Claims for Patent: 4,839,177

Summary for Patent: 4,839,177

Title:	System for the controlled-rate release of active substances
Abstract:	A system for the controlled-rate release of active substances, consisting of: (a) a deposit-core comprising the active substance and having defined geometric form; (b) a support-platform applied to said deposit-core. Said deposit-core contains, mixed with the active substance, a polymeric material having a high degree of swelling on contact with water or aqueous liqids, a gellable polymeric material, said polymeric materials being replaceable by a single polymeric material having both swelling and gelling properties, and other adjuvants able to provide the mixture with suitable characteristics for its compression and for its intake of water.
Inventor(s):	Colombo; Paolo (Pavia, IT), La Manna; Aldo (Pavia, IT), Conte; Ubaldo (Busto Arsizio, IT)
Assignee:	Jagotec AG (Hergiswill, CH)
Application Number:	06/939,810
Patent Claims:	1. A system for the controlled-rate release of active substances, consisting of: (a) a deposit-core comprising effective amounts of the active substances and having defined geometric form, (b) a support-platform applied to said deposit-core wherein said deposit-core contains, mixed with the active substance, at least one member selected from the group consisting of (a) 5-80% by weight of the total weight of the deposit-core of a polymeric material having a high degree of swelling on contact with water or aqueous liquids and 90-10% by weight of the total weight of the deposit core of a gellable polymeric material, and (b) a single polymeric material having both swelling and gelling properties, and other adjuvants able to provide the mixture with suitable characteristics for compression and for intake of water, and wherein said support-platform consists of a polymeric material insoluble in aqueous liquids and partially coating said deposit-core. 2. A system as claimed in claim 1, characterised in that said deposit-core is obtained by compressing said mixture to a pressure of between 1000 and 4000 kg/cm.sup.2. 3. A system as claimed in claim 1, characterised in that said polymeric material with a high degree of swelling comprises at least one member selected from the group consisting of cross-linked sodium carboxymethylcellulose, cross-linked hydroxypropylcellulose, high-molecular weight hydroxypropylmethylcellulose, carboxymethylamide, potassium methacrylatedivinylbenzene copolymer, polymethylmethacrylate, cross-linked polyvinylpyrrolidone and high-molecular weight polyvinylalcohols. 4. A system as claimed in claim 1, characterised in that said gellable polymeric material comprises at least one member selected from the group consisting of methylcellulose, carboxymethylcellulose, low-molecular weight hydroxypropylmethylcellulose, low-molecular weight polyvinylalcohols, polyoxyethyleneglycols and non-cross linked polyvinylpyrrolidone. 5. A system as claimed in claim 1, characterised in that said polymeric material with swelling and gelling properties comprises at least one member selected from the group consisting of medium-viscosity hydroxypropylmethylcellulose and medium-viscosity polyvinylalcohols. 6. A system as claimed in claim 1, characterised in that said support-platform covers one half of the surface of said deposit-core. 7. A system as claimed in claim 1, characterised in that said support-platform is formed by applying said water-insoluble polymeric material to said deposit-core by compression. 8. A system as claimed in claim 1, characterised in that said support-platform is formed by immersing said deposit-core in a solution of said water-insoluble polymeric material in a organic solvent. 9. A system as claimed in claim 1, characterised in that said support-platform is formed by spraying said water-insoluble polymeric material in the form of a solution in an organic solvent onto said deposit-core. 10. A system as claimed in claim 1, characterised in that said support-platform has a thickness of between 10 microns and 2 mm. 11. A system as claimed in claim 1, characterised in that said support-platform covers from 10 to 90% of the total surface of the system. 12. A system as claimed in claim 1, characterised in that said polymeric material insoluble in aqueous liquids comprises at least one member selected from the group consisting of acrylates, cellulose, ethylcellulose, cellulose acetate-propionate, polyethylene, methacrylates, acrylic acid copolymers and high-molecular weight polyvinylalcohols. 13. A system as claimed in claim 1, characterised in that the intensity and duration of the swelling force of said polymeric material with a high degree of swelling constitutes the primary control factor for the release of the active substance. 14. A system as claimed in claim 1, characterised in that the geometry of said support-platform constitutes a further control factor for the release of the active substance and directs the emission thereof. 15. A system as claimed in claim 1, characterised in that said adjuvants are magnesium stearate and mannitol. 16. A system as claimed in claim 1, characterised in that said deposit-core is formed from two layers, each of which comprises an active substance, a polymeric material with a high degree of swelling, and a gellable polymeric material. 17. A system as claimed in claim 1, characterised in that said support-platform is in the form of a coating applied to one flat, convex or concave surface of said deposit-core. 18. A system as claimed in claim 1, characterised in that said support-platform is in the form of a coating applied to two separate zones of the surface of said deposit-core. 19. A system as claimed in claim 1, characterised in that said support-platform is in the form of a coating which surrounds said deposit-core, to leave two opposing surface portions free. 20. A system as claimed in claim 1, characterised in that said support-platform is in the form of a container which encases said deposit-core, to leave one surface portion free. 21. A therapeutic system having a form and structure suitable for administration to a patient, wherein said system comprises a dosage unit consisting of a number of systems as claimed in claim 1 disposed in one container. 22. A method for preparing a system claimed in claim 1, characterised in that the mixture containing the active substance and the polymeric materials is wetted with a solution of adjuvants to obtain a granulate which is compressed to obtain the deposit-core, which is then coated over a determined area with a water-insoluble polymeric material possibly dissolved in an organic solvent. 23. A system for the controlled-rate release of active substances, consisting of: (a) a deposit-core comprising effective amounts of the active substances and having defined geometric form, (b) a support-platform applied to said deposit-core wherein said deposit-core contains, mixed with the active substance, at least one member selected from the group consisting of (a) 5-80% by weight of the total weight of the deposit-core of at least one polymeric material having a high degree of swelling on contact with water or aqueous liquids selected from the group consisting of cross-linked sodium carboxymethylcellulose, cross-linked hydroxypropylcellulose, high-molecular weight hydroxypropylmethylcellulose, carboxymethylamide, potassium methacrylatedivinylbenzene copolymer, polymethylmethacrylate, cross-linked polyvinylpyrrolidone, and high-molecular weight polyvinylalcohols; and 90-10% by weight of the total weight of the deposit-core of at least one gellable polymeric material selected from the group consisting of methylcellulose, carboxymethylcellulose, low-molecular weight hydroxypropylmethylcellulose, low-molecular weight polyvinylalcohols, polyoxyethyleneglycols and non-cross linked polyvinylpyrrolidone; and (b) a single polymeric material having both swelling and gelling properties selected from the group consisting of medium-viscosity hydroxypropylmethylcellulose and medium-viscosity polyvinylalcohols; and other adjuvants able to provide the mixture with suitable characteristics for compression and for intake of water, and wherein said support-platform consists of a polymeric material insoluble in aqueous liquids and partially coating said deposit-core. 24. A system as claimed in claim 23, wherein said deposit-core contains said polymeric material having a high degree of swelling and said gellable polymeric material. 25. A system as claimed in claim 23, wherein said deposit-core contains said single polymeric material having both swelling and gelling properties.