A Novel Polarity Switching LC-MS/MS Method for Simultaneous Quantification of Drospirenone and Estetrol: Application to Pharmacokinetic Studies in Human Plasma.
A sensitive, selective, and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using a polarity switch technique was developed and validated for the simultaneous determination of drospirenone (DSP) and estetrol (E4) in human plasma for the first time. Solid phase extraction (SPE) with Bond Elut PLEX...