The use of micro carbon pencil lead electrode for sensitive HPLC-ED analysis of selected antipsychotic drugs

Design of sonochemical assisted synthesis of Zr-MOF/g-C3N4-modified electrode for ultrasensitive detection of antipsychotic drug chlorpromazine from biological samples

The rapid fabrication is described of binary electrocatalyst based on a highly porous metal-organic framework with zirconium metal core (Zr-MOF) decorated over the graphitic carbon nitride (g-C3N4) nanosheets via facile ultrasonication method. It is used for the robust determination of antipsychotic drug chlorpromazine (CLP) from environmental samples. The electrochemical behaviour of 2D Zr-MOF@g-C3N4 was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) studies. The crystalline and porous nature of the composite was characterized by XRD and SEM analysis. The functional groups and surface characteristics were investigated by FT-IR, Raman and XPS. The major electrochemical properties of the Zr-MOF@g-C3N4 composite towards CLP detection were analyzed by CV, chronocoulometric (CC), chronoamperometric (CA) and differential pulse voltammetry (DPV) techniques. The composite exhibits a low detection limit (LOD) of 2.45 nM with a linear range of 0.02 to 2.99 µM and attractive sensitivity for CLP. The sensor system shows higher selectivity towards the possible interferences of CLP drug and exhibits better repeatability and stability. Finally, the fabricated sensor system shows a high recovery range varying from 96.2 to 98.9% towards the real samples. The proposed electrochemical probe might be a promising alternative to the prevailing diagnostic tools for the detection of CLP.

Overview of therapeutic drug monitoring and clinical practice

With the rapid development of clinical pharmacy in China, therapeutic drug monitoring (TDM) has become an essential tool for guiding rational clinical drug use and is widely concerned. TDM is a tool that combines pharmacokinetic and pharmacodynamic knowledge to optimize personalized drug therapy, which can improve treatment outcomes, reduce drug-drug toxicity, and avoid the risk of developing drug resistance. To effectively implement TDM, accurate and sophisticated analytical methods are required. By researching the literature published in recent years, we summarize the types of commonly monitored drugs, therapeutic windows, and clinical assays and track the trends and hot spots of therapeutic drug monitoring. The purpose is to provide guidelines for clinical blood drug concentration monitoring, to implement individualized drug delivery programs better, to ensure the rational use of drugs for patients, and to provide a reference for the group to carry out related topics in the future.

The application of multi-walled carbon nanotubes modified pencil graphite electrode for voltammetric determination of favipiravir used in COVID-19 treatment

This study describes the first application of an improved procedure on a pencil graphite electrode decorated with functionalized multi-walled carbon nanotubes (f-MWCNTs/PGE) for the determination of the COVID-19 antiviral drug, favipiravir (FVP). The electrochemical behavior of FVP at f-MWCNTs/PGE was examined by cyclic voltammetry and differential pulse voltammetry (DPV) methods, and it was noted that the voltammetric response significantly increased with the modification of f -MWCNTs to the surface. The linear range and limit of detection from DPV studies were determined as 1-1500 µM and 0.27 µM, respectively. In addition, the selectivity of the method was tested toward potential interferences, which can be present in pharmaceutical and biological samples, and it was found that f-MWCNTs/PGE showed high selectivity for the determination of FVP in the presence of probable interferences. The results with high accuracies and precisions from the obtained feasibility studies also revealed that the designed procedure can be used for accurate and selective voltammetric determination of FVP in real samples.

Graphical abstract

An electrochemical chlorpromazine sensor based on a gold-copper bimetallic synergetic molecularly imprinted interface on an acupuncture needle electrode

Chlorpromazine (CPZ) is a medicine for nervous system disorders. Measuring CPZ in vivo can assist doctors in evaluating patients' blood drug concentration and monitoring drug metabolism. Therefore, an accurate in vivo detection of CPZ is crucial. In recent years, the acupuncture needle, traditionally used in Chinese medicine, has emerged as a potential electrode in the field of electrochemistry, with promising applications for in vivo detection. In this study, Au/Cu nanoparticles were electrodeposited onto an acupuncture needle electrode (ANE) to improve electrical conductivity and provide an electro-catalytic surface. Subsequently, 3-aminophenylboronic acid and CPZ were attracted to each other through intermolecular forces; at the same time, the interaction force of Au-S between CPZ and the AuNPs made the polymer layer grow around the CPZ molecules on the modified electrode surface. The imprinted nanocavities showed highly selective and sensitive detection performance for CPZ after elution. Inside the recognizable site and microenvironment of the cavities, the captured CPZ molecule provided a suitable configuration for the fluent electron transfer of the electroactive group within a short range from the Au/Cu bimetal. Under ideal conditions, the MIP/Au/Cu/ANE exhibited two good linear ranges of 0.1-100 μM and 100-1000 μM with a detection limit of 0.07 μM. Moreover, the sensors showed great selectivity, good stability and excellent repeatability, making them suitable for CPZ detection in human serum. This provides a novel idea for real-time and in vivo CPZ detection.

