Greenness assessment of microextraction techniques in therapeutic drug monitoring

Aim: In this study, we evaluated the greenness and whiteness scores for microextraction techniques used in therapeutic drug monitoring. Additionally, the cons and pros of each evaluated method and their impacts on the provided scores are also discussed. Materials & methods: The Analytical Greenness Sample Preparation metric tool and white analytical chemistry principles are used for related published works (2007-2023). Results & conclusion: This study provided valuable insights for developing methods based on microextraction techniques with a balance in greenness and whiteness areas. Some methods based on a specific technique recorded higher scores, making them suitable candidates as green analytical approaches, and some others achieved high scores both in green and white areas with a satisfactory balance between principles.

Cocaine in Different Matrices: Recent Updates on Pretreatment and Detection Techniques

Cocaine abuse has attracted increased attention in the recent past since it can cause addiction and great harm to the normal human body. Due to cocaine exists in various complex matrices, the detection of it in different matrices is helpful to prevent abuse. It is thus imperative to establish efficient and accurate methods for pretreatment and detection of cocaine in different samples. The present study provides a summary of the research progress of cocaine pretreatment methods (such as different microextraction methods, QuEChERS, and solid phase extraction based on novel extraction materials) and detection approaches (such as liquid chromatography coupled with different detectors, gas chromatography and related techniques, capillary electrophoresis and sensors). A comparison of the pros and cons of different pretreatment and detection methods is presented. The findings of this study will provide a reference for selection of the most suitable cocaine pretreatment and detection techniques.

Recent sample pretreatment methods for determination of selective serotonin reuptake inhibitors (SSRIs) in biological samples

Selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (FLU), sertraline (SER), paroxetine (PAR), fluvoxamine (FLV) and citalopram (CIT) have been the first treatment drugs for pregnant and breastfeeding women. Quantitative analysis of SSRIs in biological samples is extremely needed in public health and clinical practice. During the analysis, sample pretreatment is an important step that can obtain an accurate quantitative analysis of SSRIs in the complex samples. The present paper discussed the recent development of sample preparation methods for SSRI analysis. Traditional sample preparation techniques such as liquid liquid extraction (LLE) and solid phase extraction (SPE), which have been widely used in the separation of SSRIs in biological samples, were extensively presented. Moreover, the new sample preparation techniques including liquid phase microextraction (LPME), solid phase microextraction (SPME), electromembrane extraction (EME) and other miniaturized extraction techniques, which are becoming highly popular in SSRI analysis, were also critically reviewed. In this review, both the advantages and disadvantages of these sample pretreatment methods were addressed. As a summary, we prospected the challenges and promising directions for the future of sample pretreatment methods in SSRI analysis.

Liquid chromatographic methods for determination of the new antiepileptic drugs stiripentol, retigabine, rufinamide and perampanel: A comprehensive and critical review

The new antiepileptic drugs perampanel, retigabine, rufinamide and stiripentol have been recently approved for different epilepsy types. Being them an innovation in the antiepileptics armamentarium, a lot of investigations regarding their pharmacological properties are yet to be performed. Besides, considering their broad anticonvulsant activities, an extension of their therapeutic indications may be worthy of investigation, especially regarding other seizure types as well as other central nervous system disorders. Although different liquid chromatographic (LC) methods coupled with ultraviolet, fluorescence, mass or tandem-mass spectrometry detection have already been developed for the determination of perampanel, retigabine, rufinamide and stiripentol, new and more cost-effective methods are yet required. Therefore, this review summarizes the main analytical aspects regarding the liquid chromatographic methods developed for the analysis of perampanel, retigabine (and its main active metabolite), rufinamide and stiripentol in biological samples and pharmaceutical dosage forms. Furthermore, the physicochemical and stability properties of the target compounds will also be addressed. Thus, this review gathers, for the first time, important background information on LC methods that have been developed and applied for the determination of perampanel, retigabine, rufinamide and stiripentol, which should be considered as a starting point if new (bio)analytical techniques are aimed to be implemented for these drugs.

Green bioanalytical sample preparation: fabric phase sorptive extraction

Fabric phase sorptive extraction (FPSE) is a recently introduced sample preparation technique that has attracted substantial interest of the scientific community dealing with bioanalysis. This technique is based on a permeable and flexible substrate made of fabric, coated with a sol-gel organic-inorganic sorbent. Among the benefits of FPSE are its tunable selectivity, adjustable porosity, minimized sample preparation workflow, substantially reduced organic solvent consumption, rapid extraction kinetics and superior extraction efficiency, many of which are well-known criteria for Green Analytical Chemistry. As such, FPSE has established itself as a leading green sample preparation technology of 21st century. In this review, we discuss the principal steps for the development of an FPSE method, the main method optimization strategies, as well as the applications of FPSE in bioanalysis for the extraction of a wide range of analytes (e.g., estrogens, benzodiazepines, androgens and progestogens, penicillins, anti-inflammatory drugs, parabens etc.).

