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Sample records for beta cyclodextrin inclusion

  1. Alpha- and Beta-Cyclodextrin Inclusion Complexes with 5-Fluorouracil: Characterization and Cytotoxic Activity Evaluation

    Directory of Open Access Journals (Sweden)

    Cristina Di Donato

    2016-12-01

    Full Text Available Cyclodextrins are natural macrocyclic oligosaccharides able to form inclusion complexes with a wide variety of guests, affecting their physicochemical and pharmaceutical properties. In order to obtain an improvement of the bioavailability and solubility of 5-fluorouracil, a pyrimidine analogue used as chemotherapeutic agent in the treatment of the colon, liver, and stomac cancers, the drug was complexed with alpha- and beta-cyclodextrin. The inclusion complexes were prepared in the solid state by kneading method and characterized by Fourier transform-infrared (FT-IR spectroscopy and X-ray powder diffractometry. In solution, the 1:1 stoichiometry for all the inclusion complexes was established by the Job plot method and the binding constants were determined at different pHs by UV-VIS titration. Furthermore, the cytotoxic activity of 5-fluorouracil and its complexation products were evaluated using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay on MCF-7 (breast cancer cell line, Hep G2 (hepatocyte carcinoma cell line, Caco-2 (colon adenocarcinoma cell line, and A-549 (alveolar basal epithelial carcinoma cell line. The results showed that both inclusion complexes increased the 5-fluorouracil capability of inhibiting cell growth. In particular, 5-fluorouracil complexed with beta-cyclodextrin had the highest cytotoxic activity on MCF-7; with alpha-cyclodextrin the highest cytotoxic activity was observed on A-549. The IC50 values were equal to 31 and 73 µM at 72 h, respectively. Our results underline the possibility of using these inclusion complexes in pharmaceutical formulations for improving 5-fluorouracil therapeutic efficacy.

  2. NMR spectroscopic characterization of {beta}-cyclodextrin inclusion complex with vanillin

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    Pirnau, Adrian; Bogdan, Mircea; Floare, Calin G, E-mail: adrian.pirnau@itim-cj.r [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)

    2009-08-01

    The inclusion of vanillin by {beta}-cyclodextrin was investigated by {sup 1}H NMR. The continuous variation technique was used to evidence the formation of soluble 1:1 complex in aqueous solution. The association constant of vanillin with {beta}-cyclodextrin has been obtained at 298 K by fitting the experimental chemical shifts differences, {Delta}{delta}{sub obs} {delta}{sub free} - {delta}{sub obs} of the observed guest and host protons, with a non-linear regression method. Besides the effective association constant, the fitting procedure allows a precise determination of all chemical shift parameters characterizing the pure complex. They can by used for an analysis of the geometry of the molecular complex in solution.

  3. Structural characterization of inclusion complex of hesperidin methyl chalcone and hydroxypropyl-beta-cyclodextrin

    International Nuclear Information System (INIS)

    Li, Y.; Li, F.; Chen, X.; Shen, W.

    2016-01-01

    Hesperidin methyl chalcone (HMC) was a semisynthetic derivative of hesperidin, which owned antiviral and antimicrobial activities. Owing these properties, it can be applied in pharmaceutical industry. However low stability had become a barrier to its application. In order to overcome this problem, an inclusion complex of hesperidin methyl chalcone and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) were prepared by freeze-drying, using some analytical techniques to characterize the inclusion complex, including ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The results of these analytical techniques indicated that the hesperidin methyl chalcone has been dispersed completely in the HP-beta-CD without a new compound formed, but entrapped inside the cavity of HP-beta-CD. (author)

  4. Characterization of the inclusion complex ropivacaine: {beta}-cyclodextrin; Caracterizacao do complexo de inclusso ropivacaina: {beta}-ciclodextrina

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    Fraceto, Leonardo Fernandes [Universidade Estadual Paulista Julio de Mesquita Filho, Sorocaba, SP (Brazil). Dept. de Engenharia Ambiental]. E-mail: leonardo@sorocaba.unesp.br; Goncalves, Marcos Moises [Universidade de Sorocaba, SP (Brazil); Moraes, Carolina Morales; Araujo, Daniele Ribeiro de; Zanella, Luciana; Paula, Eneida de [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Biologia. Dept. de Bioquimica; Pertinhez, Thelma de Aguiar [Universidade de Parma (Italy). Dept. de Medicina Experimental

    2007-09-15

    Ropivacaine (RVC) is a widely used local anesthetic. The complexation of RVC with {beta}-cyclodextrin ({beta}-CD) is of great interest for the development of more efficient local anesthetic formulations. The present work focuses on the characterization of the RVC:{beta}-CD complex by nuclear magnetic resonance (NMR). The stoichiometry of the complex is 1:2 RVC:{beta}-CD. DOSY-NMR shows that the association constant is 55.5 M{sup -1}. Longitudinal relaxation time results show that RVC changes its mobility in the presence of {beta}-CD. This study is focused on the physicochemical characterization of inclusion complexes that are potentials options for pain treatment. (author)

  5. Use of hydroxypropyl-beta-cyclodextrin ad polymer matrix for formation of inclusion complex with drug nifedipine

    International Nuclear Information System (INIS)

    Carneiro, Elisa F.; Araujo, Marcia V.G. de; Barbosa, Ronilson V.; Silva, Caroline W.P. da; Barisson, Andersson; Zawadzki, Sonia F.; Andrade, George Ricardo S.; Costa Junior, Nivan B. da

    2009-01-01

    In this work it was prepared and characterized an inclusion complex between the polymeric matrix hydroxypropyl-beta cyclodextrin and nifedipine, a hydrophobic drug calcium antagonistic, used for the cardiovascular diseases treatment. The study of the phase- solubility diagram showed an increase of the aqueous solubility of the drug after inclusion, was observed and The differential scanning calorimetry analysis did not show the melting point temperature of the drug in the formed complex. This fact is considered as an evidence of the encapsulation process. 1 H NMR studies suggested that the non-aromatic ring of the nifedipine would be inserted in the cavity of the hydroxypropyl-beta-cyclodextrin.This orientation was also proposed by the used molecular modelling methods. (author)

  6. Electronic structure and driving forces in {beta}-cyclodextrin: Diclofenac inclusion complexes

    Energy Technology Data Exchange (ETDEWEB)

    Bogdan, Diana [National Institute for Research and Development of Isotopic and Molecular Technologies, Donath street 71-103, 400293 Cluj-Napoca (Romania); Morari, C. [National Institute for Research and Development of Isotopic and Molecular Technologies, Donath street 71-103, 400293 Cluj-Napoca (Romania)]. E-mail: cristim@s3.itim-cj.ro

    2007-07-02

    We investigate the geometry and electronic structure for complexes of {beta}-cyclodextrin with diclofenac using DFT calculations. The effect of solvent is explicitly taken into account. This investigation allows us to draw meaningful conclusions upon the stability of the complex and the nature of the driving forces leading to the complexation process. In particular we emphasize the role of the water, by pointing out the changes in the solvent's electronic structure for different docking geometries.

  7. Investigating the inclusion properties of aromatic amino acids complexing beta-cyclodextrins in model peptides.

    Science.gov (United States)

    Caso, Jolanda Valentina; Russo, Luigi; Palmieri, Maddalena; Malgieri, Gaetano; Galdiero, Stefania; Falanga, Annarita; Isernia, Carla; Iacovino, Rosa

    2015-10-01

    Cyclodextrins are commonly used as complexing agents in biological, pharmaceutical, and industrial applications since they have an effect on protein thermal and proteolytic stability, refolding yields, solubility, and taste masking. β-cyclodextrins (β-CD), because of their cavity size are a perfectly suited complexing agent for many common guest moieties. In the case of peptide-cyclodextrin and protein-cyclodextrin host-guest complexes the aromatic amino acids are reported to be the principal responsible of the interaction. For these reasons, we have investigated the inclusion properties of nine designed tripeptides, obtained permuting the position of two L-alanines (Ala, A) with that of one L-tryptophan (Trp, W), L-phenylalanine (Phe, F), or L-tyrosine (Tyr, Y), respectively. Interestingly, the position of the aromatic side-chain in the sequence appears to modulate the β-CD:peptide binding constants, determined via UV-Vis and NMR spectroscopy, which in turn assumes values higher than those reported for the single amino acid. The tripeptides containing a tyrosine showed the highest binding constants, with the central position in the Ac-AYA-NH2 peptide becoming the most favorite for the interaction. A combined NMR and Molecular Docking approach permitted to build detailed complex models, highlighting the stabilizing interactions of the neighboring amino acids backbone atoms with the upper rim of the β-CD.

  8. Characterization of beta-cyclodextrin inclusion complexes containing an essential oil component.

    Science.gov (United States)

    Abarca, Romina L; Rodríguez, Francisco J; Guarda, Abel; Galotto, María J; Bruna, Julio E

    2016-04-01

    An important issue in food technology is that antimicrobial compounds can be used for various applications, such as the development of antimicrobial active packaging materials. Yet most antimicrobial compounds are volatile and require protection. In the present study, the inclusion complexes of 2-nonanone (2-NN) with β-cyclodextrin (β-CD), were prepared by a co-precipitation method. Entrapment efficiency (EE), thermal analysis (DSC and TGA), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), sorption isotherms and antifungal activity were evaluated for the characterization of the inclusion complex (β-CD:2-NN). A higher EE was obtained (34.8%) for the inclusion complex 1:0.5 than for other molar rates. Both DSC and TGA of the inclusion complexes showed the presence of endothermic peaks between 80 °C and 150 °C, attributed to a complexation phenomenon. Antimicrobial tests for mycelial growth reduction under atmospheric conditions proved the fungistatic behaviour of the inclusion complexes against Botrytis cinerea. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Thermodynamics and structure of inclusion compounds of tauro- and glyco-conjugated bile salts and beta-cyclodextrin

    DEFF Research Database (Denmark)

    Holm, Rene; Shi, Wei; Andersen Hartvig, Rune

    2009-01-01

    The interaction between natural beta-cyclodextrin and bile salts common in rat, dog and man, taurocholate, tauro-beta-muricholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate and glycochenodeoxycholate, was studied using isothermal titration calorimetry, and the str......The interaction between natural beta-cyclodextrin and bile salts common in rat, dog and man, taurocholate, tauro-beta-muricholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate and glycochenodeoxycholate, was studied using isothermal titration calorimetry......, and the structural differences in the interaction were investigated by H-1-ROESY NMR and molecular modeling. The beta-cyclodextrin was selected based upon its frequent use in preformulation and drug formulation as oral excipients for the solubilization of drug substances with low aqueous solubility. All...

  10. Flourimetric and prototropic studies on the inclusion complexation of 2-amino and 4-aminodiphenyl ethers with {beta}-cyclodextrin: Unusual behavior of 4-aminodiphenyl ether

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    Enoch, Israel V. Muthu Vijayan [Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu (India); Swaminathan, Meenakshisundaram [Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu (India)], E-mail: chemsam@yahoo.com

    2007-12-15

    The fluorescence characteristics of diphenyl ether (DPE), 2-aminodiphenyl ether (2ADPE) and 4-aminodiphenyl ether (4ADPE) and prototropic behavior of 2ADPE and 4ADPE on inclusion complexation with {beta}-cyclodextrin have been investigated. DPE forms 1:1 complex whereas 2ADPE and 4ADPE form 1:2 complex with {beta}-CDx. The fluorimetric and prototropic behaviors of 4ADPE in {beta}-CDx are different from those in aqueous solution. The dual fluorescence of 4ADPE in {beta}-CDx is found to be due to twisted intramolecular charge transfer (TICT) character induced by inclusion complexation. The two equilibria viz. monocation{r_reversible}monocation solvent exciplex{r_reversible}neutral reported for 4ADPE in aqueous solution are not observed in presence of {beta}-CDx. The ground and excited state pK{sub a} values for monocation-neutral equilibrium of 2ADPE and 4ADPE have been reported.

  11. Synthesis of molecular imprinted beta cyclodextrins oligomers in water

    DEFF Research Database (Denmark)

    Yu, Donghong; Nielsen, Anne Louise; Bach, Lone

    2003-01-01

    compounds in aqueous solution and, therefore, molecular imprinting of cyclodextrins polymers in aqueous solution is of great interest. In this paper, molecular imprinting of beta cyclodextrins has been performed in water by use of diiodobenzene as template and epichlorohydrin as a crosslinker. Inclusion...

  12. Preparation and physico-chemical characterization of inclusion complexes between local anesthetics and hydroxypropyl-{beta}-cyclodextrin; Preparacao e caracterizacao fisico-quimica de complexos de inclusao entre anestesicos locais e hidroxipropil-{beta}-ciclodextrina

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    Moraes, Carolina Morales; Abrami, Priscila; Goncalves, Marcos Moises; Andreo Filho, Newton [Universidade de Sorocaba, SP (Brazil); Fernandes, Sergio Antonio; Paula, Eneida de [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Biologia. Dept. de Bioquimica; Fraceto, Leonardo Fernandes [UNESP, Sorocaba, SP (Brazil). Dept. de Engenharia Ambiental]. E-mail: leonardo@sorocaba.unesp.br

    2007-07-15

    S(-) Bupivacaine (S(-)BVC) and Lidocaine (LDC) are widely used local anesthetics (LA). Hydroxypropyl {beta}-cyclodextrin (HP-{beta}-CD) is used as a drug-carrier system. The aim of this work was to characterize inclusion complexes between LA and HP-{beta}-CD. The affinity constants determined at different pHs show favourable complexation. The release kinetics experiments showed that S(-)BVC and LDC changed the released profiles in the presence of HP-{beta}-CD. Nuclear magnetic resonance experiments gave information about the interaction between LA and the cyclodextrin cavity. This study focused on the physicochemical characterization of drug-delivery formulations that come out as potentially new therapeutic options for pain treatment. (author)

  13. Inclusion complexes of azadirachtin with native and methylated cyclodextrins: solubilization and binding ability.

    Science.gov (United States)

    Liu, Yu; Chen, Guo-Song; Chen, Yong; Lin, Jun

    2005-06-02

    The inclusion complexation behavior of azadirachtin with several cyclodextrins and their methylated derivatives has been investigated in both solution and the solid state by means of XRD, TG-DTA, DSC, NMR, and UV-vis spectroscopy. The results show that the water solubility of azadirachtin was obviously increased after resulting inclusion complex with cyclodextrins. Typically, beta-cyclodextrin (beta-CD), dimethyl-beta-cyclodextrin (DMbetaCD), permethyl-beta-cyclodextrin (TMbetaCD), and hydroxypropyl-beta-cyclodextrin (HPbetaCD) are found to be able to solubilize azadirachtin to high levels up to 2.7, 1.3, 3.5, and 1.6 mg/mL (calculated as azadirachtin), respectively. This satisfactory water solubility and high thermal stability of the cyclodextrin-azadirachtin complexes, will be potentially useful for their application as herbal medicine or healthcare products.

  14. Inclusion complexation of tetrabutylammonium iodide by cyclodextrins

    Indian Academy of Sciences (India)

    Biswajit Datta

    Host-guest inclusion complex of an ionic solid (tetrabutyl ammonium iodide) with α- and β- cyclodextrin has been ... tions.2 CDs are cyclic oligomer of α-D-glucose having numerous of ... of locating at the interface of two phases (liquid–liquid.

  15. Biosynthesis of ketomycin. (II) biomimetic model for beta-lactamase catalysis: host-guest interactions in cyclodextrin-penicillin inclusion complex

    International Nuclear Information System (INIS)

    Mak, H.W.

    1986-01-01

    The antibiotic ketomycin is formed from shikimic acid via chorismic acid and prephenic acid. Phenylalanine and 2',5'-dihydrophenylalanine derived from shikimic acid are not intermediates in the biosynthesis. Degradation of ketomycin derived from [1,6- 14 C]shikimic acid showed that prephenic acid is converted into ketomycin with stereospecific discrimination between the two enantiotopic edges of the ring, the pro-S-R edge giving rise to the C-2', C-3' side of the cyclohexane ring of ketomycin. The resistance of pathogenic bacteria to the action of β-lactam antibiotics is mainly ascribed to their ability to produce β-lactamase to cleave the β-lactam ring. It is essential to understand the molecular nature of β-lactamase-penicillin recognition for designing and formulating more effective β-lactam antibiotics. A biomimetic study of β-lactamase is therefore initiated. To meet the requirements of hydrophobic and serine protease characteristics of β-lactamase, α-cyclodextrin is chosen as a biomimetic model for β-lactamase. The structural specificity and the chemical dynamics of α-cyclodextrin-phenoxymethyl penicillin inclusion complex in solid state and in solution have been determined by IR and NMR spectroscopy. The spectral results strongly indicate that the phenyl portion of the phenoxymethyl penicillin forms a stable inclusion complex with the hydrophobic cavity of α-cyclodextrin in solution as well as in the solid state. Kinetic studies followed by 1 HNMR and HPLC analyses under alkaline condition have shown that the α-cyclodextrin mimics the catalytic function of serine of β-lactamase in the stereospecific hydrolysis of the β-lactam ring of phenoxymethyl penicillin

  16. Microcalorimetric and spectrographic studies on host-guest interactions of {alpha}-, {beta}-, {gamma}- and M{beta}-cyclodextrin with resveratrol

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui; Xu, Xiangyu; Liu, Min [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China); Sun, Dezhi, E-mail: sundezhisdz@163.com [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China); Li, Linwei, E-mail: lilinwei@lcu.edu.cn [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China)

    2010-10-20

    Thermal effects of inclusion processes of {alpha}-, {beta}-, {gamma}- and M{beta}-cyclodextrin with resveratrol (RES) in aqueous solutions were determined by isothermal titration calorimetry (ITC) with nanowatt sensitivity at the temperature of 298.15 K. Standard enthalpy changes, stoichiometry and equilibrium constants of the inclusion complexes were derived from the direct calorimetric data utilizing nonlinear simulation. The thermodynamic parameters were discussed in the light of weak interactions between the host and the guest molecules combining with UV spectral message. The results indicate that all of the complexes formed in the aqueous solutions are in 1:1 stoichiometry. The binding processes of {alpha}-, {beta}- and M{beta}-cyclodextrin with the guest are mainly driven by enthalpy, while that of {gamma}-cyclodextrin with the drug is driven by both enthalpy and entropy.

  17. Determination of binding constants of cyclodextrin inclusion complexes with amino acids and dipeptides by potentiometric titration.

    Science.gov (United States)

    Kahle, Claudia; Holzgrabe, Ulrike

    2004-10-01

    Cyclodextrins are well known for their ability to separate enantiomers of drugs, natural products, and other chiral substances using HPLC, GC, or CE. The resolution of the enantiomers is due to the formation of diastereomeric complexes between the cyclodextrin and the pairs of enantiomers. The aim of this study was to determine the binding constants of the complexes between alpha- and beta-cyclodextrin and the enantiomers of a series of aliphatic and aromatic amino acids, and dipeptides, using a potentiometric titration method. The results of this method are compared to other methods, and correlated to findings in cyclodextrin-modified capillary electrophoresis and possible complex structures. Potentiometric titration was found to be an appropriate tool to determine the binding constants of cyclodextrin inclusion complexes.

  18. Spectrofluorimetric determination of stoichiometry and association constants of the complexes of harmane and harmine with beta-cyclodextrin and chemically modified beta-cyclodextrins.

