Spectrofluorimetric Assay of Temafloxacin in Pharmaceutical Formulations and in Serum

A simple and rapid assay is described for the determination of temafloxacin, 1-(2,4-difluorophenyl)-6-fluoro-7-(3-methylpiperazin-1-yl) 1,4- dihydro-4-oxoquinolin-3-carboxylic acid hydrochloride, in pharmaceutical formulations and in serum, based on the fluorescence emission of the drug. The assay of pharmaceuticals involves the measurement of fluorescence at 460 nm of the sample diluted in 0.1 H₂SO₄ with an excitation wavelenght of 276 nm and the assay of serum involves the use of the synchronous spectrofluorimetric method. An appropriate selection of the difference between the wavelengts of both monochromators (ΔΛ) allowed the direct and rapid determination of temafloxacin in serum samples without previous extraction. The procedure, which has been shown to be accurate, precise and sensitive requires only 0.25–0.4 ml of serum depending on the drug concentration.