmogenic polymer arranged to regulate the drug diffusion by a membrane effect, c) a second film applied over the preceding and which does not obstruct the drug diffusion but mechanically protects the underlying film.
Claim 2
Dependent Claim
80 words
A pharmaceutical product in sustained-release form for oral administration, characterised by comprising: a) a nucleus constituted by a continuous rigid polymer matrix which incorporates the drug and is biodegradable at pH values exceeding 5, b) a first film applied over the nucleus and constituted by a filmogenic polymer arranged to regulate the drug diffusion by a membrane effect, c) a second film applied over the preceding and which does not obstruct the drug diffusion but mechanically protects the underlying film.
Claim 3
Dependent Claim
26 words
A pharmaceutical product in sustained-release form as claimed in claim 1, wherein the nucleus comprises 10-20% of biodegradable polymer with respect to the incorporated powder materials.
Claim 4
Dependent Claim
18 words
A.pharmaceutical product in sustained-release form as claimed in claim 1, wherein the nucleus comprises 40-60% of active principle.
Claim 5
Dependent Claim
30 words
A pharmaceutical product in sustained-release form as claimed in claim 1, wherein the biodegradable polymer is chosen from the group comprising cellulose acetophthalate, polyvinyl acetophthalate, methylcellulose phthalate and hydroxypropylmethylcellulose phthalate.
Claim 6
Dependent Claim
25 words
A pharmaceutical product in sustained-release form as claimed in claim 1, wherein the thickness of the first film is proportional to the drug diffusion rate.
Claim 7
Dependent Claim
57 words
A. pharmaceutical product in sustained-release form as claimed in claim 1, wherein the first film is constituted by a polymer chosen from the group comprising acrylic polymers, acrylic copolymers, vinyl polymers, vinyl copolymers, cellulose and cellulose derivatives which are filmogenic, partly permeable to the drug in an aqueous environment, and insoluble in water at any pH value.
Claim 8
Dependent Claim
54 words
A pharmaceutical product in sustained-release form as claimed in claim 1, wherein the second film is constituted by a polymer chosen from the group comprising acrylic polymers, acrylic copolymers, vinyl polymers, vinyl copolymers, cellulose and cellulose derivatives which are filmogenic, totally permeable to the drug in an aqueous environment, insoluble in water, and swellable.
Claim 9
Dependent Claim
33 words
A pharmaceutical product in sustained-release form as claimed in claim 1, wherein a small quantity of drug is incorporated into the second protective film in order to compensate for the release time lag.
Claim 10
Dependent Claim
29 words
A pharmaceutical product in sustained-release form as claimed in claim 1, wherein the drug is a compound which produces an acid pH not exceeding 5 when in aqueous solution.
Claim 11
Dependent Claim
34 words
A pharmaceutical product in sustained-release form as claimed in claim 1, wherein the drug is miscible with acid excipients such that the mixture produces an acid pH not exceeding 5 when in aqueous solution.
Claim 12
Dependent Claim
104 words
A process for preparing a pharmaceutical product in sustained-release form, characterised in that (l) the active principle in powder form, possibly mixed with excipients and diluents, is wetted with a solution of polymer which is biodegradable at pH values exceeding 5, then granulated and dried under cold conditions, (2) a solution of filmogenic polymer insoluble in water is applied over the nuclei thus formed and the solvent is evaporated under cold conditions to form the first film, (3) a solution of filmogenic polymer is applied over the first formed film and the solvent is evaporated under cold conditions to form a second protective film.
Claim 13
Dependent Claim
104 words
A process for preparing a pharmaceutical product in sustained-release form, characterised in that (l) the active principle in powder form, possibly mixed with excipients and diluents, is wetted with a solution of polymer which is biodegradable at pH values exceeding 5, then granulated and dried under cold conditions, (2) a solution of filmogenic polymer insoluble in water is applied over the nuclei thus formed and the solvent is evaporated under cold conditions to form the first film, (3) a solution of filmogenic polymer is applied over the first formed film and the solvent is evaporated under cold conditions to form a second protective film.
Claim 14
Dependent Claim
31 words
A process as claimed in claim 11, characterised in that the solution of biodegradable polymer is prepared using a non-toxic organic solvent which is not a solvent for the active principle.
Claim 15
Dependent Claim
47 words
A process as claimed in claim 11, characterised in that the first and second films are applied in the form of successive concentric layers applied on to the preformed nuclei until the required thickness is attained, by spraying a solution of polymer in a non-toxic organic solvent.
Claim 16
Dependent Claim
36 words
A process as claimed in claim 11, characterised in that before the second film polymer solution is applied, either a solution of active principle is dissolved therein or the active principle as such is suspended therein.
References Cited (Backward Citations)
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