Separation and Simultaneous Quantitation of Montelukast Sodium and Ebastine in Tablets by using Stability-Indicating Liquid Chromatographic Method

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 Montelukast sodium and Ebastine in tablets. Methods: The chromatographic separation of drugs was attained by using Hypersil octadecyl silane C18 (250 x 4.6 mm, 5μm) column at room temperature. The composition of mobile phase was methanol, acetonitrile and 0.02M ammonium acetate buffer (pH 5.5 adjusted with dilute acetic acid) in the ratio of 80:15:05 v/v/v and flow rate of mobile phase 1.0 ml/min with isocratic elution. The signal of eluents was observed at 244 nm by using diode array detector. Results: The retention time of Montelukast sodium and Ebastine were found to be 4.28 min and 6.63 min, respectively. The linearity ranges for both drugs were found to be 10-50 μg/ml and the percent recoveries were found to be 99.16% and 100.12% for Montelukast sodium and Ebastine respectively. The drug substances and drug products were treated with various forced degradation conditions like acid hydrolysis, alkali hydrolysis, oxidative degradation, thermal degradation and photolytic degradation. The degradants were efficiently separated from the drugs by using optimized chromatographic conditions. The developed method was validated as per recommendation parameters of International conference 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 Montelukast sodium and Ebastine in combined tablet formulation in the quality control laboratory.