Tamper resistant dosage forms

A solid oral extended release pharmaceutical dosage form comprising an extended release matrix formulation, the extended release matrix formulation comprising a composition comprising at least one active agent and at least one polyethylene oxide having, based on rheological measurements, an approximate molecular weight of at least 1,000,000 and wherein the composition comprises at least about 80% (by wt) polyethylene oxide having, based on rheological measurements, an approximate molecular weight of at least 1,000,000;

• in the form of a tablet or multi particulates, wherein the tablet or the individual multi particulates can at least be flattened without breaking, characterized by a thickness of the tablet or the individual multi particulate after the flattening which corresponds to no more than about 60% of the thickness of the tablet or the individual multi particulate before flattening, and wherein the flattened or non flattened tablet or the flattened or non flattened multi particulates provide an in-vitro dissolution rate, which when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid without enzymes (SGF) comprising 40% or 0% ethanol at 37° C., is between 5 and 40% (by wt) active agent released after 0.5 hours.