    Science.gov (United States)

    Martín, L; León, A; Olives, A I; Del Castillo, B; Martín, M A

    2003-06-13

    The association characteristics of the inclusion complexes of the beta-carboline alkaloids harmane and harmine with beta-cyclodextrin (beta-CD) and chemically modified beta-cyclodextrins such as hydroxypropyl-beta-cyclodextrin (HPbeta-CD), 2,3-di-O-methyl-beta-cyclodextrin (DMbeta-CD) and 2,3,6-tri-O-methyl-beta-cyclodextrin (TMbeta-CD) are described. The association constants vary from 112 for harmine/DMbeta-CD to 418 for harmane/HPbeta-CD. The magnitude of the interactions between the host and the guest molecules depends on the chemical and geometrical characteristics of the guest molecules and therefore the association constants vary for the different cyclodextrin complexes. The steric hindrance is higher in the case of harmine due to the presence of methoxy group on the beta-carboline ring. The association obtained for the harmane complexes is stronger than the one observed for harmine complexes except in the case of harmine/TMbeta-CD. Important differences in the association constants were observed depending on the experimental variable used in the calculations (absolute value of fluorescence intensity or the ratio between the fluorescence intensities corresponding to the neutral and cationic forms). When fluorescence intensity values were considered, the association constants were higher than when the ratio of the emission intensity for the cationic and neutral species was used. These differences are a consequence of the co-existence of acid-base equilibria in the ground and in excited states together with the complexation equilibria. The existence of a proton transfer reaction in the excited states of harmane or harmine implies the need for the experimental dialysis procedure for separation of the complexes from free harmane or harmine. Such methodology allows quantitative results for stoichiometry determinations to be obtained, which show the existence of both 1:1 and 1:2 beta-carboline alkaloid:CD complexes with different solubility properties.

  19. Influence of the substitution of {beta}-cyclodextrins by cationic groups on the complexation of organic anions

    Energy Technology Data Exchange (ETDEWEB)

    Hbaieb, S. [U.R. Physico-Chimie des Materiaux Solides, Faculte des Sciences de Tunis, Manar II, 2092 Tunis (Tunisia)], E-mail: Souhairabouchaira@yahoo.fr; Kalfat, R. [U.R. Physico-Chimie des Materiaux Solides, Faculte des Sciences de Tunis, Manar II, 2092 Tunis (Tunisia); Chevalier, Y. [Laboratoire d' Automatique et de Genie des Procedes (LAGEP), UMR 5007 CNRS-Universite Claude Bernard Lyon 1, 69622 Villeurbanne (France)], E-mail: chevalier@lagep.univ-lyon1.fr; Amdouni, N. [U.R. Physico-Chimie des Materiaux Solides, Faculte des Sciences de Tunis, Manar II, 2092 Tunis (Tunisia); Parrot-Lopez, H. [Institut de Chimie et Biochimie Moleculaires et Supramoleculaires (ICBMS), UMR 5246 CNRS-Universite Claude Bernard Lyon 1, 69622 Villeurbanne (France)], E-mail: helene.parrot@univ-lyon1.fr

    2008-07-01

    The inclusion complexation of the organic anion, dansyl-acid, by cationic derivatives of {beta}-cyclodextrin has been investigated. A series of cationic {beta}-cyclodextrins with various positive charge has been synthesized by selective functionalization of the primary face of {beta}-cyclodextrin with amino groups. The complexes were of the 1:1 stoichiometry; the stability constants (K{sub 11}) have been evaluated from UV-Vis measurements by application of the Benesi-Hildebrand equation. The presence of amino groups increased the complexation ability. {beta}-cyclodextrin fully substituted at the primary face with amino groups showed the strongest inclusion binding ability towards the dansyl-acid guest. The enhanced complexation for anions was ascribed to the cationic amino groups. A simple thermodynamic model of the electrostatic contribution to the complexation is presented.

  20. Modification of polyethylene films by radiation grafting of glycidyl methacrylate and immobilization of {beta}-cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Nava-Ortiz, C.A.B. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Burillo, G. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico)], E-mail: burillo@nucleares.unam.mx; Bucio, E. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Alvarez-Lorenzo, C. [Departamento de Farmacia y Tecnologia Farmaceutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

    2009-01-15

    Glycidyl methacrylate was grafted onto polyethylene films using a preirradiation method with {gamma} rays. The effect of absorbed dose, monomer concentration, and reaction time on the degree of grafting was determined. The grafted samples were verified by FTIR-ATR spectroscopy. {beta}-Cyclodextrin was immobilized onto polypropylene modified with glycidyl methacrylate, and the ability of the cavities of {beta}-cyclodextrin to form inclusion complexes was demonstrated using the typically organic compound approach with m-toluic acid (3-MBA) as a probe.

  1. SYNTHESIS AND EVALUATION OF β-CYCLODEXTRIN-EPICHLOROHYDRIN INCLUSION COMPLEX AS A PHARMACEUTICAL EXCIPIENT

    Directory of Open Access Journals (Sweden)

    K. N. Poornima

    2015-05-01

    Full Text Available A water soluble Beta-cyclodextrin-epichlorohydrin complex (Beta-CDEPI was synthesized by one-step condensation polymerization. Drug- Beta-CDEPI inclusion complexes were prepared and characterized. Inclusion complexes prepared using lyophilization technique was used to formulate orodispersible tablets. Compatibility studies showed no interaction and characterization proved substantial inclusion complex formation. Drug content was found between 97-99%. In-vitro disintegration time was found to be less than 3 minutes and all the formulations showed complete drug release of 100% within 15 minutes. The formulations were found to be stable for a period of 6 months. Beta-CDEPI polymer enhances the solubility and thus effectively can be utilized to improve the aqueous solubility of poorly water soluble drugs.

  2. Preparation, characterization and in vitro evaluation of a new nucleotide analogue prodrug cyclodextrin inclusion complexes.

    Science.gov (United States)

    Diab, Roudayna; Jordheim, Lars P; Degobert, Ghania; Peyrottes, Suzanne; Périgaud, Christian; Dumontet, Charles; Fessi, Hatem

    2009-01-01

    Bis(tbutyl-S-acyl-2-thioethyl)-cytidine monophosophate is a new cytotoxic mononucleotide prodrug which have been developed to reverse the cellular resistance to nucleoside analogues. Unfortunately, its in vivo utilisation was hampered by its poor water solubility, raising the need of a molecular vector capable to mask its physicochemical characteristics although without affecting its cytotoxic activity. Hydroxypropyl-beta-cyclodextrin was used to prepare the prodrug inclusion complexes, allowing it to be solubilized in water and hence to be used for in vitro and in vivo experiments. A molar ratio of the cyclodextrin: prodrug of 3 was sufficient to obtain complete solubilization of the prodrug. The inclusion complex was characterized by differential scanning calorimetry, which revealed the disappearance of the melting peak of the prodrug suggesting the formation of inclusion complex. Proton Nuclear Magnetic Resonance spectroscopy provided a definitive proof of the inclusion complex formation, which was evidenced by the large chemical shift displacements observed for protons located in the interior of the hydrophobic cyclodextrin cavity. The complex retained its cytotoxic activity as shown by in vitro cell survival assays on murine leukemia cells. These results provided a basis for potential therapeutic applications of co-formulation of this new nucleotide analogue with hydroxypropyl-beta-CD in cancer therapy.

  3. Preparation, characterization and in vitro dissolution study of Nitrazepam: Cyclodextrin inclusion complex

    OpenAIRE

    Patel, J. S.; Patel, R. P.

    2012-01-01

    The objectives of this research were to prepare and characterize inclusion complexes of Nitrazepam with Hydroxypropyl-β-cyclodextrin (HPβCD) and Sulfobutyl ether β-cyclodextrin (SBEβCD) to study the effect of complexation on the dissolution rate of Nitrazepam, a water-insoluble drug. The phase solubility profile of Nitrazepam with Hydroxypropyl- β-cyclodextrin and Sulfobutyl ether β-cyclodextrin was an AP-type, indicating the formation of 2:1 stoichiometric inclusion complexes. Gibbs free ene...

  4. Compatibility of hydroxypropyl-{beta}-cyclodextrin with algal toxicity bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Fai, Patricia Bi; Grant, Alastair [School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom); Reid, Brian J. [School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom)], E-mail: b.reid@uea.ac.uk

    2009-01-15

    Numerous reports have indicated that hydrophobic organic compound bioaccessibility in sediment and soil can be determined by extraction using aqueous hydroxypropyl-{beta}-cyclodextrin (HPCD) solutions. This study establishes the compatibility of HPCD with Selenastrum capricornutum and assesses whether its presence influences the toxicity of reference toxicants. Algal growth inhibition (72 h) showed no significant (P > 0.05) difference at HPCD concentrations up to and including 20 mM. HPCD presence did not influence the toxicity of the inorganic reference toxicant (ZnSO{sub 4}), with IC50 values of 0.82 {mu}M and 0.85 {mu}M, in the presence and absence of HPCD (20 mM), respectively. However, HPCD presence (20 mM) reduced the toxicity of 2,4-dichlorophenol and the herbicides diuron and isoproturon. These reductions were attributed to inclusion complex formation between the toxicants and the HPCD cavity. Liberation of complexed toxicants, by sample manipulation prior to toxicity assessment, is proposed to provide a sensitive, high throughput, bioassay that reflects compound bioaccessibility. - Compatibility of the biomimetic HPCD extraction method with algal cell growth inhibition bioassays to assess toxicity of reference toxicants and environmental relevant herbicides.

  5. Computational study on the molecular inclusion of andrographolide by cyclodextrin

    Science.gov (United States)

    Zhou, Hongwei; Lai, Wai-Ping; Zhang, Zhiqiang; Li, Wai-Kee; Cheung, Hon-Yeung

    2009-03-01

    Due to the poor water solubility of andrographolide (andro), an inclusion technique has been developed to modify its physical and chemical properties so as to improve its bioavailability. In contrast with the immense experimental studies on the inclusion complexes of andro:cyclodextrin, no computational study has so far been carried out on this system. In this work, preliminary docking experiments with AutoDock were performed. Density Functional Theory (DFT) and Austin Model 1 (AM1) calculations upon the docking instances were applied to investigate the two possible modes of molecular inclusions between andro and x-cyclodextrin ( xCD, where x is α, β or γ). Atoms-in-Molecules (AIM) analysis based on the B3LYP/cc-pVDZ wavefunction was applied to verify the existence of the intermolecular hydrogen bonds. It was found that the most stable complex among the six possible inclusion complexes was the one formed between andro and βCD with andro's decalin ring moiety wrapped by CD at a ratio of 1:1. The hydrogen bonds between andro and CD were responsible for the stability of the inclusion complexes. The calculated data were found to be consistent with the experimental results. Thus, the results of this study can aid new drug design processes.

  6. Electrospinning of functional poly(methyl methacrylate) nanofibers containing cyclodextrin-menthol inclusion complexes

    Energy Technology Data Exchange (ETDEWEB)

    Uyar, Tamer; Besenbacher, Flemming [Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000, Aarhus C (Denmark); Nur, Yusuf; Hacaloglu, Jale [Department of Chemistry, Middle East Technical University, Ankara, 06530 (Turkey)], E-mail: tamer@inano.dk, E-mail: tamer@unam.bilkent.edu.tr

    2009-03-25

    Electrospinning of nanofibers with cyclodextrin inclusion complexes (CD-ICs) is particularly attractive since distinct properties can be obtained by combining the nanofibers with specific functions of the CD-ICs. Here we report on the electrospinning of poly(methyl methacrylate) (PMMA) nanofibers containing cyclodextrin-menthol inclusion complexes (CD-menthol-ICs). These CD-menthol-IC functionalized nanofibers were developed with the purpose of producing functional nanofibers that contain fragrances/flavors with high temperature stability, and menthol was used as a model fragrance/flavor material. The PMMA nanofibers were electrospun with CD-menthol-ICs using three type of CD: {alpha}-CD, {beta}-CD, and {gamma}-CD. Direct pyrolysis mass spectrometry (DP-MS) studies showed that the thermal evaporation of menthol occurred over a very high and a broad temperature range (100-355 deg. C) for PMMA/CDmenthol-IC nanowebs, demonstrating the complexation of menthol with the CD cavity and its high temperature stability. Furthermore, as the size of CD cavity increased in the order {alpha}-CD<{beta}-CD<{gamma}-CD, the thermal evolution of menthol shifted to higher temperatures, suggesting that the strength of interaction between menthol and the CD cavity is in the order {gamma}-CD>{beta}-CD>{alpha}-CD.

  7. The 2.0-A resolution structure of soybean beta-amylase complexed with alpha-cyclodextrin.

    Science.gov (United States)

    Mikami, B; Hehre, E J; Sato, M; Katsube, Y; Hirose, M; Morita, Y; Sacchettini, J C

    1993-07-13

    New crystallographic findings are presented which offer a deeper understanding of the structure and functioning of beta-amylase, the first known exo-type starch-hydrolyzing enzyme. A refined three-dimensional structure of soybean beta-amylase, complexed with the inhibitor alpha-cyclodextrin, has been determined at 2.0-A resolution with a conventional R-value of 17.5%. The model contains 491 amino acid residues, 319 water molecules, 1 sulfate ion, and 1 alpha-cyclodextrin molecule. The protein consists of a core with an (alpha/beta)8 supersecondary structure, plus a smaller globular region formed by long loops (L3, L4, and L5) extending from beta-strands beta 3, beta 4, and beta 5. Between the two regions is a cleft that opens into a pocket whose floor contains the postulated catalytic center near the carboxyl group of Glu 186. The annular alpha-cyclodextrin binds in (and partly projects from) the cleft with its glucosyl O-2/O-3 face abutting the (alpha/beta)8 side and with its alpha-D(1 --> 4) glucosidic linkage progression running clockwise as viewed from that side. The ligand does not bind deeply enough to interact with the carboxyl group of Glu 186. Rather, it occupies most of the cleft entrance, strongly suggesting that alpha-cyclodextrin inhibits catalysis by blocking substrate access to the more deeply located reaction center. Of the various alpha-cyclodextrin interactions with protein residues in loops L4, L5, L6, and L7, most notable is the shallow inclusion complex formed with Leu 383 (in L7, on the core side of the cleft) through contacts of its methyl groups with the C-3 atoms of four of the ligand's D-glucopyranosyl residues. All six residues of the bound alpha-cyclodextrin are of 4C1 conformation and are joined by alpha-1,4 linkages with similar torsional angles to form a nearly symmetrical torus as reported for crystalline inclusion complexes with alpha-cyclodextrin. We envision a significant role for the methyl groups of Leu 383 at the cleft entrance

  8. Development of Buccal Patches for Delivery of Darifenacin from Beta-Cyclodextrin Complexes

    Directory of Open Access Journals (Sweden)

    Swati C. Jagdale

    2014-01-01

    Full Text Available Drug-cyclodextrin complexes improve aqueous solubility and dissolution rate of poorly water-soluble drugs. Solubilisation followed by buccal delivery of poorly water-soluble drugs can be advantageous for increasing drug absorption. Darifenacin is an antispasmodic used against urinary incontinence and specifically blocks M3 muscarinic acetylcholine receptors in smooth muscle. M3 receptors are mainly located in exocrine glands, smooth muscle and vascular endothelium. The oral absorption of darifenacin is poor owing to its low solubility. It also has poor bioavailability (15-19% due to a high rate of first-pass metabolism. Complexation with beta-cyclodextrin was carried out to enhance solubility. The best results were obtained by co-grinding in a 1:1 molar ratio of drug: β-cyclodextrin. The solid inclusion complexes were characterized by DSC, X-ray diffractometry and FTIR. Inclusion complexes showed higher dissolution rates than the pure drug. Controlledrelease mucoadhesive patches were prepared with two hydroxypropyl methylcellulose (HPMC polymers, K100M CR and K15. The patches were assessed for surface pH, folding endurance, swelling, mucoadhesive properties, in-vitro residence time, vapor transmission test and in-vitro (cellophane, egg membrane and exvivo (goat buccal mucosa release. Formulations Ha2 (2% HPMC K100M CR and Pa4 (4% HPMC K15 showed good mucoadhesive strength, in-vitro and exvivo residence times, with controlled release for 10 hours.

  9. Dual fluorescence of N-phenylanthranilic acid: Effect of solvents, pH and beta-cyclodextrin.

    Science.gov (United States)

    Rajendiran, N; Balasubramanian, T

    2007-11-01

    Spectral characteristics of N-phenylanthranilic acid (NPAA) have been studied in different solvents, pH and beta-cyclodextrin (beta-CD) and compared with anthranilic acid (2-aminobenzoic acid, 2ABA). In all solvents a dual fluorescence is observed in NPAA, whereas 2ABA gives single emission. Combining the results observed in the absorption, fluorescence emission and fluorescence excitation spectra, it is found that strong intramolecular hydrogen bonding (IHB) interactions present in NPAA molecule. The inclusion complex of NPAA with beta-CD is analysed by UV-vis, fluorimetry, FT-IR, (1)H NMR, scanning electron microscope and AM 1 method. The above spectral studies show that NPAA forms a 1:1 inclusion complex with beta-CD and COOH group present in the beta-CD cavity. A mechanism is proposed to explain the inclusion process.

  10. Study on inclusion interaction of piroxicam with β-cyclodextrin derivatives

    Science.gov (United States)

    Xiliang, Guo; Yu, Yang; Guoyan, Zhao; Guomei, Zhang; Jianbin, Chao; Shaomin, Shuang

    2003-12-01

    The inclusion behavior of piroxicam (PX) with β-cyclodextrin (β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), and carboxymethyl-β-cyclodextrin (CM-β-CD) was investigated by using steady-state fluorescence and nuclear magnetic resonance (NMR) technique. The various factors affecting the inclusion process were examined in detail. The remarkable fluorescence emission enhancement upon addition of CDs suggested that cyclodextrins (CDs) were most suitable for inclusion of the uncharged species of PX. The stoichiometry of the PX-CDs inclusion complexes was 1:1, except for β-CD where a 1:2 inclusion complex was formed. The formation constants showed the strongest inclusion capacity of β-CD. NMR showed the inclusion mode of PX with CDs.

  11. Inclusion complex of amiodarone hydrochloride with cyclodextrins: preparation, characterization and dissolution rate evaluation

    Directory of Open Access Journals (Sweden)

    Alexandre Machado Rubim

    2017-06-01

    Full Text Available ABSTRACT This study aimed to improve the water solubility of amiodarone hydrochloride (AMH via inclusion complexes with β-cyclodextrin, methyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin. Inclusion complexes were developed by physical mixture, coevaporation, spray-drying and freeze-drying. Solid state analysis was performed using X-ray powder diffraction, differential scanning calorimetry and scanning electronic microscopy. Thermodynamic studies demonstrate that the inclusion complexes of drug into different cyclodextrins were an exothermic process that occurred spontaneously. Water solubility and drug dissolution rates were significantly increased after the formation of inclusion complexes with the cyclodextrins evaluated in relation to the physical mixture and pure drug. The present study provides useful information for the potential application of complexation with amiodarone HCl. This may be a good strategy for the development of solid pharmaceutical dosage forms.

  12. Inclusion and Functionalization of Polymers with Cyclodextrins: Current Applications and Future Prospects

    Directory of Open Access Journals (Sweden)

    Christian Folch-Cano

    2014-09-01

    Full Text Available The numerous hydroxyl groups available in cyclodextrins are active sites that can form different types of linkages. They can be crosslinked with one another, or they can be derivatized to produce monomers that can form linear or branched networks. Moreover, they can form inclusion complexes with polymers and different substrates, modifying their physicochemical properties. This review shows the different applications using polymers with cyclodextrins, either by forming inclusion complexes, ternary complexes, networks, or molecularly imprinted polymers (MIPs. On one hand, the use of cyclodextrins enhances the properties of each polymer, and on the other the use of polymers decreases the amount of cyclodextrins required in different formulations. Both cyclodextrins and polymers contribute synergistically in several applications such as pharmacological, nutritional, environmental, and other industrial fields. The use of polymers based on cyclodextrins is a low cost easy to use potential tool with great future prospects.

