Determination of gliclazide in human serum by high-performance liquid chromatography using an anion-exchange resin

A method for the routine clinical examination of serum gliclazide by high-performance liquid chromatography (HPLC) on a column packed with a macroporous anion-exchange resin, Diaion CDR-10, was developed. The elution was performed with acetonitrile-methyl alcohol-1.2 M ammonium perchlorate (4:3:7, v/v/v) at a flow-rate of 0.4 ml/min. The retention time of gliclazide was 15 min. It seems that the retention mechanism of gliclazide under the HPLC conditions described is not only ion-exchange mode but reversed-phase mode between the anion-exchange resin and the mobile phase. The detection limit of gliclazide was 0.2 microgram/ml in plasma. The coefficient of variation for the within-day assay was 5.0% (0.2 microgram/ml, n = 8). The decay curve of serum gliclazide in diabetic patients was determined.