An innovative Impurity profiling method development for identification and quantitation of Bilastine and Montelukast Sodium with related impurities by RP-HPLC.

A simple, rapid, precise and rugged reverse phase high performance liquid chromatographic (RP-HPLC) method has been developed for identification and quantitation of Bilastine and Montelukast active pharmaceutical ingredients along with related impurities from bulk and tablet dosage form. The separation of analytes and impurities peaks were achieved using a HPLC system equipped with photo diode array detector. A Hypersil BDS C-18 column used as stationary phase and 2mM ammonium acetate buffer: Acetonitrile used as a mobile phase operated in a gradient mode at flow rate of 0.8ml/min to 1.0ml/min with 30°C column temperature. Injection volume was 10 µl and chromatograms were analyzed at 275 nm with run time of 25 min. Under above conditions the retention time (RT) of Bilastine and Montelukast was 9.4 and 16.5 min respectively. Spiked Bilastine and Montelukast impurities i.e. BLS imidazole imp, BLS DEO imp, BLS TSO imp and MTK sulphoxide impurities were well separated at RT 1.1 min, 4.6 min, 13.5 min, and 14.3 min respectively. The calibration curve of Bilastine, Montelukast, Bilastine DEO impurity and Montelukast sulphoxide impurities were found linear with regression coefficient more than 0.999. Accuracy was determined by recovery studies and found between 95-105%. The sample was found stable in aqueous solution over 23 hours. In all the forced degradation conditions, Bilastine and Montelukast were detected along with known and unknown impurities, which were well separated from each others with high resolution. The recorded observations were proved that the proposed analytical method is reliable for quantitation and impurity profiling of Bilastine and Montelukast from bulk mixture and tablet dosage form. [ABSTRACT FROM AUTHOR]