Patent ID: 6682759
Filing Date: 2004-01-27
Classification: A61K,A61P

Abstract:
A method for the manufacture of a pharmaceutical tablet which upon oral ingestion delivers a first drug by substantially immediate release and a second drug by sustained release defined as a release rate into gastric fluid that is slow enough to leave at least about 40% of said second drug unreleased one hour after ingestion, and in which said first drug is at most sparingly soluble in water and the weight ratio of said first drug to said second drug is equal to or less than about 0.01:1, said method comprising:dispersing said second drug in a solid matrix to form a unitary core which upon immersion in gastric fluid releases said second drug by sustained release while retaining at least a portion of the mass of said solid matrix as a coherent body until said second drug is fully released therefrom; depositing on the surface of said unitary core an aqueous suspension of particles of said first drug that are equal to or less than about 10 microns in diameter, using an amount of said first drug selected to achieve said weight ratio relative to said second drug; and evaporating water from said aqueous suspension thus deposited to leave a solid shell encasing said unitary core and containing said first drug.