Development of a high‐performance liquid chromatography method with fluorescence detection for the routine quantification of tamoxifen, endoxifen and 4‐hydroxytamoxifen in plasma from breast cancer patients

Abstract

To date, several methods for the quantification of tamoxifen and its metabolites have been developed, most of which employ liquid chromatography tandem–mass spectrometry (LC–MS/MS). These methods are highly sensitive and reproducible, but are also time‐consuming and require expensive equipment; one of their main disadvantages is matrix ionization effects. A more viable option, particularly in developing countries, is high‐performance liquid chromatography coupled with UV or fluorescence detection. We developed and validated a method for simultaneous quantification of tamoxifen, endoxifen and 4‐hydroxytamoxifen based on high‐performance liquid chromatography with fluorescence detection in a reverse‐phase column. The method is rapid (16 min plus 5 min of column re‐equilibrium), accurate (80–100%) and precise (0.23–6.00%), and does not require any additional irradiation process. Sample pretreatment consists of protein precipitation with acetonitrile under alkaline conditions, employing only 200 μL plasma. The validated method's wide range allowed quantification of steady‐state levels in patients under standard tamoxifen treatment (20 mg/day). This assay is ready for application in clinical studies and routine quantification of tamoxifen, endoxifen and 4‐hydroxytamoxifen in healthcare institutions.

Analysis of tamoxifen and its main metabolites in plasma samples of breast cancer survivor female athletes: Multivariate and chemometric optimization

“…Regarding chromatography methods, such as liquid, gas, thin layer, and micellar chromatography combined with different detection systems, a number of analytical techniques have been implemented for separating and quantifying TAM and its metabolites [9][10][11][12][13]. Since these compounds are nonvolatile, the use of GC to analyze them requires a derivation step that is extremely time consuming, does not meet the principles of green chemistry, and has not been well received by researchers [10,11].…”

Electrophoretic deposition of polyaniline nanofibers on a stainless steel wire as an adsorbent for determination of tamoxifen by SPME/GC–FID in urine samples

“…However, there is an urgent need for a method for the determination of TMX in biological fluids and pharmaceutical samples, which requires the use of advanced analytical instruments. Liquid chromatography (LC) in combination with fluorescence or ultraviolet (UV) detection (Heath et al, 2014; Rangel‐Méndez et al, 2019; Sereshti et al, 2017), gas chromatography in combination with mass spectrometry analytical detection system (GC–MS) (Tauxe‐Wuersch et al, 2006), LC–MS/MS (Yong et al, 2020), GC with flame ionization detection (FID; Rodríguez et al, 2003), capillary electrophoresis (Sanders et al, 1997; Thang et al, 2015, 2016) and spectrophotometry and electrochemical techniques (Ahmed et al, 2020; Khudaish, 2020; Moghaddam et al, 2017; Radhapyari et al, 2013) are among the methods that have been utilized for determination and quantification of TMX. Thus, finding a fast, reliable and reproducible analytical process for ultra‐trace analysis of TMX in biological fluids is of great importance.…”