Novel potentiometric application for the determination of pantoprazole sodium and itopride hydrochloride in their pure and combined dosage form

Two fabricated carbon paste electrodes for novel potentiometric determination of probenecid in dosage form and human plasma

Solid contact ion selective electrodes are extensively utilized owing to their marvelous performance over traditional liquid contact ones. The main drawback of those solid contact electrodes is aqueous layer formation which affects their constancy. Herein and to overcome this common drawback, a carbon paste electrode containing poly(3,4-ethylenedioxythiophene) was constructed and used for determination of probenecid at variant pH values. This modification decreased the potential drift down to 0.8 mV/h and improved its stability over 30 days. A Nernstian slope of - 57.8 mV/decade associated with a linear range of 1.0 × 10^-6-1.0 × 10^-2 mol/L was obtained. The modified carbon paste electrode successfully detected up to 8.0 × 10^-7 mol/L probenecid. Results of this modified carbon paste electrode were also compared to unmodified one.

Facile fabrication of a portable PANI-NFs/c-MWCNT nano-composite electrochemical sensor for gefitinib: application to human plasma

A novel potentiometric solid contact (SC) sensor was developed to determine the anticancer drug gefitinib by employing a polyaniline nanofibers/carboxylated multi-walled carbon nanotube (PANI-NFs/c-MWCNT) nano-composite as an ion to electron transducer. The FDA approved gefitinib as the first line treatment of non-small cell lung cancer (NSCLC) that represents 90% of lung carcinomas. The PANI-NFs/C-MWCNT nano-composite was synthesized and characterized using Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). Twenty-three polyvinyl chloride (PVC) based sensors were fabricated through a systematic approach using different plasticizers and cationic exchangers to investigate their effects on the performance of the developed sensors. The incorporation of calix[8]arene (CX-8) notably enhanced the sensitivity of the developed sensor, confirmed by the docking study. The optimized sensor attained a fast and stable Nernstian slope of 29.14 mV per decade over the concentration range from 1.0 × 10^-2 to 1.5 × 10^-6 M with a LOD of 1.0 × 10^-6 M. The proposed method represents the first potentiometric sensor for GEF assay according to the authors' knowledge. It was validated as per the IUPAC guidelines and efficiently applied to determine GEF in its tablets and human plasma. This encourages quality control, bioavailability, and clinical centers to utilize the portable GEF sensor in its routine analysis.

Recent advances in polymeric nanostructured ion selective membranes for biomedical applications

Nano structured ion-selective membranes (ISMs) are very attractive materials for a wide range of sensing and ion separation applications. The present review focuses on the design principles of various ISMs; nanostructured and ionophore/ion acceptor doped ISMs, and their use in biomedical engineering. Applications of ISMs in the biomedical field have been well-known for more than half a century in potentiometric analysis of biological fluids and pharmaceutical products. However, the emergence of nanotechnology and sophisticated sensing methods assisted in miniaturising ion-selective electrodes to needle-like sensors that can be designed in the form of implantable or wearable devices (smartwatch, tattoo, sweatband, fabric patch) for health monitoring. This article provides a critical review of recent advances in miniaturization, sensing and construction of new devices over last decade (2011-2021). The designing of tunable ISM with biomimetic artificial ion channels offered intensive opportunities and innovative clinical analysis applications, including precise biosensing, controlled drug delivery and early disease diagnosis. This paper will also address the future perspective on potential applications and challenges in the widespread use of ISM for clinical use. Finally, this review details some recommendations and future directions to improve the accuracy and robustness of ISMs for biomedical applications.

Voltammetric determination of itopride using carbon paste electrode modified with Gd doped TiO2 nanotubes

In the present work TiO₂ nanotubes (TNT) have been synthesized by alkaline hydrothermal transformation. Then they have been doped with Gd element. Characterizations of doped and undoped TNT have been done with TEM and SEM. The chemical composition was analyzed by EDX, Raman and FTIR spectroscopy. The crystal structure was characterized by XRD. Carbon paste electrode has been fabricated and mixed with Gd doped and undoped TNT to form a nanocomposite working electrode. Comparison of bare carbon paste electrode and Gd doped and undoped TNT carbon paste electrode for 1.0 ×10^-3 M K₄ [Fe(CN)₆] voltammetric analysis; it was observed that Gd doped TNT modified electrode has advantage of high sensitivity. Gd doped TNT modified electrode has been used as working electrode for itopride assay in a pharmaceutical formulation. Cyclic voltammetry analysis showed high correlation coefficient of 0.9973 for itopride (0.04-0.2 mg/mL) with a limit of detection (LOD) and limit of quantitation values (LOQ) of 2.9 and 23.0 μg.mL^-1 respectively.

