REVERSED PHASE LIQUID CHROMATOGRAPHIC DETERMINATION OF MELOXICAM IN HUMAN PLASMA AND ITS PHARMACOKINETIC APPLICATION

Abstract

A simple, rapid, specific and reliable high performance liquid chromatographic assay of meloxicam in human plasma has been developed. Reversed phase chromatography was conducted using a mobile phase of methanol:phosphate buffer (60:40) V/V, pH 3.2, adjusted with phosphoric acid, UV detection at 346 nm. The drug after extraction from plasma was chromatographed using a C18 reversed phase analytical column. The average recoveries of Meloxicam from spiked plasma in the concentration range from (0.04–0.8) μg/ml was 93.33% and their respective CV was 2.86%. Regression analysis for the calibration plot for plasma standards obtained on three different days for the drug concentrations between (0.04–0.8)μg/ml indicated excellent linearity (r > 0.9996) and the coefficient of variation of the slopes of the three lines was < 2%. Analysis of variance of the data showed no detectable difference in the slopes of the three standard plots (F = 2.9, P > 0.01). The high correlation coefficients and the similarities in the slopes are good indication of the excellent reproducibility and linearity of the proposed method. The proposed method was applied to study the bioequivalence of a commercial product of meloxicam using as reference standard the innovator drug product. The study was conducted on using two tablets (2 × 7.5 mg) of each of the commercial product and the reference standard in a two-way open randomized crossover design involving twelve volunteers. The criteria used to assess bioequivalance of the two products were AUC(0 − ∞), Cmax, Tmax, t1/2 and K. The obtained values for these parameters were 4.225 ug.hr/ml, 0.711 ug/ml, 2.5 hour, 1.827 hour and 0.364 hr−1 for product A. Whereas for product B they were, 4.18 ug.hr/ml, 0.683 ug/ml, 2.5 hour, 0.407 hour and 0.303 hour−1.