Types Of Cyclodextrins Research Articles

The experimental investigation of bisphenol A degradation by Fenton process with different types of cyclodextrins

In this work, the degradation efficiencies of bisphenol A (BPA) by Fenton reaction were compared systematically with varying cyclodextrins. The results showed that the removal rate of BPA displays a considerable increase by Fenton reaction in presence of β-cyclodextrin (β-CD) and its derivatives. Specifically, 98±2% and 89±2% of BPA was removed with carboxymethyl-β-cyclodextrin (CMCD) and β-CD, respectively. Additionally, to understand the reaction mechanism, the structure activity of cyclodextrins with substrate and the kinetic of Fenton reaction with cyclodextrins have been investigated. Results showed that the structure activity was the major role for cyclodextrins in this system.

Structural dynamics and binding free energy of neral-cyclodextrins inclusion complexes: molecular dynamics simulation

The inclusion complexation of neral, a cis-isomer of citral found in lemon grass (Cymbopogon citratus Stapf), and four different types of cyclodextrin (β-cyclodextrin (βCD), 2,6-dimethyl-βCD (2,6DMβCD), 2,6-dihydroxypropyl-βCD (2,6DHPβCD), and 2-hydroxypropyl-βCD (2HPβCD)) was investigated using molecular docking and molecular dynamics simulation approaches. The simulations show that the neral/CD inclusion complex could be formed in an aqueous solution with a 1:1 ratio. Three possible binding orientations were assessed for the encapsulation of neral (1neral, 7neral, and uneral) inside the hydrophobic interior of the host molecule. The uneral, in which both aldehyde and alkyl terminals point outward on the secondary rim of the CD, was observed to be the most preferential conformation in all neral/CD complexes. The theoretical calculations of the binding ability of the host–guest inclusion complexes agreed well with the experimental data, thereby supporting that the neral could bind inside the hydrophobic cavity of all CDs with nearly the same potency.

Cyclodextrin-functionalized mesostructured silica nanoparticles for removal of polycyclic aromatic hydrocarbons.

Polycyclic aromatic hydrocarbons (PAHs) are the byproducts of the incomplete combustion of carbon-based fuels, and have high affinity towards DNA strands, ultimately exerting their carcinogenic effects. They are ubiquitousenvironmental contaminants,and can accumulate on tissues due to their lipophilic nature. In this article, we describe a novel concept for PAH removal from aqueous solutions using cyclodextrin-functionalized mesostructured silica nanoparticles (CDMSNs) and pristine mesostructured silica nanoparticles (MSNs). The adsorption applications of MSNs are greatly restricted due to the absence of surface functional groups on such particles. In this regard, cyclodextrins can serve as ideal functional molecules with their toroidal, cone-type structure, capable of inclusion-complex formation with many hydrophobic molecules, including genotoxic PAHs. The CDMSNs were synthesized by the surfactant-templated, NaOH-catalyzed condensation reactions of tetraethyl orthosilicate (TEOS) in the presence of two different types of cyclodextrin (i.e. hydroxypropyl-β-cyclodextrin (HP-β-CD) and native β-cyclodextrin (β-CD)). The physical incorporation of CD moieties was supported by XPS, FT-IR, NMR, TGA and solid-state 13C NMR. The CDMSNs were treated with aqueous solutions of five different PAHs (e.g. pyrene, anthracene, phenanthrene, fluorene and fluoranthene). The functionalization of MSNs with cyclodextrin moieties significantly boosted the sorption capacity (q) of the MSNs up to ∼2-fold, and the q ranged between 0.3 and 1.65mg per gram CDMSNs, of which the performance was comparable to that of the activated carbon.

Separation of 20 coumarin derivatives using the capillary electrophoresis method optimized by a series of Doehlert experimental designs

