DEVELOPMENT AND VALIDATION OF ANALYTICAL METHOD FOR SIMULTANEOUS ESTIMATION OF MONTELUKAST AND DOXYFYLLINE BY RP-HPLC

The development and validation of a reverse-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous estimation of Montelukast and Doxofylline in pharmaceutical formulations were carried out. The method was optimized using a Waters HPLC system equipped with an auto-sampler and PDA detector (996 model). A Phenomenex Luna C18 column (4.6×250mm, 5µm) was employed for the separation of both drugs. The mobile phase consisted of acetonitrile and phosphate buffer (pH 4.6) in a 45:55 (v/v) ratio, with a flow rate of 1.0 ml/min. The wavelength for detection was set at 245 nm, and the injection volume was 10 µL. The column temperature was maintained at 35°C, and the total run time was 7 minutes. The method was validated as per ICH guidelines, and the results demonstrated excellent linearity, precision, accuracy, and robustness. The proposed method offers a simple, rapid, and reliable approach for the simultaneous estimation of Montelukast and Doxofylline in tablet dosage forms, and can be effectively used for quality control in pharmaceutical industries. Keywords: Montelukast and Doxofylline, RP-HPLC, Simultaneous Estimation, Pharmaceutical Dosage Forms, Waters HPLC.