Paracetamol Concentration Research Articles

Polypyrrole-coated carbon fibre electrodes for paracetamol and clozapine drug sensing

Polypyrrole (PPy) fibre electrodes were studied to determine their ability to sense paracetamol (as a model drug) in the presence of the interferents dopamine and ascorbic acid. PPy was electropolymerised onto carbon fibres using cyclic voltammetry in the presence of two different counter anions: sodium dodecyl sulfate (SDS) and potassium nitrate (KNO3). The surface of the PPy.SDS and PPy.KNO3 fibre electrodes was characterised using Raman spectroscopy and scanning electron microscopy. The PPy.SDS-coated carbon fibre had a 14-fold larger electrochemical surface area compared to a bare carbon fibre (calculated using the Randles-Sevcik equation). The use of a large counter anion as dopant (dodecyl sulfate) produced fibres with a greater drug sensing response (cf. the use of smaller nitrate anion). The use of the PPy.SDS fibre electrode in differential pulse voltammetry (DPV) allowed sensing of paracetamol with a detection limit (3σ S/N) of 34 µM. For the anodic peak current (0.5 V vs. Ag/AgCl), a linear response range was observed for 50–500 µM. At a paracetamol concentration of 100 µM, the DPV anodic peak current (at 0.5 V vs. Ag/AgCl) was unaffected by the addition of interferents: 100 µM dopamine and 100 µM ascorbic acid. A real-world application of drug sensing was trialled with the anti-psychotic medication clozapine; where the PPy.SDS carbon fibre could sense clozapine with a detection limit of (3σ S/N) of 6 µM and a sensitivity of 15 μA cm−2 μmol−1 L.

Broadband dielectric relaxation spectroscopy and molecular dynamics simulation study of paracetamol-propylene glycol solutions

The complex permittivity ε*(ω) = ε′(ω) - ε“(ω) was studied for a series of paracetamol (PCM) – propylene glycol (PG) solutions over the broadband frequency range of 20 Hz to 20 GHz at different temperatures ranging from 293.15 K to 323.15 K. Measurements of the complex permittivity were carried out using Agilent Precision LCR meter E4980A with Agilent 16452A liquid test fixture (for 20 Hz to 2 MHz frequency region) and Anritsu Shockline Vector Network Analyser MS46322A with DAK-3.5 probe (for 200 MHz to 20 GHz frequency region). Obtained broadband frequency dependent dielectric data were analyzed to explore the interaction mechanisms and structural behavior of PCM and PG molecules in mixed state in terms of molar PCM concentration and temperature variation. Temperature dependent dc conductivity response of all solutions exhibited Arrhenius behavior from which activation energy was calculated. Microwave complex permittivity data were fitted to the Cole-Davidson model in order to determine dipolar relaxation parameters of the solutions. Dielectric constant and dielectric loss values at a spot frequency of 2.45 GHz were utilized to determine the microwave heating parameters and analyzed in view of its suitability for the microwave dielectric heating in pharmaceuticals. Molecular dynamics simulation study for selected concentrations of PCM in PG was also conducted in order to understand the actual mechanism of H-bonding interactions in the solutions and to justify the inferences derived from the experimental results.

Clinical and pharmacological approaches to the choice of a drug for a tension-type headache relief

The purpose of this study is a comparative analysis of the pharmacodynamic and pharmacokinetic parameters of ibuprofen and paracetamol as a part of fixed dose combination and as monotherapy in tension type headaches. Comparative dissolution kinetics test; Comparative analysis of pharmacokinetic parameters using the PubMed/MEDLINE database. The median Tmax of ibuprofen as a part of a fixed-dose combination and as a monotherapy is 75 minutes. The median Tmax of paracetamol is 30 min when taken in a fixed dose combination and 40 min as a monotherapy. In patients who received the fixed dose combination, the concentration of ibuprofen in the blood plasma after 10 minutes 6.64 g/ml-1; after 20 minutes 16.81 g/ml-1, while when taken in the same dose in as a monotherapy, respectively, 0.58 and 9.00 g/ml-1. The mean plasma concentrations of paracetamol after 10 and 20 minutes in patients receiving the fixed combination were 5.43 and 14.54 g/ml-1, respectively, compared with 0.33 and 9.19 g/ml-1 for paracetamol as monotherapy. dissolution kinetics test of the Paracytolgin: after 5 minutes, 20% of paracetamol passed into the solution in a system with a pH of 1.2; in a system with a pH of 4.5 36.4%; in a system with a pH of 6.8 33.5%; after 10 minutes, respectively 68.5, 98.0 and 89.6%. After 15 minutes, almost complete dissolution was noted in all systems: 98.5, 98.8 and 100.5%, respectively. The combination of ibuprofen and paracetamol makes it possible to enhance the analgesic effect as a result of additive action by the help of central mechanisms. The fixed dose combination of ibuprofen and paracetamol significantly increases the rate of absorption of paracetamol, which has potential therapeutic benefits in terms of a faster analgesias onset. The fixed dose combination of ibuprofen and paracetamol provides faster and long-term anaesthesia with a comparatively lower dosage of each analgesic.