The aim of this study was to develop the first CE-based method enabling separation of 20 structurally similar coumarin derivatives. To facilitate method optimization a series of three consequent Doehlert experimental designs with the response surface methodology was employed, using number of peaks and the adjusted time of analysis as the selected responses. Initially, three variables were examined: buffer pH, ionic strength and temperature (No. 1 Doehlert design). The optimal conditions provided only partial separation, on that account, several buffer additives were examined at the next step: organic cosolvents and cyclodextrin (No. 2 Doehlert design). The optimal cyclodextrin type was also selected experimentally. The most promising results were obtained for the buffers fortified with methanol, acetonitrile and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin. Since these additives may potentially affect acid-base equilibrium and ionization state of analytes, the third Doehlert design (No. 3) was used to reconcile concentration of these additives with optimal pH. Ultimately, the total separation of all 20 compounds was achieved using the borate buffer at basic pH 9.5 in the presence of 10mM cyclodextrin, 9% (v/v) acetonitrile and 36% (v/v) methanol. Identity of all compounds was confirmed using the in-lab build UV–VIS spectra library. The developed method succeeded in identification of coumarin derivatives in three real samples. It demonstrates a huge resolving power of CE assisted by addition of cyclodextrins and organic cosolvents. Our unique optimization approach, based on the three Doehlert designs, seems to be prospective for future applications of this technique.

Near-infrared photoswitching of cyclodextrin-guest complexes using lanthanide-doped LiYF4 upconversion nanoparticles.

This communication reports a new type of supramolecular cyclodextrin-guest complexes using cyclodextrin coated upconversion nanoparticles as hosts and monovalent and divalent azobenzenes and arylazopyrazoles as guests. A potentially biocompatible photocontrol of the interaction by isomerization of the azobenzene or arylazopyrazole was achieved by laser irradiation at 980 nm and a very low light intensity of 0.22 W cm-2.

Capillary Electrophoresis as Tool for Diastereomeric Separation in a Trichilia catigua Fraction.

The tree Trichilia catigua, popularly known as "catuaba", shows several biological activities and has emerged as a potential source of new drugs. Considering that more than 10 species are known under the same popular name, regulatory agencies require more rigorous quality control of this medicinal plant. To develop and validate a methodology using capillary electrophoresis (CE) with ultraviolet (UV) detection for analysing polyphenols in the ethyl-acetate fraction (EAF) of Trichilia catigua. Different electrophoretic conditions (such as wavelength of UV detection, voltage, buffer concentration and pH, cyclodextrin type and concentration) were investigated. After optimisation, borate buffer 80mmol/L at pH8.80 with 2-hydroxypropyl-β-cyclodextrin 10mmol/L was selected as background electrolyte. A voltage reduction was used to improve the separation of a diastereomeric pair of cinchonains. The method proved to be simple, sensitive, accurate, linear, precise and reproducible. For the first time in natural products analysis, a voltage reduction and hydroxypropyl-β-cyclodextrin were used to improve the separation of diastereomeric pairs. Until now, this is the only described methodology able to separate catechin, epicatechin, cinchonains Ia, Ib, IIa, and IIb from Trichilia catigua samples on the same run in less than 12min. When compared to the high performance liquid chromatography with photo-diode array detection (HPLC-PDA) method previously developed by our research group, the CE method was more efficient, faster, less expensive and less polluting. Our results demonstrate that this method could be employed in a quality-control laboratory for the quantification of polyphenols in EAF of Trichilia catigua. Copyright © 2016 John Wiley & Sons, Ltd.

Design and development of dry powder sulfobutylether-β-cyclodextrin complex for pulmonary delivery of fisetin

This study has investigated complexation of fisetin, a natural flavonoid, with three types of cyclodextrins to improve its solubility. Sulfobutylether-β-cyclodextrin (SBE-β-CD) showed the highest complexation efficiency while maintaining the in vitro antioxidant activity of fisetin. Addition of 20%v/v ethanol in water improved the amount of solubilized fisetin in the complex 5.9-fold compared to the system containing water alone. Spray drying of fisetin-SBE-β-CD complex solution in the presence of ethanol produced a dry powder with improved aerosolization properties when delivered from a dry powder inhaler, indicated by a 2-fold increase in the fine particle fraction (FPF) compared to the powder produced from the complex solution containing water alone. The pitted morphological surface of these particles suggested a more hollow internal structure, indicating a lighter and less dense powder. Incorporation of 20%w/w leucine improved the particle size distribution of the powder and further increased the FPF by 2.3-fold. This formulation also showed an EC50 value equivalent to fisetin alone in the A549 cell line. In conclusion, an inhalable dry powder containing fisetin-SBE-β-CD complex was successfully engineered with an improved aqueous solubility of fisetin. The dry powder may be useful to deliver high amounts of fisetin to the deep lung region for therapeutic purposes.

