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

Utilization of a pH-switchable hydrophilicity solvent for the microextraction of clomipramine from human urine samples

Clomipramine (CLP) is a tricyclic antidepressant drug, and its determination in biological samples is of high importance in clinical and forensic evaluations to assure appropriate drug concentrations. In the present study, benzoic acid was employed as a pH-switchable hydrophilicity solvent (SHS) for the microextraction of CLP from authentic human urine samples prior to its determination by high performance liquid chromatography-ultraviolet detection (HPLC-UV). The microextraction protocol was based on the phase transition of the SHS through pH alteration that resulted in its rapid dispersion and simultaneous phase separation. The obtained solid was collected in a syringe filter, dissolved in methanol, and analyzed. The main parameters that affected the efficiency of the microextraction procedure were studied and optimized to ensure high extraction efficiency for CLP and the analytical method was validated. Under optimum conditions, good linearity was observed between 0.05 and 5.0 μg mL-1. The limit of detection and limit of quantification were found to be 0.015 and 0.05 μg mL-1, respectively. The RSD values for intra-day repeatability and inter-day precision were 2.4-8.9 % and 1.7-9.1 %, respectively. The relative recovery values were within 90.0 and 110.0 % in all cases, demonstrating good method accuracy. The proposed SHS microextraction showed cost-efficiency, handling simplicity, and rapidity resulting in enhanced sample throughput. Moreover, the proposed method exhibited a green character and good applicability based on its evaluation by Green Analytical Procedure Index and Blue Applicability Grade Index.

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.

On-Chip Electromembrane Surrounded Solid Phase Microextraction for Determination of Tricyclic Antidepressants from Biological Fluids Using Poly(3,4-ethylenedioxythiophene)-Graphene Oxide Nanocomposite as a Fiber Coating

In the present study, on-chip electromembrane surrounded solid phase microextraction (EM-SPME) was employed in the determination of tricyclic antidepressants (TCAs), including amitriptyline, nortriptyline, imipramine, desipramine, maprotiline, and sertraline, from various biological fluids. In this regard, poly(3,4-ethylenedioxythiophene)-graphene oxide (PEDOT-GO) was electrodeposited on an SPME fiber as a conductive coating, then the fiber played the acceptor-electrode role during the extraction. Thus, the immigration of the analytes under the influence of an electric field and their absorption onto the fiber coating were accomplished simultaneously. Under the optimized conditions, the limits of detection for the target analytes were acquired in the range of 0.005-0.025 µg L^-1 using gas chromatography-mass spectrometry. The linearity of the method was 0.010-500 µg L^-1 for the imipramine and sertraline, 0.025-500 µg L^-1 for the amitriptyline, nortriptyline, and desipramine, and 1.000-250 µg L^-1 for the maprotiline (R² ≥ 0.9984). Moreover, this method provided suitable precision and fiber-to-fiber reproducibility, with RSDs ≤ 8.4%. The applicability of the proposed setup was eventually investigated for extraction of the drugs from human bone marrow aspirate, urine, plasma, and well water samples, in which satisfactory relative recoveries, from 93-105%, were obtained.

Elucidation of Degradation Behavior of Tricyclic Antidepressant Amoxapine in Artificial Gastric Juice

The degradation behavior of eight tricyclic antidepressants (TCAs; amitriptyline, amoxapine (AMX), imipramine, clomipramine, desipramine, doxepin, dothiepin, and nortriptyline) in artificial gastric juice was investigated to estimate their pharmacokinetics in the stomach. As a result, among the eight TCAs, only AMX was degraded in artificial gastric juice. The degradation was a pseudo first-order reaction; activation energy (Ea) was 88.70 kJ/mol and activation entropy (ΔS) was -80.73 J/K·mol. On the other hand, the recovery experiment revealed that the degradation product did not revert to AMX and accordingly, this reaction was considered to be irreversible. In the AMX degradation experiment, peaks considered to be degradation products A (I) and B (II) were detected at retention times of around 3 min and 30 min in LC/UV measurements, respectively. Structural analysis revealed that compound (I) was [2-(2-aminophenoxy)-5-chlorophenyl]-piperazin-1-yl-methanone, a new compound, and compound (II) was 2-chlorodibenzo[b,f][1,4]oxazepin-11(10H)-one. As for the degradation behavior, it was estimated that AMX was degraded into (II) via (I), i.e., (II) was the final product. The results are expected to be useful in clinical chemistry and forensic science, including the estimation of drugs to be used at the time of judicial dissection and suspected drug addiction.

