Square-wave adsorptive stripping voltammetric determination of the anti-inflammatory drug lornoxicam.

Abstract

Lornoxicam (I) (6-chloro-4-hydroxy-2-methyl-N-2-pyridyl-2H-thieno[2,3-e]thiazine-3-carboxamide-1,1-dioxide) is a new non-steroidal anti-inflammatory drug (NSAID) of the oxicam class with analgesic, anti-inflammatory and antipyretic properties. 1 It is distinguished from established oxicams by a relatively short elimination half-life, which may be advantageous from a tolerability standpoint.2 Increasingly, the monitoring of drugs is being considered a rational approach for the correct management of patient therapy. Regarding lornoxicam, attention must be given in this respect, because determining the relationship between the drug dose and the drug levels imparts an important aspect concerning the success of the treatment. Accordingly, chromatographic methods employing ultra-violet and electrochemical detection have been reported for determining the drug in biological fluids. 3,4 A literature survey revealed that no attempt has been made to study the voltammetric behavior of lornoxicam. However, the polarographic and adsorptive behaviors at a hanging mercury drop electrode of two oxicams, piroxicam and tenoxicam, have been reported. 5-9 Differential pulse polarography has been used for the piroxicam determination in drug formulation and in urine, 7 7 Square-wave (SW) and square-wave adsorptive stripping voltammetric determinations at a hanging mercury drop electrode have also been employed for the determination of piroxicam and tenoxicam in urine. 8 8 Recently, the differential-pulse polarographic determination of tenoxicam in blood has been reported. 9 The objective of the work described in this paper was to investigate the electrochemical behavior of lornoxicam and devise a suitable square-wave voltammetric method for the analysis of lornoxicam in spiked serum samples.