A green synthesis of copper nanoparticles using native cyclodextrins as stabilizing agents

In this work, a comparative study of the effect of the NCD size as a stabilizing agent, on the synthesis of copper nanoparticles (Cu-NPs) by an easy green method was reported. The nanoparticles were synthesized through the chemical reduction of aqueous solutions of copper (II) sulfate with ascorbic acid, using different native cyclodextrins (NCDs) (α-, β-, or γ-NCD) as stabilizing agents. Cu-NPs were characterized by scanning electron microscopy–energy dispersive spectroscopy (SEM–EDX), powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). The pattern showed in the typical selected area electron diffraction (SAED) and lattice fringes, evidence that the crystalline structure of Cu-NPs is face-centered cubic (FCC) with a (111), (200) and (220) lattice planes of Cu. The analysis of the TEM images show that the size of the Cu-NPs depends on the type of native cyclodextrin (NCD), also it was observed that the nanoparticles are spherical and with a size between ∼2 and 33nm. The smaller Cu-NPs were obtained with α-NCD (mode 4nm), while the nanoparticles obtained with β-NCD show the narrow size distribution (mode 6.5nm). The average particle size and particle size distribution of Cu-NPs depend upon the type of CDs.

Statistical design analysis of isophorone electrocatalytic hydrogenation: the use of cyclodextrins as inverse phase transfer catalysts

Fundamentals and applications of a 23 factorial design were performed for assessing the influence of the cyclodextrin (CyD) type, concentration and encapsulation time on the electrocatalytic hydrogenation (ECH) of isophorone. Electrolysis were carried out using nickel as electrocatalyst and sacrificial anode. A discussion of model validation is presented. The analysis of the results showed that the most significant factors to the conversion rate were the CyD type and concentration, with 3 mmol dm−3 of βCyD giving the best results. The isophorone C=C hydrogenation yield, in the presence of βCyD, was 28 % higher than in its absence, and it is comparable to those obtained by other well-established ECH procedures in terms of hydrogenation yield, selectivity and current efficiency.

Anticorrosion behavior of cyclodextrins/inhibitor nanocapsule-based self-healing coatings

The self-healing anticorrosion property of coating containing cyclodextrins/inhibitor nanocontainers was investigated by SEM, TEM, salt spray, and EIS measurements. The influences of cyclodextrin type (α-CD, β-CD and γ-CD) and nanocapsules diameter on the anticorrosive performance of the scratched samples were studied under salt spray conditions, which revealed that the coatings containing γ-CD/inhibitor nanocontainers with larger nanocapsules at room temperature demonstrated the best anticorrosion behavior. Inclusion complex formation of MBI or MBT with CDs led to encapsulated corrosion inhibitors which became active in corrosive electrolytes, and could slowly diffuse out of the host material to ensure continuous delivery of the inhibitors to corrosion sites and long-term corrosion protection. Additionally, the kinetics of the self-healing process characterized by EIS measurement was parametrically analyzed in an equivalent circuit when the coating was exposed to salt solution.

Improvement of ursolic and oleanolic acids' antitumor activity by complexation with hydrophilic cyclodextrins.

Ursolic and oleanolic acids have been brought into the spotlight of research due to their chemopreventive, anti-inflammatory and immunomodulatory properties. The most important disadvantage of ursolic and oleanolic acids is their weak water solubility which limits their bioavailability. Pentacyclic triterpenes can form inclusion complexes with different types of cyclodextrins which provide the hydrophilic matrix requested for the molecular dispersion of drugs in order to become more water soluble. The aim of the current study is the complexation of ursolic and oleanolic acids with hydrophilic cyclodextrins in order to achieve an improvement of their pharmacological effect. After the virtual screening of the binding affinities between ursolic and oleanolic acids and various cyclodextrins, 2-hydroxypropyl-β-cyclodextrin and 2-hydroxypropil-γ-cyclodextrin were selected as host-molecules for the inclusion complexation. Using the scanning electron microscopy, differential scanning calorimetry and X-ray diffraction the formation of real inclusion complexes between ursolic and oleanolic acids and the two cyclodextrins was confirmed. The anti-proliferative potential of the complexes was tested in vitro on several melanoma cell lines, using the pure compounds as reference. The complexes exhibited higher in vitro anti-proliferative activity as compared to the pure compounds; this improvement was significant for ursolic acid complexes, the highest activity being reported for the 2-hydroxypropil-γ-cyclodextrin complex. Weaker results were recorded for the oleanolic acid complexes where 2-hydroxypropyl-β-cyclodextrin proved to be the most fitted inclusion partner. The entrapment of the two active compounds inside ramified hydrophilic cyclodextrins proved to be a suitable option to increase their anti-proliferative activity.

