A controlled release pharmaceutical preparation comprising (a) a core containing a pharmaceutically active substance and an organic acid, and (b) a coating film formed on the surface of the core by aqueous coating of a water-insoluble and water-slightly permeable acrylic polymer containing a trimethylammonium-ethyl...http://www.google.fr/patents/US5395628?utm_source=gb-gplus-shareBrevet US5395628 - Controlled release succinic acid microcapsules coated with aqueous acrylics
Controlled release succinic acid microcapsules coated with aqueous acrylics
