Reliable HPLC method for therapeutic drug monitoring of frequently prescribed tricyclic and nontricyclic antidepressants

Smoking blunts sertraline response in depression: A prospective observational cohort study

Background

Smoking is common in patients of depression and is known to affect response to antidepressants. This study was undertaken to evaluate the effect of smoking on the antidepressant effect of sertraline.

Method

Patients with depression were divided into smoker and nonsmoker cohorts and followed up for 8 weeks. Serum sertraline levels were estimated using the high-performance liquid chromatography system. Response to treatment was evaluated with the Hamilton Depression Rating Scale (HAM-D).

Results

Serum sertraline levels did not differ between smokers and nonsmokers at 4 and 8 weeks. Nonsmokers responded better to sertraline than smokers after 8 weeks. Adverse drug reaction profile did not vary between the two groups and was not impacted by serum sertraline levels. Nonsmokers showed a greater fall in the HAM-D score than smokers.

Conclusion

This study found depression among smokers to be less responsive to sertraline. This was not explained by serum sertraline levels. Treatment of depression in smokers with sertraline might require higher doses and duration, with more frequent reviews.

Dispersive liquid-liquid microextraction (DLLME) for determination of tricyclic antidepressants in whole blood and plasma samples and analysis by liquid chromatography with diode array detector (LC-DAD)

Microextractions have been developed for the tricyclic antidepressants (TCAs) analysis in biological matrices, including dispersive liquid-liquid microextraction (DLLME). The proposed DLLME employed 490 µL of biological sample (whole blood or plasma), which were added 15 mg of NaCl, 10 µL of medazepam as internal standard (10 µg/mL) and 100 µL of 2 M NaOH. This mixture was homogenized by vortex (2800 rpm/10 s) and 400 µL of hexane (extractor solvent) with 600 µL of methanol (dispersing solvent) were added to the sample. After the vortex step (2800 rpm/5 s), an ultrasonic bath for 300 s was employed. Then, this content was centrifuged (10 min/10000 rpm), organic phase was collected and dried under air flow. After, 30 µL of the mobile phase was used for resuspension and 20 µL is injected into LC-DAD. This method was optimized and fully validated according to UNODC and SWGTOX guidelines, reaching limits of detection equivalent to analytical methodologies that employ mass spectrometry (MS). Also, it was applied in real cases involving suspected exposure to TCAs. So, the developed DLLME for the determination of TCAs in whole blood and plasma samples proved to be a simple, reliable, robust and reproducible method that can be used in toxicology and clinical laboratories.

Development of Visible Spectrophotometric Methods for the Determination of Tricyclic Antidepressants Based on Formation of Molecular Complexes with p-Benzoquinones

Tricyclic antidepressants are commonly employed in the management of major depressive disorders. The present work describes two visible (VIS) spectrophotometric techniques that utilize the formation of charge transfer complexes between four antidepressant compounds, namely, amitriptyline hydrochloride (AMI), imipramine hydrochloride (IMI), clomipramine hydrochloride (CLO), and trimipramine maleate (TRI) acting as electron donors and two p-benzoquinones, namely, p-chloranilic acid (pCA) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), serving as electron acceptors. The stoichiometry of the compounds produced exhibited a consistent 1:1 ratio in all instances, as established by Job's method. Molar absorptivities, equilibrium association constants, and several other spectroscopic properties were determined for all complexes. The developed spectrophotometric techniques were validated intra-laboratory and successfully applied for quantitative assessment of the four antidepressant active ingredients in several commercial pharmaceutical formulations. The methods are relatively simple, fast, and use readily available laboratory instrumentation, making them easily applicable by most quality control laboratories worldwide.

Toward Personalized Treatment of Depression: An Affordable Citalopram Test based on a Solid-Contact Potentiometric Electrode for at-Home Monitoring of the Antidepressant Dosage