Application of a Fiber Optic Refractometric Sensor to Measure the Concentration of Paracetamol in Crystallization Experiments

A refractometric sensor was applied to measure in real-time the concentration of Active Pharmaceutical Ingredients (APIs) in crystallization experiments. Paracetamol was used as a model system due to the extensive literature available for this API. The refractometric sensor was fabricated by a simple and inexpensive method that consisted in splicing a short section of a multimode fiber to a single mode fiber. The compact geometry of this sensor, with an external diameter of just 125 μm, allowed it to measure the concentration of paracetamol, both in a stirred tank crystallizer operating in batch and in an oscillatory flow crystallizer operating continuously. The proposed technique shows the potential to monitor the concentration of APIs in crystallizers of different sizes and geometries as an alternative to more expensive and complex analysis equipment.

Silver nanoparticles decorated zinc oxide nanorods supported catalyst for photocatalytic degradation of paracetamol

Visible light absorption enhanced silver nanoparticles (Ag NPs) decorated zinc oxide nanorods (ZnO NRs) were synthesized using microwave-assisted growth method and utilized as supported catalysts in degradation of pharmaceutical compound. The optimal concentration of silver nitrate precursor and annealing temperature for synthesized ZnO–Ag catalysts were investigated. Different concentrations (5–20 ppm) of paracetamol were used as test contaminant in photocatalytic degradation process. The highest photocatalytic degradation (92%) of 5 ppm paracetamol was achieved for ZnO–Ag in comparison to (54%) degradation for pristine ZnO after 4 h visible light irradiation. The stability of ZnO–Ag catalyst was also investigated. The degradation performance decreased only 2% for ZnO–Ag and 24% for pristine ZnO using 5 ppm paracetamol after four repeated cycles showing high ZnO–Ag stability. Enhanced photocatalytic activity of ZnO–Ag catalyst was due to efficient charge separation as well as visible light absorption and reduced recombination of electron and hole.

High concentrations of paracetamol in effluent dominated waters of Jakarta Bay, Indonesia

The occurrence of several aquatic contaminants, including pharmaceuticals, were investigated in seawater samples collected from effluent-dominated sites in Indonesia: 4 sites in Jakarta Bay and one on the north coast of Central Java. The data presented in this preliminary study provide a snapshot of seawater quality in these areas. Results show that nutrient parameters exceeded the Indonesian Standard Quality of Seawater limits, and some metals were also present. Interestingly, high concentrations of paracetamol were detected at Angke (610 ng/L) and Ancol (420 ng/L), both in Jakarta Bay. To date, this is the first study to report the presence of paracetamol (acetaminophen) in the coastal waters around Indonesia. The high concentrations detected, compared to other levels reported in scientific literature, raise concerns about the environmental risks associated with long-term exposure and, especially, the impact on nearby shellfish farms. Given pharmaceuticals' consideration as emerging contaminants, these data suggest further investigations are needed.

