Stability-Indicating LC Assay and Determination of System Suitability Limits with a Robustness Test of Gemifloxacin Mesylate in Tablets

A stability-indicating liquid chromatographic (LC) method was developed and validated for quantitative determination of gemifloxacin mesylate (GFM) in coated tablets. The procedure was validated by specificity, linearity, accuracy, precision and robustness. Experimental design was used during validation to determinate method robustness and system suitability limits. The chromatographic method employed the Agilent Eclipse® XDB RP-18 (150 x 4.6 mm; 5 μm) with a mobile phase consisting of 0.3%triethylamine (pH 3.0) and acetonitrile (80:20, v/v). GFM (drug and drug product) solutions were exposed to direct UV-A and UV-C radiation, alkaline and acid hydrolysis, thermal stress and an oxidation effect by hydrogen peroxide to evaluate method stability-indication, and peak purity tools were utilized to verify peak purity. There was no interference of the excipients and degradation products in the determination of the active pharmaceutical ingredient. The method showed good recovery and precision (intra- and inter-day), and the response was linear over a range from 5.0 to 40.0 μg mL-1. The GFM photodegradation kinetics in methanol showed a first order process, with a degradation rate constant (k) of 0.0352 min-1 and a t90%of 3.01 min. The results confirm that the proposed stabilityindicating method can be used for routine analysis for quantitative determination of GFM in coated tablets. The results demonstrated the robustness of the analytical method and the worst robustness results were utilized for the determination of system suitability limits.