  13. Enhancement of norfloxacin solubility via inclusion complexation with β-cyclodextrin and its derivative hydroxypropyl-β-cyclodextrin

    Directory of Open Access Journals (Sweden)

    Gabriel Onn Kit Loh

    2016-08-01

    Full Text Available The objectives of the study were to investigate the effects of β-cyclodextrin (βCD and hydroxypropyl-β-cyclodextrin (HPβCD on the solubility and dissolution rate of norfloxacin prepared using three different methods, at drug to cyclodextrin weight ratios of 1:1, 1:2, 1:4 and 1:8. All the methods increased the solubility and dissolution rate of norfloxacin via inclusion complexation with βCD and HPβCD. Norfloxacin was converted from crystalline to amorphous form through inclusion complexation. Solvent evaporation method was the most effective method in terms of norfloxacin solubilisation, while inclusion complex of HPβCD has higher solubility than βCD complex when prepared using the same procedure.

  14. Biodegradable films containing {alpha}-tocopherol/{beta}-cyclodextrin complex; Filmes biodegradaveis contendo {alpha}-tocoferol complexado em {beta}-ciclodextrina

    Energy Technology Data Exchange (ETDEWEB)

    Motta, Caroline; Martelli, Silvia M.; Soldi, Valdir, E-mail: vsoldi@qmc.ufsc.br [Lab. de Materiais Polimericos (POLIMAT), Dept. de Quimica, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil); Barreto, Pedro L.M. [Lab. de Reologia (REOLAB), Dept. de Ciencia e Tecnologia de Alimentos, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil)

    2011-07-01

    The growing environmental concern about pollution and the need to reduce dependence of plastic industry in relation to non-renewable resources has increased the interest of both researchers and industry in the use of biopolymers. In this work {beta}-cyclodextrin/{alpha}-tocopherol complexes were prepared and characterized. In order to obtain polymeric active biofilms, the {beta}-cyclodextrin/{alpha}-tocopherol complex was incorporated into a polymeric matrix of carboxymethylcellulose. The {beta}-cyclodextrin/{alpha}-tocopherol complex was characterized through of X-ray diffraction and thermogravimetric analysis. The physicochemical properties of the films incorporated with the complex were evaluated through mechanical and colorimetric analysis and moisture sorption isotherm. (author)

  15. Iodine K-edge EXAFS analysis of iodide ion-cyclodextrin inclusion complexes in aqueous solution

    International Nuclear Information System (INIS)

    Kaneko, T; Ueda, M; Nagamatsu, S; Konishi, T; Fujikawa, T; Mizumaki, M

    2009-01-01

    We study the structure of inclusion complexes of α-, β-, γ-cyclodextrin with mono-iodide ion in aqueous solution by means of iodine K-edge EXAFS spectroscopy. The analysis is based on the assumption that two kinds of iodide ions exist in KI-cyclodextrin aqueous solution i.e. hydrated mono-iodide ions and one-one mono-iodide-cyclodextrin inclusion complexes. In KI-α-cyclodextrin system, iodine K-edge EXAFS analyse show that the average coordination number of the oxygen atoms in water molecules in the first hydration shell decreases as the fraction of included ions increases. This result suggests that dehydration process accompanies the formation of the inclusion complex. This is not found in the case of β-cyclodextrin, indicating that in this case the iodide ions are included together with the whole first hydration shell.

  16. Characterization of the inclusion complex ropivacaine: β-cyclodextrin

    International Nuclear Information System (INIS)

    Fraceto, Leonardo Fernandes; Moraes, Carolina Morales; Araujo, Daniele Ribeiro de; Zanella, Luciana; Paula, Eneida de; Pertinhez, Thelma de Aguiar

    2007-01-01

    Ropivacaine (RVC) is a widely used local anesthetic. The complexation of RVC with β-cyclodextrin (β-CD) is of great interest for the development of more efficient local anesthetic formulations. The present work focuses on the characterization of the RVC:β-CD complex by nuclear magnetic resonance (NMR). The stoichiometry of the complex is 1:2 RVC:β-CD. DOSY-NMR shows that the association constant is 55.5 M -1 . Longitudinal relaxation time results show that RVC changes its mobility in the presence of β-CD. This study is focused on the physicochemical characterization of inclusion complexes that are potentials options for pain treatment. (author)

  17. Anti-aggregatory effect of cyclodextrins in the refolding process of recombinant growth hormones from Escherichia coli inclusion bodies

    DEFF Research Database (Denmark)

    Bajorunaite, Egle; Cirkovas, Andrejus; Radzevicius, Kostas

    2009-01-01

    Cyclodextrins with different ring size and ring substituents were tested for recombinant mink and porcine growth hormones aggregation suppression in the refolding process from Escherichia coli inclusion bodies. Methyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin show a positive effect...... on the aggregation suppression of both proteins. The influence of different methyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin concentrations on the renaturation yield of both growth hormones was investigated. Moreover, methyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin suppress not only folding...

  18. Preparation, characterization and in vitro dissolution study of Nitrazepam: Cyclodextrin inclusion complex

    Directory of Open Access Journals (Sweden)

    J S Patel

    2012-01-01

    Full Text Available The objectives of this research were to prepare and characterize inclusion complexes of Nitrazepam with Hydroxypropyl-β-cyclodextrin (HPβCD and Sulfobutyl ether β-cyclodextrin (SBEβCD to study the effect of complexation on the dissolution rate of Nitrazepam, a water-insoluble drug. The phase solubility profile of Nitrazepam with Hydroxypropyl- β-cyclodextrin and Sulfobutyl ether β-cyclodextrin was an AP-type, indicating the formation of 2:1 stoichiometric inclusion complexes. Gibbs free energy values were all negative, indicating the spontaneous nature Nitrazepam solubilization and their value decreased with increase in the cyclodextrin concentration, demonstrating that the reaction conditions became more favorable as the concentration of cyclodextrins increased. Complexes of Nitrazepam were prepared with cyclodextrin using various methods such as physical mixing, kneading, spray-drying and lyophilization. The complexes were characterized by Differential scanning calorimetry, Fourier-transform infrared, scanning electron microscopy and powder X-ray diffraction studies. These studies indicated that a complex prepared by lyophilization had successful inclusion of the Nitrazepam molecule into the cyclodextrin cavity. Complexation resulted in a marked improvement in the solubility and wettability of Nitrazepam. Among all the samples, a complex prepared with Sulfobutyl ether β-cyclodextrin by lyophilization had the greatest improvement in the in vitro rate of Nitrazepam dissolution. The mean dissolution time for Nitrazepam decreased significantly after preparing complexes. The similarity factor indicated a significant difference between the release profiles of Nitrazepam from complexes, physical mixtures and plain Nitrazepam. To conclude that, the tablets containing complexes prepared with Cyclodextrins had significant improvement in the release profile of Nitrazepam as compared to tablets containing Nitrazepam without cyclodextrin.

  19. Ion-exclusion chromatography with conductimetric detection of aliphatic carboxylic acids on a weakly acidic cation-exchange resin by elution with benzoic acid-beta-cyclodextrin.

    Science.gov (United States)

    Tanaka, Kazuhiko; Mori, Masanobu; Xu, Qun; Helaleh, Murad I H; Ikedo, Mikaru; Taoda, Hiroshi; Hu, Wenzhi; Hasebe, Kiyoshi; Fritz, James S; Haddad, Paul R

    2003-05-16

    In this study, an aqueous solution consisting of benzoic acid with low background conductivity and beta-cyclodextrin (beta-CD) of hydrophilic nature and the inclusion effect to benzoic acid were used as eluent for the ion-exclusion chromatographic separation of aliphatic carboxylic acids with different pKa values and hydrophobicity on a polymethacrylate-based weakly acidic cation-exchange resin in the H+ form. With increasing concentration of beta-cyclodextrin in the eluent, the retention times of the carboxylic acids decreased due to the increased hydrophilicity of the polymethacrylate-based cation-exchange resin surface from the adsorption of OH groups of beta-cyclodextrin. Moreover, the eluent background conductivity decreased with increasing concentration of beta-cyclodextrin in 1 mM benzoic acid, which could result in higher sensitivity for conductimetric detection. The ion-exclusion chromatographic separation of carboxylic acids with high resolution and sensitivity was accomplished successfully by elution with a 1 mM benzoic acid-10 mM cyclodextrin solution without chemical suppression.

  20. Study on vitamin K 3-cyclodextrin inclusion complex and analytical application

    Science.gov (United States)

    Zhenming, Dong; Xiuping, Liu; Guomei, Zhang; Shaomin, Shuang; Jinghao, Pan

    2003-07-01

    The inclusion interaction of the complexes between Vitamin K3 (VK3) and β-cyclodextrin (β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD) and sulfobutylether-β-cyclodextrin (SBE-β-CD) were studied by using steady-state fluorescence measurements. The various factors affecting the inclusion process were examined in detail. The formation constants and inclusion stoichiometry for VK3-CDs were determined. The results showed that the inclusion ability of β-CD and its derivatives was the order: SBE-β-CD>HP-β-CD>β-CD. The related inclusion mechanism is proposed to explain the inclusion process. A method of determining VK3 was established with the linear range was 2.5×10-6-5.0×10-4 M, and was used to determine the VK3 tablets. The recoveries were in the range of 97.52-103.5%. The results were satisfactory.

  1. Interaction between bradykinin potentiating nonapeptide (BPP9a) and {beta}-cyclodextrin: A structural and thermodynamic study

    Energy Technology Data Exchange (ETDEWEB)

    Lula, Ivana; De Sousa, Frederico B. [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901, Belo Horizonte, MG (Brazil); Denadai, Angelo M.L. [Centro Federal de Educacao Tecnologica de Minas Gerais, CEFET-MG, Campus VII, 35.183-006, Timoteo, MG (Brazil); Ferreira de Lima, Guilherme; Duarte, Helio Anderson [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901, Belo Horizonte, MG (Brazil); Mares Guia, Thiago R. dos [Departamento de Bioquimica e Imunologia, ICB, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG (Brazil); Faljoni-Alario, Adelaide [Departamento de Bioquimica, Instituto de Quimica, Universidade de Sao Paulo, 05508-900, Sao Paulo, SP (Brazil); Santoro, Marcelo M. [Departamento de Bioquimica e Imunologia, ICB, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG (Brazil); Camargo, Antonio C.M. de [Center for Applied Toxinology CAT-CEPID, Laboratorio Especial de Toxicologia Aplicada, Instituto Butantan, 05503-900, Sao Paulo, SP (Brazil); Santos, Robson A.S. dos [Departamento de Fisiologia e Biofisica, ICB, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG (Brazil); and others

    2012-02-01

    Herein, we demonstrate the physical and chemical characterizations of the supramolecular complex formed between {beta}-cyclodextrin ({beta}CD) and bradykinin potentiating nonapeptide (BPP9a), an endogenous toxin found in Bothrops jararaca. Circular dichroism results indicate a conformational change in the BPP9a secondary structure upon its complexation with {beta}CD. Nuclear magnetic resonance results, mainly from NOESY experiments, and theoretical calculations showed a favorable interaction between the tryptophan residue of BPP9a and the {beta}CD cavity. Thermodynamic inclusion parameters were investigated by isothermal titration calorimetry, demonstrating that {beta}CD/BPP9a complex formation is an exothermic process that results in a reduction in entropy. Additionally, in vitro degradation study of BPP9a against trypsin (37 Degree-Sign C, pH 7.2) showed higher stability of peptide in presence of {beta}CD. This {beta}CD/BPP9a complex, which presents new chemical properties arising from the peptide inclusion process, may be useful as an antihypertensive drug in oral pharmaceutical formulations. Highlights: Black-Right-Pointing-Pointer Cd and NMR showed evidences for the existence of more than one structure in solution. Black-Right-Pointing-Pointer Complexation with {beta}CD reduces the conformational rigidity of the peptide. Black-Right-Pointing-Pointer {beta}CD cavity recognize Trp and/or Pro segments of BPP9a. Black-Right-Pointing-Pointer Interactions involving disaggregation of BPP9a assemblies and binding with {beta}CD.

  2. Cyclodextrin-facilitated bioconversion of 17 beta-estradiol by a phenoloxidase from Mucuna pruriens cell cultures

    NARCIS (Netherlands)

    Woerdenbag, H.J.; Pras, N.; Frijlink, H.W.; Lerk, C.F.; Malingré, T.M.

    1990-01-01

    After complexation with beta-cyclodextrin, the phenolic steroid 17 beta-estradiol could be ortho-hydroxylated into a catechol, mainly 4-hydroxyestradiol, by a phenoloxidase from in vitro grown cells of Mucuna pruriens. By complexation with beta-cyclodextrin the solubility of the steroid increased

  3. Studies on the Inclusion Complexes of Daidzein with β-Cyclodextrin and Derivatives

    Directory of Open Access Journals (Sweden)

    Shujing Li

    2017-12-01

    Full Text Available The inclusion complexes between daidzein and three cyclodextrins (CDs, namely β-cyclodextrin (β-CD, methyl-β-cyclodextrin (Me-β-CD, DS = 12.5 and (2-hydroxypropyl-β-cyclodextrin (HP-β-CD, DS = 4.2 were prepared. The effects of the inclusion behavior of daidzein with three kinds of cyclodextrins were investigated in both solution and solid state by methods of phase-solubility, XRD, DSC, SEM, 1H-NMR and 2D ROESY methods. Furthermore, the antioxidant activities of daidzein and daidzein-CDs inclusion complexes were determined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH method. The results showed that daidzein formed a 1:1 stoichiometric inclusion complex with β-CD, Me-β-CD and HP-β-CD. The results also showed that the solubility of daidzein was improved after encapsulating by CDs. 1H-NMR and 2D ROESY analyses show that the B ring of daidzein was the part of the molecule that was most likely inserted into the cavity of CDs, thus forming an inclusion complex. Antioxidant activity studies showed that the antioxidant performance of the inclusion complexes was enhanced in comparison to the native daidzein. It could be a potentially promising way to develop a new formulation of daidzein for herbal medicine or healthcare products.

  4. Cyclodextrins and their pharmaceutical applications.

    Science.gov (United States)

    Loftsson, Thorsteinn; Duchêne, Dominique

    2007-02-01

    Cyclodextrins were first described by Villiers in 1891. Schardinger laid the foundation of the cyclodextrin chemistry in 1903-1911 and identified both alpha- and beta-cyclodextrin. In the 1930s, Freudenberg identified gamma-cyclodextrin and suggested that larger cyclodextrins could exist. Freudenberg and co-workers showed that cyclodextrins were cyclic oligosaccharides formed by glucose units and somewhat later Cramer and co-workers described their ability to form inclusion complexes. By the early 1950s the basic physicochemical characteristics of cyclodextrins had been discovered, including their ability to solubilize and stabilize drugs. The first cyclodextrin-related patent was issued in 1953 to Freudenberg, Cramer and Plieninger. However, pure cyclodextrins that were suitable for pharmaceutical applications did not come available until about 25 years later and at the same time the first cyclodextrin-containing pharmaceutical product was marketed in Japan. Later cyclodextrin-containing products appeared on the European market and in 1997 also in the US. New cyclodextrin-based technologies are constantly being developed and, thus, 100 years after their discovery cyclodextrins are still regarded as novel excipients of unexplored potential.

  5. Molecular printboards: monolayers of beta-cyclodextrins on silicon oxide surfaces.

    Science.gov (United States)

    Onclin, Steffen; Mulder, Alart; Huskens, Jurriaan; Ravoo, Bart Jan; Reinhoudt, David N

    2004-06-22

    Monolayers of beta-cyclodextrin host molecules have been prepared on SiO2 surfaces. An ordered and stable cyano-terminated monolayer was modified in three consecutive surface reactions. First, the cyanide groups were reduced to their corresponding free amines using Red Al as a reducing agent. Second, 1,4-phenylene diisothiocyanate was used to react with the amine monolayer where it acts as a linking molecule, exposing isothiocyanates that can be derivatized further. Finally, per-6-amino beta-cyclodextrin was reacted with these isothiocyanate functions to yield a monolayer exposing beta-cyclodextrin. All monolayers were characterized by contact angle measurements, ellipsometric thickness measurements, Brewster angle Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry, which indicate the formation of a densely packed cyclodextrin surface. It was demonstrated that the beta-cyclodextrin monolayer could bind suitable guest molecules in a reversible manner. A fluorescent molecule (1), equipped with two adamantyl groups for complexation, was adsorbed onto the host monolayer from solution to form a monolayer of guest molecules. Subsequently, the guest molecules were desorbed from the surface by competition with increasing beta-cyclodextrin concentration in solution. The data were fitted using a model. An intrinsic binding constant of 3.3 +/- 1 x 10(5) M(-1) was obtained, which corresponds well to previously obtained results with a divalent guest molecule on beta-cyclodextrin monolayers on gold. In addition, the number of guest molecules bound to the host surface was determined, and a surface coverage of ca. 30% was found.

  6. Effect of low-molecular-weight beta-cyclodextrin polymer on release of drugs from mucoadhesive buccal film dosage forms.

    Science.gov (United States)

    Arakawa, Yotaro; Kawakami, Shigeru; Yamashita, Fumiyoshi; Hashida, Mitsuru

    2005-09-01

    We investigated the effect of low-molecular-weight beta-cyclodextrin (beta-CyD) polymer on in vitro release of two drugs with different lipophilicities (i.e., lidocaine and ketoprofen) from mucoadhesive buccal film dosage forms. When beta-CyD polymer was added to hydroxypropylcellulose (HPC) or polyvinylalcohol (PVA) film dosage forms, the release of lidocaine into artificial saliva (pH 5.7) was reduced by 40% of the control. In contrast, the release of ketoprofen from the polymer film was enhanced by addition of beta-CyD polymer to the vehicle. When lidocaine and ketoprofen was incubated with beta-CyD polymer in the artificial saliva, concentration of free lidocaine molecules decreased in a beta-CyD polymer concentration-dependent manner. The association constant with beta-CyD polymer was 6.9+/-0.6 and 520+/-90 M(-1) for lidocaine and ketoprofen, respectively. Retarded release of the hydrophilic lidocaine by beta-CyD polymer might be due to the decrease in thermodynamic activity by inclusion complex formation, whereas enhanced release of the lipophilic ketoprofen by the beta-CyD polymer might be due to prevention of recrystallization occurring after contacting the film with aqueous solution. Thus, effects of low-molecular-weight beta-CyD polymer to the drug release rate from film dosage forms would vary according to the strength of interaction with and the solubility of active ingredient.

  7. Cyclodextrin chemistry

    International Nuclear Information System (INIS)

    Khan, M.Z.; Chuaqui, C.A.

    1990-05-01

    The chemistry of cyclodextrins was studied. This study included synthesising some cyclodextrin derivatives, preparing selected inclusion complexes with cyclodextrin and investigating the effects of gamma irradiation on cyclodextrins and certain linear oligosaccharides. This report presents a brief review of the structure and properties of cyclodextrins, the synthesis of cyclodextrin derivatives, their complexation and applications. This is followed by a description of the synthesis of some cyclodextrin derivatives and the preparation of inclusion complexes of cyclodextrin with some organic compounds. Finally, the effects of gamma irradiation on cyclodextrins, some of their derivatives and certain structurally related carbohydrates are discussed. The gamma irradiation studies were carried out for two reasons: to study the effects of gamma irradiation on cyclodextrins and their derivatives; and to investigate selectivity during the gamma irradiation of cyclodextrin derivatives

  8. Chiral separation of dansyl amino acids in capillary electrophoresis using mono-(3-methyl-imidazolium)-beta-cyclodextrin chloride as selector.

