Abstract: A process for producing an oral, controlled release preparation of tramadol or a physiologically compatible tramadol salt having a storage stable active substance release profile by coating the active substance preparation with an aqueous ethylcellulose dispersion which contains at least one physiologically compatible, lipophilic diester of a C6-C40 aliphatic or aromatic dicarboxylic acid and a C6-C8 aliphatic alcohol as plasticizer, and, during coating, drying the coating at conventional temperatures, with the result that a storage stable active substance release profile is obtained even without subsequent heat treatment. Optionally, in order to increase the active substance release profile without impairing the storage stability of the preparation, a heat treatment may be performed at temperatures of >35° C. until a desired, increased active substance release profile is achieved.

Abstract: A process for the preparation of pellets containing ≧50 wt. % of a pharmaceutical active ingredient having a solubility in water of ≧0.5 g/ml, by aqueous granulation of the mixture containing the active ingredient, extrusion, rounding and drying of the moist granules, using a mixture consisting of A) at least 50 wt. % of at least one active ingredient having a solubility in water of ≧0.5 g/ml, and B) at most 50 wt. % of the combination of a) a microcrystalline cellulose having an average particle size of 15 to 20 &mgr;m and b) a low-substituted hydropropyl cellulose having an average particle size in the range of 10 to 25 &mgr;m, the weight ratio of a):b) being in the range of 4:6 to 6:4.

Abstract: A process for producing an oral, controlled release preparation of tramadol or a physiologically compatible tramadol salt having a storage stable active substance release profile by coating the active substance preparation with an aqueous ethylcellulose dispersion which contains at least one physiologically compatible, lipophilic diester of a C6-C40 aliphatic or aromatic dicarboxylic acid and a C1-C8 aliphatic alcohol as plasticizer, and, during coating, drying the coating at conventional temperatures, with the result that a storage stable active substance release profile is obtained even without subsequent heat treatment. Optionally, in order to increase the active substance release profile without impairing the storage stability of the preparation, a heat treatment may be performed at temperatures of >35° C. until a desired, increased active substance release profile is achieved.