A novel matrix composition for pharmaceutical use. The matrix composition hasbeen designed so that it is especially suitable in those situation where animproved bioavailability is desired and/or in those situation where a slightlyor insoluble active substance is employed. Accordingly, a controlled releasepharmaceutical composition for oral use is provided in the form of a coatedmatrix composition, the matrix composition comprising i) a mixture of a firstand a second polymer that have plasticizing properties and which have meltingpoints or melting intervals of a temperature of at the most 200~C, the firstpolymer being selected from the group consisting of polyethylene glycols andpolyethylene oxides, and the second polymer being selected form blockcopolymer of ethylene oxide and propylene oxide including poly(ethylene-glycol-b-(DL-lactic acid-co-glycolic acid) - b-ethylene glycol (PEG-PLGA PEG),poly((DL-lactic acid-co-glycolic acid) - g-ethylene glycol) (PLGA-g-PEG),poloxamers and polyethylene oxide - polypropylene oxide (PEO-PPO), ii) atherapeutically, prophylactically and/or diagnostically active substance, thematrix composition being provided with a coating having at least one openingexposing at one surface of said matrix, wherein the active substance isreleased with a substantially zero order release.