    Science.gov (United States)

    Tang, Weihua; Ong, Teng Teng; Ng, Siu-Choon

    2007-06-01

    Enantioseparations of fourteen dansyl amino acids were achieved by using a positively-charged single-isomer beta-cyclodextrin, mono-(3-methyl-imidazolium)-beta-cyclodextrin chloride, as a chiral selector. Separation parameters such as buffer pH, selector concentration, separation temperature, and organic modifier were investigated for the enantioseparation in order to achieve the maximum possible resolution. Chiral separation of dansyl amino acids was found to be highly dependent on pH since the degree of protonation of these amino acids can alter the strength of electrostatic interaction and/or inclusion complexation between each enantiomer and chiral selector. In general, the chiral resolution of dansyl amino acids was enhanced at higher pH, which indicates that the carboxylate group on the analytes may interact with the imidazolium group of cationic cyclodextrin. For most analytes, a distinct maximum in enantioresolution was obtained at pH 8.0. Moreover, the chiral separation can be further improved by careful tuning of the separation parameters such as higher selector concentration (e.g. 10 mM), lower temperature, and addition of methanol. Enantioseparation of a standard mixture of these dansyl amino acids was further achieved in a single run within 30 min.

  9. Experimental, molecular docking investigations and bioavailability study on the inclusion complexes of finasteride and cyclodextrins

    Directory of Open Access Journals (Sweden)

    Mady FM

    2017-06-01

    Full Text Available Fatma M Mady,1,2 Usama Farghaly Aly2 1Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Taibah University, Medina, Saudi Arabia; 2Department of Pharmaceutics, Faculty of Pharmacy, Minia University, Minia, Egypt Abstract: Finasteride (FIN is a Class II candidate of the Biopharmaceutics Classification System (BCS. The lipophilic cavity of cyclodextrins (CyDs enables it to construct a non-covalent inclusion complex with different insoluble drugs. Only β-cyclodextrin (β-CyD and hydroxypropyl-β-CyD (HP-β-CyD have been previously examined with FIN. This study aimed to investigate the consistence of FIN with different kinds of β-CyDs, including dimethyl-β-cyclodextrin (DM-β-CyD, carboxymethyl-β-cyclodextrin (CM-β-CyD, HP-β-CyD, sulfobutyl ether-β-cyclodextrin (SBE-β-CyD, and β-CyD, by the coprecipitation method. The resultant inclusion systems were characterized by differential scanning calorimetry, infrared spectroscopy, X-ray diffractometry, and dissolution studies. Moreover, molecular docking for the selected inclusion systems was carried out to explore the suitable arrangements of FIN in the cavity of β-CyD or its derivatives. The results suggested that the DM-β-CyD inclusion system gave the higher complexation efficiency for improvement in solubility of FIN and hence enhancement of its bioavailability. Pharmacokinetic parameters displayed a higher absorption rate and higher area under the curve of the FIN/DM-β-CyD inclusion complex when compared with the drug alone, which indicates an improvement in the absorption and bioavailability of FIN in the DM-β-CyD inclusion system. Keywords: finasteride, cyclodextrins, molecular docking, pharmacokinetics, bioavailability

  10. Cyclodextrin--piroxicam inclusion complexes: analyses by mass spectrometry and molecular modelling

    Science.gov (United States)

    Gallagher, Richard T.; Ball, Christopher P.; Gatehouse, Deborah R.; Gates, Paul J.; Lobell, Mario; Derrick, Peter J.

    1997-11-01

    Mass spectrometry has been used to investigate the natures of non-covalent complexes formed between the anti-inflammatory drug piroxicam and [alpha]-, [beta]- and [gamma]-cyclodextrins. Energies of these complexes have been calculated by means of molecular modelling. There is a correlation between peak intensities in the mass spectra and the calculated energies.

  11. Novel {beta}-cyclodextrin modified CdTe quantum dots as fluorescence nanosensor for acetylsalicylic acid and metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Algarra, M. [Centro de Geologia do Porto, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Campos, B.B.; Aguiar, F.R.; Rodriguez-Borges, J.E. [Centro de Investigacao em Quimica (CIQ-UP), Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 169-007 Porto (Portugal); Esteves da Silva, J.C.G., E-mail: jcsilva@fc.up.pt [Centro de Investigacao em Quimica (CIQ-UP), Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 169-007 Porto (Portugal)

    2012-05-01

    {beta}-Cyclodextrin was modified with 11-[(ethoxycarbonyl)thio]undecanoic acid and used as a capping agent, together with mercaptosuccinic acid, to prepare water-stable CdTe quantum dots. The water soluble quantum dot obtained displays fluorescence with a maximum emission at 425 nm (under excitation at 300 nm) with lifetimes of 0.53, 4.8, 181, and 44.1 ns, respectively. The S-{beta}CD-MSA-CdTe can act as a nanoprobe that is due to the affinity of the cyclodextrin moiety for selected substances such as acetylsalicylic acid (ASA) and its metabolites as foreign species. The fluorescence of the S-{beta}CD-MSA-CdTe is enhanced on addition of ASA. Linear calibration plots are observed with ASA in concentrations between 0 and 1 mg/l, with a limit of detection at 8.5 Multiplication-Sign 10{sup -9} mol/l (1.5 ng/ml) and a precision as relative standard deviation of 1% (0.05 mg/l). The interference effect of certain compounds as ascorbic acid and its main metabolites such as salicylic, gentisic and salicyluric acid upon the obtained procedure was studied. Highlights: Black-Right-Pointing-Pointer Nanosensors constituted by CdTe quantum dots capped with modified cyclodextrin. Black-Right-Pointing-Pointer This nanomaterial shows fluorescence properties compatible with a semiconductor quantum dot. Black-Right-Pointing-Pointer The nanosensor shows fluorescence enhancement when inclusion complexes are formed with acetylsalicylic acid. Black-Right-Pointing-Pointer This nanomaterial has nanosensor potential taking into consideration the formation stability of the inclusion complex.

  12. Exploration of inclusion complexes of neurotransmitters with β-cyclodextrin by physicochemical techniques

    Science.gov (United States)

    Roy, Mahendra Nath; Saha, Subhadeep; Kundu, Mitali; Saha, Binoy Chandra; Barman, Siti

    2016-07-01

    Molecular assemblies of β-cyclodextrin with few of the most important neurotransmitters, viz., dopamine hydrochloride, tyramine hydrochloride and (±)-epinephrine hydrochloride in aqueous medium have been explored by reliable spectroscopic and physicochemical techniques as potential drug delivery systems. Job plots confirm the 1:1 host-guest inclusion complexes, while surface tension and conductivity studies illustrate the inclusion process. The inclusion complexes were characterized by 1H NMR spectroscopy and association constants have been calculated by using Benesi-Hildebrand method. Thermodynamic parameters for the formation of inclusion complexes have been derived by van't Hoff equation, which demonstrate that the overall inclusion processes are thermodynamically favorable.

  13. .beta.-Cyclodextrin-epichlorohydrin polymer/graphene oxide nanocomposite: preparation and characterization

    Czech Academy of Sciences Publication Activity Database

    Heydari, A.; Sheibani, H.; Hronský, V.; Janigová, I.; Šlouf, Miroslav; Šiffalovič, P.; Chodák, I.

    2018-01-01

    Roč. 72, č. 5 (2018), s. 1299-1313 ISSN 0366-6352 Institutional support: RVO:61389013 Keywords : beta-cyclodextrin * graphene oxide * hydrogels Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 1.258, year: 2016

  14. New compositions of cadmium selenium nanoparticles and dye molecules with cyclodextrin inclusion complexes

    International Nuclear Information System (INIS)

    Asimov, M.M.; Anufrik, S.S.; Tarkovsky, V.V.; Sazonko, H.H.

    2013-01-01

    Spectroscopic properties of new heterogeneous multicolor compositions based on cadmium selenium (CdSe/ZnS) nano crystal and inclusion complexes of dye molecule with cyclodextrin are presented. Spectral fluorescence of proposed compositions investigated in thin films. Signals from multicolor fluorescence of proposing compositions may be combined to definite spectral codes that could be used for tracking or verification of different objects. Calibration bar of signal within spectral codes guarantee high reliability in practical application of proposed multicolor compositions. Express analysis the size of nanoparticles during their synthesis and purification by spectroscopic methods is suggested. Application of Cyclodextrin molecules as target delivery systems is considered. (authors)

  15. Nanodiamonds in sugar rings: an experimental and theoretical investigation of cyclodextrin-nanodiamond inclusion complexes.

    Science.gov (United States)

    Voskuhl, Jens; Waller, Mark; Bandaru, Sateesh; Tkachenko, Boryslav A; Fregonese, Carlo; Wibbeling, Birgit; Schreiner, Peter R; Ravoo, Bart Jan

    2012-06-21

    We report on the noncovalent interactions of nanodiamond carboxylic acids derived from adamantane, diamantane, and triamantane with β- and γ-cyclodextrins. The water solubility of the nanodiamonds was increased by attaching an aromatic dicarboxylic acid via peptide coupling. Isothermal titration calorimetry experiments were performed to determine the thermodynamic parameters (K(a), ΔH, ΔG and ΔS) for the host-guest inclusion. The stoichiometry of the complexes is invariably 1:1. It was found that K(a), ΔG and ΔH of inclusion increase for larger nanodiamonds. ΔS is generally positive, in particular for the largest nanodiamonds. β-Cyclodextrin binds all nanodiamonds, γ-cyclodextrin clearly prefers the most bulky nanodiamonds. The interaction of 9-triamantane carboxylic acid shows one of the strongest complexation constants towards γ-cyclodextrin ever reported, K(a) = 5.0 × 10(5) M(-1). In order to gain some insight into the possible structural basis of these inclusion complexes we performed density functional calculations at the B97-D3/def2-TZVPP level of theory.

  16. Study on the inclusion complex between β-cyclodextrin derivatives and flurbiprofen by spectrofluorometric

    Science.gov (United States)

    Miao, Jiabing; Guo, Zhaohua; Wang, Yongwang; Chen, Dong; Li, Yifan; Zhang, Feng

    2017-08-01

    The inclusion behavior between β-cyclodextrin derivatives (β-CDs) and flurbiprofen had been studied by fluorescence spectrophotometry. The effects of type and concentration of β-CDs; ionic strength; pH as well as temperature on inclusion behavior were investigated. And then the thermodynamic parameters ΔH/ΔS and ΔG of the inclusion complex of flurbiprofen and HP-β-CD were calculated, the driving force of the inclusion reaction had been also certified. The experimental results indicate, the fluorescence intensity (F) of flurbiprofen increases with the raising of β-CDs concentration, among the studied types of β-cyclodextrin derivatives, hydroxypropy l-β-cyclodextrin (HP-β-CD) has the most obvious enhancement, namely HP-β-CD has the strongest ability to complex with flurbiprofen. Plot of 1/ (F-F0) against 1/ [β-CD] yields a straight line, indicating 1:1 stoichiometric complex formed between β-CDs and flurbiprofen. Inclusion constant is enhanced with the increase in ionic strength of solution, whereas followes an opposite tendency with the rise of pH value. In the inclusive process, under normal temperature ΔG<0, it illustrates that this process is spontaneous, and the driving force is the change of enthalpy.

  17. Spectrophotometric thermodynamic study of orientational isomers formed by inclusion of methyl orange into β-cyclodextrin nanocavity

    DEFF Research Database (Denmark)

    Kompany Zare, Mohsen; Mokhtari, Zeinab; Abdollahi, Hamid

    2012-01-01

    Spectrophotometry has been used to investigate the interaction of methyl orange (MO), an azo dye as a guest, with β-cyclodextrin (CD) as the host. Inclusion of methyl orange into β-cyclodextrin nanocavity leads to two orientational isomers, so-called inclumers, because of the asymmetric structure...

  18. Cyclodextrin inclusion complex to improve physicochemical properties of herbicide bentazon: exploring better formulations.

    Directory of Open Access Journals (Sweden)

    Claudia Yáñez

    Full Text Available The knowledge of the host-guest complexes using cyclodextrins (CDs has prompted an increase in the development of new formulations. The capacity of these organic host structures of including guest within their hydrophobic cavities, improves physicochemical properties of the guest. In the case of pesticides, several inclusion complexes with cyclodextrins have been reported. However, in order to explore rationally new pesticide formulations, it is essential to know the effect of cyclodextrins on the properties of guest molecules. In this study, the inclusion complexes of bentazon (Btz with native βCD and two derivatives, 2-hydroxypropyl-β-cyclodextrin (HPCD and sulfobutylether-β-cyclodextrin (SBECD, were prepared by two methods: kneading and freeze-drying, and their characterization was investigated with different analytical techniques including Fourier transform infrared spectroscopy (FT-IR, differential thermal analysis (DTA, X-ray diffractometry (XRD and differential pulse voltammetry (DPV. All these approaches indicate that Btz forms inclusion complexes with CDs in solution and in solid state, with a stoichiometry of 1:1, although some of them are obtained in mixtures with free Btz. The calculated association constant of the Btz/HPCD complex by DPV was 244±19 M(-1 being an intermediate value compared with those obtained with βCD and SBECD. The use of CDs significantly increases Btz photostability, and depending on the CDs, decreases the surface tension. The results indicated that bentazon forms inclusion complexes with CDs showing improved physicochemical properties compared to free bentazon indicating that CDs may serve as excipient in herbicide formulations.

  19. Per-2,3-O-alkylated beta-cyclodextrin duplexes connected with disulfide bonds

    Czech Academy of Sciences Publication Activity Database

    Tatar, Ameneh; Grishina, Anastasia; Buděšínský, Miloš; Kraus, Tomáš

    2017-01-01

    Roč. 29, č. 1 (2017), s. 40-48 ISSN 1061-0278 R&D Projects: GA MŠk LD12019 Grant - others:COST(XE) CM1005 Institutional support: RVO:61388963 Keywords : cyclodextrins * inclusion complexes * disulfide bonds Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 1.264, year: 2016

  20. Preparation, characterization and in vitro evaluation of a new nucleotide analogue prodrug cyclodextrin inclusion complexes.

    OpenAIRE

    Diab , Roudayna; Jordheim , Lars P; Degobert , Ghania; Peyrottes , Suzanne; Périgaud , Christian; Dumontet , Charles; Fessi , Hatem

    2009-01-01

    International audience; Bis(tbutyl-S-acyl-2-thioethyl)-cytidine monophosophate is a new cytotoxic mononucleotide prodrug which have been developed to reverse the cellular resistance to nucleoside analogues. Unfortunately, its in vivo utilisation was hampered by its poor water solubility, raising the need of a molecular vector capable to mask its physicochemical characteristics although without affecting its cytotoxic activity. Hydroxypropyl-beta-cyclodextrin was used to prepare the prodrug in...

  1. Formation of poly(ethylene glycol) inclusion complexes in aqueous solutions of mixed cyclodextrins

    Czech Academy of Sciences Publication Activity Database

    Horský, Jiří; Walterová, Zuzana

    2003-01-01

    Roč. 203, - (2003), s. 259-264 ISSN 1022-1360. [International Conference on Polymer-Solvent Complexes and Intercalates /4./. Prague, 22.07.2002-25.07.2002] R&D Projects: GA AV ČR IAA1050101 Institutional research plan: CEZ:AV0Z4050913 Keywords : cyclodextrins * inclusion complexes * phase separation Subject RIV: BO - Biophysics Impact factor: 0.895, year: 2003

  2. Preparation, characterization, and thermal stability of β-cyclodextrin/soybean lecithin inclusion complex.

    Science.gov (United States)

    Wang, Xinge; Luo, Zhigang; Xiao, Zhigang

    2014-01-30

    β-Cyclodextrin (β-CD), which is widely used to increase the stability, solubility, and bioavailability of guests, can form host-guest inclusion complexes with a wide variety of organic molecules. In this study the β-CD/soybean lecithin inclusion complex was prepared. The effect of reaction parameters such as reaction temperature, reaction time and the molar ratio of β-CD/soybean lecithin on inclusion ratio were studied. The inclusion ratio of the product prepared under the optimal conditions of β-CD/soybean lecithin molar ratio 2:1, reaction temperature 60°C reaction time 2h was 40.2%. The results of UV-vis, DSC, XRD and FT-IR spectrum indicated the formation of inclusion complex. The thermal stability experiment indicated that the thermal stability of soybean lecithin in inclusion complex was significantly improved compared with free soybean lecithin. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Enhancement of dibenzothiophene biodesulfurization using {beta}-cyclodextrins in oil-to-water media

    Energy Technology Data Exchange (ETDEWEB)

    Ainhoa Caro; Pedro Leton; Eloy Garcia-Calvo; Leonardo Setti [Universidad de Alcala, Madrid (Spain). Departamento de Quimica Analitica e Ingeniera Quimica

    2007-11-15

    It has been reported that biodesulfurization (BDS) of dibenzothiophene (DBT) in oil-to-water emulsions is carried out by growing cells of the aerobic Rhodococcus erythropolis IGTS8 strain and developing the so-called 4S desulfurization pathway. On adding {beta}-cyclodextrins, it is possible to improve the BDS yields, increase the diffusion of DBT into the aqueous phase or avoid the HBP accumulation. Moreover, by using greater biocatalyst initial concentrations and adding 15 ppm of {beta}-cyclodextrin, a very high BDS yield has been observed, but the presence of mass transfer limitations and the inhibition effects were not satisfactorily avoided. The Haldane kinetic model agreed well with the experimental results obtained, and the values of the kinetic parameters were determined. Short communication. 20 refs., 2 figs., 2 tabs.

  4. Carborane-beta-cyclodextrin complexes as a supramolecular connector for bioactive surfaces

    Czech Academy of Sciences Publication Activity Database

    Neirynck, P.; Schimer, Jiří; Jonkheijm, P.; Milroy, L. G.; Cígler, Petr; Brunsveld, L.

    2015-01-01

    Roč. 3, č. 4 (2015), s. 539-545 ISSN 2050-750X R&D Projects: GA MŠk(CZ) LH11027 Institutional support: RVO:61388963 Keywords : beta-cyclodextrine/carborane host-guest system * supramolecular chemistry * bioactive surfaces Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.872, year: 2015 http://pubs.rsc.org/en/content/articlepdf/2015/tb/c4tb01489h

  5. Characterisation of Catfish (Clarias Batrachus) Oil: β-Cyclodextrin Inclusion Complex

    International Nuclear Information System (INIS)

    Zaibunnisa Abdul Haiyee; Nor Izzatul Adyani Yahya; Norizzah Abd Rashid; Dzulkifly Mat Hashim

    2016-01-01

    Catfish is a cheap source of essential omega-3 fatty acids especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Catfish oil was extracted and clean-up using pressurised liquid extraction (PLE) from the viscera of catfish (Clarias batrachus). However, the characteristics of catfish oils are sticky, strong fishy odour and can easily be oxidised with short shelf-life. In this study, catfish oil was converted into powder by formation of inclusion complex with β-cyclodextrin. Inclusion complex was prepared by using co-precipitation and kneading methods and compared with physical mixture. The inclusion complex formed were characterised by using field emission scanning electron microscopy (FESEM), differential scanning calorimeter (DSC) and fourier transform infrared spectroscopy (FTIR). FESEM images revealed that inclusion complex using co-precipitation and kneading methods has smaller in crystal sizes and appeared as different morphology compared to physical mixture. DSC proved that co-precipitation method was able to form new solid phase due to shifting of melting point to higher temperature (145.22 degree Celcius). FTIR supported the result by proving strengthening of carbonyl group (C=O). Therefore, co-precipitation method was able to successfully produce inclusion complex of catfish oil, β-cyclodextrin. (author)

  6. Study on inclusion complex of cyclodextrin with methyl xanthine derivatives by fluorimetry

    Science.gov (United States)

    Wei, Yan-Li; Ding, Li-Hua; Dong, Chuan; Niu, Wei-Ping; Shuang, Shao-Min

    2003-10-01

    The inclusion complexes of β-cyclodextrin (β-CD) and HP-β-cyclodextrin (HP-β-CD) with caffeine, theophylline and theobromine were investigated by fluorimetry. Various factors affecting the formation of inclusion complexes were discussed in detail including forming time, pH effect and temperature. The results indicate that inclusion process was affected seriously by laying time and pH. The forming time of β-CD inclusion complexes is much longer than that of HP-β-CD. The optimum pH range is about 7-12 for caffeine, 8-10 for TP, 10.5-12 for TB. The intensities of their fluorescence increase with the decreasing of temperature. Their maximum excitation wavelengths are all in the range of 280-290 nm. The emission wavelength of caffeine and theophylline are both in the range of 340-360 nm, and that of theobromine is about 325 nm. The fluorescence signals are intensified with the increasing concentration of CD. The stoichiometry of the inclusion complexes of CD with these three methyl xanthine derivatives are all 1:1 and the formation constant are all calculated.

