ABSTRACT
A new simple, rapid, precise reverse phase-high performance liquid chromatographic (RP-HPLC) and ratio spectra first derivative spectroscopy (1DD) methods has been developed for the simultaneous determination of Levocetrizine dihydrochloride (Levo) and Montelukast sodium (Mont) in bulk active pharmaceutical ingredient (API) as well as in tablet dosage form. In RP-HPLC method, separation was performed using phenomex-luna 5μ C8 (2) (100Å, 250 X 4.6 mm) column by using acetonitrile: 0.5% triethylamine in water (90:10 v/v) pH adjusted to 5.5 ± 0.1 with orthophosphoric acid. The flow rate was 0.8 ml/min with UV detection monitored at 231 nm. The retention time was 3.8 and 5.2 min for Levo and Mont respectively. In ratio spectra first derivative method, linearity range was found to be 2-32 μg/mL and 3-30 μg/mL for Levo and Mont respectively. From the first derivative (1DD) suitable wavelength was selected and amplitudes were measured at 240 nm and 281 nm for the assay of Levo and Mont by considering concentration of 18 μg/mL of Mont and 24 μg/mL of Levo as a suitable divisor, respectively. The validation of method was carried out according to ICH guidelines.