ABSTRACT: 588499 The present disclosure is directed to pharmaceutical compositions, and methods of making such compositions, comprising microparticles containing a weakly basic drug core, a layer of alkaline buffer, and a controlled-release coating. Particularly disclosed is a pharmaceutical composition comprising a plurality of controlled-release particles, wherein at least one population of said particles comprises:(a) a core comprising a weakly basic drug, or a pharmaceutically 5 acceptable salt, solvate, and/or ester thereof (b) an alkaline-buffer layer disposed over the core, comprising an alkaline buffer and(c) a controlled-release coating disposed over the alkaline-buffer layer, wherein the controlled-release coating comprises a water-insoluble polymer selected from the group consisting of ethylcellulose, cellulose acetate, cellulose acetate butyrate, polyvinyl acetate, neutral methacrylic acid-methylmethacrylate copolymers, and mixtures thereof and said enteric polymer is selected from the group consisting of hydroxypropyl methylcellulose phthalate, cellulose acetate phthalate, hydroxypropyl methylcellulose acetate succinate, polyvinyl acetate phthalate, pH-sensitive methacrylic acid methylmethacrylate copolymers, shellac, and mixtures thereof. The disclosure is also directed to pharmaceutical dosage forms, including orally disintegrating tablets, conventional tablets, and capsules, and methods for their preparation.
