Simple and rapid high-performance liquid chromatography analysis of propentofylline and its main metabolites in serum using a direct injection technique

A rapid, simple and reliable high‐performance liquid chromatography (HPLC) column‐switching method with UV detection (270 nm) for the simultaneous determination of propentofylline and its metabolites in human and rat sera was developed. The method involves direct injection of serum onto an HPLC column, which contains a shielded hydrophobic stationary phase for the separation of analytes from proteins in serum, and then loading the analytes onto a short octadecylsilylated silica gel (ODS) column using a switching valve. Propentofylline and its three metabolites in serum were separated from the serum components within 30 min after the injection. The detection limits (S/N = 3) of analytes spiked in human and rat sera ranged from 0.08 to 0.57 nmol/mL, and the net volume of serum used was 20 µL. The relative standard deviations for within‐ and between‐day variations using rat serum were less than 4.3 and 5.6%, respectively. The method was used to determine propentofylline and its main metabolites in rat serum after a single intravenous dose of propentofylline (5 mg/kg). Copyright © 1999 John Wiley & Sons, Ltd.