Developing and Validating a Fast and Accurate Method to Quantify 18 Antidepressants in Oral Fluid Samples Using SPE and LC-MS-MS

Antidepressant drugs are one of the most widely used medicines for treating major depressive disorders for long time periods. Oral fluid (OF) testing offers an easy and non-invasive sample collection. Detection of antidepressants in OF is important in clinical and forensic settings, such as therapeutic drug monitoring and roadside testing for driving under influence. We developed and validated a comprehensive liquid chromatography-tandem mass spectrometry method for 18 antidepressants (amitriptyline, bupropion, citalopram, clomipramine, cyclobenzaprine, desipramine, desvenlafaxine, doxepin, duloxetine, fluoxetine, imipramine, mirtazapine, nortriptyline, paroxetine, sertraline, trazodone, trimipramine, venlafaxine) in oral fluid collected by Quantisal® oral collection devices. One-half milliliter of Quantisal® OF (125 μL of neat OF) was submitted to solid-phase extraction. The chromatographic separation was performed employing a biphenyl column in gradient mode with a total run time of 5 min. The MS detection was achieved by multiple-reaction monitoring with two transitions per compound. The range for linearity of all analytes was from 10 to 1,000 ng/mL, with a limit of detection of 10 ng/mL. Intra and inter-day accuracy and precision (n = 15) were all within acceptable limits, ±20% error and ±15% relative standard deviation. Analyte recovery at 400 ng/mL concentration (n = 15) ranged from 91 to 129%. Matrix effect ranged from 73.7 to 157%. The internal proficiency test detected all antidepressants with accuracy ranging from 83.1 to 112.1%. The authentic patient sample showed a percentage difference compared to the previously calculated concentration of 86.3-111%. This method provides for the rapid detection of 18 antidepressants and metabolites in OF, which is readily applicable to a routine laboratory.

A green and low-cost method employing switchable hydrophilicity solvent for the simultaneous determination of antidepressants in human urine by gas chromatography - mass spectrometry detection

In this study, the use of switchable hydrophilicity solvent with a simple and low-cost lab-made device for the extraction procedure in homogeneous liquid-liquid microextraction is proposed for the first time in the determination of antidepressants in human urine. The antidepressants studied consisted of fluoxetine, amitriptyline, nortriptyline, imipramine, desipramine and sertraline. The optimization of the main parameters that can influence on the extraction efficiency was performed through multivariate approaches. The analytes were separated and identified by gas chromatography coupled to mass spectrometry (GC-MS). The optimal extraction conditions consisted of using N,N-dimethylcyclohexylamine (DMCHA) as the switchable hydrophilicity solvent (SHS), 500 µL of urine sample previously diluted with ultrapure water at 1:1 ratio (v/v), 200 μL of a mixture of SHS:HCl 6 mol L^-1 (1:1 v/v), 600 μL of NaOH 10 mol L^-1 and 3 min of extraction time. A volume of 40 µL of diphenylamine at concentration of 500 µg L^-1 (20 ng) was used as internal standard. The method developed was in-house validated, providing coefficients of determination higher than 0.995 for all analytes, limits of detection (LOD) from 0.02 to 0.88 µg L^-1, limits of quantification (LOQ) from 0.05 to 2.92 µg L^-1, relative recoveries of 68 to 102%, intra-day precision from 0.5 to 15.9%, inter-day precision from 4.2 to 19.3%, selectivity and robustness. The method proposed was successfully applied in five human urine samples from a Toxicological Information Center located in Porto Alegre (Brazil). The results demonstrated that the µP-SHS-HLLME approach is highly cost-effective, rapid, simple and environmentally-friendly with satisfactory analytical performance.

