HPLC-UV Determination of Dextromethorphan in Syrup Method validation

A HPLC-UV method, for determination of dextromethorphan hydrobromide in syrup, was validated. The chromatographic analysis was performed using an RP-18, Nucleodur chromatographic column (250 mm x 4 mm, 5 pm) at constant temperature (50 degrees C) with a mobile phase consisting of a mixture of acetonitrile/methanol (70:30 v/v) with sodium docusate (as ion pair agent) and ammonium nitrate, pH = 3.4. The flow rate of the mobile phase was 1 mL/min and the detection was carried out at 280 nm. System suitability, specificity, linearity, precision, accuracy, limit of detection and limit of quantification agreed with current pharmacopeial requests. The method is suitable for routine analysis of dextromethorphan hydrobromide in syrup.