A Sensitive, Simple and Direct Determination of Pantoprazole Based on a "Turn off-on" Fluorescence Nanosensor by Using Terbium-1,10-phenanthroline-silver Nanoparticles

A new sensitive, simple, rapid, reliable and selective fluorometric method for the determination of pantoprazole (PAN) in human plasma and a pharmaceutical formulation has been developed. This technique is based on a quenching effect of silver nanoparticles (AgNPs) on the emission intensity of a fluorescent probe, terbium(III)-1,10-phenantroline (Tb(III)-phen) complex (due to a fluorescence resonance energy transfer (FRET) phenomenon between the Tb(III)-phen complex and AgNPs), and then restoring the fluorescence intensity of the Tb(III)-phen-AgNPs system upon the addition of PAN (turn off-on process). The effects of various factors on the proposed method including time, temperature, pH, order of the addition of various reagents and the concentration of AgNPs were investigated. Under the optimal conditions, a good linear relationship between the enhanced emission intensity of the Tb(III)-phen-AgNPs system and the PAN concentration was observed in the range of (10 - 1000) × 10^-8 M. The limit of detection (LOD) and the limit of quantitation (LOQ) were 7.2 × 10^-8 and 24.2 × 10^-8 M, respectively. Also, the interferences of some common interfering species on the fluorescence intensity of the system were investigated. This simple and sensitive method was successfully applied for the determination of PAN in spiked human plasma samples and in its capsule formulation. The analytical recoveries were in the range of 88.54 - 101.33 and 90.07 - 98.85%, respectively.

Voltammetric Method Development for Itopride Assay in a Pharmaceutical Formulation

Background:

Itopride used for the gastrointestinal symptoms caused by reduced gastrointestinal mobility. For the first time rapid, low cost and green voltammetric method has been applied to analyze itopride in pharmaceutical formulation.

Method:

Cyclic Voltammetry (CV), Linear Sweep Voltammetry (LSV), Square Wave Voltammetry (SWV) and Differential Pulse Voltammetry (DPV) methods have been applied in this study.

Results:

Na2SO4 (1M) supporting electrolyte exhibited sharper anodic peak current than other used supporting electrolytes; glassy carbon electrode (GC) working electrode shows better results than platinum electrode (Pt). SWV results show the lowest limit of detection and quantitation values of 2.3 and 18.1 μg.mL-1, respectively. SWV recovery is 100.56% and 100.46% for 50 μg.mL-1 and 100 μg.mL-1 of commercially available itopride tablets, respectively. Furthermore, SWV inter and intraday results precessions are better than other used methods with 0.96 and 0.56% RSD, respectively.

Conclusion:

The optimum method of applied methods in this study is SWV method. Voltammetry showed low LOD and LOQ values with high accuracy and precession in addition to comparable repeatability and reproducibility values.

Computational optimization of a novel solid-state sensor for stable assay of isoxsuprine hydrochloride in the presence of its nephrotoxic/hepatotoxic photothermal degradation products: application in different sampling matrices

The DOE optimization of a solid-state potentiometric sensor for isoxsuprine assay in the presence of its photothermal degradation products within complex matrices.

Ionophore-based potentiometric PVC membrane sensors for determination of phenobarbitone in pharmaceutical formulations

The fabrication and development of two polyvinyl chloride (PVC) membrane sensors for assaying phenobarbitone sodium are described. Sensors 1 and 2 were fabricated utilizing β- or γ-cyclodextrin as ionophore in the presence of tridodecylmethylammonium chloride as a membrane additive, and PVC and dioctyl phthalate as plasticizer. The analytical parameters of both sensors were evaluated according to the IUPAC guidelines. The proposed sensors showed rapid, stable anionic response (-59.1 and -62.0 mV per decade) over a relatively wide phenobarbitone concentration range (5.0 × 10-6-1 × 10-2 and 8 × 10-6-1 × 10-2 mol L-1) in the pH range of 9-11. The limit of detection was 3.5 × 10-6 and 7.0 × 10-6 mol L-1 for sensors 1 and 2, respectively. The fabricated sensors showed high selectivity for phenobarbitone over the investigated foreign species. An average recovery of 2.54 μg mL-1 phenobarbitone sodium was 97.4 and 101.1 %, while the mean relative standard deviation was 3.0 and 2.1 %, for sensors 1 and 2, respectively. The results acquired for determination of phenobarbitone in its dosage forms utilizing the proposed sensors are in good agreement with those obtained by the British Pharmacopoeial method.