Polyvinylpyrrolidone K-30-Based Crosslinked Fast Swelling Nanogels: An Impeccable Approach for Drug's Solubility Improvement

Poor solubility is a global issue of copious pharmaceutical industries as large number of drugs in development stage as well as already marketed products are poorly soluble which results in low dissolution and ultimately dosage increase. Current study is aimed at developing a polyvinylpyrrolidone- (PVP-K30-) based nanogel delivery system for solubility enhancement of poorly soluble drug olanzapine (OLP), as solubilization enhancement is the most noteworthy application of nanosystems. Crosslinking polymerization with subsequent condensation technique was used for the synthesis of nanogels, a highly responsive polymeric networks in drug's solubility. Developed nanogels were characterized by percent entrapment efficiency, sol-gel, percent swelling, percent drug loaded content (%DLC), percent porosity, stability, solubility, in vitro dissolution studies, FTIR, XRD, and SEM analysis. Furthermore, cytotoxicity study was conducted on rabbits to check the biocompatibility of the system. Particle size of nanogels was found with 178.99 ± 15.32 nm, and in vitro dissolution study exhibited that drug release properties were considerably enhanced as compared to the marketed formulation OLANZIA. The solubility studies indicated that solubility of OLP was noticeably improved up to 36.7-fold in phosphate buffer of pH 6.8. In vivo cytotoxicity study indicated that prepared PVP-K30-based formulation was biocompatible. On the basis of results obtained, the developed PVP-K30-co-poly (AMPS) nanogel delivery system is expected to be safe, effective, and cost-effective for solubility improvement of poorly soluble drugs.

Recent Developments in Voltammetric Analysis of Pharmaceuticals Using Disposable Pencil Graphite Electrodes

The even growing production of both well-known and new derivatives with pharmaceutical action involves the need for developing facile and reliable methods for the analysis of these compounds. Among the widely used instrumental techniques, the electrochemical ones are probably the simplest and the most rapid, also having good performance characteristics. However, the key tool in electroanalysis is the working electrode. Due to the inherent electrochemical and economic advantages of the pencil graphite electrode (PGE), the interest in its applicability in the analysis of different analytes has continuously increased in recent years. Thus, this paper aims to review the scientific reports published in the last 10 years on the use of the disposable eco- and user-friendly PGEs in the electroanalysis of compounds of pharmaceutical importance in different matrices. The PGE characteristics and designs (bare or modified with various types of materials), along with their applications and performance parameters (e.g., linear range, limit of detection, and reproducibility), will be discussed, and their advantages and limitations will be critically emphasized.

Review of Chromatographic Methods Coupled with Modern Detection Techniques Applied in the Therapeutic Drugs Monitoring (TDM)

Therapeutic drug monitoring (TDM) is a tool used to integrate pharmacokinetic and pharmacodynamics knowledge to optimize and personalize various drug therapies. The optimization of drug dosing may improve treatment outcomes, reduce toxicity, and reduce the risk of developing drug resistance. To adequately implement TDM, accurate and precise analytical procedures are required. In clinical practice, blood is the most commonly used matrix for TDM; however, less invasive samples, such as dried blood spots or non-invasive saliva samples, are increasingly being used. The choice of sample preparation method, type of column packing, mobile phase composition, and detection method is important to ensure accurate drug measurement and to avoid interference from matrix effects and drug metabolites. Most of the reported procedures used liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) techniques due to its high selectivity and sensitivity. High-performance chromatography with ultraviolet detection (HPLC-UV) methods are also used when a simpler and more cost-effective methodology is desired for clinical monitoring. The application of high-performance chromatography with fluorescence detection (HPLC-FLD) with and without derivatization processes and high-performance chromatography with electrochemical detection (HPLC-ED) techniques for the analysis of various drugs in biological samples for TDM have been described less often. Before chromatographic analysis, samples were pretreated by various procedures-most often by protein precipitation, liquid-liquid extraction, and solid-phase extraction, rarely by microextraction by packed sorbent, dispersive liquid-liquid microextraction. The aim of this article is to review the recent literature (2010-2020) regarding the use of liquid chromatography with various detection techniques for TDM.