Adsorption Of Fluoxetine Research Articles

Adsorption of fluoxetine in aqueous environments: Development of macroporous cryogels based on sodium poly(acrylate) and carboxymethyl chitosan

This study focuses on the development of macroporous monoliths using cryopolymerization of sodium acrylate/carboxymethyl chitosan solutions for the adsorption of the antidepressant fluoxetine in aqueous environments. The cryogels were characterized using various analytical techniques, and the effects of pH, temperature, initial concentration, and contact time on the adsorption capacity were investigated. The surface charge of the cryogel was negative when pHsolution > pHPZC, and pH 8.5 was optimal for swelling rates and fluoxetine removal efficiency. The NaPA4-CMCs cryogel (0.5 mg.mL−1) showed the best adsorption performance, with the pseudo-first-order model best describing the experimental kinetics data. The intraparticle diffusion model revealed rapid diffusion through macropores and mesopores. The Langmuir model fitted well to the experimental adsorption equilibrium data, with qmax = 80.6 ± 3.4 mg.g−1. The adsorption process was favorable, exothermic, and governed by physisorption, involving electrostatic, hydrogen bonding, π–π, and hydrophobic interactions. The binary solvent HCl (0.1 M)/methanol 1:1 v/v was effective for regenerating the adsorbent, with adsorption efficiency greater than 60 % after three cycles of reuse. The study highlights the potential of these macroporous monoliths for the effective removal of antidepressants from aqueous environments.

Carbon supported ternary layered double hydroxide nanocomposite for Fluoxetine removal and subsequent utilization of spent adsorbent as antidepressant

Fluoxetine (FLX) is one of the most persistent pharmaceuticals found in wastewater due to increased use of antidepressant drugs in recent decades. In this study, a nanocomposite of ternary ZnCoAl layered double hydroxide supported on activated carbon (LAC) was used as an adsorbent for FLX in wastewater effluents. The nanocomposite was characterized using Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and surface area analysis (BET). The adsorption investigations showed that the maximum removal capacity was achieved at pH 10, with a 0.1 g/L adsorbent dose, 50 mL volume of solution, and at a temperature of 25 °C. The FLX adsorption process followed the Langmuir–Freundlich model with a maximum adsorption capacity of 450.92 mg/g at FLX concentration of 50 µg/mL. Density functional theory (DFT) computations were used to study the adsorption mechanism of FLX and its protonated species. The safety and toxicity of the nanocomposite formed from the adsorption of FLX onto LAC (FLX-LAC) was investigated in male albino rats. Acute toxicity was evaluated using probit analysis after 2, 6, and 24 h to determine LD50 and LD100 values in a rat model. The FLX-LAC (20 mg/kg) significantly increased and lengthened the sleep time of the rats, which is important, especially with commonly used antidepressants, compared to the pure standard FLX (7 mg/kg), regular thiopental sodium medicine (30 mg/kg), and LAC alone (9 mg/kg). This study demonstrated the safety and longer sleeping duration in insomniac patients after single-dose therapy with FLX-LAC. Selective serotonin reuptake inhibitors (SSRIs) like FLX were found to have decreased side effects and were considered the first-line mood disorder therapies.

Chiral pharmaceutical drug adsorption to natural and synthetic particulates in water and their desorption in simulated gastric fluid

