LC determination and pharmacokinetics of meloxicam

A simple and rapid HPLC assay method for the estimation of meloxicam in plasma was developed. The method totally eliminated the solvent extraction procedure. The plasma proteins were precipitated using perchloric acid (70%) and acetonitrile mixture (1:1 v/v) and the supernatant was directly injected to the HPLC system. The separation was achieved on a Lichrospher C₁₈ 5μ (125×4.0 mm) analytical column with a mobile phase of sodium acetate buffer (pH 3.3, 170 mmol):acetonitrile (62:38 v/v) mixture. Detection was by UV detector at 355 nm. The retention time observed for meloxicam and piroxicam (internal standard) were at 6.0 and 4.0 min, respectively. The response was linear over a range of 50-1500 ng ml^-1 in human plasma. The method was simple, specific, precise and accurate. The method was also used for the bioequivalence study of meloxicam formulation in healthy, human, Indian, male volunteers.