Application of Microextraction-Based Techniques for Screening-Controlled Drugs in Forensic Context-A Review

The analysis of controlled drugs in forensic matrices, i.e., urine, blood, plasma, saliva, and hair, is one of the current hot topics in the clinical and toxicological context. The use of microextraction-based approaches has gained considerable notoriety, mainly due to the great simplicity, cost-benefit, and environmental sustainability. For this reason, the application of these innovative techniques has become more relevant than ever in programs for monitoring priority substances such as the main illicit drugs, e.g., opioids, stimulants, cannabinoids, hallucinogens, dissociative drugs, and related compounds. The present contribution aims to make a comprehensive review on the state-of-the art advantages and future trends on the application of microextraction-based techniques for screening-controlled drugs in the forensic context.

Miniaturized sample preparation methods for saliva analysis

Saliva, as the first body fluid encountering with the exogenous materials, has good correlation with blood and plays an important role in bioanalysis. However, saliva has not been studied as much as the other biological fluids mainly due to restricted access to its large volumes. In recent years, there is a growing interest for saliva analysis owing to the emergence of miniaturized sample preparation methods. The purpose of this paper is to review all microextraction methods and their principles of operation. In the following, we examine the methods used to analyze saliva up to now and discuss the potential of the other microextraction methods for saliva analysis to encourage research groups for more focus on this important subject area.

Current trends on microextraction by packed sorbent – fundamentals, application fields, innovative improvements and future applications

MEPS, the acronym of microextraction by packed sorbent, is a simple, fast and user- and environmentally-friendly miniaturization of the popular solid-phase extraction technique (SPE).

Therapeutic Drug Monitoring of Fluoxetine, Norfluoxetine and Paroxetine: A New Tool Based on Microextraction by Packed Sorbent Coupled to Liquid Chromatography

The present article reports the first liquid chromatography (LC) assay for the simultaneous quantification of fluoxetine (FLU), its metabolite norfluoxetine (NFLU) and paroxetine (PAR) in human plasma, applying the microextraction by packed sorbent (MEPS) technology in sample preparation. Chromatographic analysis of FLU, NFLU and PAR was achieved in <13 min on a reverse-phase C18 column using isocratic elution and fluorescence detection (FLD). The mobile phase was composed by an aqueous solution of 25 mM sodium phosphate monobasic anhydrous and 7.5 mM di-potassium hydrogen phosphate anhydrous (pH 3.0)/acetonitrile/methanol (70:23:7, v/v/v). The detector was set at 240/312 nm for FLU, NFLU and IS and at 295/350 nm for PAR. The method showed linearity in the ranges of 20-750 ng mL-1 for FLU and NFLU, and 5-750 ng mL-1 for PAR (r2 ≥ 0.9919). The overall intra- and interday precision did not exceed 13.6% and the corresponding accuracy (bias) ranged from 0.02 to 16.7%. The method was successfully applied in the analysis of authentic plasma samples. Hence, this new MEPS/LC-FLD assay ensures robust and low-cost analyses representing, therefore, a good alternative to support therapeutic drug monitoring and clinical studies involving these antidepressant drugs.

Development of MEPS-UHPLC–MS/MS multistatin methods for clinical analysis

Background: Statins are the microsomal 3-hydroxy-3methylglutaryl-coenzyme A reductase inhibitors used for the treatment of hypercholesterolemia. Some recent studies revealed also the extra-lipid effects and anticancer activities. Due to the wide incidence of cancer diseases, the number of studies dealing with anticancer statin activities has grown in recent years. Development of one universal multistatin method will be a very convenient way of providing practical and economical multiple statin analysis. Results/methodology: Fast and sensitive methods for determination of seven clinically relevant statins, their interconversion products and metabolites (17 analytes in total) in biological samples using microextraction by packed sorbent for sample preparation and UHPLC–MS/MS for subsequent analysis were developed and validated. Three MS platforms with different ion sources, transfer optics, collision cell technologies and scan speed parameters were compared. Conclusion: Significant differences among the methods were observed in terms of selectivity and sensitivity. Microextraction by packed sorbent was successful in the extraction of all 17 analytes from biological matrix.

