Abstract
Two spectrofluorimetric methods were developed for the determination of gemifloxacin mesylate (GFX) in pure and dosage forms. The native fluorescence of GFX allow the determination of 0.05-2.25 mu g/mL of this drug in aqueous solution containing borate buffer (pH 8), with lambda(exc) = 272 nm and lambda(em) = 400 nm. Micelle-enhanced fluorescence led to 700% higher analytical signals in presence of sodium dodecyl sulphate (pH 9), which allow the determination of 0.001-0.12 mu g/mL GFX with lambda(exc) = 272 nm and lambda(em) = 400 nm. Both methods were successfully applied to GFX determination in pharmaceutical preparations. The methods were extended to stability study of GFXX. The drug was exposed to acidic, alkaline, oxidative and photolytic degradation according to ICH guidelines. The rate of GFX degradation was found at its highest in acidic condition, and in its lowest in the neutral one. It was, however, found to be stable under dry heat and photolytic degradation conditions.