  7. NMR spectroscopic characterization of β-cyclodextrin inclusion complex with vanillin

    International Nuclear Information System (INIS)

    Pirnau, Adrian; Bogdan, Mircea; Floare, Calin G

    2009-01-01

    The inclusion of vanillin by β-cyclodextrin was investigated by 1 H NMR. The continuous variation technique was used to evidence the formation of soluble 1:1 complex in aqueous solution. The association constant of vanillin with β-cyclodextrin has been obtained at 298 K by fitting the experimental chemical shifts differences, Δδ obs δ free - δ obs of the observed guest and host protons, with a non-linear regression method. Besides the effective association constant, the fitting procedure allows a precise determination of all chemical shift parameters characterizing the pure complex. They can by used for an analysis of the geometry of the molecular complex in solution.

  8. Construction of hydroxypropyl-{beta}-cyclodextrin copolymer nanoparticles and targeting delivery of paclitaxel

    Energy Technology Data Exchange (ETDEWEB)

    Miao Qinghua; Li Suping; Han Siyuan [National Center for Nanoscience and Technology of China, CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety (China); Wang Zhi, E-mail: wangzhi@jlu.edu.cn [Jilin University, Key Laboratory for Molecular Enzymology and Engineering, Ministry of Education (China); Wu Yan, E-mail: wuy@nanoctr.cn; Nie Guangjun, E-mail: niegj@nanoctr.cn [National Center for Nanoscience and Technology of China, CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety (China)

    2012-08-15

    A novel amphiphilic copolymer with p-maleimidophenyl isocyanate-hydroxypropyl-{beta}-cyclodextrin-polylactide-1, 2-dipalmitoyl-sn-glycero-3-phosphoethanolamine to generate copolymer nanoparticles (NPs) has been designed. In order to develop an active targeting system, integrin {alpha}{sub v}{beta}{sub 3}-specific targeting peptide cyclo(Arg-Gly-Asp-D-Phe-Cys), cRGD, was conjugated to the surface of NPs (NPs-RGD). These NPs were used to encapsulate anti-tumor drug, paclitaxel. The resulting NPs exhibited high drug-loading capacity and controlled drug release in vitro at acidic pH. In vitro cytotoxicity assay demonstrates that paclitaxel-loaded NPs-RGD significantly inhibited B16 tumor cell (high {alpha}{sub v}{beta}{sub 3}) proliferation relative to free paclitaxel and paclitaxel-loaded NPs at high concentrations. Paclitaxel-loaded NPs-RGD localized mainly in lysosomes in B16 cells as revealed by confocal microscopy. These results suggest a novel strategy for fabrication-functionalizing hydroxypropyl-{beta}-cyclodextrin copolymer nanoparticles for targeting delivery of paclitaxel to integrin {alpha}{sub v}{beta}{sub 3}-rich tumor cells. These nanocarriers can be readily extended to couple other bioactive molecules for active targeting and delivery of various chemotherapeutic drugs.

  9. Fluorescence and room temperature phosphorescence of 6-bromo-2-naphthol in {beta}-cyclodextrin solution and its selective molecular recognition for cyclohexane

    Energy Technology Data Exchange (ETDEWEB)

    Zhai Yanqiang; Zhang Shuzhen; Xie Jianwei; Liu Changsong

    2003-10-08

    The room temperature phosphorescence (RTP) and fluorescence behavior of 6-bromo-2-naphthol (BN) in water and {beta}-cyclodextrin ({beta}-CD) aerated aqueous solution was investigated. The study of fluorescence behavior at different pH values indicated that three kinds of species of BN (protonated, uncharged and anionic species) formed 1:1 inclusion complexes with {beta}-CD, and RTP and fluorescence emission depended on the pH of the solution. The inclusion complex constants were 430{+-}25 l mol{sup -1} (pH 1.80), 840{+-}25 l mol{sup -1} (pH 5.80), 1850{+-}75 l mol{sup -1} (pH 11.50), respectively. Experimental results elucidated that RTP of the BN/{beta}-CD/cyclohexane solution came from the protonated and uncharged species of BN, but not from the anionic species, though the inclusion constant of the anionic species of BN with {beta}-CD was larger than that of the other two species of BN Selective molecular recognition of BN/{beta}-CD as an RTP sensor for 28 small organic molecules was studied, it was shown that BN/{beta}-CD could be develop as a new RTP sensor with high selectivity molecular recognition ability for cyclohexane.

  10. Study in aqueous solution of the praseodymium inclusion in β-cyclodextrin in 2 M of NaCl

    International Nuclear Information System (INIS)

    De la Cruz M, N.

    2013-01-01

    In the fission of uranium to produce electricity, generated between the fission products which are the lanthanides and actinides that at any given time may come into contact with aqueous media, because of this, praseodymium was including in the β-cyclodextrin in order to increase the solubility and stability of praseodymium by forming inclusion complexes Praseodymium-β-cyclodextrin (Pr-β-Cd). The inclusion study was conducted in a proportion of praseodymium and β-cyclodextrin. Infrared spectra, Raman and X-ray diffraction showed the presence of praseodymium and β-cyclodextrin in the inclusion complex, in both proportions. The analysis by scanning electron microscopy confirmed the inclusion of praseodymium in βcyclodextrin. In general, the results of characterization obtained by these techniques show the formation of the inclusion complex. Furthermore, the behaviour of praseodymium inclusion in the β-cyclodextrin was studied in 2 M NaCl at 303 K and free-CO 2 conditions. For this reason, we used two methods: spectrophotometric and potentiometric titration direct of praseodymium-β-cyclodextrin, the data were treated graphically and with the program SUPERQUAD, respectively. The values obtained for praseodymium by spectrophotometric method was: log β 1 = -8.75 calculated graphically and with the potentiometric method, using program SUPERQUAD were logβ 1,OH = -8.73 ± 0.01 logβ 1,2OH = -18.27 ± 0.16 and logβ 1,3OH = -26.44 ± 0.02 obtained simultaneously. (Author)

  11. Thermodynamics of inclusion complexes of natural and modified cyclodextrins with acetylsalicylic acid and ibuprofen in aqueous solution at 298 K

    Energy Technology Data Exchange (ETDEWEB)

    Castronuovo, Giuseppina, E-mail: giuseppina.castronuovo@unina.it [Department of Chemistry, University Federico II of Naples, Complesso Universitario a Monte S. Angelo, via Cintia, 80126 Naples (Italy); Niccoli, Marcella [Department of Chemistry, University Federico II of Naples, Complesso Universitario a Monte S. Angelo, via Cintia, 80126 Naples (Italy)

    2013-04-10

    Graphical abstract: Complexation forces acting in the association between natural and modified α- and β-cyclodextrins and acetylsalicylic acid (aspirin) or ibuprofen are examined through the analysis of the thermodynamic parameters obtained by isothermal calorimetry. Highlights: ► A calorimetric method is reported to study the association of natural and substituted cyclodextrins with acetylsalicylic acid and ibuprofen. ► The study aims to propose a hypothesis about the forces involved in the interaction. That can be useful for designing new cyclodextrins having suitable characteristics to include specific drugs. ► Enthalpic and entropic contributions on the association are discussed. The differences in the cavity dimensions of the cyclodextrins determine the values of the thermodynamic properties to be very different. - Abstract: Thermodynamic parameters for the association of natural and substituted α-, β-, and γ-cyclodextrins with acetylsalicylic acid, salicylic acid and ibuprofen have been determined by isothermal titration calorimetry. Analysis of the data shows that complexes form, all having 1:1 stoichiometry. The shape-matching between the host and guest is the factor determining the values of the thermodynamic quantities. In the case of the smallest cyclodextrin interacting with acetylsalicylic acid and salicylic acid, the parameters indicate that hydrophobic interactions play the major role. Association occurs through the shallow inclusion of the benzene ring into the cavity. In the case of substituted β-cyclodextrins, instead, inclusion of the benzene ring is deeper and the tight fitting of the guest molecule to the cavity makes the enthalpy and entropy to be both negative. Ibuprofen interacts through its isobutyl group: the values of the association constants are very high for β-cyclodextrins as determined by the large and positive entropies due to the relaxation of water molecules from the cavity and the hydration spheres of the interacting

  12. Thermodynamics of inclusion complexes of natural and modified cyclodextrins with acetylsalicylic acid and ibuprofen in aqueous solution at 298 K

    International Nuclear Information System (INIS)

    Castronuovo, Giuseppina; Niccoli, Marcella

    2013-01-01

    Graphical abstract: Complexation forces acting in the association between natural and modified α- and β-cyclodextrins and acetylsalicylic acid (aspirin) or ibuprofen are examined through the analysis of the thermodynamic parameters obtained by isothermal calorimetry. Highlights: ► A calorimetric method is reported to study the association of natural and substituted cyclodextrins with acetylsalicylic acid and ibuprofen. ► The study aims to propose a hypothesis about the forces involved in the interaction. That can be useful for designing new cyclodextrins having suitable characteristics to include specific drugs. ► Enthalpic and entropic contributions on the association are discussed. The differences in the cavity dimensions of the cyclodextrins determine the values of the thermodynamic properties to be very different. - Abstract: Thermodynamic parameters for the association of natural and substituted α-, β-, and γ-cyclodextrins with acetylsalicylic acid, salicylic acid and ibuprofen have been determined by isothermal titration calorimetry. Analysis of the data shows that complexes form, all having 1:1 stoichiometry. The shape-matching between the host and guest is the factor determining the values of the thermodynamic quantities. In the case of the smallest cyclodextrin interacting with acetylsalicylic acid and salicylic acid, the parameters indicate that hydrophobic interactions play the major role. Association occurs through the shallow inclusion of the benzene ring into the cavity. In the case of substituted β-cyclodextrins, instead, inclusion of the benzene ring is deeper and the tight fitting of the guest molecule to the cavity makes the enthalpy and entropy to be both negative. Ibuprofen interacts through its isobutyl group: the values of the association constants are very high for β-cyclodextrins as determined by the large and positive entropies due to the relaxation of water molecules from the cavity and the hydration spheres of the interacting

  13. Physico-chemical and Biological Evaluation of Flavonols: Fisetin, Quercetin and Kaempferol Alone and Incorporated in beta Cyclodextrins.

    Science.gov (United States)

    Corina, Danciu; Bojin, Florina; Ambrus, Rita; Muntean, Delia; Soica, Codruta; Paunescu, Virgil; Cristea, Mirabela; Pinzaru, Iulia; Dehelean, Cristina

    2017-01-01

    Fisetin,quercetin and kaempferol are among the important representatives of flavonols, biological active phytocomounds, with low water solubility. To evaluate the antimicrobial effect, respectively the antiproliferative and pro apoptotic activity on the B164A5 murine melanoma cell line of pure flavonols and their beta cyclodextrins complexes. Incorporation of fisetin, quercetin and kaempferol in beta cyclodextrins was proved by scanning electron microscopy (SEM), differencial scanning calorimetry (DSC) and X-ray powder diffraction (XRPD). Pure compounds and their complexes were tested for antiproliferative (MTT) and pro-apoptotic activity (Annexin V-PI) on the B164A5 murine melanoma cell line and for the antimicrobial properties (Disk Diffusion Method) on the selected strains. The phytocompounds presented in a different manner in vitro chemopreventive activity against B164A5 murine melanoma cell line and weak antimicrobial effect. The three flavonols: fisetin, quercetin and kaempferol were successfully incorporated in beta-cyclodextrin (BCD) and hydroxylpropyl-beta-cyclodextrin (HPBCD). Incorporation in beta cyclodextrins had a mix effect on the biological activity conducing to decrease, increase or consistent effect compared to pure phytocompound, depending on the screened process and on the chosen combination. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. Melarsoprol cyclodextrin inclusion complexes as promising oral candidates for the treatment of human African trypanosomiasis.

    Directory of Open Access Journals (Sweden)

    Jean Rodgers

    2011-09-01

    Full Text Available Human African trypanosomiasis (HAT, or sleeping sickness, results from infection with the protozoan parasites Trypanosoma brucei (T. b. gambiense or T. b. rhodesiense and is invariably fatal if untreated. There are 60 million people at risk from the disease throughout sub-Saharan Africa. The infection progresses from the haemolymphatic stage where parasites invade the blood, lymphatics and peripheral organs, to the late encephalitic stage where they enter the central nervous system (CNS to cause serious neurological disease. The trivalent arsenical drug melarsoprol (Arsobal is the only currently available treatment for CNS-stage T. b. rhodesiense infection. However, it must be administered intravenously due to the presence of propylene glycol solvent and is associated with numerous adverse reactions. A severe post-treatment reactive encephalopathy occurs in about 10% of treated patients, half of whom die. Thus melarsoprol kills 5% of all patients receiving it. Cyclodextrins have been used to improve the solubility and reduce the toxicity of a wide variety of drugs. We therefore investigated two melarsoprol cyclodextrin inclusion complexes; melarsoprol hydroxypropyl-β-cyclodextrin and melarsoprol randomly-methylated-β-cyclodextrin. We found that these compounds retain trypanocidal properties in vitro and cure CNS-stage murine infections when delivered orally, once per day for 7-days, at a dosage of 0.05 mmol/kg. No overt signs of toxicity were detected. Parasite load within the brain was rapidly reduced following treatment onset and magnetic resonance imaging showed restoration of normal blood-brain barrier integrity on completion of chemotherapy. These findings strongly suggest that complexed melarsoprol could be employed as an oral treatment for CNS-stage HAT, delivering considerable improvements over current parenteral chemotherapy.

  15. Covalently {beta}-cyclodextrin modified single-walled carbon nanotubes: a novel artificial receptor synthesized by 'click' chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Guo Zhen; Liang Li [Nankai University, State Key Laboratory and Institute of Elemento-Organic Chemistry (China); Liang Jiajie; Ma Yanfeng; Yang Xiaoying [Nankai University, Center for Nanoscale Science and Technology and Institute of Polymer Chemistry, College of Chemistry (China); Ren Dongmei [Nankai University, State Key Laboratory and Institute of Elemento-Organic Chemistry (China); Chen Yongsheng [Nankai University, Center for Nanoscale Science and Technology and Institute of Polymer Chemistry, College of Chemistry (China); Zheng Jianyu, E-mail: jyzheng@nankai.edu.c [Nankai University, State Key Laboratory and Institute of Elemento-Organic Chemistry (China)

    2008-08-15

    Novel {beta}-cyclodextrin covalently modified single-walled carbon nanotubes have been synthesized via a 'click' coupling reaction. The product was fully characterized with Raman, FTIR, XRD, UV-Vis-NIR spectra as well as TEM and TGA measurements. The effective functionalization via 'click' coupling has set up a facile and versatile route for modular preparation of SWNTs based functional materials. The inclusion complexation behavior of this artificial receptor with quinine has been investigated in aqueous solution by fluorescence spectroscopy.

  16. Enhancement of solubility of albendazole by complexation with {beta}-cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Moriwaki, C.; Costa, G.L.; Ferracini, C.N.; Matioli, G. [Universidade Estadual de Maringa (UEM), PR (Brazil). Dept. de Farmacia e Farmacologia]. E-mail: gmatioli@uem.br; Moraes, F.F. de; Zanin, G.M. [Universidade Estadual de Maringa (UEM), PR (Brazil). Dept. de Engenharia Quimica; Pineda, E.A.G. [Universidade Estadual de Maringa (UEM), PR (Brazil). Dept. de Quimica

    2008-04-15

    A high dosage of albendazole (ABZ) is required for treating systemic helminth infections because of its low solubility. Aiming at increasing ABZ solubility, complexation with beta-cyclodextrin ({beta}-CD) using aqueous and acetic acid solutions as ABZ solubiliser was studied. In aqueous {beta}-CD, complexation increased solubility 53.4 times, giving a complex equilibrium constant of 1266 L mol{sup -1} with a maximum ABZ concentration of 276 {mu}mol L{sup -1} for 16.3 mmol L{sup -1} {beta}-CD. For complexation in 1.05 mol L{sup -1} acetic acid, UV absorbance spectra and {sup 1}H-NMR analysis confirmed complex formation. The UV absorbance of ABZ/acid acetic/{beta}-CD solutions was modeled by the formation of two complexes with molar ratios 1:1 and 1:2 ABZ:{beta}-CD. When neutralized with NaOH these solutions did not form precipitates only for the ABZ:{beta}-CD molar ratios of 1:8 and 1:10, showing that ABZ solubility could be increased 306 times. Results show that high {beta}-CD molar ratios hold ABZ in solution by complexation enhanced by the acetate anion. (author)

  17. Enhancing Antidepressant Effect of Poloxamer/Chitosan Thermosensitive Gel Containing Curcumin-Cyclodextrin Inclusion Complex

    Directory of Open Access Journals (Sweden)

    Ye Zhang

    2018-01-01

    Full Text Available Poor solubility and bioavailability are limiting factors for the clinical application of curcumin. This study seeks to develop poloxamer/chitosan thermosensitive gel containing curcumin-cyclodextrin inclusion complex with enhanced brain bioavailability and antidepressant effect. The optimized gel had shorter gelation time and produced sustained release in vitro characterized with non-Fickian diffusion. Pharmacokinetics of gel were evaluated using male Sprague-Dawley rats receiving 240 μg/kg of curcumin and curcumin-cyclodextrin inclusion complex through intranasal administration, compared against a control group receiving intravenous curcumin (240 μg/kg. The intranasal administration of gel provided sustained release by maintaining plasma concentrations of curcumin above 21.27 ± 3.26 ng/mL for up to 8 h. Compared to intranasal administration of the inclusion complex, AUC0–8 h of curcumin from thermoreversible gel in plasma and hippocampus was increased 1.62- and 1.28-fold, respectively. The gel exhibited superior antidepressant activity in mice. The findings reported here suggested that the clinical application of curcumin can be better exploited through an intranasal administration of the thermosensitive gel.

  18. Inclusion Complexes of Sunscreen Agents with β-Cyclodextrin: Spectroscopic and Molecular Modeling Studies

    Directory of Open Access Journals (Sweden)

    Nathir A. F. Al-Rawashdeh

    2013-01-01

    Full Text Available The inclusion complexes of selected sunscreen agents, namely, oxybenzone (Oxy, octocrylene (Oct, and ethylhexyl-methoxycinnamate (Cin with β-cyclodextrin (β-CD were studied by UV-Vis spectroscopy, differential scanning calorimetry (DSC, 13C NMR techniques, and molecular mechanics (MM calculations and modeling. Molecular modeling (MM study of the entire process of the formation of 1 : 1 stoichiometry sunscreen agent/β-cyclodextrin structures has been used to contribute to the understanding and rationalization of the experimental results. Molecular mechanics calculations, together with 13C NMR measurements, for the complex with β-CD have been used to describe details of the structural, energetic, and dynamic features of host-guest complex. Accurate structures of CD inclusion complexes have been derived from molecular mechanics (MM calculations and modeling. The photodegradation reaction of the sunscreen agents' molecules in lotion was explored using UV-Vis spectroscopy. It has been demonstrated that the photostability of these selected sunscreen agents has been enhanced upon forming inclusion complexes with β-CD in lotion. The results of this study demonstrate that β-CD can be utilized as photostabilizer additive for enhancing the photostability of the selected sunscreen agents' molecules.

