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Abstract

Paracetamol is a common analgesic and antipyretic drug that is used for the relief of fever, headaches and other minor aches and pains. Their determination in pharmaceuticals is of paramount importance, since an overdose of paracetamol can cause fulminating hepatic necrosis and other toxic effects. Many analytical methodologies have been proposed for the determination of paracetamol. The aim of the present study is to evaluate the utility of different techniques for quantification of paracetamol content in pharmaceutical formulations and biological samples.

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... For propofol monitoring, perhaps the most significant such molecule is the analgesic drug paracetamol (also known as acetaminophen). It is widely used in both domestic and clinical settings [63,64], with one study reporting that 64% of ICU patients received paracetamol as part of their treatment [65]. It is oxidised at similar potentials to propofol [66], has a similar therapeutic range [54] and has a lower protein binding affinity [44,67,68], resulting in higher free fractions. ...
... cule is the analgesic drug paracetamol (also known as acetaminophen). It is widely used in both domestic and clinical settings [63,64], with one study reporting that 64% of ICU patients received paracetamol as part of their treatment [65]. It is oxidised at similar potentials to propofol [66], has a similar therapeutic range [54] and has a lower protein binding affinity [44,67,68], resulting in higher free fractions. ...
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Propofol is one of the most widely used intravenous drugs for anaesthesia and sedation and is one of the most commonly used drugs in intensive care units for the sedation of mechanically ventilated patients. The correct dosage of propofol is of high importance, but there is currently a lack of suitable point-of-care techniques for determining blood propofol concentrations. Here, we present a cytochrome P450 2B6/carbon nanotube/graphene oxide/metal oxide nanocomposite sensor for discrete measurement of propofol concentration. Propofol is converted into a quinol/quinone redox couple by the enzyme and the nanocomposite enables sensitive and rapid detection. The metal oxide nanoparticles are synthesised via green synthesis and a variety of metal oxides and mixed metal oxides are investigated to determine the optimal nanocatalyst. Converting propofol into the redox couple allows for the measurement to take place over different potential ranges, enabling interference from common sources such as paracetamol and uric acid to be avoided. It was found that nanocomposites containing copper titanium oxide nanoparticles offered the best overall performance and electrodes functionalised with such nanocomposites demonstrated a limit of detection in bovine serum of 0.5 µg/mL and demonstrated a linear response over the therapeutic range of propofol with a sensitivity of 4.58 nA/μg/mL/mm2.
... Paracetamol (PCM) also known as acetaminophen or N-acetyl-p-aminophenol is one of the most widely available and commonly used antipyretic and analgesic drug 1,2 . PCM has been used for more than a century as an effective and safe treatment for relieving pain (headache, backache, muscular aches, arthritis, and post-operative pains) and reducing fever 3,4 . ...
... For this reason, it is imperative to develop rapid, sensitive, cost-effectiveness, and efficient detection methods for quantitative determination of PCM. Since PCM is as an electroactive compound and the mechanism of electrochemical oxidation/reduction has been systematically investigated 1,14,15 , the electrochemical sensors have attracted widespread attention and great potential in the pharmaceutical quality control of PCM. Owing to the inherent advantages including rapid analysis time, cost-effectiveness, facile miniaturization, on-site detection, high sensitivity and selectivity 16,17,18 , the electrochemical sensor can be used as a promising sensing platform for the determination of PCM. ...
Article
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In this study, crystalline spinel zinc ferrite nanoparticles (ZnFe2O4 NPs) were successfully prepared and proposed as a high-performance electrode material for the construction of an electrochemical sensing platform for the detection of paracetamol (PCM). By modifying a screen-printed carbon electrode (SPE) with ZnFe2O4 NPs, the electrochemical characteristics of the ZnFe2O4/SPE and the electrochemical oxidation of PCM were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and differential pulse voltammetry (DPV) methods. The calculated electrochemical kinetic parameters from these techniques including electrochemically active surface area (ECSA), peak-to-peak separation (ΔEp), charge transfer resistance (Rct), standard heterogeneous electron-transfer rate constants (k⁰), electron transfer coefficient (α), catalytic rate constant (kcat), adsorption capacity (Γ), and diffusion coefficient (D) proved that the as-synthesized ZnFe2O4 NPs have rapid electron/mass transfer characteristics, intrinsic electrocatalytic activity, and facilitate the adsorption–diffusion of PCM molecules towards the modified electrode surface. As expected, the ZnFe2O4/SPE offered excellent analytical performance towards sensing of PCM with a detection limit of 0.29 μM, a wide linear range of 0.5–400 μM, and high electrochemical sensitivity of 1.1 μA μM⁻¹ cm⁻². Moreover, the proposed ZnFe2O4-based electrochemical nanosensor also exhibited good repeatability, high anti-interference ability, and practical feasibility toward PCM sensing in a pharmaceutical tablet. Based on these observations, the designed electrochemical platform not only provides a high-performance nanosensor for the rapid and highly efficient detection of PCM but also opens a new avenue for routine quality control analysis of pharmaceutical formulations.
... Thus, accurate and precise detection of PC in water samples is crucial to control quality and avoid negative repercussions on the natural environment and human health. Current analytical methods for sensing are primarily dependent on chromatography techniques [4], as well as fluorometry [5], colorimetry [6], enzymatic biosensors [7], and electrochemical methods [8]. These methods show a variety of drawbacks, including complex sample processing, expensive equipment, significant time requirements, and the use of toxic chemicals, thereby limiting their widespread applicability [9]. ...
Article
The purpose of this research is to develop an electrochemical sensor in order to determine paracetamol (PC) levels. To reach this objective, an indium tin oxide (ITO) electrode was modified with a composite of carbon nanosphere (CNS) and iron-doped bismuth vanadate nanoparticles (Fe0.05Bi0.95VO4), which was tested to evaluate its electrocatalytic properties for the anodic oxidation of PC. Exploiting their various structural advantages that include large exposed active surface sites, ultrathin nanosheets, and unique three-dimensional spherical nanostructure, the as-obtained hybrid electrode Fe0.05Bi0.95VO4/CNS exhibits an excellent electrochemical performance. The fabricated nanocomposite electrode Fe0.05Bi0.95VO4/CNS/ITO reacted rapidly with enhanced anodic peak current when PC analyte is added. At optimized conditions, the proposed electrochemical platform enabled a linear plot over a concentration range of 1–80 μM with a detection limit of 1 μM of PC. This research’s novelty consists of designing a new and effective electrochemical sensing system that can identify PC with high sensitivity and selectivity, helping to keep water quality under control and preventing negative effects on the environment and public health.
... A wide range of assay methods for paracetamol have been developed over the years (Espinosa et al., 2006) but most commonly used ones are those described by the BP and USP (USP, 2017 andBP, 2018). ...
Article
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Diclofenac sodium and paracetamol are Over the counter (OTC) medications used as analgesic and antipyretic agents to relieve pains, fever and headaches. The aim of this work was determine the mg content of paracetamol and diclofenac sodium in selected samples across the Maiduguri metropolis using High Performance liquid chromatography (HPLC) method. For paracetamol samples an intersil ODS-3V column (150 mm × 4.6 mm; 5 μm pore size) was used at the temperature of 35oC the mobile phase was methanol: water (20:80) using isocratic elution at the flow rate of 2 mL/min, injection volume of 10 μL and a diode array detector. For diclofenac sodium samples, the chromatographic conditions were the same except the mobile phase which was methanol: water (63:37), flow rate of 0.8 mL min, injection volume of 20 μL and column temperature was set at 30 oC. A total of 45 samples were analysed; which comprised of paracetamol tablet, paracetamol syrup and diclofenac sodium tablet which were randomly selected from three different sources; hospital pharmacy, community pharmacy and drug patent stores. The percentage mg content for paracetamol tablets ranged from 48 to 83 % while that of the paracetamol syrups ranged from 72 to 120 % and finally diclofenac sodium tablets ranged from 73 to 174 %. Adopting the United State Pharmacopoeia (USP) as reference for assessment tool, it was observed that all the paracetamol tablet samples failed, 4 out of 15 paracetamol syrup samples failed, and 11 out of 15 diclofenac sodium tablet samples failed. There was statistical significance (p< 0.05) between class of drug and percentage mg content but there was no significance (p< 0.05) between source of drug and percentage constituent. HPLC technique was used successfully for quantitative determination of paracetamol and diclofenac sodium dosage forms.
... 401-413 О Р И Г И Н А Л Ь Н А Я С Т А Т Ь Я Парацетамол (ПЦ) (ацетоаминофен), обладающий свойствами анальгетика и антипиретика, стал основным анальгетиком и жаропонижающим средством для детей [7]. Действие препарата связано с ингибированием циклооксигеназ преимущественно в центральной нервной системе, воздействуя на центры боли и терморегуляции [8]. ...
