Hantzsch Reaction–Based Fluorimetric Approach for Sensitive Determination of Besifloxacin in Pharmaceutical Eye Drops and Aqueous Humor

Abstract

An innovative and sensitive analytical tool (fluorimetric spectroscopy) for quantifying besifloxacin (BFC) in eye drops and aqueous humor is introduced. The method presented here utilizes a well-known derivatization reaction called Hantzsch reaction to activate BFC's fluorescence. All the factors affecting the sensitivity of the developed approach were optimized to boost the method's sensitivity. After optimizations, this reaction enables the fluorimetric determination (at 485 nm) of BFC in eye drops and spiked aqueous humor without any obstructions from the naturally present biointerferents. The dynamic range for BFC determination in the pure state is 0.15–1.0 (μg/mL), with detection and quantification limits of 0.02 and 0.05 (μg/mL), respectively. The approach exhibits favorable recovery rates in spiked aqueous humor (95.5% ± 1.15%–100.3% ± 0.50%).