Population pharmacokinetics of immediate-release and modified-release paracetamol and its major metabolites in a supratherapeutic dosing study

Objectives Overdose with paracetamol modified-release (MR) formulation, a bilayer tablet containing 69% slow-release component, has been increasing since its introduction to the market. However, little evidence exists for the management of MR paracetamol overdose. We aimed to develop a population pharmacokinetic (PK) model for immediate-release (IR) and MR paracetamol and its major metabolism, and quantitatively understand the formulation difference in toxicity assessment based on the nomogram line. Methods Data from a cross-over study design in nine healthy volunteers administered a single supratherapeutic oral dose (80 mg/kg) of either IR and MR paracetamol were available from a published study. Plasma concentrations for paracetamol and its metabolites glucuronide (APAPG) and sulfate conjugate (APAPS) for both formulations were measured and analysed with population pharmacokinetic (PK) method using NONMEM. Toxicity in both formulations was assessed by comparing the simulated paracetamol concentrations under different paracetamol dose levels with the 150 mg/L nomograms. The difference in the assessment was compared between the two formulations. Results Paracetamol concentrations for the IR formulation were described with a two-compartment model with first-order input and a lag time. The delayed time-course of MR paracetamol concentrations was best captured by a parallel absorption model in which the slow-release component was a serial zero-order then the first-order process. The formation of APAPG was linear, while APAPS concentrations were best fitted by a Michaelis-Menten process. The relative bioavailability of MR paracetamol compared to IR () was estimated as 0.81. The simulated probability of making different toxicity assessments based on nomogram line was increased with dose levels and was as high as 14.6% after 22 g IR or MR paracetamol ingested. Conclusions A joint parent-metabolite model to describe time-course profiles of both IR and MR paracetamol and its metabolites APAPG and APAPS concentrations was developed. Simulations from the model showed that toxicity assessment based on the 150 mg/L nomograms is not suitable in MR paracetamol overdoses.

CuS nanoparticles-enhanced luminol-O2 chemiluminescence reaction used for determination of paracetamol and vancomycin

A new chemiluminescence (CL) method was proposed to measure two widely used drugs, including paracetamol (PCM) and vancomycin (VAN). The CL reaction used was the CuS nanoparticles (CuS NPs)-luminol-O2 system. In this system, CuS NPs played the role of catalyst and increased the CL intensity. CuS NPs were easily synthesized by quick-precipitation. CuS NPs were characterized by spectroscopic techniques, and the mean size of NPs was estimated to be about 9 nm. In the developed CL methods, PCM and VAN decreased the CL intensity. In the proposed method, the linear concentration ranges were 4.0 × 10−5–4.0 × 10−4 mol L-1 of PCM and 2.0 × 10−5–6.0 × 10−4 mol L−1 of VAN. The limit of detections were 2.9 × 10-5 mol L-1 and 8.9 × 10-6 mol L-1 for PCM and VAN, respectively. The relative standard deviations (RSD) of the CL method were 2.99 and 4.31 (n = 6) for the determination of 3.0 × 10−4 mol L−1 PCM and VAN, respectively. It was also shown that the CL methods can measure PCM and VAN concentrations in various real samples.

Modeling the Formation of Gas Bubbles inside the Pores of Reactive Electrochemical Membranes in the Process of the Anodic Oxidation of Organic Compounds.

The use of reactive electrochemical membranes (REM) in flow-through mode during the anodic oxidation of organic compounds makes it possible to overcome the limitations of plate anodes: in the case of REM, the area of the electrochemically active surface is several orders of magnitude larger, and the delivery of organic compounds to the reaction zone is controlled by convective flow rather than diffusion. The main problem with REM is the formation of fouling and gas bubbles in the pores, which leads to a decrease in the efficiency of the process because the hydraulic resistance increases and the electrochemically active surface is shielded. This work aims to study the processes underlying the reduction in the efficiency of anodic oxidation, and in particular the formation of gas bubbles and the recharge of the REM pore surface at a current density exceeding the limiting kinetic value. We propose a simple one-dimensional non-stationary model of the transport of diluted species during the anodic oxidation of paracetamol using REM to describe the above effects. The processing of the experimental data was carried out. It was found that the absolute value of the zeta potential of the pore surface decreases with time, which leads to a decrease in the permeate flux due to a reduction in the electroosmotic flow. It was shown that in the solution that does not contain organic components, gas bubbles form faster and occupy a larger pore fraction than in the case of the presence of paracetamol; with an increase in the paracetamol concentration, the gas fraction decreases. This behavior is due to a decrease in the generation of oxygen during the recombination reaction of the hydroxyl radicals, which are consumed in the oxidation reaction of the organic compounds. Because the presence of bubbles increases the hydraulic resistance, the residence time of paracetamol—and consequently its degradation degree—increases, but the productivity goes down. The model has predictive power and, after simple calibration, can be used to predict the performance of REM anodic oxidation systems.