Microextraction by packed sorbent

Microextraction by packed sorbent (MEPS) is a miniaturized form of SPE. MEPS can handle small sample volumes and be connected on-line with LC or GC without any modifications. In addition, the MEPS sorbent bed is integrated into an injection syringe and can be used for more than 100 extractions. The key aspect of MEPS is that the solvent volume used for the elution of the analytes is of a suitable order of magnitude to be injected directly into GC or LC systems. MEPS has been used in many research fields such as environmental, biological and food analysis. This article gives an overview of the MEPS technique, including fields of application and common formats.

First MEPS/HPLC assay for the simultaneous determination of venlafaxine and O-desmethylvenlafaxine in human plasma

Background: A new high-performance liquid chromatography–fluorescence detection assay based on microextraction by packed sorbent as sample preparation approach is described to quantify venlafaxine (VEN) and its main metabolite [O-desmethylvenlafaxine (ODV)]in human plasma. Methods & results: Chromatographic separation of the target analytes (VEN and ODV) and internal standard (licarbazepine) was achieved in less than 6 min on a reverse-phase C18 column using isocratic elution. Calibration curves were linear in the ranges of 10–1000 ng ml-1 for VEN and 20–1000 ng ml-1 for ODV. The method was successfully applied to real plasma samples. Conclusion: This microextraction by packed sorbent/high-performance liquid chromatography–fluorescence detection assay offers a cost-effective tool that can be applied for therapeutic drug monitoring and also support other pharmacokinetic-based studies in humans.

Determination of amphetamine and methadone in human urine by microextraction by packed sorbent coupled directly to mass spectrometry: an alternative for rapid clinical and forensic analysis

Speed and low cost, together with regulatory approval, are the most important requirements of clinical assays. Therefore, a fast and automated on-line sample preparation method is essential for the routine analysis of biological samples. Microextraction by packed sorbent is an option for optimal sample preparation due to its easy automation, minimal requirements for the sample and elution solvent volumes, elimination of evaporation and reconstitution steps, and ability to integrate sample preparation and injection into one step. The use of effective sample preparation steps circumvents the need for chromatographic separation and therefore allows more rapid and less expensive sample analysis in clinical and forensic practice. Two biologically active compounds, amphetamine and methadone, were chosen as representative drugs of abuse for the application of microextraction by packed sorbent coupled directly to mass spectrometry. The developed method was validated, with the results confirming the suitability of the combination of these techniques for the analysis of biological samples. The approach was confirmed to be appropriate for use in clinical and forensic practice with regard to cost and time requirements for analysis.

Development of microextraction by packed sorbent for toxicological analysis of tricyclic antidepressant drugs in human oral fluid

The aim of this study was to apply microextraction by packed sorbent (MEPS) to the isolation of six tricyclic antidepressants (TCADs): nordoxepin, doxepin, desipramine, nortriptyline, imipramine, and amitriptyline from human oral fluid. Samples were collected from healthy volunteers via free spillage from the oral cavity to disposable test tubes. A method of oral fluid sample pretreatment was developed and optimized in terms of suitability for MEPS extraction and removing of interfering agents (protein, food debris, or air bubbles). Moreover, it was short and simple to perform with limited sample consumption (150μL). Extracts were analysed by UHPLC-MS. The MEPS/UHPLC-MS method was validated at three concentration levels (2.00, 4.00 and 8.00ng/mL) of all analytes in the range 1.25-10.0ng/mL. The following parameters were determined: limit of detection, limit of quantification, precision, and accuracy. For all tested concentration levels, the intra- and inter-day repeatability did not exceeded 8.1% and 12.2%, respectively. Gained LOQ value, 0.50ng/mL, made the MEPS/UHPLC-MS method to be a useful tool in clinical and forensic laboratories, which was demonstrated on the basis of analysis of real samples.

Microextraction by Packed Sorbent (MEPS) and Solid-Phase Microextraction (SPME) as Sample Preparation Procedures for the Metabolomic Profiling of Urine

For a long time, sample preparation was unrecognized as a critical issue in the analytical methodology, thus limiting the performance that could be achieved. However, the improvement of microextraction techniques, particularly microextraction by packed sorbent (MEPS) and solid-phase microextraction (SPME), completely modified this scenario by introducing unprecedented control over this process. Urine is a biological fluid that is very interesting for metabolomics studies, allowing human health and disease characterization in a minimally invasive form. In this manuscript, we will critically review the most relevant and promising works in this field, highlighting how the metabolomic profiling of urine can be an extremely valuable tool for the early diagnosis of highly prevalent diseases, such as cardiovascular, oncologic and neurodegenerative ones.