Patent ID: 8216613

Claim:
A pellet ranging from 300 to 1,100 μm in diameter comprising: a pharmaceutically active substance embedded in a polymer matrix comprising one or more water-insoluble polymers, and at least one anionic polymer in an amount of 10 to 90% by weight of the polymer matrix; with the proviso that the pellet releases no more than 10% of said active compound in a release test according to USP in artificial gastric juice at pH 1.2 after 120 min, and releases at least 50% of the active compound after altogether a further 300 min at pH 6.8 and/or pH 7.5; wherein the water-insoluble polymer comprises: a C 1 - to C 4 -alkyl ester of acrylic or methacrylic acid; and a (meth)acrylate monomer having a quaternary ammonium group or a mixture of at least two (meth)acrylate monomers each having a quaternary ammonium group; and wherein the anionic polymer comprises: a C 1 - to C 4 -alkyl ester of acrylic or methacrylic acid; and (meth)acrylate-monomers having an anionic group.