HPLC analysis of the second-generation antidepressant sertraline and its main metabolite N-desmethylsertraline in human plasma

A liquid chromatographic method with ultraviolet detection was developed for the analysis of the recent antidepressant sertraline and its main metabolite N-desmethylsertraline in human plasma. The analytes were separated on a C8 reversed phase column, using a mobile phase composed of acetonitrile and a 12.3 mM, pH 3.0 phosphate buffer containing 0.1% triethylamine (35:65, v/v). Clomipramine was used as the Internal Standard. Using a solid phase extraction procedure with C2 cartridges high extraction yields (> 94%) and good purification from matrix interference were obtained. Good linearity was obtained in the 7.5 - 250.0 ng/mL range for sertraline and in the 10 - 500 ng/mL range for N-desmethylsertraline. The analytical method was validated in terms of precision, extraction yield and accuracy. These assays gave RSD% values for precision always lower than 3.9% and mean accuracy higher than 90%. Thanks to its good selectivity, the method proved to be suitable for the analysis of plasma samples from patients treated with sertraline as either monotherapy or polypharmacy.