Dextromethorphan and bromide counter-ion were analyzed by mixed-mode HPLC on core-shell reversed-phase anion exchange column. Dextromethorphan is retained by strong hydrophobic interaction and the bromide ion is retained by an anion-exchange interaction. Order of elution for basic drug and it’s acidic counter-ion can be changed by modifying the amount of ACN, buffer pH, and buffer concentration. The Coresep SB column can be used for analysis of hydrophobic basic drugs and acidic counter-ions in one run without a ion-pairing reagent. Compounds can be monitored by all common detection techniques.