SELECTIVE ASSAYS FOR QUANTITATION OF TENOXICAM IN PRESENCE OF ITS PHOTODEGRADATION PRODUCTS.

Tenoxicam, a thienothiazine oxicam, is a potent anti- inflammatory and antirheumatic drug. A comprehensive study on the photostability of tenoxicam is presented, including a comparison of three different methods (HPTLC/densitometry, HPLC, CE) developed for the photostability testing of the title compound. The stability indicating capability of the respective assays is proven with sample solutions forcedly degraded by artificial irradiation from a xenon source. The chromatograms and the electropherogram of the resulting solution, show tenoxicam well resolved from the degradation products. The methods are applied for testing the photostability of solutions containing tenoxicam in various concentrations (2 mg mL-1; 250 μg mL-1; 40 μg mL-1), and stored under different conditions. The stability of tenoxicam was found to be dependent on the nature of the light source, as well as on the concentration of the sample solution. The assays are validated and compared with respect to performance and precision. [ABSTRACT FROM AUTHOR]