  19. Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound.

    Science.gov (United States)

    Pais, Joana M; Barroca, Maria João; Marques, Maria Paula M; Almeida Paz, Filipe A; Braga, Susana S

    2017-01-01

    Fisetin is a natural antioxidant with a wide range of nutraceutical properties, including antidiabetic, neuroprotecting, and suppression or prevention of tumors. The present work describes the preparation of a water-soluble, solid inclusion compound of fisetin with gamma-cyclodextrin (γ-CD), a cyclic oligosaccharide approved for human consumption. A detailed physicochemical analysis of the product is carried out using elemental analysis, powder X-ray diffraction (PXRD), Raman, infrared and 13 C{ 1 H} CP-MAS NMR spectroscopies, and thermal analysis (TGA) to verify fisetin inclusion and to present a hypothetical structural arrangement for the host-guest units. The antioxidant activity of the γ-CD·fisetin inclusion compound is evaluated by the DPPH assay.

  20. Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound

    Directory of Open Access Journals (Sweden)

    Joana M. Pais

    2017-10-01

    Full Text Available Fisetin is a natural antioxidant with a wide range of nutraceutical properties, including antidiabetic, neuroprotecting, and suppression or prevention of tumors. The present work describes the preparation of a water-soluble, solid inclusion compound of fisetin with gamma-cyclodextrin (γ-CD, a cyclic oligosaccharide approved for human consumption. A detailed physicochemical analysis of the product is carried out using elemental analysis, powder X-ray diffraction (PXRD, Raman, infrared and 13C{1H} CP-MAS NMR spectroscopies, and thermal analysis (TGA to verify fisetin inclusion and to present a hypothetical structural arrangement for the host–guest units. The antioxidant activity of the γ-CD·fisetin inclusion compound is evaluated by the DPPH assay.

  1. Empirical, thermodynamic and quantum-chemical investigations of inclusion complexation between flavanones and (2-hydroxypropyl)-cyclodextrins.

    Science.gov (United States)

    Liu, Benguo; Li, Wei; Nguyen, Tien An; Zhao, Jian

    2012-09-15

    The inclusion complexation of (2-hydroxypropyl)-cyclodextrins with flavanones was investigated by phase solubility measurements, as well as thermodynamic and quantum chemical methods. Inclusion complexes were formed between (2-hydroxypropyl)-α-cyclodextrin (HP-α-CD), (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD), (2-hydroxypropyl)-γ-cyclodextrin (HP-γ-CD) and β-cyclodextrin (β-CD) and four flavanones (naringenin, naringin, hesperetin and dihydromyricetin) in aqueous solutions and their phase solubility was determined. For all the flavanones, the stability constants of their complexes formed with different CDs followed the rank order: HP-β-CD (MW 1540)>HP-β-CD (MW 1460)>HP-β-CD (MW 1380)>β-CD>HP-γ-CD>HP-α-CD. Experimental results and quantum chemical calculations showed that the ability of flavanones to form inclusion complex with (2-hydroxypropyl)-cyclodextrins was determined by both the steric effect and hydrophobicity of the flavanones. For flavanones that have similar molecular volumes, the hydrophobicity of the molecule was the main determining factor of its ability to form inclusion complexes with HP-β-CD, and the hydrophobicity parameter Log P is highly correlated with the stability constant of the complexes. Results of thermodynamic study demonstrated that hydrophobic interaction is the main driving force for the formation process of the flavanone-CD inclusion complexes. Quantum chemical analysis of the most active hydroxyl groups and HOMO (the highest occupied molecular orbital) showed that the B ring of the flavanones was most likely involved in hydrogen bonding with the side groups in the cavity of the CDs, through which the inclusion complex was stabilised. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Preparation of hydroxyapatite nanoparticles facilitated by the presence of {beta}-cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Perez, Carlos A., E-mail: camartin@uacj.mx [Institute of Engineering and Technology, Autonomous University of Juarez, UACJ, Ave. del Charro 610 norte, C.P. 32320, Cd. Juarez, Chihuahua (Mexico); Garcia-Montelongo, Jorge; Garcia Casillas, Perla E.; Farias-Mancilla, Jose R. [Institute of Engineering and Technology, Autonomous University of Juarez, UACJ, Ave. del Charro 610 norte, C.P. 32320, Cd. Juarez, Chihuahua (Mexico); Monreal Romero, Humberto [School of Odontology, Autonomous University of Chihuahua, UACH, Ave. Universidad s/n Campus Universitario I, C.P. 31170, Chihuahua (Mexico)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer It was found that {beta}-cyclodextrin can control the particle size in the production of nanohydroxyapatite. Black-Right-Pointing-Pointer Particle size in the range of 30-50 nm was obtained. Black-Right-Pointing-Pointer A new simple methodology for the preparation of hydroxyapatite nanoparticles with a well controlled size and narrow particles size distribution was developed. - Abstract: Hydroxyapatite nanoparticles with uniform morphology have been successfully synthesized by a chemical coprecipitation method and facilitated by the presence of the {beta}-cyclodextrin. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM); and Fourier Transformed Infrared Spectroscopy (FT-IR) were used in order to characterize the hydroxyapatite samples. The experimental results indicate that the obtained HA is in the range of 20-50 nm. Also it was found that the content of {beta}-CD has an impact on the purity of the HA as well in the particle size of the hydroxyapatite nanoparticles.

  3. Efficient photosensitized splitting of the thymine dimer/oxetane unit on its modifying beta-cyclodextrin by a binding electron donor.

    Science.gov (United States)

    Tang, Wen-Jian; Song, Qin-Hua; Wang, Hong-Bo; Yu, Jing-Yu; Guo, Qing-Xiang

    2006-07-07

    Two modified beta-cyclodextrins (beta-CDs) with a thymine dimer and a thymine oxetane adduct respectively, TD-CD and Ox-CD, have been prepared, and utilized to bind an electron-rich chromophore, indole or N,N-dimethylaniline (DMA), to form a supramolecular complex. We have examined the photosensitized splitting of the dimer/oxetane unit in TD-CD/Ox-CD by indole or DMA via an electron-transfer pathway, and observed high splitting efficiencies of the dimer/oxetane unit. On the basis of measurements of fluorescence spectra and splitting quantum yields, it is suggested that the splitting reaction occurs in a supramolecular complex by an inclusion interaction between the modified beta-CDs and DMA or indole. The back electron transfer, which leads low splitting efficiencies for the covalently-linked chromophore-dimer/oxetane compounds, is suppressed in the non-covalently-bound complex, and the mechanism has been discussed.

  4. Electrospinning of functional poly(methyl methacrylate) nanofibers containing cyclodextrin-menthol inclusion complexes

    International Nuclear Information System (INIS)

    Uyar, Tamer; Besenbacher, Flemming; Nur, Yusuf; Hacaloglu, Jale

    2009-01-01

    Electrospinning of nanofibers with cyclodextrin inclusion complexes (CD-ICs) is particularly attractive since distinct properties can be obtained by combining the nanofibers with specific functions of the CD-ICs. Here we report on the electrospinning of poly(methyl methacrylate) (PMMA) nanofibers containing cyclodextrin-menthol inclusion complexes (CD-menthol-ICs). These CD-menthol-IC functionalized nanofibers were developed with the purpose of producing functional nanofibers that contain fragrances/flavors with high temperature stability, and menthol was used as a model fragrance/flavor material. The PMMA nanofibers were electrospun with CD-menthol-ICs using three type of CD: α-CD, β-CD, and γ-CD. Direct pyrolysis mass spectrometry (DP-MS) studies showed that the thermal evaporation of menthol occurred over a very high and a broad temperature range (100-355 deg. C) for PMMA/CDmenthol-IC nanowebs, demonstrating the complexation of menthol with the CD cavity and its high temperature stability. Furthermore, as the size of CD cavity increased in the order α-CD β-CD>α-CD.

  5. [Study on two preparation methods for beta-CD inclusion compound of four traditional Chinese medicine volatile oils].

    Science.gov (United States)

    Li, Hailiang; Cui, Xiaoli; Tong, Yan; Gong, Muxin

    2012-04-01

    To compare inclusion effects and process conditions of two preparation methods-colloid mill and saturated solution-for beta-CD inclusion compound of four traditional Chinese medicine volatile oils and study the relationship between each process condition and volatile oil physical properties and the regularity of selective inclusion of volatile oil components. Volatile oils from Nardostachyos Radix et Rhizoma, Amomi Fructus, Zingiberis Rhizoma and Angelicaesinensis Radix were prepared using two methods in the orthogonal test. These inclusion compounds by optimized processes were assessed and compared by such methods as TLC, IR and scanning electron microscope. Inclusion oils were extracted by steam distillation, and the components found before and after inclusion were analyzed by GC-MS. Analysis showed that new inclusion compounds, but inclusion compounds prepared by the two processes had differences to some extent. The colloid mill method showed a better inclusion effect than the saturated solution method, indicating that their process conditions had relations with volatile oil physical properties. There were differences in the inclusion selectivity of components between each other. The colloid mill method for inclusion preparation is more suitable for industrial requirements. To prepare volatile oil inclusion compounds with heavy gravity and high refractive index, the colloid mill method needs longer time and more water, while the saturated solution method requires higher temperature and more beta-cyclodextrin. The inclusion complex prepared with the colloid mill method contains extended molecular weight chemical composition, but the kinds of components are reduced.

  6. NMR Study on the Inclusion Complexes of β-Cyclodextrin with Isoflavones

    Directory of Open Access Journals (Sweden)

    Rui Zhao

    2016-03-01

    Full Text Available The structure of the inclusion complexes of β-cyclodextrin (β-CD with daidzein and daidzin in D2O were investigated using NMR spectroscopy. For the β-CD and daidzein system, two types of 1:1 complexes were formed with the daidzein deeply inserted into the CD cavity with different orientations. For the β-CD/daidzin system, a 1:1 complex was formed with the flavonoid part of daidzin entering the CD cavity from the wide rim. The inclusion complexes determined by NMR were constructed using molecular docking. Furthermore, the mixture of puerarin, daidzein and daidzin, which are the major isoflavonoid components present in Radix puerariae, was analyzed by diffusion-ordered spectroscopy (DOSY alone and upon addition of β-CD in order to mimic chromatographic conditions and compare their binding affinities.

  7. Cyclodextrin inclusion complexes with thiocholesterol and their self-assembly on gold: A combined electrochemical and lateral force microscopy analysis

    International Nuclear Information System (INIS)

    Pandey, Rakesh K.; Lakshminarayanan, V.

    2014-01-01

    The present study is an attempt to understand the properties of an interesting self-assembled monolayer system composed of inclusion complexes of thiocholesterol and cyclodextrins. Cyclodextrins were used as host compound while thiocholesterol was used as the entrant molecule into the cavity of cyclodextrins. The improved electron transfer barrier property towards a redox couple indicates a sturdy inclusion complex monolayer. A very large R ct value, 64.6 kΩ·cm 2 for a redox system was obtained in the case of methyl-β-cyclodextrin and thiocholesterol inclusion complex self-assembled monolayer. A rather low value of capacitance 1.2 μF cm −2 measured in supporting electrolyte further signifies the fact that inclusion complex monolayer is quite impermeable for ionic species. In addition lateral force microscopy combined with force–distance analysis revealed the presence of an interesting mixed hydrophilic/hydrophobic surface. - Highlights: • Self-assembled monolayer of inclusion complexes on gold surface • Lateral force microscopy study of the regions of varying hydrophilicities • Could find applications in patterning surfaces to be hydrophilic/hydrophobic • Improved electron transfer barrier properties

  8. Inclusion of Paracetamol into β-cyclodextrin nanocavities in solution and in the solid state

    Science.gov (United States)

    El-Kemary, Maged; Sobhy, Saffaa; El-Daly, Samy; Abdel-Shafi, Ayman

    2011-09-01

    We report on steady-state UV-visible absorption and emission characteristics of Paracetamol, drug used as antipyretic agent, in water and within cyclodextrins (CDs): β-CD, 2-hydroxypropyl- β-CD (HP- β-CD) and 2,6-dimethyl- β-CD (Me- β-CD). The results reveal that Paracetamol forms a 1:1 inclusion complex with CD. Upon encapsulation, the emission intensity enhances, indicating a confinement effect of the nanocages on the photophysical behavior of the drug. Due to its methyl groups, the Me- β-CD shows the largest effect for the drug. The observed binding constant showing the following trend: Me- β-CD > HP- β-CD > β-CD. The less complexing effectiveness of HP- β-CD is due to the steric effect of the hydroxypropyl-substituents, which can hamper the inclusion of the guest molecules. The solid state inclusion complex was prepared by co-precipitation method and its characterization was investigated by Fourier transform infrared spectroscopy, 1H NMR and X-ray diffractometry. These approaches indicated that Paracetamol was able to form an inclusion complex with CDs, and the inclusion compounds exhibited different spectroscopic features and properties from Paracetamol.

  9. Production, Characterization, and Stability of Orange or Eucalyptus Essential Oil/β-Cyclodextrin Inclusion Complex.

    Science.gov (United States)

    Kringel, Dianini Hüttner; Antunes, Mariana Dias; Klein, Bruna; Crizel, Rosane Lopes; Wagner, Roger; de Oliveira, Roberto Pedroso; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

    2017-11-01

    The aim of this study was to produce and characterize inclusion complexes (IC) between β-cyclodextrin (β-CD) and orange essential oil (OEO) or eucalyptus essential oil (EEO), and to compare these with their pure compounds and physical mixtures. The samples were evaluated by chemical composition, morphology, thermal stability, and volatile compounds by static headspace-gas chromatography (SH-GC). Comparing the free essential oil and physical mixture with the inclusion complex, of both essential oils (OEO and EEO), it was observed differences occurred in the chemical composition, thermal stability, and morphology. These differences show that there was the formation of the inclusion complex and demonstrate the necessity of the precipitation method used to guarantee the interaction between β-CD and essential oils. The slow loss of the volatile compounds from both essential oils, when complexed with β-CD, showed a higher stability when compared with their physical mixtures and free essential oils. Therefore, the results showed that the chemical composition, molecular size, and structure of the essential oils influence the characteristics of the inclusion complexes. The application of the β-CD in the formation of inclusion complexes with essential oils can expand the potential applications in foods. © 2017 Institute of Food Technologists®.

  10. Synthesis of anatase TiO2 nanoparticles with beta-cyclodextrin as a supramolecular shell.

    Science.gov (United States)

    Li, Landong; Sun, Xiaohong; Yang, Yali; Guan, Naijia; Zhang, Fuxiang

    2006-11-20

    We report a novel, green hydrothermal-synthesis route to well-dispersed anatase TiO2 nanoparticles with particle sizes of 9-16 nm in the presence of beta-CD (beta-cyclodextrin). During the synthesis process, the CD-containing synthesis mixture assembled in both longitudinal and latitudinal directions. Driven by the interaction between molecules, the beta-CDs assembled in the longitudinal direction to form long-chain compounds, whereas in the latitudinal direction, they tended to form regular aggregates through coordination with the Ti species from the hydrolysis of tetrabutyl titanate. In view of the effect of the coordination and the steric hindrance of beta-CDs as a supramolecular shell, homogeneous nuclei and slow growth of TiO2 crystals during the synthesis process was observed, which was responsible for the formation of uniform TiO2 nanoparticles. The low beta-CD dosage and the high product yield (>90%) demonstrated well the potential of this synthesis route in the large-scale industrial production of anatase nanoparticles.

  11. Fluorescently labeled methyl-beta-cyclodextrin enters intestinal epithelial Caco-2 cells by fluid-phase endocytosis.

    Directory of Open Access Journals (Sweden)

    Ferenc Fenyvesi

    Full Text Available Cyclodextrins are widely used excipients for increasing the bioavailability of poorly water-soluble drugs. Their effect on drug absorption in the gastrointestinal tract is explained by their solubility- and permeability-enhancement. The aims of this study were to investigate penetration properties of fluorescently labeled randomly methylated-beta-cyclodextrin (FITC-RAMEB on Caco-2 cell layer and examine the cellular entry of cyclodextrins on intestinal cells. The permeability of FITC-RAMEB through Caco-2 monolayers was very limited. Using this compound in 0.05 mM concentration the permeability coefficient was 3.35±1.29×10(-8 cm/s and its permeability did not change in the presence of 5 mM randomly methylated-beta-cyclodextrin. Despite of the low permeability, cellular accumulation of FITC-RAMEB in cytoplasmic vesicles was significant and showed strong time and concentration dependence, similar to the characteristics of the macropinocytosis marker Lucifer Yellow. The internalization process was fully inhibited at 0°C and it was drastically reduced at 37°C applying rottlerin, an inhibitor of macropinocytosis. Notably, FITC-RAMEB colocalized with the early endosome organizer Rab5a. These results have revealed that FITC-RAMEB is able to enter intestinal epithelial cells by fluid-phase endocytosis from the apical side. This mechanism can be an additional process which helps to overcome the intestinal barrier and contributes to the bioavailability enhancement of cyclodextrins.

  12. β-Cyclodextrin Inclusion Complex to Improve Physicochemical Properties of Pipemidic Acid: Characterization and Bioactivity Evaluation

    Directory of Open Access Journals (Sweden)

    Gaetano Malgieri

    2013-06-01

    Full Text Available The aptitude of cyclodextrins (CDs to form host-guest complexes has prompted an increase in the development of new drug formulations. In this study, the inclusion complexes of pipemidic acid (HPPA, a therapeutic agent for urinary tract infections, with native β-CD were prepared in solid state by kneading method and confirmed by FT-IR and 1H NMR. The inclusion complex formation was also characterized in aqueous solution at different pH via UV-Vis titration and phase solubility studies obtaining the stability constant. The 1:1 stoichiometry was established by a Job plot and the inclusion mechanism was clarified using docking experiments. Finally, the antibacterial activity of HPPA and its inclusion complex was tested on P. aeruginosa, E. coli and S. aureus to determine the respective EC50s and EC90s. The results showed that the antibacterial activity of HPPA:β-CD against E. coli and S. aureus is higher than that of HPPA. Furthermore, HPPA and HPPA:β-CD, tested on human hepatoblastoma HepG2 and MCF-7 cell lines by MTT assay, exhibited, for the first time, antitumor activities, and the complex revealed a higher activity than that of HPPA. The use of β-CD allows an increase in the aqueous solubility of the drug, its bioavailability and then its bioactivity.

  13. Inclusion Complexes of Copaiba (Copaifera multijuga Hayne Oleoresin and Cyclodextrins: Physicochemical Characterization and Anti-Inflammatory Activity

    Directory of Open Access Journals (Sweden)

    Jonas Gabriel de Oliveira Pinheiro

    2017-11-01

    Full Text Available Complexation with cyclodextrins (CDs is a technique that has been extensively used to increase the aqueous solubility of oils and improve their stability. In addition, this technique has been used to convert oils into solid materials. This work aims to develop inclusion complexes of Copaifera multijuga oleoresin (CMO, which presents anti-inflammatory activity, with β-cyclodextrin (β-CD and hydroxypropyl-β-cyclodextrin (HP-β-CD by kneading (KND and slurry (SL methods. Physicochemical characterization was performed to verify the occurrence of interactions between CMO and the cyclodextrins. Carrageenan-induced hind paw edema in mice was carried out to evaluate the anti-inflammatory activity of CMO alone as well as complexed with CDs. Physicochemical characterization confirmed the formation of inclusion complex of CMO with both β-CD and HP-β-CD by KND and SL methods. Carrageenan-induced paw edema test showed that the anti-inflammatory activity of CMO was maintained after complexation with β-CD and HP-β-CD, where they were able to decrease the levels of nitrite and myeloperoxidase. In conclusion, this study showed that it is possible to produce inclusion complexes of CMO with CDs by KND and SL methods without any change in CMO’s anti-inflammatory activity.

