Cyclodextrin enhanced spectrofluorimetric determination of fluoxetine in pharmaceuticals and biological fluids

The characteristics of host-guest complexation between methyl-beta-cyclodextrin and fluoxetine were investigated by fluorescence spectrometry. A 1:1 stoichiometry of the complex was established and association constant of 4.35x10(-3) M(-1) at 20 degrees C was calculated. A spectrofluorimetric method for the determination of fluoxetine, with a range of application between 40 and 1000 mug l(-1) was developed. Overall least squares regression was used to find the straight line that fitted the experimental data. The detection limit, according to the error propagation theory, was 9.6 mug l(-1) and the detection limit proposed by Clayton was 15.8 mug l(-1). Repeatability and relative standard deviation were also determined according to this theory, with satisfactory results. The method was successfully applied to the determination of fluoxetine in pharmaceuticals and biological fluids.