Citalopram (CTLP) is one of the most common antidepressants prescribed worldwide. It has a narrow therapeutic window and can cause severe toxicity and mortality if the dosage exceeds the safe level. Reports indicated that at-home monitoring of citalopram dosage considerably benefits the patients, yet there are no devices capable of such measurement of citalopram in biofluids. This work presents an affordable citalopram test for at-home and point-of-care monitoring of citalopram levels in urine, ensuring a safe and effective drug compliance. Our platform consists of a citalopram-selective yarn-based electrode (CTLP-SYE) that uses polymeric sensing membranes to provide valuable information about drug concentration in urine. CTLP-SYE is noninvasive and has a response time of fewer than 10 s. The fabricated electrode showed near-Nernstian behavior with a 52.3 mV/decade slope in citalopram hydrobromide solutions ranging from 0.5 μM to 1.0 mM, with a detection limit of 0.2 μM. Results also indicated that neither interfering ions nor pH affects electrode performance. We showed that CTLP-SYE could accurately and reproducibly measure citalopram in human urine (RSD 2.0 to 3.2%, error <12%) at clinically relevant concentrations. This work paves the way for the personalized treatment of depression and accessible companion diagnostics to improve treatment efficacy and safety.

LCMS/MS-based multiplex antibacterial platform for therapeutic drug monitoring in intensive care unit patients

Empirically prescribed standard dosing regimens of antibacterial agents may result in insufficient or excess plasma concentrations with persistently poor clinical outcomes, especially for patients in intensive care units (ICUs). Therapeutic drug monitoring (TDM) of antibacterial agents can guide dose adjustments to benefit patients. In this study, we developed a robust, sensitive, and simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) platform for the quantification of 14 antibacterial and antifungal agents (beta-lactams piperacillin, cefoperazone, and meropenem; beta-lactamase inhibitors tazobactam and sulbactam; antifungal agents fluconazole, caspofungin, posaconazole, and voriconazole; and daptomycin, vancomycin, teicoplanin, linezolid, and tigecycline) that can be used for patients with severe infection. This assay requires only 100 µL of serum with rapid protein precipitation. Chromatographic analysis was performed using a Waters Acquity UPLC C8 column. Three stable isotope-labeled antibacterial agents and one analogue were used as internal standards. Calibration curves ranged from 0.1-100 μg/mL, 0.1-50 μg/mL, and 0.3-100 μg/mL for different drugs, and all correlation coefficients were greater than 0.9085. Intra- and inter-day imprecision and inaccuracy values were below 15%. After validation, this new method was successfully employed for TDM in routine practice.

Selective LC-MS/MS determination of citalopram enantiomers and application to a pharmacokinetic evaluation of generic and reference formulations

Two methods using LC-MS/MS were validated to quantify citalopram (CTP) racemate [(R/S)-CTP] and the enantiomers (R)-CTP and (S)-CTP in human plasma, respectively. Paroxetine hydrochloride was used as the internal standard, and samples were extracted by protein precipitation with acetonitrile. The non-enantioselective method was conducted using a C18 column, and the mobile phase consisted of water for solvent A and acetonitrile for solvent B, both with 0.1% formic acid. For the chiral method, an analytical column Lux Cellulose-1 was used. Mobile phase A was composed of water with 0.025% of formic acid and 0.05% of diethylamine, and mobile phase B consisted of acetonitrile:2-propanol (95:5, v/v). No significant matrix effects were observed at the retention times of analytes and internal standard. The mean recovery was 89%, and the assays were linear in the concentration range of 1-50 and 5-30 ng/mL for the non-enantioselective and enantioselective methods, respectively. The intra- and inter-day precisions of both methods were less than 12.30%, and the accuracies were less than 12.13%. The validated methods were successfully applied to a pharmacokinetic study in which 20-mg CTP tablets were administered to healthy volunteers, and their plasma levels were monitored over time in a bioequivalence study. HIGHLIGHTS: Simple and rapid LC-MS/MS method for the quantification of citalopram and its enantiomers in human plasma. Both methods were demonstrated to be selective, reliable, and sensitive. Both methods have sufficient sensitivity to quantify the steady state through concentrations already reported for citalopram and escitalopram. Validated method presented in this study can be suitably applied to pharmacokinetic studies involving citalopram and escitalopram. Bland-Altman analysis suggested that non-enantioselective and enantioselective methods can be applied in pharmacokinetic studies.

