Abstract

This article describes the development of flow injection methods for the determination of Candesartan Cilexetil using spectrophotometery and spectrofluorimetry in pharmaceutical formulations. The first method is based on the UV absorption at 270 nm in phosphate buffer containing cetyl trimethylammonium bromide (CTAB) and methanol at pH 6.5. The second method based on the fluorescence excitation and emission at 260 and 384 nm respectively, in phosphate buffer containing sodium dodecyl sulphate (SDS) and methanol at pH 4.0. Calibration graphs were linear over the concentration range of 0.1 to 4.0 µg/ml for UV-method and 0.03 to 2.0 µg/ml for fluorescence method. The limits of detection (3 s) of 0.01 µg/ml for both methods with sample throughput of 80 and 100/h were obtained respectively. The relative standard deviations of 1.2 to 3.2% (n = 4) for UV-method and 0.5 to 1.8% for fluorescence method were achieved in the concentration range studied. The developed methods were applied to pharmaceuticals and the results obtained were compared with HPLC reference method and no significant difference between these methods was observed at 95% confidence level.

Key words: Candesartan cilexetil, spectrophotometery, spectrofluorimetry, pharmaceuticals, flow injection analysis.