Development of expeditious RP-HPLC method for simultaneous estimation of bilastine and montelukast in fixed dosage combination

Background: Bilastine and montelukast are used to treat allergic rhinitis and chronic urticaria. Due to the recent increase in highly allergic disorders, demand for this combination has risen. Therefore, for regular quality control analysis, a new, rapid, and cost-effective method has become crucial. Compared with the previously reported methods, the present method is ultra-fast, with well-separated peaks within ̴ 3.0min and a total run time of 8 min. Because it uses a methanol-buffer system, it is less expensive, more environmentally friendly, and safer than an acetonitrile-based method. This study presents a rapid, specific, and economical “reversed-phase high-performance liquid chromatography (RP-HPLC)” method for the simultaneous estimation of Bilastine and Montelukast. Methodology: The chromatographic conditions for the separation of drugs are achieved by leveraging a tailored composition of mobile phase with methanol and acidic phosphate buffer with a volume ratio of 55:45v/v, the “Zorbax C18 column (4.6×150mm, 5µ)” maintained at 35ºC with an optimized flow rate of 1.0 mL/min and detected at a wavelength of 260 nm. The injection volume is 10 µL, and the run time is 8 min. Results and Discussion: The retention times for the drugs bilastine and montelukast are 2.061 and 2.462 min, respectively. Linearity is observed with correlation coefficients of 0.9993 and 0.9994, respectively, for montelukast and bilastine at 1-5 µg/mL and 100-500 µg/mL. Efficient separation and quantification of these two therapeutically important compounds were achieved in this method. Conclusion: The developed analytical method has been validated in accordance with International Conference on Harmonisation (ICH) guidelines, demonstrating satisfactory performance with respect to specificity, accuracy, precision, linearity, and robustness. This novel RP-HPLC approach provides a valuable tool for pharmaceutical analysis and quality control.