The present invention relates to storage stable prolonged release pharmaceutical dosage forms comprising oxycodone or a pharmaceutically acceptable salt thereof and naloxone or a pharmaceutically acceptable salt thereof, the manufacture thereof as well as their use for administration to human beings.本發明係關於貯存安定性緩釋型藥學劑型,其包含羥可酮(oxycodone)或其藥學上可接受之鹽和納洛酮(naloxone)或其藥學上可接受之鹽,彼之製造,以及彼於投服至人類上之用途。