The present invention relates to an oral pharmaceutical composition of aliphatic amine polymer or salts thereof comprising mixture of water and organic solvent(s) and/or less than of about 10% of plasticizing agent in the coating composition. In particular, present invention relates to a coated pharmaceutical composition of aliphatic amine polymer or salt thereof which comprises mixture of water and organic solvent(s) and less than of about 10% of plasticizing agent in coating. The invention also includes process of preparing such composition.