Stability-Indicating LC Method for Analysis of Lornoxicam in the Dosage Form

A simple, rapid, and precise method has been developed for quantitative analysis of lornoxicam (Lxm) in pharmaceutical dosage forms. Chromatographic separation of Lxm and its degradation products was achieved on a C₁₈ analytical column with 0.05% (v/v) aqueous trifluoroacetic acid–acetonitrile, 70:30 (v/v), as mobile phase. The flow rate was 1.0 mL min^?1, the column temperature 30 °C, and detection was by absorption at 295 nm using a photodiode-array detector. The number of theoretical plates and tailing factor for Lxm were 6,577 and 1.03, respectively. Lxm was exposed to thermal, photolytic, hydrolytic, and oxidative stress, and the stressed samples were analysed by use of the proposed method. Peak homogeneity data for Lxm in the chromatograms from the stressed samples, obtained by use of the photodiode-array detector, demonstrated the specificity of the method for analysis of Lxm in the presence of the degradation products. The linearity of the method was excellent over the range 10–200 μg mL^?1 Lxm. The correlation coefficient was 0.9999. Relative standard deviations of peak areas from six measurements were always less than 2%. The proposed method was found to be suitable and accurate for quantitative analysis of Lxm and study of its stability.