Development and Validation of Fast and Robust Stability Indicating RP-HPLC Method for Simultaneous Estimation of Tolperisone Hydrochloride and Etoricoxib in Pharmaceutical Dosage Form

Objectives: A precise, accurate and selective stability-indicating reverse phase high performance liquid chromatographic assay method has been developed for the simultaneous quantitative determination of Tolperisone hydrochloride and Etoricoxib in tablets. Methods: The chromatographic separation of drugs was attained by using Eclipse plus C18 (150 mm × 4.6 mm, Agilent 5µm) column at room temperature. The composition of mobile phase was mixture of 0.035M triethylamine (pH 3.0 adjusted with ortho phosphoric acid) and acetonitrile in ratio of 70:30 v/v and flow rate of mobile phase 1.0 ml/min with isocratic elution. The signal of eluents was observed at 290 nm by using diode array detector. Results: The retention time of Tolperisone hydrochloride and Etoricoxib were found to be 2.826 min and 7.566 min, respectively. The linearity ranges for both drugs were found to be 5-15 μg/ml and the percent recoveries were found to be 99.39% and 99.15% for Tolperisone hydrochloride and Etoricoxib respectively. Various forced degradation conditions, such as alkali hydrolysis, acid hydrolysis, thermal degradation, photolytic degradation, and oxidative degradation, were applied to the drug ingredients and drug formulation. The degradants were efficiently separated from the drugs by using optimized chromatographic conditions. The developed method was validated as per recommendation parameters of International council on harmonization guidelines Q2(R1). Conclusion: The validation parameters indicate that the drug substances were efficiently separated from its degradants and developed method can be routinely applied for the simultaneous quantitative determination of Tolperisone hydrochloride and Etoricoxib in combined tablet formulation in the quality control laboratory.