... 28 Paracetamol, a widely used analgesic, is determined in pharmaceutical formulations and biological samples to ensure appropriate dosage. 29 These compounds can be found with pesticides such as KB in various contexts. For example, pesticide exposure in human blood and urine, especially during medical treatments or dietary intake, can coincide with dopamine, uric acid, ascorbic acid and paracetamol. ...
Article
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We investigated the electrochemical behavior of carbamate pesticide-type karbutylate (KB) with boron-doped diamond (BDD), glassy carbon (GC), and pencil graphite (PG) electrode, and analytical determination in real samples. Similar to organophosphate insecticides, carbamate pesticides are produced from carbamic acid and are extensively utilized in agriculture, gardens, and residences. Therefore, a rapid and simple detection of KB in real samples is important. Carbon-based electrodes are widely used in electroanalytical chemistry due to their rich surface chemistry, chemical inertness, broad potential window, low background current, and congruency for various demanding applications. Three different carbon-based electrodes were used. The effect of buffer solutions, scan rate, square wave (SWV), and differential pulse voltammetry parameters on the voltammetric response of KB was tested. The optimum working media for all three electrodes was determined as pH 2.00 phosphate buffer solution and voltammetric measurements were carried out in this media. Under optimum experimental conditions, linear calibration dependences for KB were obtained as 6.00 × 10⁻⁷–8.00 × 10−5 M, 4.00 × 10⁻⁷–8.00 × 10−5 M, and 8.00 × 10⁻⁸–8.00 × 10−5 M with a limit of detection of 2.18 × 10⁻⁷, 3.71 × 10−8 M, and 2.66 × 10−8 M by the BDD, GC, and PG electrodes, respectively, using SWV. As a result, sensitive determination of KB has been successfully performed using different carbon-based electrodes in real soil samples.
... Various techniques for PCT detection have been explored [4], including titrimetry [5], high performance thin layer chromatography [6,7], micellar electrokinetic chromatography [8], capillary electrophoretic methods [9], and electrochemical sensors [10]. Other approaches, such as differential derivative spectroscopy, require complex calculations [9]. ...
Article
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This study introduces a novel method for the rapid and efficient detection of paracetamol, leveraging a colorimetric sensing mechanism predicated on the utilization of TMB-MnO2 nanosheets. The interaction of paracetamol with MnO2 is characterized by a selective reaction mechanism, leading to the reduction of MnO2 to Mn²⁺ ions and consequent attenuation of the oxidase-mimetic activity of MnO2. The developed colorimetric sensor exhibits a linear detection range for paracetamol extending from 5 × 10⁻⁴ to 10⁻² M, with a lower detection limit quantified at 5.24 × 10⁻⁷ M. Empirical assessments conducted to ascertain the influence of potential interferents prevalent in actual samples revealed a negligible impact on the colorimetric sensor. Furthermore, the application of this sensor system to real-world samples demonstrated its capability to detect paracetamol with a notable recovery rate and a relative standard deviation of < 6.65%. This approach manifests significant promise for the efficacious detection of paracetamol in various sample matrices. Graphical abstract
... There has been a growth in the regular usage of medications to extend the lifecycle and prevent various diseases [1,2]. Acetaminophen, also known as paracetamol (PCA) N-acetyl-p-aminophenol, is a commonly used analgesic and antipyretic drug in the medical field for the treatment of discomfort, fever, for individuals who cannot take aspirin for pain relief, headaches, menstrual cramps, and fever [3][4][5][6]. PCA, a weak acid, rapidly reacts, later circulates in oral management, and is excreted in urine [7]. Most of the time, PCA does not have any negative effects on health. ...
Article
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The current research work introduces the development of a modest and green electrochemical sensor for the analysis of paracetamol (PCA) and dopamine (DA), using a polymerized l-alanine layered carbon nanotube paste electrode [(L-AN)LCNTPE]. The constructed sensor, comparing both (L-AN)LCNTPE and a bare carbon nanotube paste electrode [BCNTPE], enhancing electro-analytical performance. The electrochemical responses of PCA were studied using different methods, including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV), and scanning electron microscopy (SEM) were employed to study PCA electrochemical responses and characterize the working electrode surface. PCA investigation in 0.2 M phosphate-buffered solution (PBS) at pH 7.0 using the Poly (L-AN)LCNTPE showed high electrocatalytic activity and more active spots compared to BCNTPE. pH variation from 5.5 to 8.0 showed optimum performance at pH 7.0, shows superior current response in a 0.2 M PBS. At pH 7.0, scan rate effects (0.025 to 0.65 V/s) and PCA absorption, along with simultaneous DA detection on (L-AN)LCNTPE, were studied. The results indicated pH-controlled, adsorption-proceeded redox behaviour of PCA on (L-AN)LCNTPE. The sensor detected PCA in the range of 0.2 µM to 100.0 µM, with a low detection limit of 1.0 × 10–7 M and a low quantification limit of 3.5 × 10–7 M. The (L-AN)LCNTPE shows good stability, reproducibility, and repeatability, in PCA detection. The applicability in medicinal samples (tablets) was also studied.
... Aminophenols are important chemical compounds in synthesizing metal-complex dyes and are also used in hairdying agents, corrosion inhibition, and polymer production [48]. To our knowledge, only few investigations have been reported on the use of hybrid organic-inorganic materials as catalysts for their reduction. ...
Article
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Three new organic–inorganic hybrid phosphites salts, namely, (enH2)[M(H2O)6](HPO3)2, with [M = Co (1), Ni (2) and Mg (3), and “en” refers to ethylenediamine C2N2H8] have been synthesized at room temperature by the slow evaporation method. The solid-state structures were solved from single crystal X-ray diffraction data. These compounds are isostructural, all crystallizing in the orthorhombic system, space group, Pbca (no 61). The FTIR spectroscopy shows the expected bands of ethylenediamine (en), water molecules, and hydrogen-phosphite oxoanion groups. The thermal stability until 100 °C of the three compounds was confirmed using combined analyses (TGA/DTA, powder X-ray diffraction and Raman spectroscopy). Two catalytic activity performances were investigated: the catalytic efficiency on the water decontamination of the three compounds by the reduction of three nitrophenol isomers and the Hydrogen Evolution Reaction (HER) in an alkaline environment. The three hybrid compounds turned out to be very efficient new catalysts for reducing the three nitrophenol isomers. The fastest electron transport and the most favorable HER reaction kinetics are displayed by (enH2)[Ni(H2O)6](HPO3)2, while the highest current density with the lowest overpotential was obtained for (enH2)[Co(H2O)6](HPO3)2. Graphical abstract
... PAR & ORP were determined in their pharmaceutical formulation by using spectrophotometric methods [1][2][3][4][5][6], HPLC methods [7][8][9], TLC and microemulsion HPLC method [10], square wave voltammetric method [11] and capillary electrophoresis method [12]. Several methods have been reported for determination of PAR alone in biological matrix including spectrophotometric methods [13][14][15][16], HPLC methods [17][18][19][20][21], HPTLC method [22], GC method [23] and voltammetric methods [24][25][26]. On the other hand, only chromatographic methods have been reported for determination of ORP alone in biological matrix including HPLC method [27] and GC methods [28][29][30]. ...
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Three simple, specific, accurate and precise chemometric methods have been developed for the analysis of paracetamol and orphenadrine citrate in their mixture form without prior separation. CLS, PLS and PCR methods were used for simultaneous determination of paracetamol and orphenadrine citrate by using different sets of data in which better results were produced. The validity of these chemometrics has been carried out by using 8 synthetic mixtures for determination of the power of prediction for each method. Latent variable number is different from one model to another concurrent with changing the set of data. PRESS (predicted residual error sum of squares) and RMSEP (Root mean square error of prediction) were used for the comparison between different methods and for determination the predictive power of each set of data. Statistical comparison between the proposed methods (zero absorption data) and the reference reported methods was carried out and Statistical comparison between the proposed chemometric methods in different sets of data was also performed.
... It has been frequently used for the treatment of cold and flu. [1] PCT is rapidly absorbed in human metabolism after its oral administration. In addition, 2.0-5.0 % of PCT remains unchanged form in human urine and mostly excreted as its sulphates, glucuronide, cysteine and mercapturic acid conjugates. ...
