Determination of neostigmine in human plasma and cerebrospinal fluid by high-performance liquid chromatography with ultraviolet detection

A high-performance liquid chromatographic assay coupled with ultraviolet de tection has been developed for the determination of neostigmine in human pl asma and cerebrospinal fluid. A novel solid-phase extraction procedure was first used for this analyte and allowed good recovery (89+/-4.5%) together with ease and speed of execution. The method was sensitive, reproducible (C .V.<4.5%) and accurate (100+/-6.6%) over the range 2.6-167.0 ng/ml neostigm ine concentrations in plasma or cerebrospinal fluid, and was applied succes sfully to study the pharmacokinetics of neostigmine in patients suffering f rom chronic postoperative abdominal pain. (C) 1999 Elsevier Science B.V. Al l rights reserved.