Recent Advances in the HPLC Analysis of Tricyclic Antidepressants in Bio-Samples

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Tricyclic Antidepressants (TCAs) are a group of the main category of antidepressant drugs, which are commonly prescribed to treat major depressive disorder. Determination of TCA drugs is very important for clinical and forensic toxicology, especially for therapeutic drug monitoring in various biofluids. High Performance Liquid Chromatography (HPLC) is a well-established technique for this purpose. A lot of progress has been made in this field since the past 10 years. Novel extraction techniques, and novel materials for sample preparation, novel columns and novel applications of analysis of various biofluids for the determination of TCAs in combination with other drugs are some typical examples. Moreover, advances have been performed in terms of Green Analytical Chemistry principles. Herein, we aim to discuss the developed HPLC methods that were reported in the literature for the time span of 2008-2018.

Characterization of an Amphetamine Interference from Gabapentin in an LC-HRMS Method

An amphetamine interference was observed during the development of an liquid chromatography-high-resolution mass spectrometry (LC-HRMS) multi-class confirmation method for the determination of 47 drugs and metabolites in urine. The interference passed all qualitative criteria for amphetamine leading to potential false-positive results. Upon investigation, it was found that the amphetamine interference was correlated with the presence of high levels of gabapentin. Gabapentin is routinely detected in patient urine specimens at levels in excess of 1 mg/mL as it is widely prescribed at high doses and does not undergo significant metabolism. The source of the interference was identified as a gabapentin in-source fragment isomeric with protonated amphetamine. Here we describe the characterization of this interference and how its effect was mitigated in the LC-HRMS method.

Storage of urine specimens in point of care (POC) urine drug testing cups reduces concentrations of many drugs

BACKGROUND

Many clinical toxicology laboratories receive urine specimens in urine cups that contain point of care (POC) drug testing strips. We conducted this study to evaluate the effect on the stability of commonly measured drugs in the clinical toxicology laboratory when urine is exposed to POC urine drug testing cups.

METHODS

Drug free urine was spiked with 85 drugs that were measured by a validated liquid chromatography mass spectrometry (LCMS) method after exposure to POC urine drug testing cups at ambient and 2-6 °C temperatures. Alterations ≥20% were defined as significant changes in the drugs concentration.

RESULTS

Concentrations of amitriptyline, cyclobenzaprine, fentanyl, fluoxetine, flunitrazepam, nortriptyline, paroxetine, and sertraline were significantly reduced when urine specimens were stored inside POC urine drug testing cups for 24 h at ambient temperature. Storage of urine in urine chemistry dipsticks reduced the concentration of several drugs. When spiked urine was exposed to an increasing number of POC urine drug testing strips, the concentrations of some drugs were reduced in a dose-dependent manner. The drugs that were absorbed by POC urine drug testing strips were partially back extracted from the strips.

CONCLUSION

Exposure of urine specimens to POC urine drug testing strips reduces the concentration of several drugs measured by LCMS method.

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.