Article
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This study proposed a precise/accurate analytical method for the paracetamol (PCT) determination in human serum/urine matrices. PCT was simultaneously derivatized and preconcentrated by dispersive liquid‐liquid microextraction (DLLME). Benzoyl chloride dissolved in dichloromethane was used as derivatization agent in the extraction solvent. Quadruple isotope dilution (QID) method with three calibration mixtures (A*B‐x, x=1,2,3) and one sample mixture (AB) was performed to enhance the method accuracy and precision. In our research laboratory, paracetamol benzoate‐d3 (PCT benzoate‐d3) was synthesized and used as isotopically labelled substance (B) to conduct QID method. After the combination of QID and DLLME‐GC‐MS systems, percent recovery results for human serum/urine matrices were found to be 99.3–101.0 % and 98.8–99.9 %, respectively.
... Acetaminophen (AC) is a relatively safe over-the-counter drug, mainly used for colds and fever, arthralgia, migraine and neuralgia, cancer pain and analgesia after surgery [1][2][3][4] which is an effective option for patients who are allergic to intolerant, aspirin or unsuitable to use aspirin. 5 Nevertheless, overdose of AC can result critical illness such as pancreatitis, liver toxicity and kidney toxicity. ...
Article
Full-text available
Herein, a hybrid nanomaterial of copper-nickel bimetal and reduced graphene (rGO) was simply and quickly synthesized by hydrothermal method, which was characterized by transmission electron microscope, field emission scanning electron microscopy, fourier transform infrared spectroscopy, electrochemical impedance and X-ray diffractometry. A new type of electrochemical sensor was constructed by fixing this hybrid on the glassy carbon electrode (GCE). Square wave voltammetry and cyclic voltammetry indicate that this Cu-Ni/rGO/GCE sensor has highly sensitive electrocatalytic activities to 4-aminophenol (4-AP) and acetaminophen (AC). The linear detection ranges were 0.10∼50.00 μM for AC and 0.10∼30.00 μM for 4-AP, with the detection limits of 2.13 nM for AC and 2.19 nM for 4-AP, respectively. The Cu-Ni/rGO/GCE was successfully used for the determination of 4-AP and AC simultaneously of paracetamol tablets, and satisfactory results were obtained.
... Paracetamol (PCT), also known as acetaminophenol, is chemically named N-acetyl-p-aminophenol. It is a commonly used as over-the-counter analgesic (pain reliever) and antipyretic (fever reducer) having actions similar to those of aspirin, and it is more suitable for patients who are sensitive to aspirin (Lau et al., 1989;Goyal et al., 2005;Bosch et al., 2006;Kachoosangi et al., 2008;Kang et al., 2010). ...
Article
The lower body tolerance of paracetamol (PCT) is 50 ppm and if it surpasses; PCT will led to accumulation of toxic metabolites. A carbon paste electrode modified with glycine (GlyCPE) is used for the detection of PCT at relatively low concentrations. In contrast to the bare carbon paste electrode (CPE), an improved onset potential with a shifting of 85 mV and enhancement of anodic peak current at the modified electrode resulted in a the GlyCPE surface with a material that possesses an electroanalytical activity toward the oxidation of PCT. Differential pulse stripping voltammograms (DPSV) of PCT oxidation on the GlyCPE yielded a well-defined oxidation peak of 0.61 V in a 0.1 M phosphate buffer solution of pH 6.0 with a linear calibration from 5.0 to 1000 mM with R2 = 0.995. The DPSV detection limit was projected to be 0.12 mM. In the presence of the interfering ascorbic acid (AA) of 50 and 100 mM, the GlyCPE was able to detect the PCT (100 mM) with a percentage of detection of 100.16 and 97.79, respectively, which did not affect significantly the peak current response of the PCT. Besides, the fabricated GlyCPE accurately measured the amount of PCT in three brand pharmaceutical samples.
... Being probably the most used drug worldwide, PAR has been widely studied, as evidenced by the many analytical methods developed for its quantification [8][9][10]. Moreover, there are some analytical methods used for the determination of GFS, PHE and PAR combined with other active ingredients in various pharmaceutical products. ...
Article
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Guaifenesin (GFS), phenylephrine (PHE) and paracetamol (PAR), drugs used in combination for the relief of cold and flu symptoms, were determined at electrochemically pretreated pencil graphite electrode. Differential pulse voltammetry (DPV) was used for the first time for the concomitant determination of the target compounds based on the electro-oxidation of PAR at 0.43 V, PHE at 0.74 V and GFS at 1.14 V in Britton–Robinson buffer pH 6.0. Under optimized experimental conditions, two linear ranges were obtained for PAR (2.50 × 10−6 M–1.00 × 10−5 M and 1.00 × 10−5 M–1.00 × 10−4 M) and for PHE and GFS linearity was proved between 5.00 × 10−6 M–2.00 × 10−4 M and 2.50 × 10−6 M–2.00 × 10−4 M, respectively. The detection limits were 8.12 × 10−7 M for PAR, 1.80 × 10−6 M for PHE and 8.29 × 10−7 M for GFS. The selective and sensitive DPV method and the electrochemically treated electrode were employed for simultaneous analysis of the analytes in pharmaceutical samples with good recoveries.
... This drug was introduced in 1983 by Von Mering as an analgesic/antipyretic [4]. It is the most widely used over-the-counter drug globally [5]. This compound has an excellent safety profile. ...
Article
We studied the effect of urea on TiO2–CeO2 and paracetamol photodegradation. The contribution of TiO2, CeO2, and urea was analyzed by simplex-centroid mixture. Solid-state combustion at 500 °C was the method of synthesis. All samples were characterized by X-ray diffraction, nitrogen adsorption/desorption, Uv spectroscopy, and scanning electron spectroscopy (SEM). According to the results, urea influences particle morphology. Bandgap decreases due to interactions with residual urea carbon. The surface area depended on the crystallinity of the samples. The value of the kinetic constant increased as a function of the amount of urea. The selectivity to CO2 was the roll of cerium oxide.
... Several methods have been reported for determination of PAR alone in biological matrices including spectrophotometric methods [21][22][23][24], HPLC methods [25][26][27][28][29], HPTLC method [30], GC method [31] and voltametric methods [32][33][34]. Only chromatographic methods have been reported for determination of ORP alone in biological matrices including HPLC method [35] and GC methods [36][37][38]. ...
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Herein, it is the first developed and fully validated LC-MS/MS method for simultaneous determination of paracetamol (PAR) and orphenadrine citrate (ORP) in rat plasma after oral administration in respect of therapeutic drug monitoring, bioequivalence, pharmacokinetic (PK) and drug-drug interaction (DDI) studies. PAR and ORP were extracted from plasma sample using ACN-induced protein precipitation method. The separation procedure was carried out on an Agilent Eclipse Plus ODS (4.60 x 100 mm, 3.50 μm) column using water-enriched gradient mobile phase consisting of 6 mM ammonium formate plus 0.1% formic acid and ACN at a flow rate of 0.5 mL min ⁻¹ . The mass spectrometry parameters were optimized and multiple reaction monitoring (MRM) in positive ion mode of two transitions was utilized for quantification of precursor to production at m/z 152 → 110 & 65 for PAR as [M+2H] ²⁺ , 270.3 → 181 for ORP as [M + H] ⁺ . According to US-FDA bioanalytical requirements, the proposed method was verified in terms of linearity, selectivity, recovery, accuracy, precision, matrix effects, and stability. The method was linear in the range of 1-5000 and 1-500 ng mL ⁻¹ with detection limits (S/N of 3) of 0.12 and 0.07 ng mL ⁻¹ for PAR and ORP, respectively. The selectivity and high sensitivity of the method succeeded in the study of PK parameters and DDI between PAR and ORP after oral dose administration. The synergistic action between the two drugs was confirmed by studying variable parameters like K a , T max , C max , AUC 0-24 , MRT, and Cl/F. PAR affects the absorption of ORP and decreases its C max but increases its T max in accordance with elevating AUC 0–24 and reducing Cl/F for both drugs. The current PK research is a useful tool for determining the DDI of both medicines and might be used in therapeutic drug monitoring and bioequivalence studies.
... However, in recent studies, it has been shown that paracetamol is associated with hepatic toxicity and renal impairment even though paracetamol is non-destructive. At normal medicinal doses, very rapidly and completely metabolized paracetamol undergoes glucuronidation and sulfation of the slow metabolites and is excreted in the urine (Bosch et al., 2006). So it is necessary to measure the presence of paracetamol with precision so as not to harm the patient. ...
