DETERMINATION OF MONTELUKAST SODIUM AND LEVOCETIRIZINE DIHYDROCHLORIDE IN COMBINED TABLET DOSAGE FORM BY HPTLC AND FIRST-DERIVATIVE SPECTROPHOTOMETRY

Two simple, rapid, precise, and reproducible methods were developed for the simultaneous determination of montelukast sodium and levocetirizine dihydrochloride in combined tablet dosage form. The first method was based on high performance thin layer chromatography using paracetamol as an internal standard. In this method, the precoated silica gel 60F254 aluminium plate was selected as the stationary phase and the mixture of ethyl acetate: methanol:triethylamine (5:5:0.02 v/v/v) was used as mobile phase. The detection was carried out at 240 nm. Beer's law was obeyed in the range of 400–1200 ng/spot for montelukast sodium and 200–600 ng/spot for levocetirizine dihydrochloride, respectively. The second method involved first derivative spectrophotometry. In this method, the zero-crossing technique was applied for the determination of montelukast sodium at 291.60 nm and for levocetirizine dihydrochloride at 238.20 nm. Both method passes f tests and t test. The proposed methods were validated statistically and by performing recovery study.