DEVELOPMENT AND VALIDATION OF A NEW ISOCRATIC RP-HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF DEXTROMETHORPHAN HYDROBROMIDE, PHENYLEPHRINE HYDROCHLORIDE AND TRIPROLIDINE HYDROCHLORIDE IN THEIR COMBINED LIQUID DOSAGE FORM

A new isocratic HPLC method based on reverse phase separation has been developed for simultaneous estimation of Dextromethorphan hydrobromide (DMP), Triprolidine hydrochloride (TPN), and Phenylephrine hydrochloride (PHE) in their mixed liquid dosage form. The chromatographic separation was accomplished on Agilent TC-C18 (250 x 4.6 mm, 5× m) column with a flow rate of 1 ml/min, UV detection (271 nm). Mobile phase consisting of 5 g DOSS, methanol, tetrahydrofuran, and water in the ratio of (70:10:20) pH 4.0 adjusted by acetic acid. The method was found to be selective for PHE, TPN, and DMP with retention time 4.7 min, 5.9 min, and 6.9 min, respectively. The linearity was established over the concentration range of 160-240 mcg/ml, 40-60 mcg/ml and 320-480 mcg/ml for PHE, TPN and DMP, respectively. Limit of detection and Limit of quantification for PHE was found to be 37.87 μg/ml, and 114.77 μg/ml, respectively, for TPN was found to be 10.19 μg/ml and 30.89 μg/ml, respectively and for DMP was found to be 57.50μg/ml and 174.26 μg/ml, respectively. The developed method was further validated in compliance with ICH guidelines. The statistical result showed that the method was precise, accurate, reproducible, and specific for the analysis of PHE, TPN and DMP.