A pellet contains a core, which contains one or more biologically active ingredients, and a coating layer on the core. The coating layer contains a mixture of a first polymer and a second polymer. The first polymer is a core-shell polymer, containing 50 to 90% by weight of a core, containing polymerized units of 60 to 85% by weight of ethyl acrylate and 20 to 40% by weight of methyl methacrylate; and 10 to 50% by weight of a shell, containing polymerized units of 40 to 60% by weight ethyl acrylate and 40 to 60% by weight methacrylic acid. The second polymer contains polymerized units of 40 to 60% by weight of methacrylic acid and 60 to 40% by weight of ethyl acrylate or methyl methacrylate. A Multi-Unit Pellet System (MUPS), preferably a compressed tablet, contains a multitude of the pellets.