A new simple, rapid, precise and accurate assay method was developed for simultaneous estimation of Bilastine and Montelukast in pure form and tablet form. The analytes were separated by RP HPLC on a RP-Purosnosphere C18 column (5 µm, 4.6mm* 250 mm).The mobile phase was Acetonitrile: water: methanol (30:25:45 v/v) at 1.1 ml/min flow rate satisfactorily resolve the tertiary mixture. The UV detector was operated at 214 nm for the determination of all the drugs. Linearity, accuracy and precision were found to be acceptable over the concentration ranges of 10-50 µg/ml for Bilastine and 5-25 µg/ml for Montelukast with a R2 0.9960 and 0.9974 values respectively. The optimized methods proved to be specific, robust and accurate for the quality control of drugs in bulk drug and pharmaceutical formulations.

Keywords: Bilastine, Montelukast sodium, ICH, Validation etc.