Paracetamol poisoning: a population-based study from Iceland

Objective To examine the incidence and severity of paracetamol poisoning in a population-based cohort in Iceland. A previous study showed a decrease in the incidence during a financial crisis in Iceland, by approximately half (16/100,000 annually). The aims of the study were to assess the incidence and nature of paracetamol poisoning after economic recovery in Iceland and to compare intentional and accidental poisoning. Methods Paracetamol serum concentrations were used to identify patients in this retrospective study from 2010–2017. A search was undertaken in laboratory databases for patients with serum paracetamol concentrations, which were grouped by <66 µmol/L (below detection limit) and ≥66 µmol/L. Medical records were reviewed and relevant laboratory and clinical information obtained to determine whether paracetamol poisoning had occurred. Results Altogether 542 cases of paracetamol poisoning were identified. The mean annual incidence was 27/100,000 (range 22–33). Intentional poisoning was observed in 437/542 (81%) cases, most frequently among females 16–25 years of age. Males ≥65 years were more likely to overdose by accident, which was associated with worse outcomes. Twenty-five (4.6%) patients developed severe paracetamol-induced liver injury and coagulopathy. Overall, six (1.1%) cases were fatal in which paracetamol contributed to the cause of death, with accidental poisoning found in 67% (4/6). Conclusions The incidence of paracetamol poisoning has increased in recent years associated with economic recovery in Iceland. Most patients had favourable outcomes. Intentional overdose was most common in young females, whereas accidental overdose was more common in older males and more frequently associated with a fatal outcome.

Long-term exposure of marine mussels to paracetamol: is time a healer or a killer?

Pharmaceuticals pose a major threat to the marine environment, and several studies have recently described their negative effects on marine organisms. Pharmaceutical compounds are constantly being released into aquatic ecosystems, and chronic exposure, even at low concentrations, may have a major impact on marine organisms. The purpose of the present study is to evaluate the biological changes induced by one of the most widely used pharmaceuticals—paracetamol—in the blue mussel Mytilus edulis, after a long-term exposure at environmentally relevant concentrations. We present our data alongside and in comparison with results from a previous short-term exposure, to demonstrate the significance of exposure period on the effects of paracetamol in adult blue mussels. After 24 days of laboratory exposure, seven potential target genes were selected to examine toxicological effects in mussels’ gonads and possible disruptive effects on reproductive processes. The results show the modulation of some important reproduction-related genes: estrogen receptor-2 (ER2), vitelline envelope zona pellucida domain-9 (V9), and vitellogenin (VTG). Variations in mRNA expression of four other genes involved in apoptosis (HSP70, CASP8, BCL2, and FAS) are also highlighted. Histopathological alterations caused by paracetamol, together with neutral red retention time response in mussels’ hemocytes, are presented herein. Overall, this study highlights the exacerbated effects of low concentration of paracetamol after chronic exposure, similar to the damage induced by higher concentrations in a short exposure scenario, thus emphasizing the importance of length of exposure period when studying the effects of this substance. Additionally, this study also discusses the potential of paracetamol to inflict several major changes in the reproductive system of mussels and thus possibly affect the survival of populations.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-021-14136-6.

In vitro and in vivo comparison of microcontainers and microspheres for oral drug delivery

