A Simple and Sensitive HPLC Method for Antipyrine in Plasma

Abstract

A rapid, simple and sensitive high-performance liquid chromatographic (HPLC) method was developed for the determination of antipyrine in small volume (50 μl) 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 μm 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 μg/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%.