Development and Validation of a Novel LC Method for the Simultaneous Determination of Montelukast and Doxofylline in Bulk and Pharmaceutical Dosage Forms

A novel rapid HPLC method was developed for simultaneous determination of montelukast and doxofylline in bulk and pharmaceutical dosage forms. Development of an analytical method for simultaneous estimation of drugs requires a lot of efforts and of course it is a challenging task. The method was developed by using C18 (150 mm × 4.6 mm, 5 \(\mu\)\(\mu\)m) column; mobile phase consisting of methanol and phosphate buffer at pH 4.5; the flow rate of 1.0 mL/min and ultraviolet detection at 280 nm. Both drugs were sufficiently resolved having retention time of 4.7 min and 1.9 min for montelukast and doxofylline, respectively. The method was validated as per ICH Guidelines for various parameters like precision, linearity, accuracy, ruggedness, and robustness. The validated method was applied to the commercially available pharmaceutical dosage form and obtained the desired result. It is concluded that this method can be used by the industries and academic institutions for their combination drug estimation, which is fast as well as novel.