#$%^&*AU2018260929A120181129.pdf#####ABSTRACT An abuse deterrent pharmaceutical composition comprising: a particle portion comprising a pharmaceutically active ingredient; an acid soluble ingredient comprising a cationic copolymer based on methyl methacrylate; and magnesium hydroxide; and a pH modifying ingredient, wherein the pH modifying ingredient is present in an amount sufficient to inhibit dissolution of the particle portion when the abuse deterrent pharmaceutical composition is ingested in an excess amount.