Sensitive determination of Fluoxetine and Citalopram antidepressants in urine and wastewater samples by liquid chromatography coupled with photodiode array detector

A new analyte separation and preconcentration method for the trace determination of antidepressant drugs, Fluoxetine (FLU) and Citalopram (CIT) in urine and wastewaters, was developed based on HPLC-DAD analysis after magnetic solid phase extraction (MSPE). In the proposed method, FLU and CIT were retained on the newly synthetized magnetic sorbent (Fe₃O₄@PPy-GO) in the presence of buffer (pH 10.0) and then were desorbed into a lower volume of acetonitrile prior to the chromatographic determinations. Before HPLC analysis, all samples were filtered through a 0.45 µm PTFE filter. Experimental parameters such as interaction time, desorption solvent and volume, and pH were studied and optimized in order to establish the detection limit, linearity, enrichment factor and other analytical figures of merit under optimum operation conditions. In the developed method, FLU and CIT were analyzed by diode array detector at the corresponding maximum wavelengths of 227 and 238 nm, respectively, by using an isocratic elution of 60% pH 3.0 buffer, 30% acetonitrile, and 10% methanol. By using the optimum conditions, limit of detections for FLU and CIT were 1.58 and 1.43 ng mL^-1, respectively, while the limit of quantifications was 4.82 and 4.71 ng mL^-1, respectively. Relative standard deviations (RSD%) for triplicate analyses of model solutions containing 100 ng mL^-1 target molecules were found to be less than 5.0 %. Finally, the method was successfully applied to urine (both simulated and real healthy human) and wastewater samples, and quantitative results were obtained in recovery experiments.

Determination of Mirtazapine and Desmethyl Mirtazapine in Human Plasma by a New Validated HPLC Ultraviolet Method with a Simple and Reliable Extraction Method: Application to Therapeutic Drug Monitoring Study by 62 Real Patient Plasma

Determination of mirtazapine (MRP) during psychopharmacotherapy in biological fluids is essential to achieve successful therapy, to avoid toxicity related to drug interactions, genetic variability, and poor compliance. A new, rapid, and sensitive high-performance liquid chromatography method has been developed in human plasma for the determination of MRP and N-desmethylmirtazapine (NDM) that is an active metabolite.

The separation was achieved on a reverse-phase C18 250 x 4.6 mm i.d., ODS-3 column using programmed gradient elution at 40 °C. 20 mM potassium phosphate buffer (pH 3.9), acetonitrile, and triethylamine (75.0:24.9:0.1, v/v/v) were used as mobile phase A. Mobile phase B consisted of absolute acetonitrile. Clozapine was used as an internal standard. The method showed linearity with good determination coefficients (r²≥0.9981) for each analyte. Intra-day and interday assay precisions (RSD%) were found less than 3.4 and 2.9 for MRP and NDM, respectively. The intra-day and interday accuracy (RE%) of the method were calculated between (-2.8) and 5.5. A new extraction method was used in the study and an excellent recovery (average) values for MRP and NDM (94.4%, 106.6%, respectively) was obtained. The method was specific and sensitive as the limit of detection (LOD) were 0.17 for MRP and 0.15 ng/mL for NDM.

This method was applied properly to plasma samples taken from patients receiving MRI (n = 62) treated with 15-30 mg / day. The obtained and statistically evaluated plasma MRP and NDM levels which were 28.6 ± 13.8 and 12.3 ± 6.5 (mean ± SD). The described procedure is relatively simple, precise, and applicable for routine therapeutic drug monitoring especially in psychiatry clinics and toxicology reference laboratories.

Capillary electrophoresis for the analysis of antidepressant drugs: A review

Depression is a common mental disorder that may lead to major mental health problems, and antidepressant drugs have been used as a treatment of choice to mitigate symptoms of major depressive disorders by ameliorating the chemical imbalances of neurotransmitters in brain. Since abusing antidepressant drugs such as selective serotonin reuptake inhibitors and tricyclic antidepressant drugs can cause severe adverse effects, continuous toxicological monitoring of the parent compounds as well as their metabolites using numerous analytical methods appears pertinent. Among them, capillary electrophoresis has been popularly utilized since the method has a lot of advantages viz. using small amounts of sample and solvents, ease of operation, and rapid analysis. This review paper brings a survey of more than 30 papers on capillary electrophoresis of antidepressant drugs published approximately from 1999 until 2018. It focuses on the reported capillary electrophoresis techniques and their applications and challenges for determining antidepressant drugs and their metabolites. It is organized according to the commonly used capillary zone electrophoresis method, followed by non-aqueous capillary electrophoresis and micellar electrokinetic chromatography, with details on breakthrough findings. Where available, information is given about the background electrolyte used, detector utilized, and sensitivity obtained.