Development of particulate drug formulation against C. parvum: Formulation, characterization and in vivo efficacy

This research aims towards developing an alternative therapy against Cryptosporidium parvum using bioadhesive paromomycin and diloxanide furoate-loaded microspheres. Microspheres were prepared using chitosan and poly(vinyl alcohol) and two types of cyclodextrins (β-CD and DM-β-CD) for the potential use of treating cryptosporidiosis. This pathogen is associated with gastrointestinal illness in humans and animals. Microparticle formulations were characterized in terms of size, surface charge, drug release and morphology. In vivo bioadhesion properties of CHI/PVA microspheres were also evaluated in mice. Finally, the in vivo efficacy of CHI/PVA microspheres against C. parvum was tested in neonatal mouse model. In this work, microspheres prepared by spray-drying showed spherical shape, diameters between 6.67±0.11 and 18.78±0.07μm and positively surface charged. The bioadhesion studies demonstrated that MS remained attached at +16h (post-infection) to the intestinal cells as detected by fluorescence. This finding was crucial taking use of the fact that the parasite multiplication occurs between 16 and 20h post-infection. The efficacy of treatment was determined by calculating the number of oocysts recovered from the intestinal tract of mice after 7days of post-infection. Mice receiving orally administered microspheres with and without drug exhibited significantly lower parasite loads compared with the control mice. Ultrastructural observations by TEM bring to light the uptake of smallest particles by enterocytes associated with conspicuous changes in enterocytic cells. Completely recovery of cell morphology was detected after 24h of first inoculation with MS. CHI/PVA microspheres appear to be a safe and simple system to be used in an anticryptosporidial treatment. The distinctive features of neonatal mice requires further work to determine the suppressive effect of this particulate delivery system on C. parvum attachment in other animal models.

Synthesis and characterization of poly(2-hydroxyethylacrylate)/β-cyclodextrin hydrogels obtained by frontal polymerization

For the first time, the synthesis of polymeric hydrogels containing cyclodextrins (CDs) obtained by frontal polymerization (FP) is reported. In particular, the effects of CDs on poly(2-hydroxyethylacrylate) hydrogel properties are investigated. In a first series of materials, β-cyclodextrin is dispersed into the polymer matrix, while in the second one acryloyl-β-cyclodextrin is grafted to poly(2-hydroxyethylacrylate) chains. FP parameters (front velocity and maximum temperature), swelling properties, glass transition temperatures and mechanical properties of the hydrogels are studied. Results show that both types of cyclodextrin influence the above properties, and the major effects are found for concentration higher than 1mol% of acryloyl-β-cyclodextrin. Namely, a significant increase of glass transition temperature and of compression moduli are found. Finally, this study demonstrates that FP is a convenient technique to obtain CD-containing hydrogels, in which the type and amount of cyclodextrin can be suitably modulated to tune polymer properties, in function of the desired hydrogel applications.

Cyclodextrin type dependent host-guest interaction mode with phthalocyanine and their influence on photodynamic activity to cancer

Three host-guest complexes of phthalocyanines (Pc) with α-, β- or γ-cyclodextrins (CDs) were prepared and their interaction modes, reactive oxygen species (ROSs) generation ability and in vitro anticancer activities were studied and compared. After forming complex with CD, the aggregation degree of Pc was greatly decreased and the water solubility and photodynamic activity was sharply increased. Computer modeling results indicated that the interaction modes between Pc and CDs were varied with different kinds of CD. Especially, the complex of Pc and β-CD has superior stability, ROSs generation ability, and anticancer activity to other complexes.

