A capillary zone electrophoresis assay for the analysis of meloxicam has been developed and validated. The influence of buffer concentration, buffer pH, methanol as organic modifier, capillary temperature, applied voltage and injection time was systemically investigated in a fused silica capillary (i.d. 50 mum, total length 44 cm and effective length 35.5 cm). Optimum results were obtained with a 100 mM borate buffer (pH 8.5) containing 5% methanol, capillary temperature 25 degreesC, applied voltage 20 kV and injection time 3 s hydrodynamic injection. The detection wavelength was set to 205 nm. Diflunisal was used as internal standard. The method showed good selectivity, accuracy, precision, linearity and sensitivity according to the evaluation of the validation parameters. The method was applied to the determination of six pharmaceutical preparations including two dosage forms. The relative standard deviation of 7 replicate analyses for each sample was less than 0.66%. The results were compared with a spectrophotometric method reported in literature and no significant difference was found statistically. (C) 2002 Elsevier Science B.V. All rights reserved.