Abstract: The present invention relates to extended release matrix tablets for oral administration that include a cationic polymer, a water-swellable polymer, and an alginic acid derivative to cause the release rate of the active ingredient of the tablets to be independent of pH and gastric residence time. The active pharmaceutical ingredient may be one or more of antibiotics, sympathomimetics, sympatholytic agents, cholinergic agents, antimuscarinics, gastro-intestinal drugs, gentio-urinary smooth muscle relaxants, cardiac drugs, anticonvulsants, tranquilizers and sedatives, and in particular may be an antibiotic, such as cefaclor, or may be a sympatholytic agent, such as carvedilol.