Simultaneous Monitoring of Selective Serotonin Reuptake Inhibitors in Human Urine, Plasma and Oral Fluid by Reverse-Phase High Performance Liquid Chromatography

Abstract

A simple and rapid reverse-phase high-performance liquid chromatography method is developed for the simultaneous determination of selective serotonin reuptake inhibitors (sertraline, citalopram, paroxetine and fluoxetine) in urine, plasma and oral fluid. Separation was performed on a Crestpack-18 column (4.6 × 250 mm × 5 µ) within 17.5 min. The mobile phase was composed of water (50 mL) [with glacial acetic acid (0.15 mL) + triethyl amine (0.30 mL)]-acetonitrile (40 mL)-methanol (10 mL), delivered isocratically (0.6 mL/min) at 270 nm. Liquid-liquid extraction was performed for isolation of analytes from biofluids. The developed methodology was validated in terms of sensitivity, linearity, accuracy, precision, stability and selectivity. The calibration curves were linear in the range of 5-1,000 ng/mL for all the compounds in three matrices, with coefficients of determination between 0.9991 to 0.9998. The average extraction recoveries for all the four analytes were above 90%. The limits of detection and limits of quantification were in the ranges of 0.02-1.20 and 0.12-2.51 ng/mL, respectively. The intra-day and inter-day variation coefficients were less than 8.0 and 11%, respectively. Moreover, the results were compared statistically for each analyte in three matrices and found to be equivalent, which signifies the absence of matrix effect. Thus, the method can be applied for the determination of selective serotonin reuptake inhibitors in urine, plasma and oral fluid for routine therapeutic and toxicological screening.

Simultaneous Quantification of Citalopram and its Main Metabolite, Desmethylcitalopram, in Human Saliva by UHPLC

“…When LLE with dichloromethane was applied, the recovery of CIT was similar to findings in the literature, where ether was used for extraction [19]. It can, therefore, be confirmed that absolute recovery obtained in this study is consistent with literature data.…”

“…These relatively low values may be due to the simultaneous determination of nine antidepressants and some of their metabolites in saliva. The recovery of CIT and DCIT from plasma following LLE procedure stood at approximately 77 and 53%, respectively [8], while the efficiency of extraction from saliva for citalopram was 94% [19].…”

“…In the quantification of CIT alone in saliva using UV detection, LOD was found to be between 0.6 ng/mL [19] and 5.48 ng/mL [20], whereas LOQ varied between 1.82 ng/mL [19] and 18.25 ng/mL [20]. Comparable values of LOQ (2 ng/mL) were attained with LC-MS [4].…”

“…Another biological material often used for the analysis of CIT and DCIT is urine [3, 10, 15], but have also been determined in hair and nails from living bodies [16] and different tissues or organs such as muscle, brain and kidney procured from the dead [17, 18]. Saliva is an underrated biological material which can also be used for the monitoring of CIT and DCIT concentrations, but so far only CIT has been determined in oral fluid [4, 19, 20]. Saliva is readily available, indicates biological activity in the human organism and only allows the unbounded fraction of the drug to be determined, i.e .…”

“…Thus far, various extraction procedures have been applied for the isolation of both CIT and DCIT from blood and urine, i.e . Solid-Phase Extraction (SPE) [5, 6, 12-14, 17, 18, 20], its modification such as SBSE ( Stir Bar Sorptive Extraction ) [10, 15], and Liquid-Liquid Extraction (LLE) [3, 8, 9, 16, 19, 21]. Biological samples have also been purified using deproteinization with organic solvents [7,11].…”