A Rugged and Sensitive Bioanalytical Method for the Determination of Sertraline and N-desmethylsertraline in Human Plasma by LC-MS-MS
Authors
William S. Edgemond, Michael P. Sullivan, Christopher J.L. Buggé, David B. Garcia and Anders Ljungqvist
Purpose
Sertraline is a selective serotonin reuptake inhibitor (SSRI) used for the treatment of depression, obsessive compulsive disorder, and panic disorder. N -Desmethylsertraline is the less active principal metabolite of sertraline. We present a method for measuring sertraline and N -desmethylsertraline in EDTA human plasma by LC-MS-MS.
Method
Human plasma (0.2 mL) containing sertraline, N -desmethylsertraline and the internal standard ketamine was extracted with ethyl acetate/cyclohexane, 4:1. The organic layer was transferred, evaporated, reconstituted, and injected onto a YMC ODS AQ 50 x 4.6 mm HPLC column connected to a Sciex API 3000 LC-MS-MS in positive ion APCI mode. The mobile phase was acetonitrile/0.1 M ammonium acetate pH 6.2, 1:1 pumped at 1.0 mL/min. The precursor/product ions were monitored in MRM mode with a run time of approximately 2.5 minutes. The assay validation was performed over a range of 10 ng/mL to 400 ng/mL.
Results
No matrix interference was observed across the elution windows of the analytes. Ruggedness of the assay was tested with quality control (QC) samples analyzed over three days. The overall precision (%CV) of replicate QC samples was better than 9% for sertraline and better than 10% for N -desmethylsertraline for the QC pools. The %CV for four days at the lowest limit of quantitation (LLOQ) was 11.6% and 12.1% for sertraline and N -desmethylsertraline, respectively. The mean (n=6) correlation coefficients were 0.9984 and 0.9986, respectively, showing acceptable linearity over the 10 to 400 ng/mL range. Average extraction recovery was approximately 80% for both sertraline and N -desmethylsertraline. Stability tests (3 cycles of freeze/thaw, 6h bench top, 48h extract and 4 weeks at –20°C) demonstrated the compounds were stable in plasma during normal sample handling.
Conclusion
These data demonstrate a rugged, sensitive method for quantitating sertraline and N -desmethylsertraline in human plasma. Samples can be quickly processed for a fast analysis of a large number of samples.