Microcontainers, which are microfabricated cylindrical devices with a reservoir function, have shown promise as an oral drug delivery system for small molecular drug compounds. However, they have never been evaluated against a relevant control formulation. In the current study, we prepared microcrystalline cellulose (MCC) microspheres as a control for in vitro and in vivo testing of SU-8 microcontainers as an oral drug delivery system. Both dosage forms were loaded with paracetamol and coated with chitosan or polyethylene glycol (PEG) (12 kDa). These coatings were followed by an additional enteric coating of Eudragit® S100. In addition, a control dosage form was coated with Eudragit® alone. The dosage forms were evaluated in vitro, in a physiologically relevant two-step model simulating rat gastrointestinal fluids, and in vivo by oral administration to rats. In vitro, the microcontainers coated with PEG/Eudragit® resulted in a prolonged release of paracetamol compared to the respective microspheres, which was consistent with in vivo observations of a later time (Tmax) for maximum plasma concentration (Cmax) for the microcontainers. For microspheres and microcontainers coated with chitosan/Eudragit®, the time for complete in vitro release of paracetamol was very similar, due to an earlier release from the microcontainers. This trend was supported by very similar Tmax values in vivo. The in vitro in vivo relation was confirmed by a linear regression with R2 = 0.9, when Tmax for each dosage form was plotted as a function of time for 90% paracetamol release in vitro. From the in vivo study, the average plasma concentration of paracetamol 120 min after dosing was significantly higher for microcontainers than for microspheres (0.3 ± 0.1 µg/mL and 0.1 ± <0.1 µg/mL, respectively) – regardless of the coating applied.

Kinetic modelling of paracetamol degradation by photocatalysis: Incorporating the competition for photons by the organic molecule and the photocatalyst

The design of a photoreactor is a complex task due to the different involved parameters. These parameters are mainly included in the kinetic model and its robustness directly impacts the photoreactor design. In this context, it is a common practice to assume that the reagents, i.e. organic molecules, are transparent to radiation. There are many cases, however, when this is not accurate. In such circumstances, the photons absorbed by the organic molecule should be accounted for in the corresponding kinetic model. This work aimed to achieve so in the Paracetamol oxidation photocatalyzed by TiO2 at 254 nm. At this wavelength both, TiO2 and Paracetamol, absorb energy. A kinetic model was developed, and this includes a local volumetric rate of energy absorption function (LVREA) that takes into account that the reagent is capable of interact with radiation thus modifying the radiant field. To simulate the radiant field, the Monte Carlo method described in the literature was modified to consider the competition for energy absorption between the catalyst and Paracetamol. The resulting model allows to predict the effect on Paracetamol degradation of catalyst concentration, initial Paracetamol concentration, intensity of emitted radiation and thickness of the reaction space. The results of computer simulation are in good agreement with experimental data for both, photolytic and photocatalytic degradation using the commercial DP25 catalyst.

Paracetamol modulates biofilm formation in Staphylococcus aureus clonal complex 8 strains

Staphylococcus aureus biofilms are a major problem in modern healthcare due to their resistance to immune system defenses and antibiotic treatments. Certain analgesic agents are able to modulate S. aureus biofilm formation, but currently no evidence exists if paracetamol, often combined with antibiotic treatment, also has this effect. Therefore, we aimed to investigate if paracetamol can modulate S. aureus biofilm formation. Considering that certain regulatory pathways for biofilm formation and virulence factor production by S. aureus are linked, we further investigated the effect of paracetamol on immune modulator production. The in vitro biofilm mass of 21 S. aureus strains from 9 genetic backgrounds was measured in the presence of paracetamol. Based on biofilm mass quantity, we further investigated paracetamol-induced biofilm alterations using a bacterial viability assay combined with N-Acetylglucosamine staining. Isothermal microcalorimetry was used to monitor the effect of paracetamol on bacterial metabolism within biofilms and green fluorescent protein (GFP) promoter fusion technology for transcription of staphylococcal complement inhibitor (SCIN). Clinically relevant concentrations of paracetamol enhanced biofilm formation particularly among strains belonging to clonal complex 8 (CC8), but had minimal effect on S. aureus planktonic growth. The increase of biofilm mass can be attributed to the marked increase of N-Acetylglucosamine containing components of the extracellular matrix, presumably polysaccharide intercellular adhesion. Biofilms of RN6390A (CC8) showed a significant increase in the immune modulator SCIN transcription during co-incubation with low concentrations of paracetamol. Our data indicate that paracetamol can enhance biofilm formation. The clinical relevance needs to be further investigated.

