Dextromethorphan is one of the common cough suppressants used in many drug composition. It is in tablets and syrups as an antitussive drug. Composition often has preservatives like parabens. Dextromethorphan is a hydrophobic, basic drug which is used as a bromide salt in drug compositions. Dextromethorphan and two parabens (methyl paraben and propyl paraben) were separated on Primesep C reversed-phase cation-exchange column. Several impurities were observed and are well separated from the main components of the drug composition. Method can be used for various formulations in QC and production environment.