Development and validation of UPLC‐MS/MS method for simultaneous determination of gestodene and ethinyl estradiol in rat plasma

Abstract

A selective and sensitive ultra-performance liquid chromatography method with tandem mass spectrometric detection for simultaneous determination of gestodene (GES) and ethinyl estradiol (EE) in rat plasma was developed and validated. GES, EE and the internal standard, norgestrel, were extracted with ethyl acetate, derivatized (EE only) with dansyl chloride and then back-extracted into diethyl ether-hexane (2:1, v/v). The separation was performed on an ACQUITY UPLC BEH C(18) column with gradient elution using mobile phase consisting of acetonitrile and water (both containing 0.1% formic acid). The detection was carried out by means of electrospray ionization (ESI) mass spectrometry in positive ion mode with multiple-reaction monitoring. Calibration curves of GES and EE were linear (r(2) >or= 0.99) over the concentration ranges 1.59-159 and 0.196-78.4 ng/mL, respectively. The intra- and inter-day precisions were not more than 6.9 and 12.9% for GES and 10.6 and 9.0% for EE, and the accuracies were -2.5-8.0% for GES, and -7.2-0.19% for EE, respectively. The method herein described was superior to previous methods and was applicable to the pharmacokinetic study of GES and EE in rats.

UPLC–QTOF/MS-based screening and identification of the constituents and their metabolites in rat plasma and urine after oral administration of Glechoma longituba extract

“…In a previous study, the metabolism of some compound had been reported by this multiple combination technique method [21,22], while there has been no fully integrated study of the metabolite of multiple components in CHMs. Metabolite identification has been greatly improved by the availability of modern mass spectrometers that are capable of providing high resolution (15,000 at full width at half maximum) and accurate mass (error < 5 ppm).…”

Dealing with matrix effect: should there be a cut‐off limit for signal ion suppression in quantitative assay validation?

“…In the example of sildenafil, the choice of deuterated internal standard (sildenafild 3 ) enabled a good assay performance in spite of a high signal ion suppression (Witjes et al, 2010). Norgestrel was selected as an internal standard for gestodene/ethinyl estradiol assay because of its structural resemblance to the analytes and structural properties that included ionization potential and comparable extraction recovery (Xiong et al, 2010). Interestingly, Nirogi et al (2009) chose to use two internal standards, namely rosuvastatin and propranolol, for the determination of emtricitabine, efavirenz and tenofovir.…”

Simultaneous determination of etonogestrel and ethinyl estradiol in human plasma by UPLC‐MS/MS and its pharmacokinetic study

“…Shou, Jiang, and Weng (2004) described an LC-MS/MS method for the analysis of EE2 with dansyl chloride derivatization. EE in combination with norethindrone has been determined by HPLC-MS/MS in human plasma using a derivatization agent by Li et al (2010). A bioequivalence study of generic formulation having EE and chlormadinone acetate has been reported by Bonn, Urte, Martin, and Lucio (2009) in healthy female subjects.…”