  14. Development and Validation Dissolution Analytical Method of Nimesulide beta-Cyclodextrin 400 mg Tablet

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Carvalho Pereira

    2016-10-01

    Full Text Available The nimesulide (N-(4-nitro-2-phenoxyphenylmethanesulfonamide belongs to the class of non-steroidal anti-inflammatory drugs (NSAIDs and category II of the biopharmaceutical classification, The complexation of nimesulide with b-cyclodextrin is a pharmacological strategy to increase the solubility of the drug The objective of this study was to develop and validate an analytical methodology for dissolving the nimesulide beta-cyclodextrin 400 mg tablet and meets the guidelines of ANVISA for drug registration purposes. Once developed, the dissolution methodology was validated according to the RE of parameters no.  899/2003. In the development of the method it was noted that the duration of the dissolution test was 60 minutes, the volume and the most suitable dissolution medium was 900 mL of aqueous solution of sodium lauryl sulfate 1% (w/ v. It was also noted that rotation of 100 rpm and the paddle apparatus was the most appropriate to evaluate the dissolution of the drug. Spectrophotometric methodology was used to quantify the percentage of dissolved drug. The wavelength was 390 nm using the quantification. The validation of the methodology, system suitability parameters, specificity/selectivity, linearity, precision, accuracy and robustness were satisfactory and proved that the developed dissolution methodology was duly executed. DOI: http://dx.doi.org/10.17807/orbital.v8i5.827

  15. Luminescent properties and structure of multicomponent naphthalene-{beta}-cyclodextrin complexes. 1. Effect of adding third parties, o-carborane or/and adamantane

    Energy Technology Data Exchange (ETDEWEB)

    Nazarov, Valery B. [Institute of Problems of Chemical Physics of Russian Academy of Sciences, 142432 Moscow region, Chernogolovka (Russian Federation); Avakyan, Vitaly G., E-mail: avak@photonics.ru [Photochemistry Center of Russian Academy of Sciences, 119421 Moscow, Novatorov 7a (Russian Federation); Rudyak, Vladimir Y.; Alfimov, Michail V. [Photochemistry Center of Russian Academy of Sciences, 119421 Moscow, Novatorov 7a (Russian Federation); Vershinnikova, Tatiana G. [Institute of Problems of Chemical Physics of Russian Academy of Sciences, 142432 Moscow region, Chernogolovka (Russian Federation)

    2011-09-15

    Luminescence spectra of water solution of {beta}-cyclodextrin ({beta}-CD) inclusion complexes with naphthalene have been studied in the presence of carcass compounds (CC), adamantane and ocarborane, added in solution as the third parties. It was observed that the CC structure completely determines luminescence type displayed by the three-component complex. Adding adamantane to the solution leads to the disappearance of the spontaneous excimer fluorescence observed usually along with a monomer fluorescence of naphthalene and the appearance of the long lived phosphorescence at room temperature. At the same time, introducing o-carborane in solution of {beta}-CD inclusion complexes with naphthalene results in the dramatic growth of intensity of the excimer band at the expense of lowering intensity of monomer fluorescence. These phenomena were explained using results of the quantum-chemical calculation of the structure and complexation energies at the semi-empirical PM3 and DFT levels of theory. - Highlights: > Structure of carcass compounds determines luminescence types for naphthalene - betaCD complex. > Adding o-carborane leads to the growth of excimer fluorescence at low naphthalene concentrations. > Adding adamantane leads to the room temperature phosphorescence without deoxygenation.

  16. Sensitive detection of rutin based on {beta}-cyclodextrin-chemically reduced graphene/Nafion composite film

    Energy Technology Data Exchange (ETDEWEB)

    Liu Kunping; Wei Jinping [School of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Wang Chunming, E-mail: wangcm@lzu.edu.cn [School of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China)

    2011-05-30

    Highlights: > {beta}-CD-graphene composite obtained via a simple sonication-induced assembly. > Accelerating electron transfer on electrode to amplify the electrochemical signal. > A highly sensitive electrochemical sensor for rutin detection. > Good selectivity and reproducibility for the detection of rutin in real samples. - Abstract: An electrochemical sensor based on chemically reduced graphene (CRG) was developed for the sensitive detection of rutin. To construct the base of the sensor, a novel composite was initially fabricated and used as the substrate material by combining CRG and {beta}-cyclodextrin ({beta}-CD) via a simple sonication-induced assembly. Due to the high rutin-loading capacity on the electrode surface and the upstanding electric conductivity of graphene, the electrochemical response of the fabricated sensor was greatly enhanced and displayed excellent analytical performance for rutin detection from 6.0 x 10{sup -9} to 1.0 x 10{sup -5} mol L{sup -1} with a low detection limit of 2.0 x 10{sup -9} mol L{sup -1} at 3{sigma}. Moreover, the proposed electrochemical sensor also exhibited good selectivity and acceptable reproducibility and could be used for the detection of rutin in real samples. Therefore, the present work offers a new way to broaden the analytical applications of graphene in pharmaceutical analysis.

  17. Ocular pharmacokinetics of topically-applied ketoconazole solution containing hydroxypropyl beta-cyclodextrin to rabbits.

    Science.gov (United States)

    Zhang, Junjie; Wang, Liya; Gao, Changfeng; Zhang, Li; Xia, Huiyun

    2008-10-01

    The aim of this study was to develop an aqueous ketoconazole (KET) eye drop in order to increase the corneal permeability and improve ocular bioavailability following topical application. Hydroxypropyl beta-cyclodextrin (HP-beta-CD) was used to formulate an aqueous eye drop to improve the aqueous solubility of KET. A single dose of of either KET suspension (1.5%; KET-SP) or KET (1.5%)/HP-beta -CD (12.5%) solution (KET-CD) was applied to rabbits. Aqueous humor and cornea were collected after 5, 10, 20, 30, 45, 60, 90, 120, and 180 min. KET concentrations were determined by high-performance liquid chromatography after extraction. After topically applying KET-CD, the KET concentrations in aqueous humor were significantly increased at 10 approximately 120 min, compared with those of KET-SP (P cornea (118.24 microg/g) was achieved within 5 min after the instillation of KET-CD, 18.4 times higher than that of KET-SP at the same time point, whereas the highest KET level in cornea was only 8.57 microg/g after a 10-min application of KET-SP. The KET levels in corneas obtained after the application of KET-CD were all much higher than those obtained by KETSP (P corneas over the KET-SP.

  18. Spectroscopic methods for aqueous cyclodextrin inclusion complex binding measurement for 1,4-dioxane, chlorinated co-contaminants, and ozone

    Science.gov (United States)

    Khan, Naima A.; Johnson, Michael D.; Carroll, Kenneth C.

    2018-03-01

    Recalcitrant organic contaminants, such as 1,4-dioxane, typically require advanced oxidation process (AOP) oxidants, such as ozone (O3), for their complete mineralization during water treatment. Unfortunately, the use of AOPs can be limited by these oxidants' relatively high reactivities and short half-lives. These drawbacks can be minimized by partial encapsulation of the oxidants within a cyclodextrin cavity to form inclusion complexes. We determined the inclusion complexes of O3 and three common co-contaminants (trichloroethene, 1,1,1-trichloroethane, and 1,4-dioxane) as guest compounds within hydroxypropyl-β-cyclodextrin. Both direct (ultraviolet or UV) and competitive (fluorescence changes with 6-p-toluidine-2-naphthalenesulfonic acid as the probe) methods were used, which gave comparable results for the inclusion constants of these species. Impacts of changing pH and NaCl concentrations were also assessed. Binding constants increased with pH and with ionic strength, which was attributed to variations in guest compound solubility. The results illustrate the versatility of cyclodextrins for inclusion complexation with various types of compounds, binding measurement methods are applicable to a wide range of applications, and have implications for both extraction of contaminants and delivery of reagents for treatment of contaminants in wastewater or contaminated groundwater.

  19. Crystallographic and theoretical studies of an inclusion complex of β-cyclodextrin with fentanyl.

    Science.gov (United States)

    Ogawa, Noriko; Nagase, Hiromasa; Loftsson, Thorsteinn; Endo, Tomohiro; Takahashi, Chisato; Kawashima, Yoshiaki; Ueda, Haruhisa; Yamamoto, Hiromitsu

    2017-10-15

    The crystal structure of an inclusion complex of β-cyclodextrin (β-CD) with fentanyl was determined by single crystal X-ray diffraction analysis. The crystal belongs to the triclinic space group P1 and the complex comprises one fentanyl, two β-CD, and several water molecules. β-CD and fentanyl form a host-guest inclusion complex at a ratio of 2:1 and the asymmetric unit of the complex contains two host molecules (β-CDs) in a head-to-head arrangement that form dimers through hydrogen bonds between the secondary hydroxyl groups of β-CD and one guest molecule. Fentanyl is totally contained within the β-CD cavity and the structure of the phenylethyl part of fentanyl inside the dimeric cavity of the complex is disordered. Furthermore, theoretical molecular conformational calculations were conducted to clarify the mobility of the guest molecule in the β-CD cavity using CONFLEX software. Crystal optimization and crystal energy calculations were also conducted. The results of the theoretical calculations confirmed that the conformation of disorder part 1, which was high in occupancy by crystal structure analysis, was more stable. The phenylethyl part of fentanyl existed in several stable conformations. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Formulation of cyclodextrin inclusion complex-based orally disintegrating tablet of eslicarbazepine acetate for improved oral bioavailability

    International Nuclear Information System (INIS)

    Desai, Samixa; Poddar, Aditi; Sawant, Krutika

    2016-01-01

    The present investigation was aimed towards developing a beta-cyclodextrin (β-CD) solid dispersion (SD) based orally disintegrating tablet (ODT) of eslicarbazepine acetate (ESL), for improving the dissolution and providing fast onset of anti-epileptic action. Optimum ratio of ESL and β-CD was determined by Job's plot. Thereafter, solid dispersions were prepared by solvent evaporation method and evaluated for yield, assay, Differential scanning calorimetry (DSC), Fourier transform infra red spectroscopy (FTIR), X-ray diffraction (XRD), and in vitro dissolution. Optimized SD was compressed into ODT by direct compression using super disintegrants and evaluated for wetting time, drug content, in vitro drug release and in vivo studies. The results of DSC, FTIR and XRD analysis supported the formation of inclusion complex. An improved dissolution with 99.95 ± 2.80% drug release in 60 min was observed in comparison to 24.85 ± 2.96% release from a plain drug suspension. Tablets with crosspovidone as a super disintegrant showed the least disintegration time of 24.66 ± 1.52 s and higher in vitro drug release against marketed tablets. In vivo studies indicated that the formulated tablets had 2 times higher bioavailability than marketed tablets. Thus, the developed β-CD–ESL SD-ODT could provide faster onset of action and higher bioavailability, which would be beneficial in case of epileptic seizures. - Highlights: • β-cyclodextrin–eslicarbazepine acetate complex developed with enhanced solubility. • Formulated Orally disintegrating tablets (ODT) disintegrated within 30 s. • Bioavailability from ODT was 2 times higher than marketed tablets. • Onset of action for ODT was also faster than marketed tablets. • Formulated ODT would aid epileptic patients incapable of swallowing tablets.

  1. Formulation of cyclodextrin inclusion complex-based orally disintegrating tablet of eslicarbazepine acetate for improved oral bioavailability

    Energy Technology Data Exchange (ETDEWEB)

    Desai, Samixa; Poddar, Aditi; Sawant, Krutika, E-mail: dr_krutikasawant@yahoo.co.in

    2016-01-01

    The present investigation was aimed towards developing a beta-cyclodextrin (β-CD) solid dispersion (SD) based orally disintegrating tablet (ODT) of eslicarbazepine acetate (ESL), for improving the dissolution and providing fast onset of anti-epileptic action. Optimum ratio of ESL and β-CD was determined by Job's plot. Thereafter, solid dispersions were prepared by solvent evaporation method and evaluated for yield, assay, Differential scanning calorimetry (DSC), Fourier transform infra red spectroscopy (FTIR), X-ray diffraction (XRD), and in vitro dissolution. Optimized SD was compressed into ODT by direct compression using super disintegrants and evaluated for wetting time, drug content, in vitro drug release and in vivo studies. The results of DSC, FTIR and XRD analysis supported the formation of inclusion complex. An improved dissolution with 99.95 ± 2.80% drug release in 60 min was observed in comparison to 24.85 ± 2.96% release from a plain drug suspension. Tablets with crosspovidone as a super disintegrant showed the least disintegration time of 24.66 ± 1.52 s and higher in vitro drug release against marketed tablets. In vivo studies indicated that the formulated tablets had 2 times higher bioavailability than marketed tablets. Thus, the developed β-CD–ESL SD-ODT could provide faster onset of action and higher bioavailability, which would be beneficial in case of epileptic seizures. - Highlights: • β-cyclodextrin–eslicarbazepine acetate complex developed with enhanced solubility. • Formulated Orally disintegrating tablets (ODT) disintegrated within 30 s. • Bioavailability from ODT was 2 times higher than marketed tablets. • Onset of action for ODT was also faster than marketed tablets. • Formulated ODT would aid epileptic patients incapable of swallowing tablets.

  2. Estimation of apparent binding constant of complexes of selected acyclic nucleoside phosphonates with beta-cyclodextrin by affinity capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Šolínová, Veronika; Mikysková, Hana; Kaiser, Martin Maxmilian; Janeba, Zlatko; Holý, Antonín; Kašička, Václav

    2016-01-01

    Roč. 37, č. 2 (2016), s. 239-247 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA13-17224S; GA ČR(CZ) GA15-01948S Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * affinity capillary electrophoresis * binding constant * nucleotide analogs * beta-cyclodextrin Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 2.744, year: 2016

  3. ESR, electrochemical and cyclodextrin-inclusion studies of triazolopyridyl pyridyl ketones and dipyridyl ketones derivatives

    Science.gov (United States)

    Olea-Azar, C.; Abarca, B.; Norambuena, E.; Opazo, L.; Jullian, C.; Valencia, S.; Ballesteros, R.; Chadlaoui, M.

    2008-11-01

    The electron spin resonance (ESR) spectra of free radicals obtained by electrolytic reduction of triazolopyridyl pyridyl ketones and dipyridyl ketones derivatives were measured in dimethylsulfoxide (DMSO). The hyperfine patterns indicate that the spin density delocalization is dependent of the rings presented in the molecule. The electrochemistry of these compounds was characterized using cyclic voltammetry, in DMSO as solvent. When one carbonyl is present in the molecule one step in the reduction mechanism was observed while two carbonyl are present two steps were detected. The first wave was assigned to the generation of the correspondent free radical species, and the second wave was assigned to the dianion derivatives. The phase-solubility measurements indicated an interaction between molecules selected and cyclodextrins in water. These inclusion complexes are 1:1 with βCD, and HP-βCD. The values of Ks showed a different kind of complexes depending on which rings are included. AM1 and DFT calculations were performed to obtain the optimized geometries, theoretical hyperfine constants, and spin distributions, respectively. The theoretical results are in complete agreement with the experimental ones.

  4. Binding mode and free energy prediction of fisetin/β-cyclodextrin inclusion complexes

    Directory of Open Access Journals (Sweden)

    Bodee Nutho

    2014-11-01

    Full Text Available In the present study, our aim is to investigate the preferential binding mode and encapsulation of the flavonoid fisetin in the nano-pore of β-cyclodextrin (β-CD at the molecular level using various theoretical approaches: molecular docking, molecular dynamics (MD simulations and binding free energy calculations. The molecular docking suggested four possible fisetin orientations in the cavity through its chromone or phenyl ring with two different geometries of fisetin due to the rotatable bond between the two rings. From the multiple MD results, the phenyl ring of fisetin favours its inclusion into the β-CD cavity, whilst less binding or even unbinding preference was observed in the complexes where the larger chromone ring is located in the cavity. All MM- and QM-PBSA/GBSA free energy predictions supported the more stable fisetin/β-CD complex of the bound phenyl ring. Van der Waals interaction is the key force in forming the complexes. In addition, the quantum mechanics calculations with M06-2X/6-31G(d,p clearly showed that both solvation effect and BSSE correction cannot be neglected for the energy determination of the chosen system.

  5. Associating Polymer Networks Based on Cyclodextrin Inclusion Compounds for Heavy Oil Recovery

    Directory of Open Access Journals (Sweden)

    Xi Li

    2018-01-01

    Full Text Available This work evaluates an approach to improve the enhanced heavy oil recovery performance of hydrophobic associating polymer. A polymeric system based on water-soluble hydrophobic associating polymer (WSHAP and cyclodextrin (CD polymer was proposed in this work. Addition of CD polymer to WSHAP forms interpolymer bridges by inclusion of CD groups with hydrophobic tails, and thereby the network structure is strengthened. The proposed system offers good viscoelasticity, pronounced shear thinning, and interesting viscosity-temperature relations. Sand pack tests indicated that the proposed system can build high resistance factor during the propagation in porous media, and its moderate adsorption phenomenon was represented by the thickness of the adsorbed layer. The relationship between effective viscosity and oil recovery increment indicated that the proposed system can significantly reduce the residual oil saturation due to the “piston-like” propagation. The overall oil recovery was raised by 5.7 and 24.5% of the original oil in place compared with WSHAP and partially hydrolyzed polyacrylamide (HPAM, respectively.

  6. Effects of Two Surfactants and Beta-Cyclodextrin on Beta-Cypermethrin Degradation by Bacillus licheniformis B-1.

    Science.gov (United States)

    Zhao, Jiayuan; Chi, Yuanlong; Liu, Fangfang; Jia, Dongying; Yao, Kai

    2015-12-23

    The biodegradation efficiency of beta-cypermethrin (β-CY) is low especially at high concentrations mainly due to poor contact between this hydrophobic pesticide and microbial cells. In this study, the effects of two biodegradable surfactants (Tween-80 and Brij-35) and β-cyclodextrin (β-CD) on the growth and cell surface hydrophobicity (CSH) of Bacillus licheniformis B-1 were studied. Furthermore, their effects on the solubility, biosorption, and degradation of β-CY were investigated. The results showed that Tween-80 could slightly promote the growth of the strain while Brij-35 and β-CD exhibited little effect on its growth. The CSH of strain B-1 and the solubility of β-CY were obviously changed by using Tween-80 and Brij-35. The surfactants and β-CD could enhance β-CY biosorption and degradation by the strain, and the highest degradation was obtained in the presence of Brij-35. When the surfactant or β-CD concentration was 2.4 g/L, the degradation rate of β-CY in Brij-35, Tween-80, and β-CD treatments was 89.4%, 50.5%, and 48.1%, respectively. The half-life of β-CY by using Brij-35 was shortened by 69.1 h. Beta-CY content in the soil with both strain B-1 and Brij-35 decreased from 22.29 mg/kg to 4.41 mg/kg after incubation for 22 d. This work can provide a promising approach for the efficient degradation of pyrethroid pesticides by microorganisms.

