A rapid and sensitive liquid chromatography-tandem mass spectrometric assay for cycloserine in 50μL of human plasma: Its pharmacokinetic application.

Abstract This paper describes a simple, rapid and sensitive liquid chromatography/tandem mass spectrometry assay for the determination of cycloserine in human plasma using carbamazepine as internal standard (IS). Analyte and the IS were extracted from the 50 μL of human plasma via protein precipitation using acetonitrile. The chromatographic separation was achieved on a C 18 column by using a mixture of acetonitrile–0.5% formic acid buffer (60:40, v/v) as the mobile phase at a flow rate of 0.8 mL/min. The calibration curve obtained was linear ( r 2  ≥ 0.99) over the concentration range of 50–15,000 ng/mL. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. A run time of 2.5 min for each sample made it possible to analyze more number of samples in short time, thus increasing the productivity. The proposed method was found to be applicable to pharmacokinetic studies.