The invention relates to a pharmaceutical dosage form for oral administration having a breaking strength of at least 300 N and comprising (i) a pharmacologically active ingredient (ii) an opioid antagonist and/or an aversive agent (iii) a polyalkylene oxide having an average molecular weight of at least 200,000 g/mol and (a) further comprising (iv) an anionic polymer and/or (b) having a storage stability at 40° C. of at least 3 months.
