Highly sensitive spectrofluorimetric determination of lomefloxacin in spiked human plasma, urine and pharmaceutical preparations

A sensitive, simple and selective spectrofluorimetric method was developed for the determination of lomefloxacin in biological fluids and pharmaceutical preparations.The method is based on the reaction between the drug and 4-chloro-7-nitrobenzodioxazole in borate buffer of pH 8.5 to yield a highly fluorescent derivative that is measured at 533 nm after excitation at 433 nm. The calibration curves were linear over the concentration ranges of 12.5–625, 15–1500 and 20–2000 ng/mL for plasma, urine and standard solution, respectively.The limits of detection were 4.0 ng/mL in plasma, 5.0 ng/mL in urine and 7.0 ng/mL in standard solution. The intra-assay accuracy and precision in plasma ranged from 0.032 to 2.40% and 0.23 to 0.36%, respectively, while inter-assay accuracy and precision ranged from 0.45 to 2.10% and 0.25 to 0.38%, respectively. The intra-assay accuracy and precision estimated on spiked samples in urine ranged from 1.27 to 4.20% and 0.12 to 0.24%, respectively, while inter-assay accuracy and precision ranged from 1.60 to 4.00% and 0.14 to 0.25%, respectively. The mean recovery of lomefloxacin from plasma and urine was 98.34 and 98.43%, respectively. The method was successfully applied to the determination of lomefloxacin in pharmaceuticals and biological fluids.

Graphical abstractA simple and highly sensitive method is proposed for the fluorimetric determination of lomefloxacin in human plasma, urine and eye drops. The method involves the reaction of lomefloxacin with 4-chloro-7-nitrobenzodioxazole in borate buffer of pH 8.5 to give a highly fluorescent derivative that was measured at 433 nm using an excitation wavelength of 533 nm. The method was validated with the concentration range 12.5–625 ng/mL in plasma and 5–150 ng/mL in urine and the calibration curves were linear with correlation coefficients >0.999. The limits of detection were 6 ng/mL in plasma and 3 ng/mL in urine. The intra-assay accuracy and precision in plasma ranged from 0.032 to 2.40% and 0.23 to 0.36%, respectively, while inter-assay accuracy and precision ranged from 0.45 to 2.10% and 0.25 to 0.38%, respectively. The intra-assay accuracy and precision estimated on spiked samples in urine ranged from 1.27 to 4.20% and 0.12 to 0.24%, respectively, while inter-assay accuracy and precision ranged from 1.60 to 4.00% and 0.14 to 0.25%, respectively. The mean recovery of lomefloxacin from plasma and urine was 99.34 and 99.43%, respectively. The method is highly sensitive and specific. The method was successfully applied to the determination of lomefloxacin in pharmaceuticals and biological fluids.Figure optionsDownload full-size imageDownload as PowerPoint slide