Article
Paracetamol is a commom analgesic and antipyretic drug which used for reliefing fever and head ache. The determination of paracetamol dose in pharmaceuticals is very important, becauce an overdose can cause fulminating hepatic necrosis and other toxic effects. Therefore, it is necessary to measure the dose of paracetamol for the patient with precision to avoid harm. Many analytical methodologies have been proposed for determination of paracetamol dose. One of the methods was developed in the past two decades. Generally, electroanalytical approach especially voltammetry method is particularly design for determination of paracetamol dose especially in modifying electrode. This study aims to modified carbon paste electrode with molecularly imprinted polymer (MIP). Significant advantages of using MIP are the superior stability, low cost and ease of preparation. The poly (3-aminiophenol) film was prepared by cyclic voltammetry method and 3-aminophenol monomer in supporting electrolyte (HClO4) with and whitout presence of paracetamol molecule. The effect of paracetamol was seen at cyclic voltammogram was founded, where oxidation peak potential of poly (3-aminophenol) shifted to more cathodic potentials from 0.948 to 0.780 V, in presence of paracetamol. The Ipa showed a good linear relationship with concentration in the range 0.01–0.1 mM, and the detection limit was 4,63 μM.
... Currently, in the manufacturing of paracetamol tablets and the quantitation of the final product, HPLC is usually used to measure the API content, presenting disadvantages such as the consumption of the chromatographic column and solvent, complicated preprocessing, and deviations in results obtained by different operators. In addition, electroanalytical [21], capillary electrophoretic [22,23], and spectrophotometric methods [24] have also been applied to the determination of paracetamol content [25]. ...
Article
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In recent years, transmission Raman spectroscopy (TRS) has emerged as a potent new tool for rapid, nondestructive quantitation in pharmaceutical manufacturing. In order to expand the applicability of TRS and enhance its use in product quality monitoring during drug production, we aimed, in the present study, to apply partial least-squares (PLS) approaches to build a model consisting of 150 handmade tablets and covering 15 levels through the use of a multifactor orthogonal design of experiment (DOE), which was used to predict concentrations of validation tablets made by hand. The difference between results according to HPLC and TRS were negligible. The model was used to predict the active pharmaceutical ingredient (API) content in four random commercial paracetamol tablets, and corrected with the spectra of the commercial tablets to obtain four corresponding models. The results show that the content relative error in the model’s predictions after correction with commercially available tablets was significantly lower than that before correction. The corrected model was used to make predictions for 20 tablets from the brand Panadol. Compared with the HPLC results, the prediction relative error was basically less than 4.00%, and the relative standard deviation (RSD) of the content was 0.86%.
... Paracetamol (PAR) (Figure 1) is an analgesic antipyretic drug which was introduced into medical practice many years ago and it is still accepted as a very effective treatment for the relief of fever and several types of pain in adults and children [1]. PAR has several related substances and potential impurities that should be considered during assay of the bulk powder and final dosage forms. ...
Article
Objective: This research describes the simultaneous quantitation of Paracetamol (PRM) and Lornoxicam (LRX) with five of their related substances and toxic impurities, including, 4-nitrophenol (NTP), 4-aminophenol (AMP), 4-chloroacetanilide (CAC), N-phenylacetamide (NPA), and 2-aminopyridine (APD) using a specific HPLC-DAD method. Methods: The chromatographic separation involves the use of XTerra C18 column as the stationary phase and a mobile phase consisting of acetonitrile and 0.025 M phosphate buffer (pH 6). The separation was performed using gradient elution mode at 1.0 mL min-1 flow rate and detection at 260 nm for the determination of PRM and LRX. While for detecting PRM, LRX in presence of their toxic impurities, 270 nm was convenient. Validation of the suggested HPLC method was accomplished in regards to linearity, ranges, detection and quantitation limits, robustness, accuracy, precision and specificity. Results: Excellent resolution of the mixture components was accomplished at retention times 4.2, 4.8, 7.4, 11.1, 13.5, 14.7 and 15.3 min for APD, AMP, PRM, NPA, LRX, NTP and CAC, respectively. Linearity was established for PRM and LRX within concentration ranges of 10-100 and 10-60 µg/mL, respectively. The correlation coefficients obtained were > 0.9997. The suggested method was confirmed to be a specific stability-indicating through the selective separation of PRM and LRX from their related substances, degradants and impurities. Conclusion: The proposed method was successfully utilized for the sensitive and selective determination of PRM and LRX in their pharmaceutical formulation. Highlights: To the best of our knowledge, this is the first impurity profiling assay method for this combination in presence of five of their toxic related substances and impurities. Taking into consideration that at least 2 of the studied impurities (AMP and APD) are actually reported degradation products for the main drugs, therefore the suggested method can be considered stability-indicating as well.
... It is commercially available in the form of tablets, syrups, suspension, and injection dependent on the requirement of the patients. Paracetamol formulated by 4-AP is non-degradable in nature and with an elongated half-life, and there is a great possibility to accumulate in the human body, which can cause distinctive pathological symptoms including nephrotoxicity and hepatotoxicity [13][14][15][16]. Thus, considering the side effects of 4-AP in paracetamol, the USA and European community have provided a restriction to use 4-AP in paracetamol no more than 50 ppm [17,18]. ...
Article
Magnetic Co(0.8-x)ZrxNa0.2Fe2O4 nanocomposites (NCs) with controlled size were successfully synthesized by a facile low-temperature sol–gel method. The morphological and chemical properties of Co(0.8-x)ZrxNa0.2Fe2O4 NCs were controlled by (0.1–0.4) Zr content and particle size have been analyzed. The X-ray photoelectron spectroscopy (XPS) confirmed the chemical states for magnetic nanocomposites. Moderate saturation and coercivity (~ 200–500 Oe) of the nanocomposites remark the plausible soft magnetic behavior with adjustable factors. Here, glassy carbon electrode (GCE) was covered by a thin film of the prepared Co(0.8-x)ZrxNa0.2Fe2O4 NCs, and 5% Nafion in ethanol was applied on the glassy carbon electrode (GCE) to obtain the desired 4-aminophenol (4-AP) sensor and was applied to electrochemical analysis in detail in the phosphate buffer (pH = 7.0). A plot of current versus concentration of 4-AP is found linear in the concentration of 0.1 nM ~ 0.01 mM labeled as the dynamic range (LDR) for the detection and the resulting plot is known as calibration curve. The slope of the calibration curve divided by a cross-section of GCE (0.0316 cm2) results in the sensitivity (10.5665 µA µM−1 cm−2) of the 4-AP sensor. Using the signal-to-noise ratio (S/N ~ 3), the lower limit of detection (98.45 ± 4.92 pM) of the sensor is calculated. The 4-AP sensor exhibited substantial characteristics in terms of analytical parameters concluding response time, sensitivity, reproducibility, response time, and long-term stability in phosphate buffer. It is also evaluated in the detection of 4-AP with Co0.4Zr0.4Na0.2Fe2O4 NCs/GCE sensor in real environmental and extracted samples by applying the electrochemical approach. For environmental toxin monitoring, this noble approach might be potential in the development of future sensor technology with doped nanocomposite material by electrochemical approach on a broad scale.
... PAR & ORP were determined in their pharmaceutical formulation by using spectrophotometric methods [1][2][3][4][5][6], HPLC methods [7][8][9], TLC and microemulsion HPLC method [10], square wave voltammetric method [11] and capillary electrophoresis method [12]. Several methods have been reported for determination of PAR alone in biological matrix including spectrophotometric methods [13][14][15][16], HPLC methods [17][18][19][20][21], HPTLC method [22], GC method [23] and voltammetric methods [24][25][26]. On the other hand, only chromatographic methods have been reported for determination of ORP alone in biological matrix including HPLC method [27] and GC methods [28][29][30]. ...
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Three simple, specific, accurate and precise chemometric methods have been developed for the analysis of paracetamol and orphenadrine citrate in their mixture form without prior separation. CLS, PLS and PCR methods were used for simultaneous determination of paracetamol and orphenadrine citrate by using different sets of data in which better results were produced. The validity of these chemometrics has been carried out by using 8 synthetic mixtures for determination of the power of prediction for each method. Latent variable number is different from one model to another concurrent with changing the set of data. PRESS (predicted residual error sum of squares) and RMSEP (Root mean square error of prediction) were used for the comparison between different methods and for determination the predictive power of each set of data. Statistical comparison between the proposed chemometric methods was also performed.
... Paracetamol is a widely used analgesic drug that has been on the market for more than three decades. It is highly effective against fever and pain in humans [3,4]. However, the undesirable buildup of toxic metabolites of paracetamol such as 4-Aminophenol and acetic acid can cause adverse side-effects. ...
