Therapeutic drug monitoring of ziprasidone

A new high performance liquid chromatographic (HPLC) method with column switching was developed for quantitative analysis of the new antipsychotic drug ziprasidone in serum. On-line sample clean-up was conducted on silica C8 material (20µm particle size). The drug was separated on ODS Hypersil C18 material (5µm; column size 250×4.6mm I. D.) within 20min. The limit of quantification was 10 ng/ml. At therapeutic concentrations of the drug, the inter-assay reproducibility (coefficients of variation) of quality control samples was below 10%. The application of the method on serum of 41 patients treated with ziprasidone (mean±SD dose 117±47mg/day) revealed serum concentrations between 5 and 424 ng/ml (mean±SD, 71±75 ng/ml, median 52 ng/ml, 25th and 75th percentile 31 to 81 ng/ml, respectively. This new method is suitable for TDM and pharmacokinetic studies of ziprasidone.