Selective isolation of components from natural volatile oil by countercurrent chromatography with cyclodextrins as selective reagent

Selective separation of chemical components from seven kinds of volatile oil by countercurrent chromatography with three types of cyclodextrins as selective reagent was investigated in this work. Preparative separation of chemical components from volatile oil is generally quite challenging due to their extremely complexity of the composition. A biphasic solvent system n-hexane-0.10molL−1 cyclodextrin (1:1, v/v) was selected for separation of components from volatile oil and three types of cyclodextrins were investigated, including β-cyclodexrin, methyl-β-cyclodexrin and hydroxypropyl-β-cyclodexrin. All kinds of volatile oils are from seven kinds of traditional Chinese herb. Results showed that some chemical components could be well separated with high purity from each kind of volatile oil using different type of cyclodextrin as selective reagent. For example, germacrone and curcumenone could be selectively separated from volatile oil of Curcumae Rhizoma with methyl-β-cyclodexrin and hydroxypropyl-β-cyclodexrin as selector respectively, and other five components were selectively separated from volatile oil of Chuanxiong Rhizoma, Myristicae Semen, Aucklandiae Radix and Angelicae Sinensis Radix by countercurrent chromatography with different cyclodexrin as selective reagent. Separation mechanism for separation of components from volatile oil by countercurrent chromatography with cyclodextrin as selective reagent was proposed. Peak resolution of the present separation method could be greatly influenced by the chemical compositions of volatile oil.

Thermal inverse phase transition of azobenzene hydroxypropylcellulose in aqueous solutions

Water soluble 2-azobenzenoxy-ethoxy-hydroxpropylcelluloses (azo-EHPC) were synthesized by etherification reaction of bromoethoxy-azobenzene (BEA) with hydroxypropylcellulose (HPC) to study their phase transition behavior in aq. solution. The degree of substitution (DS) of the water soluble azo-EHPCs was less than 0.066. Their chemical structure and thermal property were characterized by proton nuclear magnetic resonance (1H-NMR), fourier transform infrared spectroscopy (FT-IR), and differential scanning calorimetry. The azo-EHPC showed a reversible sol–gel transition behavior in its aq. solution, i.e. a clear azo-EHPC aq. solution became turbid when the solution temperature surpassed a lower critical solution temperature (LCST). The sol–gel transition phenomenon was investigated by optical microscopy and turbidimetric measurement. It was found that the LCST was related to the cis-/trans- conformation of the azobenzene side group, the type of cyclodextrin (CD), concentration of azo-EHPC, and NaCl concentration. The LCST of azo-EHPC was lower than that of HPC (36.6 °C) by at most 13.6 °C, and the LCST of trans-azo-EHPC was less than that of cis-azo-EHPC by ca. 3 °C. Additionally, the presence of CD in solutions displayed a positive effect on the LCST, i.e. increasing the LCST by 3–5 °C. And this impact was more profound on the azo-EHPC with higher DS values. The thermoreversible phase transition mechanism was discussed. We proposed that the effect of DS, conformation of azobenzene group, azo-EHPC concentration, salt concentration, and CD on the LCST of azo-EHPCs was a rearrangement of the hydrophilic/hydrophobic interaction between side azobenzene groups and water molecules.

Characterisation of the Self-Assemblies Properties and Interaction with Models Membranes of New Type of Amphiphilic Cyclodextrins : A DLS and SS-NMR Study

Thanks to their abilities to form inclusion complexes and nanoparticles with many hydrophobic drugs, cyclodextrins are widely used for vectorization(1). Nevertheless, the poor diffusion of these systems through cell membrane and the low stability of their aggregates remain major obstacles, particularly for pharmaceutical applications(2). To deal with this problem, amphiphilic cyclodextrins are commonly used in the literature(3). This work presents the characterization of the nanoparticles obtained by the aggregation of new types of amphiphilic cyclodextrins(4), lipophosphoramidyl-cyclodextrins and glycerolipidyl-cyclodextrins, as well as the study of their influences on model membranes. Dynamic Light Scattering (DLS) shows that the nanoparticles have a diameter lower than 400nm and stability greater than 14 days. Amphiphilic cyclodextrin/lipid interactions have been studied by 31P and 2H Solid-State NMR (SS-NMR) on multilamellar vesicles (MLV) with different composition used to mimic cell membranes. 31P NMR experiment shows a global insertion of amphiphilic cyclodextrins and 2H NMR data suggest disturbance of the lipid dynamics due to cyclodextrins, which seems to be influenced by the nature of the lipid chains. Indeed, in the case of MLV of DMPC (C14:0), a rigidification has been observed whereas an increase of the lipid dynamics is noted for liposomes constituted by POPC (18:1; 16:0). Finally, results obtained on a third model, POPC-d31/CH/SM (5.2/3.3/1.5), which contains cholesterol and sphingomyelin, two major lipid class found in natural plasma membrane, show also a fluidification.Reference:(1)S. V. Kurkov. & T. Loftsson, International Journal of Pharmaceutics, (2013), 453, 167-180.(2)H. Parrot-Lopez et al., Annales Pharmaceutiques Francaises, (2010), 68, 12-26.(3)V. Bonnet et al., Drug Discovery Today, (2015), 20(9), 1120-1126.(4)C. Gervaise et al., Biochimie, (2012), 94, 66-74.

