Determination of Paroxetine in Human Plasma by High-Performance Liquid Chromatography Using 7,7,8,8-Tetracyanoquinodimethane as the Derivatization Reagent

Paroxetine hydrochloride

Paroxetine hydrochloride (3S-trans)-3-[(1,3-benzodioxol-5-yloxy)methyl]-4-(4-fluorophenyl)-piperidine hydrochloride (or (-)-(3S,4R)-(4-(p-fluorophenyl)-3-[[3,4-(methylenedioxy)-phenoxy]methyl]piperidine hydrochloride), a phenylpiperidine derivative, is a selective serotonin reuptake inhibitor. Paroxetine is indicated for the treatment of depression, generalized anxiety disorder, obsessive-compulsive disorder, panic disorder, posttraumatic stress disorder, and social anxiety disorder. The physicochemical properties, spectroscopic data (1D and 2D NMR, UV, FT-IR, MS, PXRD), stability, methods of preparation and chromatographic methods of analysis of pharmaceutical, and biological samples of paroxetine are documented in this review. Pharmacokinetics, metabolism, and pharmacological effects are also discussed.

Modern bioanalytical methods for the rapid detection of antidepressants: SNRIs and SSRIs in human biological samples

Serotonin–norepinephrine-reuptake inhibitors (SNRIs) and selective serotonin-reuptake inhibitors (SSRIs) belong to a new generation of antidepressants used in the treatment of depression and other mood disorders. SSRIs act as reuptake inhibitors primarily via the inhibition of the neuronal reuptake of serotonin (5-HT) in the CNS. SNRIs have additional inhibitory activity at noradrenaline-reuptake sites. Different analytical methods for the routine monitoring and toxicological screening of SNRIs and SSRIs have been developed. Rapid quantification is a necessity for clinical use, allowing the possibility of diagnostics. This review focuses on recent advances of the methods that concern the determination of SSRIs and SNRIs in human biological samples. Sample preparation methodologies are discussed, because sample pretreatment is the most limiting and crucial step in analysis of biological matrices. Furthermore, information concerning the mechanism of action, side effects and toxicity are also given.

Determination of the antidepressant paroxetine and its three main metabolites in human plasma by liquid chromatography with fluorescence detection

A high-performance liquid chromatographic method has been developed for the determination in human plasma of the specific serotonin reuptake inhibitor (SSRI) antidepressant paroxetine and its three main metabolites (M1, M2, M3). Fluorescence detection was used, exciting at lambda = 294 nm and monitoring emission at lambda = 330 nm for paroxetine (lambda(exc) = 280 nm, lambda(em) = 330 nm for M1 and M2; lambda(exc) = 268 nm, lambda(em) = 290 nm for M3). Separation was obtained on a reversed-phase C18 column using a mobile phase composed of 66.7% aqueous phosphate at pH 2.5 and 33.3% acetonitrile. Imipramine (lambda(exc) = 252 nm, lambda(em) = 390 nm) was used as the internal standard. A careful pre-treatment of plasma samples was developed, using solid-phase extraction with C8 cartridges (50 mg, 1 mL). The calibration curves were linear over a working range of 2.5-100 ng mL(-1) for paroxetine and of 5-100 ng mL(-1) for all metabolites. The limit of detection (LOD) was 1.2 ng mL(-1) for PRX and 2.0 ng mL(-1) for the metabolites. The method was applied with success to plasma samples from depressed patients undergoing treatment with paroxetine. Hence, the method seems to be suitable for the therapeutic drug monitoring of paroxetine and its main metabolites in depressed patients' plasma.