Claims for Patent: 6,485,748

Summary for Patent: 6,485,748

Title:	Once daily pharmaceutical tablet having a unitary core
Abstract:	A controlled release tablet is disclosed which comprises: (a) a homogeneous compressed core which comprises: (i) a medicament which is very slightly soluble to practically insoluble in water at 25.degree. C.; (ii) a water soluble osmotic compound (iii) one or more osmotic polymers; and (b) a membrane coating which completely covers said core tablet which comprises a mixture of a: (i) a water insoluble pharmaceutically acceptable polymer; and (ii) a pH dependent polymer such as an enteric coating polymer, the weight ratio of the pH dependent polymer to the water insoluble pharmaceutically acceptable polymer being 0.1:1 to 0.75:1. A controlled release tablet which comprises: (a) a medicament (a) a homogeneous compressed core which comprises: (i) a medicament; (ii) a water soluble osmotic compound (iii) one or more osmotic polymers; and (b) a membrane coating which completely covers said core tablet which comprises a mixture of: (i) a water insoluble pharmaceutically acceptable polymer; and (ii) an enteric polymer.
Inventor(s):	Chen; Chih-Ming (Davie, FL), Chou; Joseph C. H. (Coral Springs, FL)
Assignee:	Andrx Pharmaceuticals, Inc. (Davie, FL)
Application Number:	08/990,129
Patent Claims:	1. A controlled release tablet which comprises: (a) a homogeneous compressed core which comprises: (i) a medicament which is very slightly soluble to practically insoluble in water at 25.degree. C.; (ii) a water soluble osmotic compound (iii) one or more osmotic polymers which comprise poly(ethylene oxide); and (b) a membrane coating which completely covers said core tablet which comprises a mixture of a: (i) a water insoluble pharmaceutically acceptable polymer; and (ii) a pH dependent polymer such as an enteric coating polymer, the weight ratio of the pH dependent polymer to the water insoluble pharmaceutically acceptable polymer being 0.1:1 to 0.75:1. 2. A controlled release pharmaceutical tablet as defined in claim 1 wherein the medicament is a calcium channel blocker compound. 3. A controlled release pharmaceutical tablet as defined in claim 2 wherein the medicament is nifedipine. 4. A controlled release pharmaceutical tablet as defined in claim 1 which includes two osmotic polymers. 5. A controlled release pharmaceutical tablet as defined in claim 1 wherein one of the osmotic polymers is a water swellable osmotic polymer. 6. A controlled release pharmaceutical tablet as defined in claim 5 wherein the membrane around the core contains an enteric polymer which is a methacrylic acid/methyl methacrylate polymer. 7. A controlled release pharmaceutical tablet as defined in claim 1 wherein the water insoluble polymer in the membrane around the core is a water insoluble cellulose derivative. 8. A controlled release pharmaceutical tablet as defined in claim 7 wherein the water insoluble cellulose derivative in the membrane around the core is cellulose acetate. 9. A controlled release pharmaceutical tablet as defined in claim 1 wherein the mixture of the water insoluble polymer and the enteric polymer contain a plasticizer. 10. A controlled release pharmaceutical tablet as defined in claim 1 wherein the plasticizer is triacetin. 11. A controlled release pharmaceutical tablet as defined in claim 9 wherein the mixture of the water insoluble polymer and the enteric polymer contain a water soluble channeling agent. 12. A controlled release pharmaceutical tablet as defined in claim 9 wherein the mixture of the water insoluble polymer and the enteric polymer is overcoated with an additional layer of an enteric polymer. 13. A controlled release pharmaceutical tablet as defined in claim 12 wherein the enteric polymer overcoat is hydroxypropyl methylcellulose phthalate which is plasticized with acetyltributyl citrate. 14. A controlled release tablet which comprises: (a) a homogeneous compressed core which comprises: (i) a medicament which is very slightly soluble to practically insoluble in water at 25.degree. C.; (ii) a water soluble osmotic compound (iii) poly(ethylene oxide); and (b) a membrane coating which completely covers said core tablet which consists essentially of a mixture of a: (i) cellulose acetate; (ii) a plasticizer; (iii) a water soluble channeling agent; and (iv) poly(methacrylic acid-methylmethacrylate polymer having a 1:2 ratio of polymethacrylic acid to methylmethacrylate and a number average molecular weight of 135,000, the weight ratio of cellulose acetate to said poly(methacrylic acid, methylmethacrylate polymer being 0.1:1 to 0.75:1.