Fast and simple spectrophotometric methods for determination of gemifloxacin in the presence of its photocatalytic degradation products

Abstract

Gemifloxacin (GEM) is a fourth generation flouroquinolones (FQs) and is a novel antibacterial agent. The presence of GEM in hospital and industrial wastewater is associated with antibiotic resistance and genotoxicity. In this work, GEM was subjected to photodegradation using titanium dioxide nanoparticles (TiO2NP) / hydrogen peroxide (H2O2) as a catalyst under UV light. At the optimum conditions (pH 7.0, 254.0 nm for 45 ± 5 min), complete degradation, for elimination of the residual drug with antibacterial activity, has been achieved. Four spectrophotometric methods, namely; first derivative (D1), derivative ratio (DR), ratio difference (RD) and mean centering of ratio spectra (MCR), have been established for the determination of GEM in the presence of its photodegraded products. Specificity was assessed by determination of the synthetic mixtures with different ratios of photodegraded products. Accuracy, precision and linearity ranges were determined for each method as per International Conference on Harmonization (ICH) guidelines for analytical method validation. Linearity was achieved in the range of 1.00–20.00 µg/mL for D1, DR, and RD methods, and 1.00–25.00 µg/mL for MCR one. Satisfactory recoveries (approximately 100%) and RSD% values (< 2.00%) were obtained for accuracy and precision assessment, respectively. Cross validation of the proposed methods was performed using a reported validated spectrophotometric method. The proposed spectrophotometric methods were applied for the determination of GEM in its pure drug substance, tablet dosage form and in presence of its photodegraded products.