Study on fluorescence characteristics of duloxetine hydrochloride.

The fluorescence characteristics of duloxetine hydrochloride are studied in this paper. The fluorescence emission spectra of duloxetine demonstrate that intramolecular charge-transfer takes place between thiophene ring and napthalenyloxy group upon irradiation. The effects of excitation light, solvent system, variation of solution pH value, metal ions and vitamin C on the fluorescence spectra of duloxetine hydrochloride are elucidated, respectively. A spectrofluorometric method of quantitative determination of duloxetine in dosage form is reported for the first time, the linear range is 7.14 x 10(-8)mol/L to 1.43 x 10(-5)mol/L, the linear correlation coefficient r is equal to 0.9997, and the detection limit is 3.5 x 10(-8)mol/L. The accuracy and the precision are satisfactory.