Process for the manufacture of a sustained release tramadol preparation with a storage stable release profile without curing of the coated product

摘要

Production of an orally administered retard preparation containing tramadol (I) (or its salt) involves forming a coating with an aqueous ethyl cellulose (EC) dispersion containing at least one lipophilic diester plasticizer (II) (derived from a 6-40C aliphatic or aromatic dicarboxylic acid and a 1-8C aliphatic alcohol) and drying the coating at the usual temperature. This gives a storage-stable release profile, and release is optionally accelerated (without affecting the stability of the profile) by tempering above 35 degrees C. An Independent claim is included for a preparation obtained by the process, having a coalescent EC coating.