HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ANALYSIS OF ISOXICAM IN HUMAN-PLASMA AND URINE

A sensitive, selective and rapid high-performance liquid chromatographic procedure was developed for the determination of [the antiinflammatory agent] isoxicam in human plasma and urine. Acidified plasma or urine were extracted with toluene. Portions of the organic extract were evaporated to dryness, the residue dissolved in tetrahydrofuran (plasma) or acetonitrile (urine) and chromatographed on a .mu.Bondapak C18 column preceded by a 4-5 cm .times. 2 mm I.D. column packed with Corasil C18. Quantitation was obtained by UV spectrometry at 320 nm. Linearity in plasma ranged from 0.2-10 .mu.g/ml. Recoveries from plasma samples seeded with 1.8, 4 and 8 .mu.g/ml isoxicam were 1.86 .+-. 0.077, 4.10 .+-. 0.107 and 8.43 .+-. 0.154 .mu.g/ml with relative SD of 3.3, 2.5 and 5.4%, respectively. The linearity in urine ranged from 0.125-2 .mu.g/mlo. The precision of the method was 3.3-9.0% relative standard deviation over the linear range.