Moringa oleifera seed pod‐based adsorbent for the removal of paracetamol from aqueous solution: A novel approach toward diversification

AbstractThe removal of paracetamol (PCM) from aqueous solution using chemically modified Moringa seed pod activated carbon (MOSPAC) was investigated. MOSPAC was characterized using Fourier transform infrared spectroscopy, electron dispersive X‐ray (EDX), and scanning electron microscopy, respectively. EDX results show that carbon in MOSP is 61.69% by weight and 61.18% by atom, while MOSPAC is 78.44% by weight and 88.80% by atom. The effects of operational parameters such as adsorbent dosage, initial PCM concentration, contact time, pH, and temperature were investigated. Langmuir model described the adsorption process mostly with adsorption capacity, qo of 20.284 mg g−1. The Dubinin–Radushkevich (D‐R) isotherm showed that the mean free energy, ED‐R, ranged from 100 to 408 kJ mol−1, suggesting that the mechanism of adsorption of PCM was chemisorption in nature. Similarly, the adsorption kinetic study was adequately described by the pseudo‐second order with R2 values ranging from 0.95 to 0.9998. Thermodynamic parameters, ΔS, ΔH, and ΔG gave (+493.79 kJ mol−1 K−1, +134.8679 kJ mol−1, and −35.3681 kJ mol−1, respectively) revealed that the adsorption process is endothermic, feasible, and spontaneous. The value of Ea (&gt;80 kJ mol−1) shows the mechanism of adsorption follows chemisorption. The cost analysis provides a simple proof that MOSPAC (40.17 USD per kg) is approximately 10 times cheaper than commercial activated carbon (398.70 USD per kg) providing a saving of 358.53 USD per kg. MOSPAC proved to be an effective adsorbent in the removal of PCM from aqueous solution. The use of functionalized Moringa seed pod in removing paracetamol drug even at very low concentration was demonstrated in this study to be efficient and cost effective.Statement of novelty The adsorption of paracetamol (PCM) on Moringa oleifera seed pod activated carbon (MOSPAC) was investigated. MOSPAC adsorbent gave a higher qo value for PCM removal from aqueous solution than other similar ones. MOSPAC is 78.44% by weight and 88.80% by atom, suggesting a promising adsorbent for PCM removal from aqueous solution

Electrochemical oxidation and electroanalysis of paracetamol on a boron-doped diamond anode material in aqueous electrolytes

Electrochemical oxidation of paracetamol on boron-doped diamond (BDD) anode has been studied by cyclic voltammetry and preparative electrolysis. Quantification of paracetamol during electrolysis has been mainly realized by differential pulse voltammetry technique in the Britton-Robinson buffer solutions used as the supporting electrolyte. Various parameters such as current intensity, nature of the supporting electrolyte, temperature, and initial concentration of paracetamol have been investigated. The electrochemical characterization by the outer sphere Fe(III)/Fe(II) redox couple has also been performed, showing the metallic character of BDD electrode. The obtained linear dependency of the oxidation peak current intensity and paracetamol concentration indicates that BDD electrode can be used as an electrochemical sensor for the detection and quantification of paracetamol. The investi­gation of paracetamol degradation during preparative electrolysis showed that: (i) the degradation rate of paracetamol increases with increase of current intensity applied; (ii) for the initial concentrations of 10, 6 and 1 mM of paracetamol, its oxidation rate reaches 60, 78 and 99 % respectively, after 1 h of electrolysis in 0.3 M H2SO4 (pH 0.6) at applied current density of 70 mA cm-2; (iii) at temperatures of electrolyte solution of 28, 55 and 75 °C, paracetamol oxidation rate reached 85, 92 and 97 % respectively, after 2 h at applied current density of 70 mA cm2. From the investigation of the effect of pH value of electrolyte solution, it appears that oxidation of paracetamol is more favorable in acidic solution at pH 3 than solutions of higher pH values.

Controlled drug release from electrospun PCL non-woven scaffolds via multi-layering and e-beam treatment

Currently, electrospun synthetic bioresorbable polymer scaffolds are applied in regenerative medicine and tissue engineering as targeted drug delivery devices because of their mechanical and physico-chemical properties. To control the rate of polymer degradation and drug release from polymer scaffolds, surface modification techniques are widely used. In this study, paracetamol-loaded poly (ε-caprolactone) electrospun fibrous scaffolds were treated by the pulsed electron beam irradiation. Pure control PCL scaffold, as well as scaffolds with four paracetamol concentrations (2 wt./wt. %, 8 wt./wt. %, 16 wt./wt. %, and 32 wt./wt.%) were modified. The mechanical and chemical properties and morphology of modified materials were examined. The sustained release of the model drug over a period of one hour for both non-treated and treated samples was demonstrated. It was shown that treatment leads to an increase in drug release rate and does not change surface morphology of scaffolds and fibers diameter distribution.

