A reverse phase high performance liquid chromatographic method was developed for the simultaneous determination of Doxylamine Succinate and Dextromethorphan HBr in pharmaceutical dosage forms. The estimation was performed by using Purospher® STAR RP18 end capped (250 x 4.6) mm, 5μ) column as stationary phase and ACN: Water (70: 30 v/v) pH adjust to 3.4 by using Glacial Acetic Acid as mobile phase with 1mL/min as flow rate of mobile phase. The effluents were monitored at 250nm. The retention time of Doxylamine Succinate and Dextromethorphan HBr were found as 5.83 min and 7.72 min respectively. The method shows linearity in the concentration range of 20.84 - 62.51μg/mL and 50.02 - 150.07μg/mL for Doxylamine Succinate and Dextromethorphan HBr respectively. This method was found free of any interference from any excipients. The recovery studies for Doxylamine Succinate and Dextromethorphan HBr in formulations was found to be in the range of 98.0-103.0% and 98-99% respectively. The developed method was validated for specificity, precision, linearity, accuracy, LOD, LOQ and robustness. Recovery of Doxylamine Succinate and Dextromethorphan HBr in formulations was found to be in the range of 99.50-101.30% and 99-73- 100.7 % respectively. The developed method was validated in compliance with ICH Q2 (R1) guideline for Linearity, Accuracy, Precision, Specificity, and Forced Degradation studies. Due to its simple, rapidness and high precision, the proposed RP- HPLC method can be used for the simultaneous determination of these two drugs in Quality control department for regular analysis.
