Determination of tamsulosin in human plasma by liquid chromatography/tandem mass spectrometry and its application to a pharmacokinetic study
Choi CI, Lee HI, Bae JW, Lee YJ, Byeon JY, Jang CG, Lee SY. J Chromatogr B Analyt Technol Biomed Life Sci. 2012 Nov 15;909:65-9. doi: 10.1016/j.jchromb.2012.10.012. Epub 2012 Oct 13.


School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea.


Tamsulosin, a selective α(1)-adrenoceptor antagonist, is used for the treatment of benign prostatic hyperplasia (BPH). We developed and validated a rapid, sensitive, and simplified liquid chromatography analytical method utilizing tandem mass spectrometry (LC-MS/MS) for the determination of tamsulosin in human plasma. After liquid-liquid extraction with methyl t-butyl ether, chromatographic separation of tamsulosin was achieved using a reversed-phase Luna C(18) column (2.0mm×50mm, 5μm particles) with a mobile phase of 10mM ammonium formate buffer (pH 3.5)-methanol (25:75, v/v) and quantified by MS/MS detection in ESI positive ion mode. The flow rate of the mobile phase was 200μL/min and the retention times of tamsulosin and the internal standard (IS, diphenhydramine) were 0.8 and 0.9min, respectively. The calibration curves were linear over a range of 0.01-20ng/mL (r>0.999). The lower limit of quantification using 500μL of human plasma was 0.01ng/mL. The mean accuracy and precision for intra- and inter-day validation of tamsulosin were both within acceptable limits. The present LC-MS/MS method showed improved sensitivity for quantification of tamsulosin in human plasma compared with previously described analytical methods. The validated method was successfully applied to a pharmacokinetic study in humans.