A simple stripping voltammetric method for the determination of a new anticancer prodrug in serum

The determination of ethyl [4-oxo-8-(3-chlorophenyl)-4,6,7,8-tetrahydroimidazo[2,1-c][1,2,4]triazin-3-yl]acetate (ETTA), a new anticancer prodrug, using adsorptive stripping voltammetry (AdSV) was described for the first time. This method is based on adsorptive/reductive behaviour of ETTA at an in situ plated bismuth film electrode (BiFE) as a sensor. A number of experimental variables (e.g., a composition and pH of the supporting electrolyte, the conditions of bismuth film deposition, an accumulation potential and time, the scan rate, etc.) were thoroughly studied in order to achieve a high sensitivity. Experimental results under optimized conditions revealed an excellent linear correlation between the monitored voltammetric peak current and the ETTA concentration in the range of 2-50μgL^-1 following an accumulation time of 300s. The limit of detection (LOD) for ETTA following 300s of an accumulation time was 0.4μgL^-1. The proposed facile, sensitive and inexpensive method was successfully applied to the determination of ETTA in serum. The investigated prodrug was extracted from serum using SPE method.

Electrochemical microfluidic chip based on molecular imprinting technique applied for therapeutic drug monitoring

In this work, a novel electrochemical detection platform was established by integrating molecularly imprinting technique with microfluidic chip and applied for trace measurement of three therapeutic drugs. The chip foundation is acrylic panel with designed grooves. In the detection cell of the chip, a Pt wire is used as the counter electrode and reference electrode, and a Au-Ag alloy microwire (NPAMW) with 3D nanoporous surface modified with electro-polymerized molecularly imprinted polymer (MIP) film as the working electrode. Detailed characterization of the chip and the working electrode was performed, and the properties were explored by cyclic voltammetry and electrochemical impedance spectroscopy. Two methods, respectively based on electrochemical catalysis and MIP/gate effect were employed for detecting warfarin sodium by using the prepared chip. The linearity of electrochemical catalysis method was in the range of 5×10^-6-4×10^-4M, which fails to meet clinical testing demand. By contrast, the linearity of gate effect was 2×10^-11-4×10^-9M with remarkably low detection limit of 8×10^-12M (S/N=3), which is able to satisfy clinical assay. Then the system was applied for 24-h monitoring of drug concentration in plasma after administration of warfarin sodium in rabbit, and the corresponding pharmacokinetic parameters were obtained. In addition, the microfluidic chip was successfully adopted to analyze cyclophosphamide and carbamazepine, implying its good versatile ability. It is expected that this novel electrochemical microfluidic chip can act as a promising format for point-of-care testing via monitoring different analytes sensitively and conveniently.

Graphene/graphite paste electrode incorporated with molecularly imprinted polymer nanoparticles as a novel sensor for differential pulse voltammetry determination of fluoxetine

Molecularly imprinted polymer (MIP) nanoparticles including highly selective recognition sites for fluoxetine were synthesized, utilizing precipitation polymerization. Methacrylic acid and vinyl benzene were used as functional monomers. Ethylene glycol dimethacrylate was used as cross-linker agent. The obtained polymeric nanoparticles were incorporated with carbon paste electrode (CPE) in order to construct a fluoxetine selective sensor. The response of the MIP-CP electrode to fluoxetine was remarkably higher than the electrode, modified with the non-imprinted polymer, indicating the excellent efficiency of the MIP sites for target molecule recognition. It was found that the addition of a little amount of graphene, synthesized via modified hummer's method, to the MIP-CP resulted in considerable enhancement in the sensitivity of the electrode to fluoxetine. Also, the style of electrode components mixing, before carbon paste preparation, was demonstrated to be influential factor in the electrode response. Some parameters, affecting sensor response, were optimized and then a calibration curve was plotted. A dynamic linear range of 6×10(-9)-1.0×10(-7)molL(-1) was obtained. The detection limit of the sensor was calculated equal to 2.8×10(-9)molL(-1) (3Sb/m). This sensor was used successfully for fluoxetine determination in the spiked plasma samples as well as fluoxetine capsules.