Fabrication of polypyrrole/Au nanoflowers modified gold electrode for highly sensitive sensing of paracetamol in pharmaceutical formulation

Paracetamol (PC) is one of the most common non-steroidal anti-inflammatories, pain-killer, and antipyretic drugs. Thus, the development of a cheap, access, and accurate analytical technique is necessary for monitoring the purity of the PC in their pharmaceutical formulations. Herein, a layer of polypyrrole (PPy) was used to modify gold nanoflowers/gold electrodes and then applied to determine PC in the presence of 4-aminophenol. The relationship between the PC concentrations (within a range from 100 nmol L − 1 to 25 µmol L − 1) and their corresponding current peaks demonstrated a linear curve with a limit of detection (LOD) as low as 133 nmol L − 1. The synthesized PPy/Au nanoflowers nanocomposite modified Au electrode was successfully used to monitor the purity of the Novadol tablets. Then the electrochemical results were validated by the gas chromatography technique. Hence, the developed electrode displays a significant PC-sensing capability even at trace concentrations, maintaining functionality for reuse without substantial deterioration in its original performance.

Removal of analgesics from aqueous solutions onto montmorillonite KSF

Due to increasing consumption of analgesic drugs associated with their occurrence in wastewater, it is necessary to pay attention to find new accessible types of sorbents for effective drug removal. The objective of this work is the assessment of ability of commercial montmorillonites for the removal of drugs from aqueous solutions since these inexpensive materials exhibit both adsorption and ion exchange properties as well as environmental stability. The commercial montmorillonite KSF, primarily used as acidic catalyst, was used in both unmodified and cetyltrimethylammonium bromide (CTAB) modified form as potential sorbent for three analgesics: paracetamol (PAR), ibuprofen (IBU) and diclofenac (DC) from aqueous solutions. The samples were characterized by X-ray fluorescence (XRFS), X-ray powder diffraction (XRD), simultaneous thermogravimetry and differential thermal analysis (TG/DTA) and high-performance liquid chromatography (HPLC). XRD confirmed the intercalation of CTAB into the montmorillonite structure with the increasing of basal spacing. Thermal analysis also determined the presence of CTAB associated with increasing of the hydrophobicity accompanied by a decrease in dehydration temperature. Also, due to surfactant modification, the temperature of constitution water removal decreased. Adsorption experiments were carried out in a batch mode with different initial concentration of paracetamol, ibuprofen and diclofenac solutions. Montmorillonite samples especially in organically modified form demonstrated sufficient sorption ability of pharmaceuticals from aqueous solutions in the order diclofenac > ibuprofen > paracetamol.

Effect of Pseudomonas moorei KB4 Cells' Immobilisation on Their Degradation Potential and Tolerance towards Paracetamol.

Pseudomonas moorei KB4 is capable of degrading paracetamol, but high concentrations of this drug may cause an accumulation of toxic metabolites. It is known that immobilisation can have a protective effect on bacterial cells; therefore, the toxicity and degradation rate of paracetamol by the immobilised strain KB4 were assessed. Strain KB4 was immobilised on a plant sponge. A toxicity assessment was performed by measuring the concentration of ATP using the colony-forming unit (CFU) method. The kinetic parameters of paracetamol degradation were estimated using the Hill equation. Toxicity analysis showed a protective effect of the carrier at low concentrations of paracetamol. Moreover, a pronounced phenomenon of hormesis was observed in the immobilised systems. The obtained kinetic parameters and the course of the kinetic curves clearly indicate a decrease in the degradation activity of cells after their immobilisation. There was a delay in degradation in the systems with free cells without glucose and immobilised cells with glucose. However, it was demonstrated that the immobilised systems can degrade at least ten succeeding cycles of 20 mg/L paracetamol degradation. The obtained results indicate that the immobilised strain may become a useful tool in the process of paracetamol degradation.