Abstract: Disclosed is a pharmaceutical sustained release tablet for oral administration of a drug which is made of a compressed blend of at least three dry powders including a powder of a drug, a powder of a sustained release matrix for the drug, and a powder of at least one electrolyte. The sustained release matrix consisting of an un-cross-linked high amylose starch wherein the high amylose is substituted by at least one organic substituent comprising at least one carboxyl group. This organic substituent is preferably a carboxyalkyl having 2 to 4 carbon atoms, its salt or mixture thereof. This tablet has the advantage of having an improved integrity.