Sustainable and Stability Indicating Liquid Chromatography–Mass Spectrometry Method for the Quantitation of Delafloxacin in Pharmaceutical Formulations

A sensitive, precise, accurate, and green analytical HPLC–ESI–MS method for the quantification of delafloxacin and its degradation products in pharmaceutical dosage forms has been optimized and validated. The best separation was achieved with isocratic elution, the mobile phase is composed of a mixture of 0.1% trifluoroacetic acid in water and acetonitrile 65:35 (v/v), the flow rate is 0.5 mL min−1, and the column used is Kinetex Core‐Shell C18 (250 × 4.6 mm, 5 µm). Forced degradation studies were performed to prove that the method indicates stability. The pharmaceutical substance is prone to oxidative (H2O2 3%), acidic (HCl 0.1 M), and basic (0.1 M) conditions. Delafloxacin proved to be susceptible to acidic (HCl 0.1 M), basic (0.1 M), and oxidative (H2O2 3%) conditions. The proposition of the structures of degradation products has been based on the MS spectrum and the known reactivity of delafloxacin in the oxidative medium. The validation of the analytical method was carried out following the International Conference on Harmonization guidelines. The method was validated in terms of specificity, precision, linearity, and accuracy. The limits of detection and quantification of delafloxacin are, respectively, 0.005 and 0.017 µg mL−1.