A SIMPLE AND SENSITIVE HPLC METHOD FOR ANTIPYRINE IN PLASMA

A rapid, simple and sensitive high-performance liquid chromatographic (HPLC) method was developed for the determination of antipyrine in small volume (50-mu-l) of plasma samples. Aminopyrine was employed as the internal standard. The sample preparation is a direct plasma protein precipitation procedure so is less tedious and rapid. The assay employs a column packed with a C18 reversed-phase material (5-mu-m Nucleosil) with an isocratic mixture of acetonitrile and water (25:75, v/v) as the mobile phase. The eluant was detected at 254 nm. The assay achieves the level of sensitivity (0.5-mu-g/ml) and accuracy required to obtain meaningful data about the single-dose pharmacokinetics of antipyrine in guinea pig and rat. The method gave high reproducibility with coefficients of variation less than 5%.