Article
Herein, we report the theoretical insight into the adsorption mechanism of p-Aminophenol on graphene and silver graphene composites. DFT calculations are performed at M06-2X/LANL2DZ level of theory to explore the adsorption mechanism of p-Aminophenol (p-AP) over a bare coronene, a coplanar silver cluster (Ag6), and two isomers of silver-graphene composites (isomer 1 and isomer 2). The highest Eint is found in p[email protected]6 (−15.15 kcal mol⁻¹) while the lowest is calculated for isomer 2 (−12.31 kcal mol⁻¹). NCI results show that electrostatic forces have a strong influence on the stability of p[email protected]6 and also of isomer 1, which results in their higher stability. Additionally, MD simulations confirmed that the adsorption of p-Aminophenol over silver-graphene composite is stable and efficient at room temperature. The adsorption mechanism in these complexes is further explored through variations in; absorption maximum (λmax), excitation energies, and oscillator strength (fo). The values of Eint and shift of λmax decreases in the order p[email protected]6 ˃ isomer 1 ˃ p[email protected] ˃ isomer 2. NBO and CDA analysis are performed to gain a deeper insight into the direction and amount of charge transfer between donor and acceptor units. The degree of charge transfer as measured by the NBO charges decreases in the order isomer 1 ˃ p[email protected]6 ˃ isomer 2 ˃ p[email protected] The transfer of electron density from the analyte in the complexes is solely due to the contribution of the p-orbital in the HOMO. Orbital hybridization in the complexes results in the generation of new occupied and virtual energy states, and the appearance of new energy states close to the Fermi level causes a reduction in HOMO-LUMO gaps, and hence enhanced conductivity of p-Aminophenol complexes. The outcome of the current study will provide useful guidelines in the development of promising sensing material for p-Aminophenol.
... Therefore, the concentration of acetaminophen in pharmaceutical formulations is highly controlled and regulated. Various analytical methods are employed in the analysis of acetaminophen-containing formulations [4], including chromatography [5] and various spectroscopy techniques [6,7]. While all these techniques can be employed successfully, they are not always suitable for routine analysis, with high equipment costs, time-consuming analyses, and in some cases poor selectivity and low sensitivity is observed. ...
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Acetaminophen is a well-known drug commonly used to provide pain relief, but it can also lead to acute liver failure at high concentrations. Therefore, there is considerable interest in monitoring its concentrations. Sensitive and selective acetaminophen electrochemical sensors were designed by cycling a glassy carbon electrode (GCE) to high potentials in the presence of β-CD in a phosphate electrolyte, or by simply activating the GCE electrode in the phosphate solution. Using cyclic voltammetry, adsorption-like voltammograms were recorded. The acetaminophen oxidation product, N-acetyl benzoquinone imine, was protected from hydrolysis, and this was attributed to the adsorption of acetaminophen at the modified GCE. The rate constants for the oxidation of acetaminophen were estimated as 4.3 × 10 –3 cm ² s –1 and 3.4 × 10 –3 cm ² s –1 for the β-CD-modified and -activated electrodes, respectively. Using differential pulse voltammetry, the limit of detection was calculated as 9.7 × 10 –8 M with a linear concentration range extending from 0.1 to 80 μM. Furthermore, good selectivity was achieved in the presence of caffeine, ascorbic acid and aspirin, enabling the determination of acetaminophen in a commercial tablet. Similar electrochemical data were obtained for both the β-CD-modified and activated GCE surfaces, suggesting that the enhanced detection of acetaminophen is connected mainly to the activation and oxidation of the GCE. Using SEM, EDX and FTIR, no evidence was obtained to indicate that the β-CD was electropolymerised at the GCE.
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A phosphoronitrile-based COF (HP-COF) was prepared employing a facile heat reflux method. Then, HP-COF was employed as the precursor to acquire N, P-doped porous carbon materials by carbonization. A novel...
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This work aims to create an electrochemical sensor to detect paracetamol (PAR). The sensor is constructed by modifying an electrode with carbon paste and incorporating nanostructures of manganese cobaltite (MnCo2O4.5) onto reduced graphene oxide that is doped with nitrogen and boron (BN-rGO). MnCo2O4.5 provides a stable structure and N, B-doped rGO enhances conductivity and provides additional active sites. The hybrid nanostructure facilitates charge transfer between the components. This synergy improves sensitivity and faster response times, for electrochemical sensors. The following techniques characterized the MnCo2O4.5/BN-rGO nanocomposite: FE-SEM, TEM, HR-TEM, XRD, XPS, Raman, FT-IR, and EDX. The electrochemical characteristics and efficiency of the sensor for the electrooxidation of paracetamol were examined using CV, DPV, and EIS methods. The addition of MnCo2O4.5/BN-rGO to the carbon paste electrode improved the catalytic performance of the modified electrode for the oxidation of PAR. The linear dynamic ranges of the MnCo2O4.5/BN-rGO/CPE sensor were 5.0-120 μM and 155.0 - 1333.0 μM with a low detection limit (LOD) of 0.19 μM (S/N = 3). When used for the electrochemical determination of PAR, this modified electrode demonstrated good selectivity, reproducibility, and repeatability. Moreover, the examination of human blood serum samples indicated the biological significance of the proposed sensor, as shown by the high recoveries in the range of 96.97% to 106.43%.
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Objective To ensure quality-assured care for patients, validation of a cleaning process for blister machines is essential. Due to the high operating costs of maintaining high-performance liquid chromatography (HPLC) which is mainly used for this type of analysis, a new, quick and cost-effective analysis method using UV-Vis spectroscopy has been developed. Method Marker substances (metamizole (dipyrone) and paracetamol tablets) were packed in blisters. Afterwards test tablets were packaged before and after cleaning the blister machine and examined for contamination using UV-Vis spectroscopy. Results UV-Vis spectroscopy has been shown to be superior to HPLC analysis for cleaning validation of blister machines, as it is much faster and cheaper, requires less equipment and personnel effort, while maintaining the same reliability and sensitivity. Conclusion Unit-dose blistering is becoming increasingly popular in the daily routine of hospital pharmacies worldwide due to a variety of advantages. Therefore, cleaning validation of blistering machines has become a mandatory duty of care. The UV-Vis spectroscopic method presented here is the first innovative method suitable for the cleaning validation of blister machines to date.
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In the present study, a glassy carbon electrode (GCE) modified with Pd nanoparticles deposited on poly(acrylamide) gel brush‐grafted magnetic particles (Pd/PAAm GB @Fe 3 O 4 ) with core‐shell structure was fabricated for simultaneous electrochemical detection of dopamine (DA) and paracetamol (PA). Electrochemical performance of Pd/PAAm GB @Fe 3 O 4 /GCE was evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). The fabricated sensor exhibited voltammetric sensing with a satisfactory linear determination range from 0.4–41 μM for DA and from 0.5–95 μM for PA. The limit of detection (LOD) was 0.1 μM for DA and 0.17 μM for PA based on signal to noise ratio of 3. The proposed sensor also had excellent reusability and selectivity, good reproducibility and stability, and satisfactory recovery in biomedical examples. It is believed that metal nanoparticles deposited on polymer gel brush composites may offer promising new horizons for sensor growth.
Conference Paper
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N-acylated aromatic amines, characterized by the presence of an acyl group (RCO-) on the nitrogen atom, play a significant role in non-prescription headache remedies. Among the over-the-counter drugs, paracetamol stands out as the primary survivor within the category of "aniline derivatives" or "aniline analgesics," which includes acetanilide, phenacetin, and paracetamol (acetaminophen). Both phenacetin and paracetamol are derivatives of acetanilide. Paracetamol, also known as 4-hydroxyacetanilide or para-hydroxyacetanilide in industrial chemistry, serves as a crucial end product and a key precursor for the synthesis of various organic compounds. Acetaminophen, sometimes known as paracetamol, is one of the most widely used analgesics andantipyretic medications worldwide, both in single- and multi-component formulations, and accessible without a prescription. It is the recommended medication for patients who are not responsive to non-steroidal anti-inflammatory medicines (NSAIDs), including those with peptic ulcer disease, hemophilia, bronchial asthma, salicylate-sensitized individuals,youngsters under the age of twelve, expectant mothers, and nursing mothers. It is advised as a first-line therapy for osteoarthritis-related pain. The intricate mechanism of action involves the interplay between the redox and peripheral antinociception mechanisms, such as COX inhibition, and the central mechanisms of COX, serotonergic descending neuronal pathway, L-arginine/NO pathway, and cannabinoid system. This article explores the historical evolution of paracetamol, its synthesis by chemists, reactions in the presence of certain precursors, dosage considerations, adverse effects, and its usage. While paracetamol has gained popularity as an easily accessible analgesic, its potential adverse effects become pronounced when not taken in the correct dosage or when combined with certain foods or drugs. It is essential to be cautious when handling this drug, particularly due to its potential interactions with other medications such as warfarin, as the otherwise beneficial drug can turn harmful.