Determination of selective serotonin reuptake inhibitors in biological samples via magnetic stirring-assisted dispersive liquid–liquid microextraction followed by high performance liquid chromatography

This work reports an efficient, quick and low-cost procedure for the determination of serotonin reuptake inhibitors (SSRIs) in low concentration levels in biological fluids.

Magnetized silane-coupling agent KH-570 based solid-phase extraction followed by gas chromatography-flame ionization detection to determine venlafaxine in human hair and aqueous environmental samples

In the present study, a novel adsorbent, Fe3O4 magnetic nanoparticles (MNPs) functionalized by silane-coupling agent KH-570, was successfully synthesized. The prepared MNPs were characterized by Fourier-transform infrared spectroscopy and transmission electron microscopy. It was applied as functionalized magnetic nano-adsorbent for magnetic solid-phase extraction of trace levels of venlafaxine using gas chromatography with flame ionization detector. This method was developed and optimized for use in analysis of venlafaxine in human hair and aqueous environmental samples. The main factors influencing the extraction efficiency including pH of sample, amount of the MNPs, adsorption time, volume of sample, and desorption conditions such as volume of solvent and desorption time were studied and optimized. Under the optimized experimental conditions, good linearity was observed in the range of 1-1,000 µg L(-1) for aqueous environmental samples with correlation coefficients (R (2)) 0.996. The limits of detection and quantification were 0.1 and 0.5 μg L(-1), respectively. Good reproducibility with the relative standard deviations (n = 5) 3.21 % was obtained. The developed method was successfully applied to the extraction of venlafaxine from spiked human hair, river water, and surface water samples and the relative recoveries of 89.36, 93.43, and 94.99 % were obtained, respectively. The results indicated that Fe3O4/KH-570 MNPs have a satisfying extraction efficiency and can be served as a sensitive, inexpensive, and reliable method for analysis of antidepressant drugs such as venlafaxine in biological and aqueous environmental samples.

Quality by Design approach in the development of a solvent-modified micellar electrokinetic chromatography method: finding the design space for the determination of amitriptyline and its impurities

A solvent-modified micellar electrokinetic chromatography method was set up for the simultaneous determination of the tricyclic antidepressant amitriptyline (AMI) and its main impurities. The method was developed following Quality by Design (QbD) principles according to ICH Guideline Q8(R2). QbD approach made it possible to find the design space (DS), where quality was assured. After a scouting phase, aimed at selecting a suitable capillary electrophoresis pseudostationary phase, risk assessment tools were employed to define the critical process parameters (CPPs) to be considered in a screening phase (applied voltage, concentration and pH of the background electrolyte, concentration of the surfactant sodium dodecyl sulphate, of the cosurfactant n-butanol and of the organic modifiers acetonitrile and urea). The effects of the seven selected CPPs on critical quality attributes (CQAs), namely resolution values between critical peak pairs and analysis time, were investigated throughout the knowledge space by means of a symmetric screening matrix. Response surface study was then carried out on four selected CPPs by applying a Doehlert Design. Monte-Carlo simulations were performed in order to estimate the probability of meeting the desired specifications on CQAs, and thus to define the DS by means of a risk of failure map. Additional points at the edges of the DS were tested in order to verify the requirements for CQAs to be fulfilled. A control strategy was implemented by defining system suitability tests. The developed method was validated following ICH Guideline Q2(R1), including robustness assessment by Plackett-Burman design, and was applied to the analysis of real samples of amitriptyline coated tablets.

A critical review of microextraction by packed sorbent as a sample preparation approach in drug bioanalysis

Sample preparation is widely accepted as the most labor-intensive and error-prone part of the bioanalytical process. The recent advances in this field have been focused on the miniaturization and integration of sample preparation online with analytical instrumentation, in order to reduce laboratory workload and increase analytical performance. From this perspective, microextraction by packed sorbent (MEPS) has emerged in the last few years as a powerful sample preparation approach suitable to be easily automated with liquid and gas chromatographic systems applied in a variety of bioanalytical areas (pharmaceutical, clinical, toxicological, environmental and food research). This paper aims to provide an overview and a critical discussion of recent bioanalytical methods reported in literature based on MEPS, with special emphasis on those developed for the quantification of therapeutic drugs and/or metabolites in biological samples. The advantages and some limitations of MEPS, as well as its comparison with other extraction techniques, are also addressed herein.

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.

