The quantitation of atorvastatin in human plasma by solid phase micro-extraction followed by LC-MS/MS and its application to pharmacokinetics study

Determination of atorvastatin in human plasma using LC-MS/MS has been widely accepted as an effective methodowing to its practical applicability in routine drug analysis in pharmacokinetic and pharmacogenetic study. Nevertheless, themethod sensitivity can be compromised when limited sample volume is available. This problem is typically encountered inpharmacokinetics studies for which only a small volume of plasma sample can be obtained. Drug extraction from humanplasma was performed with the aid of reversed-phase C18 solid phase micro-extraction. The detection was accomplished byLC-MS/MS. The need of plasma volume of less than 250 μl for each sample made it possible to decrease the sample preparation time. The method was successfully validated and proved appropriate for the analysis of atorvastatin in human plasmaand can be applied to pharmacokinetics and pharmacogenetics study.