Natural and synthetic particulates in aquatic environments can act as a vector for chiral pharmaceutical drugs. Understanding enantiomer enrichment in the particulate phase of water matrices is essential considering the enantiospecific effects that chiral drugs can have on exposed organisms. Therefore, the enantiospecific adsorption of the cationic drugs fluoxetine and propranolol to polyhydroxyalkanoate bioplastic, polyamide microplastic, and cellulose particulates was investigated in 0.01 M calcium chloride (CaCl2) buffer and real environmental matrices. Fluoxetine enantiomers adsorbed to all particulate types under all conditions studied. Yet, propranolol only adsorbed to polyamide in 0.01 M CaCl2 buffer at pH 11, and in samples prepared using real matrices (river water and wastewater). No enantioselectivity was observed in the adsorption of fluoxetine or propranolol, or their subsequent desorption in a simulated gastric environment. Findings showed the enantiomeric composition of the adsorbed drug will reflect that of the dissolved drug assuming no degradation takes place. However, further enantiospecific adsorption studies are now needed on a broader range of chiral drugs and particulate matter found in water. Importantly, drug adsorption was considerably greater in river water and wastewater compared to 0.01 M CaCl2 buffer (2.1 to 5.3 times for fluoxetine). Most adsorption studies reported in the literature use 0.01 M CaCl2 buffer to conform with international guidelines for assessing the adsorption behaviour of chemicals. Although such conditions enable direct comparison with similar studies, they can underestimate cationic drug adsorption to particulates in engineered and natural environments. This needs consideration in future studies on drug adsorption to microplastics and other particulate matter in laboratory studies.

Geometry influenced adsorption of fluoxetine over the surface of RuFeO3 and CeFeO3 nanoparticles: Kinetics and thermodynamic studies

Novel mesoporous ferrite nanoparticles of ruthenium (RuFeO3) and cerium (CeFeO3) with large surface area were successfully fabricated by hydrothermal method and applied for the removal of fluoxetine from aqueous solution. The morphology and physicochemical properties of meso-porous metal ferrites were characterized by different analytical techniques. The obtained results showed that the particle size of 20–30 nm for meso-CeFeO3, and 80–100 nm for meso-RuFeO3 respectively. Study of the adsorption of fluoxetine over metal ferrite nanoparticles was explored using UV–vis spectroscopy at different experimental conditions such as temperature, pH, initial fluoxetine concentration and time. The adsorption data were fitted and analyzed with kinetic and different adsorption isotherm models, and the results showed that both the metal ferrites effectively adsorbed fluoxetine (>99%). The maximum adsorption capacity of 729.6 mg g−1 for CeFeO3, and 683.5 mg g−1 for RuFeO3 at neutral pH and at 25 °C were observed. The amount adsorbed over the surface of metal ferrite nanoparticles increased with increasing initial fluoxetine concentration, reaction time, and temperature, and the adsorption performance improved under neutral conditions (pH 7 and 8). The pseudo-second order kinetic and Langmuir isotherm models satisfactorily fitted the adsorption data, showing that the adsorption of fluoxetine involved physical adsorption through intermolecular electrostatic force between the metal ferrites and fluoxetine which is further confirmed by intra-particle diffusion model. The observed wide band/gap, 3.815eV for CeFeO3, and 3.360eV for RuFeO3 respectively showed their stability towards visible light suggesting their real sample applicability, recovery and reuse capability involving physisorption with fluoxetine molecules. In addition, the feasible adsorption process of fluoxetine is analyzed with its geometry that is determined by theoretical energy calculations using DFT.

Adsorption of Pharmaceutical Contaminants from Aqueous Solutions Using N,O-Carboxymethyl Chitosan/Polyethylene Oxide (PEO) Electrospun Nanofibers