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In this work, the carbon paste electrode was electro-polymerized using l-phenylalanine in 0.2 M phosphate buffer solution of pH 8.0. This l-phenylalanine modified carbon paste electrode (PLPAMCPE) was used for the study of paracetamol (PCL). The modified electrode was characterized by cyclic voltammetry, differential pulse voltammetry (DPV), scanning electron microscopy, and electrochemical impedance spectroscopy. The PLPAMCPE showed an excellent current response towards the oxidation of PCL. During the pH study ranging from 5.0 to 8.0 pH, pH 6.0 showed high peak current hence considered as the optimum pH. The scan rate study showed that the reaction was adsorption-controlled reaction. Further study i.e., by varying concentration of PCL in the linear range of 1.2 µM to 12 µM, the current increases linearly. The limit of quantification of 18.2 μM and the limit of detection of 5.4 μM was obtained for the DPV method. The study also showed that the presence of different metal ions did not hinder the PCL analysis. The developed electrode showed good repeatability, stability, and reproducibility. Simultaneous study of PCL with dopamine shows good selectivity for PCL. This method is desirable due to its quickness, low cost, ease of handling, and its applicability to real sample.
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Thesis
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Electrochemical sensors play a crucial role in the accurate detection of chemical compounds in various areas, including clinical analysis and environmental monitoring. In this context, nanocomposites of carbonaceous materials and metal oxides have emerged as highly promising materials. This work aims to synthesize and characterize nanocomposites for application in electrochemical sensors. A new nanocomposite was obtained by decorating multi-walled carbon nanotubes (MWCNTs) with Nb₂O₅ using the peroxide oxidative complex method (OPM) combined with hydrothermal treatment. Additionally, the nanocomposite with MWCNTs and TiO₂ was obtained by the solvothermal method. The materials were characterized using techniques such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The nanocomposites were used as modifiers of glassy carbon electrodes (GCE) in the fabrication of GCE/MWCNT/Nb₂O₅ and GCE/MWCNT/TiO₂ sensors. The electrochemical response of these sensors was evaluated through cyclic voltammetry (CV) in solutions such as H₂SO₄ (pH 2.0) and Britton-Robinson buffer solution (pH 7.0). The sensors demonstrated promising sensitivity and selectivity in the detection of H₂O₂ and paracetamol in an aqueous medium. By means of cyclic voltammetry, the GCE/MWCNT/Nb₂O₅ sensor exhibited a detection limit (LD) of 1.5 μM and a quantification limit (LQ) of 5.0 μM for H₂O₂. The GCE/MWCNT/TiO₂ sensor revealed an LD of 4.0 μM and an LQ of 14.0 μM. The electrocatalytic activity of the GCE/MWCNT/Nb₂O₅ sensor in paracetamol detection, even in the presence of interferents such as epinephrine and tryptophan, was also remarkable. Square wave voltammetry achieved an LD of 0.11 nM and an LQ of 0.49 nM, surpassing previous studies. These results indicate the potential of these nanocomposites as materials for the development of more efficient electrochemical sensors, with promising application in clinical and environmental samples. Keywords: Nb₂O₅; MWCNT nanocomposite; Electrochemical sensor; H2O2; Paracetamol.
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The development of a disposable electrochemical paper-based analytical device (ePAD) is described using a novel formulation of conductive ink that combines graphite powder, polyester resin, and acetone. As a proof of concept, the proposed sensor was utilized for paracetamol (PAR) sensing. The introduced ink was characterized via morphological, structural, and electrochemical analysis, and the results demonstrated appreciable analytical performance. The proposed ePAD provided linear behavior (R² = 0.99) in the concentration range between 1 and 60 µmol L⁻¹, a limit of detection of 0.2 µmol L⁻¹, and satisfactory reproducibility (RSD ~ 7.7%, n = 5) applying a potential of + 0.81 V vs Ag at the working electrode. The quantification of PAR was demonstrated in different pharmaceutical formulations. The achieved concentrations revealed good agreement with the labeled values, acceptable accuracy (101% and 106%), and no statistical difference from the data obtained by HPLC at the 95% confidence level. The environmental impact of the new device was assessed using AGREE software, which determined a score of 0.85, indicating that it is eco-friendly. During the pharmacokinetic study of PAR, it was found that the drug has a maximum concentration of 23.58 ± 0.01 µmol L⁻¹, a maximum time of 30 min, and a half-life of 2.15 h. These results are comparable to other studies that utilized HPLC. This suggests that the combination of graphite powder and polyester resin can transform conductive ink into an effective ePAD that can potentially be used in various pharmaceutical applications. Graphical abstract
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In this work, we propose a modified solid-state 8 approach for the sustainable preparation of a SrWO4 bifunctional catalyst using thymol−menthol-based natural deep eutectic green solvents (NADESs). Various spectroscopic and morphological techniques analyzed the as-synthesized SrWO4 particles. Acetaminophen (ATP) and metformin (MTF) were selected as the model drug compounds. The electrochemical detection and photocatalytic degradation of ATP and MTF upon ultraviolet−visible (UV−vis) light irradiation in the presence of as-prepared SrWO4 particles as an active catalyst are examined. The present study displayed that the proposed catalyst SrWO4 has enhanced catalytic activity in achieving the optimum experimental conditions, and linear ranges of ATP = 0.01−25.90 μM and MTF = 0.01−25.90 μM, a lower limit of detection (LOD) value (ATP = 0.0031 μM and MTF = 0.008 μM), and higher sensitivity toward ATP and MTF determination were obtained. Similarly, the rate constant was found to be k = ATP = 0.0082 min−1 and MTF = 0.0296 min−1 according to the Langmuir−Hinshelwood model, benefitting from the excellent synergistic impact of the SrWO4 catalyst toward the photocatalytic degradation of the drug molecule. Hence, this work offers innovative insights into the applicability of the as-prepared SrWO4 bifunctional catalyst as an excellent functional material for the remediation of emerging pollutants in water bodies with a recovery range of 98.2−99.75%.
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Background: Paracetamol compound remains the most used pharmaceutical as an analgesic and antipyretic for pain and fever. It has been detected in aquatic environments. The recovery of this compound from wastewater is one of the important operations carried out by modern industries. Its recovery is especially important for environmental protection. Currently, research is focused on membrane technology that has gained considerable interest over the last decades due to the various advantages that it presents. Result: Our work reports the selective extraction of paracetamol from liquid solution using two types of affinity polymer membranes: (i) polymer inclusion membrane (PIM) and (ii) grafted polymer membrane (GPM). The same extractive agent, gluconic acid (GA), is used for both. After total characterization, the developed membranes were adopted. Kinetic and thermodynamic models have been used to determine the values of various macroscopic parameters, permeability (P), and initial flux (J0), to understand the membrane performance. The same techniques have been used to determine the values of different microscopic parameters, association constant (Kass), and apparent diffusion coefficient (D*) that determine the interaction between the paracetamol substrates and the extractive agent, necessary for the diffusion of paracetamol molecules through the membrane. Similarly, the effects of initial concentration (C0), acidity (pH), and temperature were examined. Conclusion: The experimental results allow the determination of values of activation and thermodynamic parameters (Ea, ΔH#, ΔS#, ΔH#dis, and ΔH#th). The results explain the membrane performances and confirm that the energetic or kinetic aspects control the mechanisms related to the oriented processes. The results also indicate that it is possible to recycle wastewater and eliminate contaminants such as paracetamol.
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Nanowall is unique nanostructure made up of graphene, carbon, polymer, or inorganic compounds. The graphene nanowall, carbon nanowall, polymer nanowall, zinc oxide nanowall, nickle oxide nanowall, molybdenum disulfide nanowall, and gold nanowall have been produced through chemical vapor deposition, solution growth, hydrothermal, and plasma/microwave assisted techniques. Due to its high surface area, structural, morphological, conducting, optical, catalytic, photovoltaic, energy density, and capacitance properties, nanowall nanofillers have expanded use for polymeric matrices. Polymers used with nanowalls, so far, are poly(dimethylsiloxane), polyacrylonitrile, polyacetylene, poly(azomethine), poly(methyl methacrylate), polyaniline, and other conducting polymers. Polymer/nanowall nanocomposites have employed for solar cells, energy harvesting devices, and sensors.
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Bivariate calibration algorithm is compared with the results obtained by the usage of high-dimensional calibration methods such as partial least squares (PLS) and multi-way partial least-squares (N-PLS) by using UV-Vis spectrophotometric data of first and second-order. The algorithms were applied to the determination of a mixture of an analgesic and a stimulant compound and their actual concentrations of them were calculated by using spectroscopic data. The direct reading of absorbance values at 227 nm and 271 nm were employed for quantification of the compounds in the case of the bivariate method. The approaches of first-order and multi-way methods were applied with a previous optimization of the calibration matrix by constructing sets of calibration and validation with 20 and 10 samples (mixtures) respectively according to a central composite design and their UV absorption spectra were recorded at 200-350 nm. All algorithms were satisfactorily applied to the simultaneous determination of these compounds in pharmaceutical formulations with mean percentage recovery of 100.5 ± 3.67, 98.7 ± 3.42, and 100.5 ± 3.74 for bivariate, PLS-1, and N-PLS, respectively. The statistical evaluation of the bivariate method showed that this procedure is comparable with those algorithms that employ high-dimensional structured information. The aim of the work is to compare the methods under study and it can be seen that there are no significant differences, so a simple spectrophotometer can be used up to a very specialized one. However, the advantage of bivariate calibration is its simplicity, due to the minimal experimental manipulation.
