Measurement of Tamsulosin in Human Serum by Liquid Chromatography–Tandem Mass Spectrometry

The study developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to measure tamsulosin levels in human serum, achieving high sensitivity with a lower limit of quantitation of 0.2 ng/mL and a lower limit of detection at 0.13 ng/mL. The method used d9-finasteride as an internal standard and required only 100 μL of serum, demonstrating high recovery rates and specificity. It was validated with samples from 3 treated and 3 untreated male subjects, showing reliable results within quantitation limits. This assay provided a simple, efficient, and sensitive alternative for clinical studies of benign prostatic hyperplasia (BPH) treatment, with potential adaptation for measuring finasteride.