Abstract: A solid, controlled release pharmaceutical composition is provided with enhanced levels of control over drug release. The composition comprises an acid addition salt or a quarternary ammonium salt of an organic base drug complexed with an anionic surfactant and distributed in a matrix of a hydrophilic polymer. The complex formation between the drug which is preferably an acid addition salt of an organic an organic amine, and the surfactant, which is preferably a sulphosuccinate, distributed in the hydrophilic polymer matrix, which is preferably a water soluble hydroxyalkylcelulose ether results in a composition with excellent controlled released characteristics.

Abstract: The invention relates to a novel method of producing slow-release pharmaceutical forms administered per os, by simultaneously employing two resins having anionic character, the proportions of said resins being variable.By varying the ratio of the amounts of active principles on the respective two resins, it is possible to modify the release kinetics of active principle; and by independently varying the amount of carboxylic resin it is possible to produce stabile pharmaceutical preparations which are in liquid, semi-liquid, or solid form.