Flow-injection spectrophotometric methods for the determination of tenoxicam

Two sensitive and rapid flow-injection spectrophotometric methods are proposed for the determination of tenoxicam (TX). In the first method, a Fe(III)–tenoxicam complex is formed in a methanolic medium and the absorbance is measured at 540 nm, while the second method involves measurement of the absorbance at 355 nm of a solution containing the drug in hydrochloric acid medium. In both methods, the peak heights were proportional to tenoxicam concentration over the ranges 7.0–320 and 0.5–8.5 mg l −1, respectively. The methods have been applied to the routine determination of the drug in dosage forms.