Residues of pharmaceutical and direct metabolites discharged into the aquatic environment have become a challenge for wastewater treatment facilities due to their increase in concentration and their different physicochemical properties. These emerging contaminants are daily detected in surface water and wastewater discharged by municipalities. To remediate the contaminated water, various methods are currently used including primary, secondary, and tertiary advanced treatments. However, some economic and environmental limitations have forced the scientific community to develop alternative disinfection processes to purify wastewater. As such, the adsorption strategy represents a “green” low-cost and effective solution to remove pollutants from water. In this study, a nanomaterial made of N,O-carboxymethyl chitosan (N,O-CMCS) was prepared using chitosan (CS) and monochloroacetic acid under various conditions. N,O-CMCS electrospun was synthetized with the copolymer polyethylene oxide (PEO) to create nanofiber membranes showing a better specificity toward diversified contaminants depending on the pH of medium. The developed adsorbent was used to remove fluoxetine (FLX) from aqueous solutions. The new nanomaterial was characterised using FTIR, NMR, and SEM techniques. Sorption batch tests were carried out using high-performance liquid chromatography and ultraviolet diode array detector (HPLC-UV DAD) under controlled pH experimental conditions to determine the contaminant removal capacity of the nanomaterial. The promising adsorption results obtained with N,O-CMCS/PEO nanofibers are among the best ones obtained so far in comparison to other commercial and synthetized adsorbents tested for FLX’s adsorption. Kinetic experiments were also performed to investigate effects of contact times on the FLX adsorption. Experimental results were fitted to both common kinetic models pseudo-first and second order. The latter kinetic model described the best the sorption on surface. It revealed a possible chemisorption mechanism with electrostatic bounding for N,O-CMCS/PEO nanofibers.

An approach towards Zero-Waste wastewater technology: Fluoxetine adsorption on biochar and removal by the sulfate radical

The appearance of pharmaceuticals in the aquatic environments has become a serious problem because of their hazardous effect on the biota. Therefore, great efforts are focussed in the removal to these pollutants from wastewaters. In this study, an innovative technology based on the principles of Zero-Waste for the management of wastewater streams is presented. Hence, adsorption of fluoxetine (FLX), selected as a model pollutant, in an eco-friendly adsorbent, biochar, was followed by an in situ removal of the pharmaceutical in the solid matrix by the action of sulfate radicals. Initially, an in-depth characterisation of the adsorbent and the adsorption process was carried out. The pseudo-second order kinetic and Freundlich isotherm described well the process, and the electrostatic attractions were revealed as the primary adsorption mechanism. Later, the removal of the FLX was studied by the sulfate radicals, in the presence of activators (Fe2+ and citric acid), in liquid and onto the biochar medium. It was concluded that in order to enhance the pollutant removal it is necessary the presence of both activators in liquid media. However, in in situ removal onto biochar, it was not necessary the Fe2+ presence and only the addition of complexing agents was required as a result of biochar’s mineral content. Finally, the applicability of the proposed approach was studied in fixed-bed column assays where the adsorption and the removal of the pollutant were efficiently accomplished. This fact confirms the suitability of the developed process as a viable alternative in the treatment of wastewaters.

Effect of fluoxetine at different concentrations on the adsorption behavior of Langmuir monolayers

Fluoxetine (FLX), approved for the treatment of depression and anxiety by the FDA in 2002, is an amphiphilic antidepressant. In general, amphiphilic drugs have high membrane permeability. Therefore, the interactions between these drugs and monolayers have been widely concerned. In this study, the adsorption of FLX on dipalmitoylphosphatidylcholine (DPPC) monolayers at different concentrations and surface pressures have been investigated by pressure-area isotherms (π-A), adsorption curves, compression-expansion curves, and atomic force microscopy (AFM). Our data showed that the adsorption behavior was related to the surface pressures and FLX concentrations in the subphase. The FLX that was added in the subphase under lower surface pressure (π = 10 mN/m) was easily adsorbed on DPPC monolayers. The stability of the monolayers was strong. The adsorption of FLX on DPPC monolayers and the stability decreased when π = 20 mN/m. In addition, the adsorption behavior and stability increased with increasing FLX concentrations. The AFM images of the monolayers confirmed the results of fitted adsorption curves. This study will be critical to our understanding of the interactions between drugs and lipid monolayers.

Surface Interactions during the Removal of Emerging Contaminants by Hydrochar-Based Adsorbents.

