Patent ID: 7632521
Filing Date: 2009-12-15
Classification: A61K

Abstract:
1. A process for preparing a controlled release tablet of potassium chloride comprising: (a) microencapsulating potassium chloride crystals with an inner membrane comprising ethylcellulose by coacervation or phase separation to form potassium chloride microcapsules; (b) coating said potassium chloride microcapsules with an outer membrane comprising a plasticized polymer to form compressible coated microcapsules; (c) preparing a compressible blend comprising said compressible coated microcapsules, microcrystalline cellulose, and colloidal silicon dioxide; and (d) compressing said compressible blend into tablets, wherein the tablet hardness is at least about 14 kP, the friability of the tablets does not exceed about 0.3%, and the tablet exhibits a dissolution profile substantially corresponding to the following pattern when tested by USP Apparatus 2 (Paddles @50 rpm) in purified water: after 2 hours, about 30% to about 50% of the total potassium chloride is released; after 4 hours, about 60% to about 75% of the total potassium chloride is released; and after 8 hours, not less than 80% of the total potassium chloride is released, wherein said plasticized polymer comprises a polymer selected from the group consisting of ethylcellulose, polyvinylpyrrolidone, and hydroxypropyl methylcellulose, wherein said colloidal silicon dioxide is present in an amount of from about 0.1% to about 0.3% by weight of said tablet, wherein said outer membrane coating comprises from about 0.5% to about 5.0% by weight of said compressible coated microcapsules, and wherein said compressible blend is substantially free of lubricants.