Abstract
A novel sensitive fluorimetric method was investigated for the assay of Cefixime (CEF) using Calcein (CA) fluorescence (FL) probe. Fluorescent bio-macromolecules interact with medicinally important compounds (antibiotics), causing the FL to quench due to complex formation between them. Based on this assumption, a novel, simple, rapid, stable and selective fluorimetric method was developed for the determination of CEF. Under the optimum conditions, the quenched FL intensity was linear with the concentration of CEF in the range of 1.33 x 10(-7) to 1.60 x 10(-4) mol.L-1 (r = 0.9824, n = 5), and the detection limit, defined as three times the S.D for the reagent blank signal, was 6.2 x 10(-8) mol.L-1 CEF. The proposed method was applied for the quantification of CEF in pharmaceutical formulations (Cefix and Suprax tablets) and biological fluids (human serum and urine) with high average% recovery. For example, in pharmaceutical formulations Cefix and Suprax, the average% recovery of CEF was 100.4 and 101.6, whereas the Cefix and Suprax average% recoveries in the human serum and urine sample were 102.5 and 103.5, and 102.4 and 99.1, respectively. The results were compared statistically with published methods, which showed no significant difference.