Effect of Cyclodextrin Types and Co-Solvent on Solubility of a Poorly Water Soluble Drug.

The aim of the study was to investigate the solubility of piroxicam (Prx) depending on the inclusion complexation with various cyclodextrins (CDs) and on ethanol as a co-solvent. The phase-solubility method was applied to determine drug solubility in binary and ternary systems. The results showed that in systems consisting of the drug dissolved in ethanol–water mixtures, the drug solubility increased exponentially with a rising concentration of ethanol. The phase solubility measurements of the drug in aqueous solutions of CDs, β-CD and γ-CD exhibited diagrams of AL-type, whereas 2,6-dimethyl-β-CD revealed AP-type. The destabilizing effect of ethanol as a co-solvent was observed for all complexes regardless of the CD type, as a consequence of it the lowering of the complex formation constants. In systems with a higher concentration of ethanol, the drug solubility was increased in opposition to the decreasing complex formation constants. According to this study, the type of CDs played a more important role on the solubility of Prx, and the use of ethanol as a co-solvent exhibited no synergistic effect on the improvement of Prx solubility. The Prx solubility was increased again due to the better solubility in ethanol.

New strategies for the use of Linum usitatissimum cell factories for the production of bioactive compounds

In this work, suspension-cultured cells of Linum usitatissimum L. were used to evaluate the effect of two types of cyclodextrins, β-glucan and (Z)-3-hexenol separately or in combination on phytosterol and tocopherol production. Suspension-cultured cells of L. usitatissimum were able to produce high levels of phytosterols in the presence of 50 mM methylated-β-cyclodextrins (1325.96 ± 107.06 μg g dry weight−1) separately or in combination with β-glucan (1278.57 ± 190.10 μg g dry weight−1) or (Z)-3-hexenol (1507.88 ± 173.02 μg g dry weight−1), being cyclodextrins able to increase both the secretion and accumulation of phytosterols in the spent medium, whereas β-glucan and (Z)-3-hexenol themselves only increased its intracellular accumulation. Moreover, the phytosterol values found in the presence of hydroxypropylated-β-cyclodextrins were lower than those found in the presence of methylated-β-cyclodextrins in all cases studied. However, the results showed that the presence of methylated-β-cyclodextrins did not increase the tocopherols production and only an increase in tocopherol levels was observed when cells were elicited with 50 mM hydroxypropylated-β-cyclodextrins in combination with β-glucan (174 μg g dry weight−1) or (Z)-3-hexenol (257 μg g dry weight−1). Since the levels of tocopherol produced in the combined treatment were higher than the sum of the individual treatments, a synergistic effect between both elicitors was assumed.To sum up, flax cell cultures elicited with cyclodextrins alone or in combination with β-glucan or (Z)-3-hexenol were able produce phytosterols and tocopherols, and therefore, these elicited suspension-cultured cells of L. usitatissimum can provide an alternative system, which is at the same time more sustainable, economical and ecological for their production.

Cyclodextrin polymers for ibuprofen extraction in aqueous solution: recovery, separation, and characterization

Novel cyclodextrin polymers prepared by using citric acid as cross-linked agent were employed for removal of ibuprofen from aqueous solution; five insoluble cyclodextrin polymers with different cyclodextrin types were used. Adsorption tests were carried out, with experimental apparatus consisting of a continuous up flow column. Results of adsorption experiments showed that these polymers exhibited high adsorption capacities toward ibuprofen. Studies concerning the effect of several operating variables (i.e. the effects of contact time, ibuprofen concentration, and mass of adsorbent, pH, and ionic strength) are presented and discussed. Moreover, the extraction of ibuprofen has been studied alone and in a mixture of two pharmaceuticals, and the extraction mechanism was investigated by using numerous methods of characterization.