Transdermal delivery of imipramine and doxepin from newly oil-in-water nanoemulsions for an analgesic and anti-allodynic activity: development, characterization and in vivo evaluation

Antidepressants have been considered by their analgesic activity in numerous studies, and specifically tricyclic antidepressants to possess the greatest efficacy. Imipramine and doxepin have been reported to exhibit local anaesthetic properties. In order to investigate their cutaneous analgesic effect after topical application a nanoemulsion vehicle was developed. This nanoemulsion is composed of propilenglicol, Transcutol, water, Labrasol, Plurol Oleique, isostearyl isostearate, oleic acid, and d-limonene. The final concentration of imipramine or doxepin in the nanoemulsion system was 3% (w/w). The nanoemulsions were characterized by pH, viscosity, droplet size, polydispersity index and finally, a morphological and structural examination was carried out by using transmission electron microscopy. Furthermore, the present work also reports stability studies on the nanoemulsion formulations to evaluate the integrity of the formulation; these indicate that formulations are stable for a period of three months. Moreover ex vivo studies were performed to evaluate permeation behaviour through human skin and predict plasma concentrations concluding that topically applied imipramine and doxepin loaded nanoemulsions were safe for a local effect. Similarly, the in vivo analgesic and anti-allodynic activity in rats was evaluated being stronger for the doxepin loaded nanoemulsion. This study demonstrated that nanoemulsion containing doxepin could be promising as an alternative analgesic therapy with a potential clinical application.

Liquid chromatography-tandem mass spectrometry method for determination of five antidepressants and four atypical antipsychotics and their main metabolites in human serum

The rapid and simple ultra performance liquid chromatography-tandem mass spectrometry method was developed and validated for simultaneous determination parent drugs: sertraline, fluoxetine, citalopram, paroxetine, venlafaxine, clozapine, olanzapine, quetiapine, risperidone, and their active and nonactive metabolites N-desmethylsertraline, norfluoxetine, desmethylcitalopram, didemethylcitalopram, N-desmethylvenlafaxine, O-desmethylvenlafaxine, N-desmethylclozapine, N-desmethylolanzapine, 2-hydroxyolanzapine and 9-hydroxyrisperidone in human serum. Precipitation of serum proteins was performed with a precipitation reagent consisting of 0.05% solution of ZnSO(4)·7H(2)O in acetonitrile/methanol (40:60, v/v). Alprenolol was used as an internal standard. Chromatographic separation was carried out on a BEH C18 column using gradient elution mobile phase A (2 mmol/L ammonium acetate, 0.1% formic acid in 5% acetonitrile, v/v/v) and B (2 mmol/L ammonium acetate, 0.1% formic acid in 95% acetonitrile, v/v/v). Electrospray in positive mode was used for ionization. Detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring. Analysis time was 5 min. Drugs were separated into three groups with low, medium and high levels. Correlation coefficients of calibration curves were in the range 0.995-1.000. Coefficients of variation were 4.2-9.5% for intra-assay and 3.0-11.9% for inter-assay. Recoveries were 87.1-110% for intra-assay and 88.1-108.2% for inter-assay. The method was fully validated and can be successfully applied for routine analyses.

Detection and quantification of tricyclic antidepressants and other psychoactive drugs in urine by HPLC/MS/MS for pain management compliance testing

A sensitive, specific, and rapid high-pressure liquid chromatography/mass spectrometry/mass spectrometry method was developed for the quantitation of 11 tricyclic antidepressants and/or their metabolites; fluoxetine and norfluoxetine; cyclobenzaprine; and trazodone in urine. Samples were alkalinized with 0.2 N NaOH and extracted into 2 ml of hexane: ethyl acetate (1:1), evaporated to dryness, and reconstituted with 100 μl of 20 mM ammonium formate: methanol (20:80). The chromatographic separation was performed using an Allure Biphenyl 100 × 3.2 mm, 5-μ column with a mobile phase consisting of 20 mM ammonium formate: methanol (20:80 v/v) at a flow rate of 0.5 ml/min. The detection was accomplished by multiple-reaction monitoring via electrospray ionization source operating in the positive ionization mode. The calibration curve was linear over the investigated concentration range, 25-2,000 ng/ml, for each analyte using 1.0 ml of urine. The lower limit of quantitation for each analyte was 25 ng/ml. The intra- and inter-day precisions had coefficient of variation less than 15% and the accuracy was within the range from 88% to 109%. The method proved adequate for the tricyclic antidepressants analysis of urine for emergency clinical toxicology and pain management compliance testing.

