Abstract: An oral pharmaceutical preparation containing a therapeutically effective amount of a salt of morphine for administration once daily is provided. The preparation contains particles which have a core containing a salt of morphine coated with a barrier layer. The barrier layer is formed from a coating liquid that contains at least one water insoluble barrier forming component selected from the group consisting of ethyl cellulose, copolymers of acrylic and methacrylic esters and natural or synthetic waxes, and a plasticizer. The mean serum concentration of morphine obtained is at least 50% of the maximum serum concentration during at least 12 hours after the administration of a single dose of the preparation.

Abstract: A method for manufacturing an oral controlled release pharmaceutical preparation in the form of a capsule containing a plurality of coated particles comprising a therapeutically effective amount of a salt of morphine coated with a barrier membrane providing a controlled, preferably pH-independent, release of morphine in that the serum concentration of morphine obtained is at least 50% of the maximum serum concentration during at least 12 hours after administration of a single dose, comprising spray coating the morphine containing particles with a coating liquid and drying.