Analysis of tricyclic antidepressants in human plasma using online-restricted access molecularly imprinted solid phase extraction followed by direct mass spectrometry identification/quantification

The use of a new class of hybrid materials, called restricted access molecularly imprinted polymers (RAMIPs) seems to present a good strategy for the sample preparation of complex matrices, since these materials combine good protein elimination capacity with high degree selectivity. Mass spectrometers (MS) have been successfully used for polar drug identification and quantification. In order to combine the advantages of both RAMIPs and mass spectrometry, we proposed a study that joins these properties in a single system, where we could analyse tricyclic antidepressants from human plasma, without offline extraction or chromatographic separation. A RAMIP for amitriptyline was synthesised by the bulk method, using methacrylic acid as a functional monomer and glycidilmethacrylate as a hydrophilic co-monomer. Then, epoxide ring openings were made and the polymer was covered with bovine serum albumin (BSA). A column filled with RAMIP-BSA was coupled to a MS/MS instrument in an online configuration, using water as loading and reconditioning mobile phase and a 0.01% acetic acid aqueous solution: acetonitrile at 30:70 as elution mobile phase. The system was used for on-line extraction and simultaneous quantification of nortriptyline, desipramine, amitriptyline, imipramine, clomipramine and clomipramine-d3 (IS) (from 15.0 to 500.0μgL^-1) from plasma samples. The correlation coefficient was higher than 0.99 for all analytes. The CV (coefficient of variation) values ranged from 1.34% to 19.13% for intra assay precision and 1.32-19.77% for inter assay precision. The E% (relative error) values ranged from -19.15% to 19.51% for intra assay accuracy and from -9.04% to 16.22% for inter assay accuracy.

Ultrasensitive label-free immunoassay for optical determination of amitriptyline and related tricyclic antidepressants in human serum

The present work focuses on the development of a label-free and ultrasensitive immunoassay for the detection of the drug amitriptyline in human serum. Reflectometric interference spectroscopy is used as the detection method, providing a simple, but highly sensitive optical setup. Amitriptyline is a common antidepressant; however, it has a small therapeutic window and can cause severe side effects in case of wrong dosage. Therefore, it is highly recommended for therapeutic drug monitoring to control the drug level. The limit of detection for this optical immunosensor was determined in buffer (0.3 μg/L) and in human serum (0.5 μg/L). It has become evident that this assay can compete with HPLC measurements. For drug concentrations at a normal level or above, the sample can be diluted up to 1:100. Especially for limited sample volumes, this is a great advantage. The sensor surface shows very high stability, and together with the regeneration solution 80 measurement cycles can be performed on each transducer chip. Cross-reactivity experiments indicate that a sum determination of several tricyclic antidepressants is possible.

Abuse and misuse of antidepressants

BACKGROUND

Rates of prescription drug abuse have reached epidemic proportions. Large-scale epidemiologic surveys of this under-recognized clinical problem have not included antidepressants despite their contribution to morbidity and mortality. The purpose of this review is to look specifically at the misuse of antidepressants and how this behavior may fit into the growing crisis of nonmedical use of prescription drugs.

METHODS

We conducted a comprehensive search on PubMed, Medline, and PsycINFO using the search terms "antidepressant", "abuse", "misuse", "nonmedical use", "dependence", and "addiction", as well as individual antidepressant classes (eg, "SSRI") and individual antidepressants (eg, "fluoxetine") in various combinations, to identify articles of antidepressant misuse and abuse.

RESULTS

A small but growing literature on the misuse and abuse of antidepressants consists largely of case reports. Most cases of antidepressant abuse have occurred in individuals with comorbid substance use and mood disorders. The most commonly reported motivation for abuse is to achieve a psychostimulant-like effect. Antidepressants are abused at high doses and via a variety of routes of administration (eg, intranasal, intravenous). Negative consequences vary based upon antidepressant class and pharmacology, but these have included seizures, confusion, and psychotic-like symptoms.

CONCLUSION

The majority of individuals prescribed antidepressants do not misuse the medication. However, certain classes of antidepressants do carry abuse potential. Vulnerable patient populations include those with a history of substance abuse and those in controlled environments. Warning signs include the presence of aberrant behaviors. Physicians should include antidepressants when screening for risky prescription medication use. When antidepressant misuse is detected, a thoughtful treatment plan, including referral to an addiction specialist, should be developed and implemented.