The aim of this work was to test activated carbons derived from hydrochars produced from sunflower stem, olive stone and walnut shells, as adsorbents for emerging contaminants in aqueous solution, namely fluoxetine and nicotinic acid. The adsorption capacity was determined by the chemical nature of the adsorbents, namely the presence of specific functional groups and their positive or negative ionization in aqueous solutions and also by steric factors. The activated carbons produced by air showed a higher adsorption capacity of fluoxetine, whilst the samples produced by carbon dioxide activation were more useful to remove nicotinic acid. In general, surface acidity was advantageous for fluoxetine adsorption and detrimental for nicotinic acid removal. The adsorption mechanisms involved in each case were discussed and related to the adsorbents characteristics. The maximum adsorption capacity, Q0, given by the Langmuir model was 44.1 and 91.9 mg g−1 for fluoxetine and nicotinic acid adsorption, respectively.

CNTs coated charcoal as a hybrid composite material: Adsorption of fluoxetine probed by zebrafish embryos and its potential for environmental remediation.

Although traditional water treatment systems can remove various substances from wastewater, these conventional systems fail to remove many chemical molecules that pose potential ecological and health risks. Carbon nanotubes (CNTs) appear attractive to adsorption of many substances, but CNTs adsorbed with toxic substances becomes a nanocomposite still more toxic. Here, we employ zebrafish embryos as biosensor to examine how a hybrid micro/nanostructured carbonaceous material (HMNC) derived from a combination of activated carbon (AC) with hydrophilic carbon nanotubes (CNTs) can remediate wastewater contaminated with the pharmaceutical fluoxetine hydrochloride (FLX). AC and HMNC are practically non-toxic to zebrafish embryos (LC50 > 1000 mg.L−1). HMNC addition to culture medium containing FLX significantly reduces sublethal effects and lethality. Interaction between FLX and HMNC involves chemical adsorption such that embryo co-exposure to HMNC adsorbed with FLX in the range of concentrations evaluated herein does not elicit any behavioral changes in zebrafish.

Biphasic apatite-carbon materials derived from pyrolysed fish bones for effective adsorption of persistent pollutants and heavy metals

Biphasic apatite-carbon biochar-type materials were prepared from pyrolysed cod fish bones and were assessed for the adsorption of persistent organic pollutants (pharmaceuticals diclofenac and fluoxetine), and heavy metals (Pb(II)).The materials, prepared with a simple pyrolysis process at different temperatures (200–1000°C), were characterised with XRD, FTIR, Raman and SEM. Results showed that the pyrolysis temperature had a significant effect on the features/composition of the materials: up to 800 °C, carbonate apatite Ca10(PO4)6(CO3) was the main component, while for higher temperatures oxyapatite Ca10(PO4)6O was the dominant phase. Graphitic carbon was also detected.The mixed apatite-carbon products (bone char) exhibited high adsorption efficiency.Graphite carbon was the main adsorber for the pharmaceuticals, the best performing material being that pyrolysed at 1000°C. Xm values of 43.29 and 55.87mg/g were observed (Langmuir fitting), while KF values of 5.40 and 12.53 (mg/g)(L/mg)nF were obtained with the Freundhlich model (diclofenac and fluoxetine respectively). This is the first time that a biochar-like material has been used for fluoxetine adsorption. For Pb (II), the powder pyrolysed at 600°C was the most effective, with the apatite playing a key role (Xm=714.24mg/g).This work shows that a by-product of the fish industry could be converted into efficient materials for environmental remediation; according to the pyrolysis conditions, powders effective in the removal of either organics or heavy metals can be obtained. Moreover, with pyrolysis at intermediate temperatures, materials capable of adsorbing both kinds of pollutants can be produced, even if less efficient.

DFT, NBO and molecular docking studies of the adsorption of fluoxetine into and on the surface of simple and sulfur-doped carbon nanotubes

In this study, noncovalent interactions between Fluoxetine (FX) and different carbon nanotubes (CNTs) or sulfur doped carbon nanotubes (SCNTs) were fully considered using DFT, natural bond orbital (NBO) and molecular docking calculations. Two different CNTs (and SCNTs) with 7,7 and 8,8 chiralities were considered as the adsorbents and the adsorption of FX by these adsorbents were studied in two cases: into the nanotubes and on their surfaces. The results of DFT and NBO calculations proposed that the 8,8 nanotubes are more suitable adsorbents for FX because the energies of their adsorptions are minimum.Population: analyses were also proposed that the adsorption of FX by SCNTs lead to more changes in electronic and sensing properties than the adsorption by CNTs. Moreover, the adsorption energies, obtained from molecular docking calculations (using 94 different models), proposed that the adsorption of FX into (versus out of) the nanotubes, adsorption processes by double-walled or triple-walled (versus single-walled) nanotubes and the adsorption by nanotubes with 8,8 chiralities are the most favorable adsorption processes.

