Sensitive high-performance liquid chromatographic determination of indomethacin in human plasma. Pharmacokinetic studies after single oral dose.

A sensitive high-performance liquid chromatographic assay for the specific determination of indomethacin at concentrations down to 20 ng/ml in human plasma is described. This method has been applied to investigate the disappearance of indomethacin from plasma of ten subjects following the intake of two formulations (Indocid and generic form). An initial half-life of 1.32 +/- 0.44 h-1 was found which is in good agreement with other findings, but the terminal phase was much longer (13.6 +/- 6.9 h-1) than previously reported. There is no difference between the two galenic forms (p less than 0.001).