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Herein, we report on the catalytic activity of ABO3 perovskites (A = La or Sr, B = Co, Sn, Fe, or Al) synthesized by nanocasting technique with silica-based KIT-6 as a hard template. The physical and chemical characteristics of the perovskites were determined using various techniques such as powder X-ray diffraction, nitrogen sorption, transmission and scanning electron microscopes and temperature programmed desorption. The synthesized ABO3 perovskites were used as heterogeneous catalysts in the reduction of 4-nitrophenol (4NP) by sodium borohydride (NaBH4) to 4-aminophenol (4AP). The perovskites exhibit surface areas ranging from 19 to 101 m²/g. Among the as-synthesized perovskites SnAlO3 was the most acidic catalyst and exhibited the highest catalytic activity towards 4NP reduction. We further explored the role of electron scavengers in elucidating the catalytic mechanism and postulate that the reduction of 4NP follows a surface-driven electron transfer mechanism.
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Electrochemical oxidation of paracetamol (PCT) has exclusively been investigated using polycrystalline gold electrode modified with iodine adlayer [I(ads)|Au(pc)] in alkaline medium. Irreversible adsorption of PCT makes Au(pc) surface unfeasible for studying PCT oxidation reaction. This limitation of Au(pc) surface could be eliminated simply by iodide (I⁻) adsorption. It was noticed that the spontaneous I⁻ adsorption blocks PCT adsorption sites on Au(pc) surface, which additionally improves PCT oxidation reaction by increasing electron transfer rate. Iodine adlayer (I-adlayer) formulated electrode facilitated PCT electro-oxidation via an alternative diffusion-controlled pathway with an anodic electron transfer coefficient (β) of 0.47 and heterogeneous rate constant (ko) of 0.0911 cm s⁻¹ where an electron transfer step determines the reaction rate. The sensing experiments revealed that the [I(ads)|Au(pc)] electrode attained linear dynamic range from 4.5 to 1600 μM of PCT. The obtained sensitivity and limit of detection (LOD) of the [I(ads)|Au(pc)] electrode surface was determined to be 8.37(±1.6)×10-4 mA cm⁻² μM⁻¹ and 0.65±0.02 μM, respectively. The formulated [I(ads)|Au(pc)] catalyst was applied to quantify the relative PCT percentage in commercial tablets using batch injection analysis supported by chronoamperometry. Obtained relative percentage closely matched with the corresponding analysis performed with Raman spectroscopy. Therefore, developed I-adlayer coated Au(pc) electrode is analytically robust and validated for routine analysis of PCT concentration in relevant pharmaceutical applications.
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Introduction The voltammetric sensing of Acetaminophen (AN) using modified Dysprosium Copper Oxide (DyCuO) Nanoparticles (NP) mixed Carbon Paste Electrode (MCPE) was successfully developed. Methods The modification of bare NPMCPE was achieved by the polymerisation of DL-Phenylalanine (DLPA). The electroanalysis of the AN was achieved by utilizing the Cyclic voltammetry (CV) approaches. The crystallographic nature of the nanoparticle was studied via X-ray Powder Diffraction (XRD) technique. The surface morphology and electrochemical feature of the prepared electrode were evaluated by Field Emission Scanning Electron Microscopy (FE-SEM) and Electrochemical Impedance Spectroscopy (EIS) techniques. Results The modified sensor exhibited an excellent electrocatalytic activity towards the electroanalysis of the AN. Several aspects, such as the number of polymerisation cycles, variation of pH, and the impact of scan rate were investigated in 0.2 M supporting electrolyte (pH 7) at a sweep rate of 0.1 Vs ⁻¹ . The suggested sensor shows a very low detection limit (11.95×10 ⁻⁸ M) with a linear range of 2.0 to 50.0 µM, which exhibits excellent sensitivity. Conclusion The stable and reusable sensor was applied for the estimation of AN in the tablet sample. Thus, P(DLPA)MNPMCPE was utilized as the most capable sensor for the voltammetric detection of AN.
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The present work demonstrates the first example of an electro-sensor platform based on disposable graphite surface that was coated electrochemically with poly(3-aminophenylboronic acid)-graphene for highly sensitive and selective determination of paracetamol. Fabrication of this sensing platform was realized using constant potential electrolysis with 3-aminophenylboronic acid monomer and graphene in a single step preparation. Optimization of the electrochemical polymerization conditions was done with different electrolysis durations and various concentrations of the monomer and graphene. Coated electrodes were then characterized by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Electrochemical determination studies performed with differential pulse voltammetry (DPV) presented that the electro-sensor platform had a good linear paracetamol concentration range of 0.15 μM to 100 μM and a very low detection limit of 0.028 μM (R²=0.9941, n=3). The effect of a possible and important interferent, dopamine was also examined. The results proved the simultaneous determination of these two analytes with a good separation and high sensitivity. These results were compared with the results of the bare electrode: 15-fold and 13-fold improvements were achieved at the coated electrode for the electrooxidation of dopamine and paracetamol, respectively. In addition, this robust platform showed a good long-term stability. At last, recovery studies were done in urine samples in order to present the possible use of the electro-sensor in clinical studies. The outputs highlighted the high accuracy of the system by giving good recoveries (94.0% - 103.7%).
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In this paper, acetaminophen (AP), typically consumed as a painkiller, was sensitively detected using an electrochemical sensor through cyclic voltammetry. Therefore, special attention focused on fabricating a sensitive voltammetric sensor based on cetrimide (CA) incorporated on a poly oxalic acid modified carbon nanotube paste electrode (POAMCNTPE). The topographical features and electrochemical characterisations of unmodified and modified electrodes were compared using a variable pressure scanning electron microscope (VP-SEM) and electrochemical impedance spectroscopy (EIS). The scan rate study reveals that the redox reaction of the AP at the surface of the modified electrode was controlled by diffusion. The detection limit (DL) of 1.50 × 10−8 M and quantification limit (QL) of 5.02 × 10−8 M was gained by utilising differential pulse voltammetry (DPV). The constructed electrochemical sensor displayed acceptable repeatability, excellent stability, and adequate reproducibility. The prepared sensor exhibited an outstanding selectivity to detect the AP in the presence of dopamine (DA) and folic acid (FA). The practicability of the proposed electrode was examined to be successful towards the quantification of AP in both pharmaceutical and biological samples.Graphic Abstract
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Active pharmaceutical ingredients (APIs) constitute a significant and growing global market. In the past few decades, labor costs, concerns regarding chemical waste, and more stringent regulations in developed countries have...
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A spectrophotometric method for the selective determination of paracetamol based on its reaction with pyrochatechol violet under basic conditions to form an ion-pair complex is described. The absorption maximum of the coloured ion-pair formed is observed at 652 nm and the molar absorptivity is 4.54 × 10 -3l mol -1 cm -1. Beer's law is obeyed over the concentration range 0.5-34.0 μg ml -1, while that obtained using Ringbom method is in the range 3.5 -32.0 μg ml -1. There is no interference from common additives, excipients and commercial drugs present in their formulations suggesting a highly selective procedure compared with others. Statistical analysis of the obtained results showed that there is, no significant difference and absence of any systematic error in the method compared with the official one. The method is simple, rapid and convenient and was applied successfully to the determination of paracetamol in pure and in its dosage forms compared with the official method.
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The use of nitrous acid (HNO2) for determination of paracetamol (acetoaminophen) in liquid and solid formulations employing flow injection system is described. The determination of this drug was carried out by reacting paracetamol with nitrous acid generated in-line and the product yielded was measured at 430 nm in alkaline medium. The analytical curve ranged from 9.7x10-5 to 6.2x10-3 mol L-1 of paracetamol, with a detection limit of 2.5x10-5 mol L-1. The relative standard deviations (RSDs) were smaller than 2% for solutions containing 1.2x10-4 and 2.8x10-4 mol L-1 of paracetamol (n=10) and 60 determinations per hour were obtained. The results of determination of paracetamol in pharmaceutical formulations obtained by the proposed FI procedure were in good agreement with those obtained using theUSP procedure at a confidence level of 95% and within an acceptable range of error.