Improvement and validation the method using dispersive liquid-liquid microextraction with in situ derivatization followed by gas chromatography-mass spectrometry for determination of tricyclic antidepressants in human urine samples

A simple, rapid and sensitive method termed dispersive liquid-liquid microextraction (DLLME) combined with gas chromatography-mass spectrometry (GC/MS) was developed for the determination of tricyclic antidepressants (TCAs) in human urine sample. An appropriate mixture of methanol (disperser solvent), carbon tetrachloride (extraction solvent), and acetic anhydride (derivatization reagent) was injected rapidly into human urine sample. After extraction, the sedimented phase was analyzed by GC/MS. The calibration curves obtained with human urine were linear with a correlation coefficient of over 0.99 in the range of 2.0/5.0-100 ng mL(-1). Under the optimum conditions (carbon tetrachloride: 10 μL, methanol: 150 μL), the detection limits and the quantification limits of the tricyclic antidepressants were 0.5-2.0 ng mL(-1) and 2.0-5.0 ng mL(-1), respectively. The average recoveries of TCAs were 88.2-104.3%. Moreover, the inter- and intra-day precision and accuracy was acceptable at all concentrations. The results showed that DLLME is applicable to the determination of trace amounts of TCAs in human urine sample.

Development and validation of stability indicating method for determination of sertraline following ICH guidlines and its determination in pharmaceuticals and biological fluids

BACKGROUND

Sertraline is a well known antidepressant drug which belongs to a class called selective serotonin reuptake inhibitor. Most published methods do not enable studying the stability of this drug in different stress conditions.

RESULTS

Two new methods were developed for the determination of sertraline (SER). Both methods are based on coupling with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) in borate buffer of pH 7.8 and measuring the reaction product spectrophotometrically at 395 nm (Method I) or spectrofluorimetrically at 530 nm upon excitation at 480 nm (Method II). The response-concentration plots were rectilinear over the range 2-24 μg/mL and 0.25-5 μg/mL for methods I and II respectively with LOD of 0.18 μg/mL and 0.07 μg/mL, and LOQ of 0.56 μg/mL and 0.21 μg/mL for methods I and II, respectively.

CONCLUSION

Both methods were applied to the analysis of commercial tablets and the results were in good agreement with those obtained using a reference method. The fluorimetric method was further applied to the in vivo determination of SER in human plasma. A proposal of the reaction pathway was presented. The spectrophotometric method was extended to stability study of SER. The drug was exposed to alkaline, acidic, oxidative and photolytic degradation according to ICH guidelines. Moreover, the method was utilized to investigate the kinetics of oxidative degradation of the drug. The apparent first order rate constant and t1/2 of the degradation reaction were determined.

Spectrofluorimetric determination of sertraline in dosage forms and human plasma through derivatization with 9-fluorenylmethyl chloroformate

BACKGROUND

Sertraline is primarily used to treat major depression in adult outpatients as well as obsessive-compulsive, panic and social anxiety disorders in both adults and children. A survey of the literature reveals that most of the reported methods are either insufficiently sensitive or tedious and require highly sophisticated and dedicated instrumentation. The proposed method is considered to be specific for determination of SER in presence of its metabolite (deaminated form).

RESULTS

A sensitive, simple and specific spectrofluorimetric method was developed for the determination of sertraline (SER) in pharmaceutical formulations and biological fluids. The method is based on its reaction with 9-fluorenylmethyl chloroformate (FMOC-Cl) in borate buffer of pH 8.0 to yield a highly fluorescent derivative peaking at 315 nm after excitation at 265 nm. The different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence concentration plot was rectilinear over the range of 0.05-1.0 μg mL-1 with a lower detection limit of 5.34 × 10-3 μg mL-1 and limit of quantitation of 0.016 μg mL-1.

CONCLUSIONS

The proposed method was successfully applied to the analysis of commercial tablets and the results obtained were in good agreement with those obtained using the reference method. Furthermore, the method was applied for the determination of SER in spiked and real human plasma. The mean % recovery (n = 3) was 94.33 ± 1.53 and 92.00 ± 2.65, respectively. A proposal of the reaction pathway was postulated.