Abstract

Vaishnavi Khushalrao Jadhao, Ravindra H. Kale, Kailash R. Biyani

ABSTRACT

The present study describes the development and validation of a simple, precise, and robust reverse-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous estimation of Bilastine and Montelukast in bulk and pharmaceutical dosage forms. Bilastine, a selective H1-receptor antagonist, and Montelukast, a leukotriene receptor antagonist, are widely prescribed in the management of allergic conditions. Their combined therapeutic use necessitates a reliable analytical method for routine quality control and regulatory compliance. Chromatographic separation was achieved using a C18 column (250 mm × 4.6 mm, 5 µm) with an isocratic mobile phase consisting of acetonitrile and phosphate buffer (pH 3.5) in a 60:40 ratio, at a flow rate of 1.0 mL/min. Detection was carried out at 230 nm, with retention times of 3.25 minutes for Bilastine and 5.20 minutes for Montelukast. The method was validated according to ICH Q2(R1) guidelines. Linearity was established across the ranges of 10–100 µg/mL for Bilastine and 10–100 µg/mL for Montelukast, with correlation coefficients (R²) greater than 0.999. Accuracy was confirmed through recovery studies, with mean recoveries between 98–102%. Precision studies demonstrated %RSD values below 2%, confirming reproducibility. Specificity was verified by the absence of interference from excipients, while robustness testing under deliberate variations in chromatographic conditions showed no significant changes in retention time or peak symmetry. System suitability parameters, including resolution, theoretical plates, and tailing factors, were all within acceptable limits. In conclusion, the developed RP-HPLC method is accurate, precise, specific, and robust, making it suitable for routine quality control analysis of Bilastine and Montelukast in bulk and dosage forms. Its compliance with ICH guidelines ensures reliability and applicability for pharmaceutical industries and regulatory submissions.