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A simple, fast and precise reverse phase high performance liquid chromatographic method developed for the simultaneous determination of Ibuprofen, Paracetamol and Methocarbamol in its tablet form. A μBondapak(TM) phenyl column 30 cm from waters in isocratic mode, with mobile phase 0.2% orthophosphoric acid and methanol (45 : 55 v/v) pH adjusted to 6.5 with Triethylamine were used. The flow rate was 1.0 ml/min and effluent was monitored at 215 nm. Diclofenac sodium was used as an internal standard.
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A simple, fast, accurate and precise gas chromatographic method is described for the estimation of 1) Chlorzoxane and Paracetamol. 2) Chlormezanone and Paracetamol in single and combined dosage forms using 10% OV-17 column and flame ionisation detector; phenacetin is used as internal standard.
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A high performance liquid chromatographic, a high performance thin layer chromatographic and a gas chromatographic method has been described for the simultaneous determination of paracetamol, ibuprofen and chlorzoxazone from their combined dosage form. The methods were statistically validated to determine their accuracy and precision. The proposed methods were found to be comparable on the basis of the statistical parameters obtained for the assay and recovery experiments.
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A method has been established for the rapid and accurate identification and quantitative determination of acetylsalicylic acid, ascorbic acid, paracetamol, caffeine, and salicylic acid. Complex analgesic and antipyretic pharmaceutical products of domestic and foreign origin have been examined and assessed in terms of their free salicylic acid content. Densitometric measurement was performed in the ultraviolet region at λ = 280 nm.
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The present work describes application of different chromatographic techniques viz., GC, HPLC and HPTLC for the simultaneous determination of chlorzoxazone, paracetamol and diclofenac sodium. The methods developed were applied to the determination of chlorzoxazone, paracetamol and diclofenac sodium from their commercially available formulation and subjected to statistical validation to determine their accuracy and precision. The results obtained by the different techniques are comparable.
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The present communication describes application of a simple, accurate and fast HPLC method for the simultaneous determination of Chlorzoxazone and Paracetamol from its pharmaceutical formulation using salicylic acid as an internal standard. The statistical validations were also carried out to find its applicability in the routine quality control.
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A rapid, accurate and simple method is proposed for the determination of p-acetaminophen (paracetamol) in raw material, tablets and syrups. The method is based on measuring the intensity of the yellow color that developed when acute acetaminophen is allowed to react with p-dimethylaminobenzaldehyde in 2M HCl after heating. The color which absorbs in the visible region of λ 450nm is stable for several hours and the intensity is directly proportional to the concentration of the drug, that is, Beer-lambert law is obeyed. The method can be used to analyse paracetamol in raw material and in pharmaceutical dosage forms.
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A simple first derivative spectrophotometric method has been developed for the simultaneous determination of paracetamol and codeine in pharmaceutical formulations. Dimethylformamide was used as solvent for extracting the drugs from the formulations and subsequently the samples were evaluated directly by first order derivative spectrophotometry. Simultaneous determination of the both drugs can be carried out using the graphical and zero-crossing methods for paracetamol and codeine, respectively. The method does not require simultaneous equations to be solved as it is commonly necessary in zero-order spectrophotometry. The calibration graphs were linear between the ranges 4.3·10-5 M to 1.0·10-3 M for codeine and 6.1·10-5 M to 1.6·10-3 M for paracetamol. The simultaneous determination is reliable only when the molar ratio of paracetamol to codeine is lower than 4/1. Commonly the pharmaceutical formulations contain both drugs in a mass ratio between 5/1 to 33/1, therefore a previous enrichment of the samples were carried out with pure codeine in order to reach the above mentioned ratio. The ingredients commonly found in commercial pharmaceutical formulations do not interfere, hence the proposed method can be applied to the determination of these drugs in tablets.
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A fourier transform infrared (FTIR) spectrometric technique is described for the simultaneous determination of ibuprofen and paracetamol in two compositions of pharmaceutical tablets. Quantification was carded out by measuring the absorbances at 1684 and 1740 cm -1 for paracetamol and ibuprofen, respectively, using the baseline established at 1780 cm -1 for measurement correction. The linear correlations with high values of correlation coefficients (0.9999) were obtained at a concentration range of 2.0-10.0 mg ml -1 for both analytes. The detection limits were found to be 0.34 and 0.21 mg ml -1 for paracetamol and ibuprofen, respectively. A HPLC method was developed as reference method for the determination of both compounds. The results obtained from the FTIR technique are in good agreement with those from HPLC.
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In this paper, determination of paracetamol and hyoscine N-butyl bromide in their binary mixture was realized by precipitating hyoscine N-butyl bromide with ammonium reineckate at pH 6,0 selectively and reading the absorbance of the solution of the precipitate in acetone at 525.0 nm for hyoscine N-butyl bromide by measuring the dA/dλ values at 254.5 nm in the first derivative spectra of the remaining solution for paracetamol. The relative standard deviation of the method was found to be 0.90% for hyoscine N-butyl bromide and 0.10% for paracetamol. Recoveries were found to be 98.3% and 99.8% for hyoscine N-butyl bromide and paracetamol respectively. The method has been succesfully applied to a film-coated tablets containing hyoscine N-butyl bromide and paracetamol.
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Two simple and sensitive calorimetric procedures for the determination of p-aminophenol with 3-cyano-N-methoxypyridinium perchlorate are presented. One is based on reaction in methoxyethanol in presence of sodium acetate, with direct measurement at 410 nm. The reaction product obtained by this procedure has been separated and identified. The other is based on reaction in methoxyethanol in presence of chloramine-T and direct measurement at 448 nm. The method has been applied to the determination of p-aminophenol in pure form and as an impurity in paracetamol and paracetamol- containing tablets, with a coefficient of variation less than 2%.
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Spectrophotometric Determination of acetaminophen in pharmaceutical preparations is described. Acetaminophen was hydrolysed by refluxing with perchloric acid to produce p-aminophenol which was reacted with p-dimethyl aminocinnamaldehyde in dilute trichloracetic acid solution to give a red color, which showed absorption maximum at 520 nm. Interference by the presence of phenacetin and sulpyrine can be eliminated by their extraction with chloroform in basic medium or extraction with ethyl acetate in acidic medium.
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A new simple and accurate kinetic method for the analysis of paracetamol in pure form and formulations is described. The kinetics parameters have been applied successfully in determining paracetamol when it reacts with persulfate in alkaline medium. The spectrophotometric measurements have been recorded at 315 nm and found to be valid over the concentration range of 5–30 ppm. The molar absorptivity is equal to 6.55×103 l mol−1 cm−1. The analysis of paracetamol content in mixture of different substances has been carried out without prior separation. The precision and accuracy of the method and the effect of foreign substances have been studied and the results obtained were compared with reference method.
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The compounds to be determined are oxidised by cerium(IV). The concentration of cerium(III) formed is measured spectrofluorimetrically. The method has been used both in solution and, by fluorodensitometry, on t.l.c. plates. Detection limits of some substances are 15 ng ml-1 for the solution method and 5 ng per spot for the t.l.c. method.
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A simple and sensitive spectrophotometric method for the assay of three antipyretic drugs through their nitration and subsequent complexation with an nucleophilic reagent is proposed. The experimental conditions leading to optimum chromagen stability and intensity were studied. The results of the application of the method to the assay of the test compounds in unit doses were compared statistically with those obtained by official methods, and demonstrated good accuracy and precision.
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Two stability-indicating methods, HPLC and derivative difference spectrophotometry, have been described for the determination of acetaminophen as well as its degradation product, 4-aminophenol. The former method is based on the selection of two chromatographic systems using an octadecylsilane (C18) stationary phase. The latter involves the use of derivative (first and second) difference spectrophotometric technique. Interference from the coformulated excipients (colorant, flavour, preservative) of liquid formulations is completely eliminated. Accuracy, precision and the limit of detection of 4-aminophenol are discussed. The proposed methods are applied for determination of acetaminophen and 4-aminophenol in pharmaceutical formulations.
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A reversed phase high-performance liquid chromatography (HPLC) method for simultaneous measurement of acetaminophen (I), acetylsalicylic acid (II), caffeine (III) and d-propoxyphene (IV), using phenacetin (V) as an internal standard was developed. Using a 6.5 μ C-8 reversed phase column (RPP) with a mobile phase consisting of 0.01M sodium acetate solution: methanol (85:15%) at pH 4.1 enabled the Chromatographic separation of the four components in about 12 min. Quantitation was achieved by measuring the peak height ratio of each component relative to the internal standard. the validity of the developed method was tested by analyzing laboratory-prepared mixtures containing the four components in various proportions. Assay precision and sensitivity have been established for each component. the developed method proved to be stability-indicating as it can be applied to monitor salicylic acid as a degradation product in acetylsalicylic acid samples.