Study of the Contributions of Non‐Specific and Specific Interactions during Fluoxetine Adsorption onto Activated Carbons

AbstractThe adsorption of fluoxetine onto activated carbons (ACs) prepared from almond tree pruning by steam and CO2 activation under different temperature conditions (650–950°C), was studied. In both series increasing the temperature caused an increase in the BET apparent surface area, yielding ACs with SBET up to 870 and 710 m2 g−1 after steam and CO2 activation, respectively. Also, a slight widening of the porosity was found in both cases. In order to modify the functionality of the ACs, two of them were impregnated with triethylenediamine (TEDA) prior to the adsorption process, which caused a decrease in the AC apparent surface mainly due to micropore blockage. The fluoxetine adsorption isotherms at 25°C showed maximum adsorption capacities between 110 and 224 mg g−1. The adsorption isotherms were analyzed using Langmuir and Freundlich models. Although the impregnation reduced the pore volume, it did not cause a decrease in the fluoxetine maximum adsorption capacity, but a modification in the adsorption mechanism was observed.

In vitro adsorption study of fluoxetine in activated carbons and activated carbon fibres

We study the in vitro adsorption of fluoxetine hydrochloride by different adsorbents in simulated gastric and intestinal fluid, pH 1.2 and 7.5, respectively. The tested materials were two commercial activated carbons, carbomix and maxsorb MSC30, one activated carbon fibre produced in our laboratory and also three MCM-41 samples, also produced by us. Selected samples were modified by liquid phase oxidation and thermal treatment in order to change the surface chemistry without significant modifications to the porous characteristics. The fluoxetine adsorption follows the Langmuir model. The calculated Q 0 values range from 54 to 1112 mg/g. A different adsorption mechanism was found for the adsorption of fluoxetine in activated carbon fibres and activated carbons. In the first case the most relevant factors are the molecular sieving effect and the dispersive interactions whereas in the activated carbons the mechanism seams to be based on the electrostatic interactions between the fluoxetine molecules and the charged carbon surface. Despite the different behaviours most of the materials tested have potential for treating potential fluoxetine intoxications.

Electrochemical studies and square wave adsorptive stripping voltammetry of the antidepressant fluoxetine

The electrochemical reduction of the antidepressant drug fluoxetine was investigated by cyclic, linear sweep, differential pulse and square wave voltammetry using a hanging mercury drop electrode in alkaline buffer solution in water and in a water/acetonitrile mixed solvent. Cyclic voltammograms in aqueous solution showed very strong adsorption of fluoxetine on the electrode with formation of a compact film. The effect of addition of different percentages of acetonitrile on the voltammetric response was evaluated. It is shown that acetonitrile protects the electrode surface, thus preventing the adsorption of fluoxetine as a compact film, although reduction occurs at more negative potentials. Adsorption was used to accumulate the drug onto the electrode surface. The adsorbed species were measured voltammetrically by reduction at −1.3 V in an aqueous 0.05 M Ringer buffer, pH 12, 20% acetonitrile v/v. Linear calibration graphs were obtained in the range 0.52–5.2 M. The quantification of fluoxetine in pharmacological formulations existing in the market was performed using adsorptive square wave cathodic stripping voltammetry. and compared with data from UV spectrophotometry. The method is simple and not time-consuming. A comparative high performance liquid chromatography assay with UV detection was performed. Recovery data for both methods are reported.