Rapid method for the determination of piroxicam in rat plasma using high-performance liquid chromatography.

A previously published method was used for the determination of piroxicam in plasma samples obtained from rat. The sample preparation involved liquid extraction, centrifugation and evaporation. Separation of piroxicam from internal standard occurred on a reversed-phase C18 column with a mobile phase consisting of methanol-phosphate buffer pH 2 (45:55). The detection limit of the assay was 0.02-20 micrograms/ml. The assay linearity was good (typically r = 0.9992). The method was applied for determination of piroxicam in rats after administration of an oral dose of 2 mg/kg piroxicam.