  7. Diffusion coefficients of the ternary system (2-hydroxypropyl-{beta}-cyclodextrin + caffeine + water) at T = 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Ana C.F. [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal)], E-mail: anacfrib@ci.uc.pt; Santos, Cecilia I.A.V. [Departamento de Quimica Fisica, Facultad de Farmacia, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain)], E-mail: cecilia.alves@uah.es; Lobo, Victor M.M. [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal)], E-mail: vlobo@ci.uc.pt; Cabral, Ana M.T.D.P.V. [Faculty of Pharmacy, University of Coimbra, 3000-295 Coimbra (Portugal)], E-mail: acabral@ff.uc.pt; Veiga, Francisco J.B. [Faculty of Pharmacy, University of Coimbra, 3000-295 Coimbra (Portugal)], E-mail: fveiga@ci.uc.pt; Esteso, Miguel A. [Departamento de Quimica Fisica, Facultad de Farmacia, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain)], E-mail: miguel.esteso@uah.es

    2009-12-15

    Ternary mutual diffusion coefficients measured by Taylor dispersion method (D{sub 11}, D{sub 22}, D{sub 12}, and D{sub 21}) are reported for aqueous solutions of 2-hydroxypropyl-{beta}-cyclodextrin (HP-{beta}-CD) + caffeine at T = 298.15 K at carrier concentrations from (0.000 to 0.010) mol . dm{sup -3}, for each solute, respectively. These diffusion coefficients have been measured having in mind a better understanding of the structure of these systems and thermodynamic behaviour of caffeine and 2-hydroxypropyl-{beta}-cyclodextrin in solution. For example, from these data it will be possible to estimate some parameters, such as the fraction of associated species HP-{beta}-CD (X{sub 1}) and caffeine (X{sub 2}) in this complex, the monomer and dimer fractions, X{sub 2}{sup M} and X{sub 2}{sup D}, respectively, and the limiting diffusion coefficients of the HP-{beta}-CD, D{sub HPBCD}{sup 0}, of the dimers caffeine entities, D{sub D}{sup 0}, and of those complexes (1:1), D{sub complex}{sup 0}.

  8. Preparation and physico-chemical characterization of inclusion complexes between local anesthetics and hydroxypropyl-β-cyclodextrin

    International Nuclear Information System (INIS)

    Moraes, Carolina Morales; Abrami, Priscila; Goncalves, Marcos Moises; Andreo Filho, Newton; Fernandes, Sergio Antonio; Paula, Eneida de; Fraceto, Leonardo Fernandes

    2007-01-01

    S(-) Bupivacaine (S(-)BVC) and Lidocaine (LDC) are widely used local anesthetics (LA). Hydroxypropyl β-cyclodextrin (HP-β-CD) is used as a drug-carrier system. The aim of this work was to characterize inclusion complexes between LA and HP-β-CD. The affinity constants determined at different pHs show favourable complexation. The release kinetics experiments showed that S(-)BVC and LDC changed the released profiles in the presence of HP-β-CD. Nuclear magnetic resonance experiments gave information about the interaction between LA and the cyclodextrin cavity. This study focused on the physicochemical characterization of drug-delivery formulations that come out as potentially new therapeutic options for pain treatment. (author)

  9. Sorption of agrochemical model compounds by sorbent materials containing beta-cyclodextrin.

    Science.gov (United States)

    Wilson, Lee D; Mohamed, Mohamed H; Guo, Rui; Pratt, Dawn Y; Kwon, Jae Hyuck; Mahmud, Sarker T

    2010-04-01

    Polymeric sorbent materials that incorporate beta-cyclodextrin (CD) have been prepared and their sorption behavior toward two model agrochemical contaminant compounds, p-nitrophenol (PNP) and methyl chloride examined. The sorption of PNP was studied in aqueous solution using ultraviolet-visible (UV-Vis) spectroscopy, whereas the sorption of methyl chloride from the gas phase was studied using a Langmuir adsorption method. The sorption results for PNP in solution were compared between granular activated carbon (GAC), modified GAC, CD copolymers, and CD-based mesoporous silica hybrid materials. Nitrogen porosimetry at 77 K was used to estimate the surface area and pore structure properties of the sorbent materials. The sorbents displayed variable surface areas as follows: copolymers (36.2-157 m(2)/g), CD-silica materials (307-906 m(2)/g), surface modified GAC (657 m(2)/g), and granular activated carbon (approximately 10(3) m(2)/g). The sorption capacities for PNP and methyl chloride with the different sorbents are listed in descending order as follows: GAC > copolymers > surface modified GAC > CD-silica hybrid materials. In general, the differences in the sorption properties of the sorbents were related to the following: (i) surface area of the sorbent, (ii) CD content and accessibility, (iii) and the chemical nature of the sorbent material.

  10. NMR studies of inclusion complexes formed by (R)-α-lipoic acid with α-, β-, and γ-cyclodextrins

    International Nuclear Information System (INIS)

    Ikeda, Hiroshi; Ikuta, Naoko; Nakata, Daisuke; Ishida, Yoshiyuki; Terao, Keiji

    2015-01-01

    The structures of inclusion complexes of (R)-α-lipoic acid with α-, β-, and γ-cyclodextrin (CD) were constructed using restraints derived from ROESY spectra and MMFF94 molecular mechanics calculations. (R)-α-lipoic acid and α-CD generate a single stable inclusion complex, in which the 1,2-dithiolane ring of the (R)-α-lipoic acid is oriented toward the secondary hydroxy side of the α-CD. NMR data suggests that β-CD produces two kinds of inclusion complexes with α-lipoic acid. Finally, γ-CD yields 1:1 and 1:2 host/guest complexes with (R)-α-lipoic acid. The estimated structure of the 1:1 γ-CD inclusion complex has the 1,2-dithiolane ring oriented toward the primary hydroxy side of the γ-CD. (author)

  11. Inclusion complex of tamibarotene with hydroxypropyl-β-cyclodextrin: Preparation, characterization, in-vitro and in-vivo evaluation

    Directory of Open Access Journals (Sweden)

    Ying Yang

    2017-03-01

    Full Text Available The goal of this study was to improve the solubility and oral bioavailability of tamibarotene by complexing it with hydroxypropyl-β-cyclodextrin (HP-β-CD. The inclusion complex of tamibarotene with hydroxypropyl-β-cyclodextrin (Am80-HP-β-CD was prepared through a freeze-drying method at the mole ratio of 1:1 (Am80: HP-β-CD. Fourier transform infrared spectroscopy (FT-IR and differential scanning calorimetry (DSC indicated the formation of Am80-HP-β-CD. In vitro dissolution studies showed that the solubility and dissolution percentage of Am80-HP-β-CD was improved substantially compared to Am80. An improved dissolution with approximately 97% drug release in 3 min was observed, in comparison with Am80 with approximately 60% release in 45 min. In vivo studies indicated that the AUC0-∞ has increased 2.79 times and the Cmax 4.37 times after the formation of inclusion complex. The decrease of tmax indicated the Am80-HP-β-CD inclusion complex can be absorbed into blood faster. In short, the solubility and bio-availability of Am80 has notably increased with the complexation of HP-β-CD. Therefore, using the inclusion technique is a promising method to improve the solubility of insoluble drugs.

  12. Statistically designed enzymatic hydrolysis of an icariin/β-cyclodextrin inclusion complex optimized for production of icaritin

    Directory of Open Access Journals (Sweden)

    Xin Jin

    2012-02-01

    Full Text Available This study focuses on the preparation and enzymic hydrolysis of an icariin/β-cyclodextrin inclusion complex to efficiently generate icaritin. The physical characteristics of the inclusion complex were evaluated by differential scanning calorimetry (DSC. Enzymatic hydrolysis was optimized for the conversion of icariin/β-cyclodextrin complex to icaritin by Box–Behnken statistical design. The inclusion complex formulation increased the solubility of icariin approximately 17-fold, from 29.2 to 513.5 μg/mL at 60 °C. The optimum conditions were predicted by Box–Behnken statistical design as follows: 60 °C, pH 7.0, the ratio of enzyme/substrate (1:1.1 and reaction time 7 h. Under the optimal conditions the conversion of icariin was 97.91% and the reaction time was decreased by 68% compared with that without β-CD inclusion. Product analysis by melting point, ESI-MS, UV, IR, 1H NMR and 13C NMR confirmed the authenticity of icaritin with a purity of 99.3% and a yield of 473 mg of icaritin from 1.1 g icariin.

  13. Ethyl substituted {beta}-cyclodextrin enhanced fluorimetric method for the determination of trace amounts of oxytetracycline in urine, serum, feed of chook and milk

    Energy Technology Data Exchange (ETDEWEB)

    Hongjian, Wang [Department of Chemistry, Shandong Normal University, Jinan 250014 (China); Faju, Hou [Department of Chemistry, Shandong Normal University, Jinan 250014 (China); Chongqiu, Jiang [Department of Chemistry, Shandong Normal University, Jinan 250014 (China)

    2005-05-15

    A simple sensitive spectrofluorimetric method was developed for the determination of oxytetracycline (OTC). Ethyl substituted {beta}-cyclodextrin (DE-{beta}-CD) can remarkably enhance the fluorescence intensity of the OTC-Eu{sup 3+} complex at {lambda}=612nm and the enhanced fluorescence intensity of Eu{sup 3+} ion is in proportion to the concentration of OTC. Optimum conditions for the determination of OTC were also investigated. The linear range of this method for the determination of OTC is 8.28x10{sup -8}-1.73x10{sup -5}mol/L and the limit of detection is 6.76x10{sup -9}mol/L, respectively. The developed method is practical and relatively free interference from coexisting substances and can be successfully applied to determination of OTC in samples of urine, serum, feed of chook and milk. The enhancement of the fluorescence at {lambda}{sub em}=612nm of Eu{sup 3+} ion is because of the inclusion complex OTC-Eu{sup 3+}-DE-{beta}-CD.

  14. Study of inclusion complex formation between chlorpromazine hydrochloride, as an antiemetic drug, and β-cyclodextrin, using conductometric technique

    International Nuclear Information System (INIS)

    Rafati, Amir Abbas; Hamnabard, Nazanin; Ghasemian, Ensieh; Nojini, Zabiolah Bolboli

    2009-01-01

    The behavior of micellization of chlorpromazine hydrochloride (CPH) as an antiemetic drug and its inclusion complex formation with β-cyclodextrin (β-CD) was studied using conductometric technique. The binding or association constant of the complexation equilibrium is evaluated from conductometric measurements by using a nonlinear regression method. The resulting K values for micellization as well as complexation are analyzed. The experiments were carried out at different temperatures. It has been found that CPH form only the 1:1 complex. The association constant values are used for evaluation of thermodynamic parameters of complexation, such as ΔG complex o , ΔH complex o and ΔS complex o .

  15. [Solubilization Specificities Interferon beta-1b from Inclusion Bodies].

    Science.gov (United States)

    Zhuravko, A S; Kononova, N V; Bobruskin, A I

    2015-01-01

    A new solubilization method of recombinant interferon beta-1b (IFNβ-1b) from the inclusion bodies was developed. This method allows to extract the target protein selectively in the solutions of different alcohols, such as ethanol, propanol and isopropanol. It was shown that the more effective IFNβ-1b solubilization was achieved in the 55% propanol solution. This method allowed to extract the target protein from inclusion bodies around 85-90%, and significantly reduced Escherichia coli content in the solubilizate, in comparison with standard methods.

  16. Study in aqueous solution of the praseodymium inclusion in β-cyclodextrin in 2 M of NaCl; Estudio en solucion acuosa de la inclusion del praseodimio en la β-ciclodextrina en 2 M de NaCl

    Energy Technology Data Exchange (ETDEWEB)

    De la Cruz M, N.

    2013-07-01

    In the fission of uranium to produce electricity, generated between the fission products which are the lanthanides and actinides that at any given time may come into contact with aqueous media, because of this, praseodymium was including in the β-cyclodextrin in order to increase the solubility and stability of praseodymium by forming inclusion complexes Praseodymium-β-cyclodextrin (Pr-β-Cd). The inclusion study was conducted in a proportion of praseodymium and β-cyclodextrin. Infrared spectra, Raman and X-ray diffraction showed the presence of praseodymium and β-cyclodextrin in the inclusion complex, in both proportions. The analysis by scanning electron microscopy confirmed the inclusion of praseodymium in βcyclodextrin. In general, the results of characterization obtained by these techniques show the formation of the inclusion complex. Furthermore, the behaviour of praseodymium inclusion in the β-cyclodextrin was studied in 2 M NaCl at 303 K and free-CO{sub 2} conditions. For this reason, we used two methods: spectrophotometric and potentiometric titration direct of praseodymium-β-cyclodextrin, the data were treated graphically and with the program SUPERQUAD, respectively. The values obtained for praseodymium by spectrophotometric method was: log β{sub 1}= -8.75 calculated graphically and with the potentiometric method, using program SUPERQUAD were logβ{sub 1,OH}= -8.73 ± 0.01 logβ{sub 1,2OH}= -18.27 ± 0.16 and logβ{sub 1,3OH}= -26.44 ± 0.02 obtained simultaneously. (Author)

  17. Microencapsulation of caffeic acid phenethyl ester and caffeic acid phenethyl amide by inclusion in hydroxypropyl-β-cyclodextrin.

    Science.gov (United States)

    Garrido, E Manuela P J; Cerqueira, Ana S; Chavarria, Daniel; Silva, Tiago; Borges, Fernanda; Garrido, Jorge M P J

    2018-07-15

    Caffeic acid phenethyl ester (CAPE) is a bioactive polyphenolic compound obtained from propolis extract. Although it has a broad therapeutic potential, the bioavailability of CAPE is limited, due to reduced solubility and poor plasmatic stability. Efforts to reduce these pharmacokinetic drawbacks resulted in the synthesis of caffeic acid phenethyl amide (CAPA). Cyclodextrins have been proved as promising excipients for the formulation of active ingredients. Herein, we report the inclusion complexation behavior and binding ability of CAPE and CAPA with hydroxypropyl-β-cyclodextrin (HP-β-CD). The supramolecular interactions were examined through UV and FTIR spectroscopy, DSC, 1 H NMR and 2D ROESY. The CAPE/HP-β-CD and CAPA/HP-β-CD inclusion complexes stability constants were determined to be, respectively, 2911.6 and 584.6 M -1 in water and 2866.2 and 700.1 M -1 at physiological pH. The aqueous solubility increased notably, proving that HP-β-CD can be potentially useful to improve the biological, chemical and physical properties of CAPE and CAPA. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Thermodynamics of inclusion complex formation of β-cyclodextrin with a variety of surfactants differing in the nature of headgroup

    International Nuclear Information System (INIS)

    Benkő, Mária; Király, Zoltán

    2012-01-01

    Highlights: ► Inclusion complexation of β-cyclodextrins with various surfactants. ► Thermodynamic parameters determined by titration microcalorimetry. ► Stoichiometry of complexation is 1:1. ► The binding constant decreases linearly with increasing temperature. ► Enthalpy–entropy compensation is independent of the nature of the headgroup. - Abstract: The inclusion complexation of β-cyclodextrin with various surfactants, possessing the same alkyl chain length but differing in the hydrophilic headgroup, was investigated by isothermal titration microcalorimetry. Sodium dodecyl sulfate, sodium dodecyl sulfonate, dodecyltrimethylammonium bromide and dodecyl(dimethyl)amine oxide were investigated. The major aim of this study was to elucidate the effects of temperature and the nature of the headgroup on the complex formation. Thermometric titrations were effected between the temperatures (288 and 348) K. The results provided the stoichiometry, the equilibrium constant and the reaction enthalpy of complexation. Changes in Gibbs energy, entropy and van’t Hoff enthalpy were additionally calculated.

  19. The preparation, characterization, and pharmacokinetic studies of chitosan nanoparticles loaded with paclitaxel/dimethyl-β-cyclodextrin inclusion complexes

    Directory of Open Access Journals (Sweden)

    Ye YJ

    2015-07-01

    Full Text Available Ya-Jing Ye,1 Yun Wang,1 Kai-Yan Lou,1 Yan-Zuo Chen,1 Rongjun Chen,2 Feng Gao1,3,4 1Department of Pharmaceutics, School of Pharmacy, East China University of Science and Technology, Shanghai, People’s Republic of China; 2Department of Chemical Engineering, Imperial College London, London, United Kingdom; 3Shanghai Key Laboratory of Functional Materials Chemistry, 4Shanghai Key Laboratory of New Drug Design, East China University of Science and Technology, Shanghai, People’s Republic of China Abstract: A novel biocompatible and biodegradable drug-delivery nanoparticle (NP has been developed to minimize the severe side effects of the poorly water-soluble anticancer drug paclitaxel (PTX for clinical use. PTX was loaded into the hydrophobic cavity of a hydrophilic cyclodextrin derivative, heptakis (2,6-di-O-methyl-β-cyclodextrin (DM-β-CD, using an aqueous solution-stirring method followed by lyophilization. The resulting PTX/DM-β-CD inclusion complex dramatically enhanced the solubility of PTX in water and was directly incorporated into chitosan (CS to form NPs (with a size of 323.9–407.8 nm in diameter using an ionic gelation method. The formed NPs had a zeta potential of +15.9–23.3 mV and showed high colloidal stability. With the same weight ratio of PTX to CS of 0.7, the loading efficiency of the PTX/DM-β-CD inclusion complex-loaded CS NPs was 30.3-fold higher than that of the PTX-loaded CS NPs. Moreover, it is notable that PTX was released from the DM-β-CD/CS NPs in a sustained-release manner. The pharmacokinetic studies revealed that, compared with reference formulation (Taxol®, the PTX/DM-β-CD inclusion complex-loaded CS NPs exhibited a significant increase in AUC0→24h (the area under the plasma drug concentration–time curve over the period of 24 hours and mean residence time by 2.7-fold and 1.4-fold, respectively. Therefore, the novel drug/DM-β-CD inclusion complex-loaded CS NPs have promising applications for the

  20. β-cyclodextrin inclusion complexes containing Citrus sinensis (L.) Osbeck essential oil: An alternative to control Aedes aegypti larvae

    Energy Technology Data Exchange (ETDEWEB)

    Galvão, J.G., E-mail: julianaggalvao@gmail.com [Pharmacy Department, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil); Silva, V.F.; Ferreira, S.G. [Pharmacy Department, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil); França, F.R.M. [Chemical Engineering Department, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil); Santos, D.A.; Freitas, L.S.; Alves, P.B. [Chemistry Department, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil); Araújo, A.A.S.; Cavalcanti, S.C.H.; Nunes, R.S. [Pharmacy Department, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil)

    2015-05-20

    Highlights: • Thermal analysis was useful to determine the formation of inclusion complexes by paste and co-precipitation methods. • HS/GC-FID quantitative analysis revealed that the best method of obtaining a CSEO/β-CD complex was the PWE, with the largest inclusion content [78.5%]. • The inclusion complex revealed LC{sub 50} of 23.01 ppm, close to CSEO LC{sub 50} 21.5 ppm. - Abstract: The development of β-cyclodextrin (β-CD) complexes is an interesting way for increasing the aqueous solubility of essential oils. The aim of this study was to prepare inclusion complexes of Citrus sinensis essential oil (CSEO) with β-CD using paste complexation (with and without co-solvent) and co-precipitation methods. Additionally, the physicochemical properties of the inclusion complexes using thermal analysis, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy were evaluated. Furthermore, CSEO content (%) and solubility of complexes were measured. The biological activity against the Aedes aegypti Linn. larvae was further evaluated. For comparison purposes, a physical mixture between β-CD and CSEO was prepared and evaluated. Thermal analysis clearly indicated the formation of complexes by paste and co-precipitation methods. The headspace/gas chromatography quantitative analysis showed inclusions contents higher than 50%. On the other hand, the product revealed LC{sub 50} of 23.01 ppm, close to CSEO LC{sub 50} 21.5 ppm.

  1. β-cyclodextrin inclusion complexes containing Citrus sinensis (L.) Osbeck essential oil: An alternative to control Aedes aegypti larvae

    International Nuclear Information System (INIS)

    Galvão, J.G.; Silva, V.F.; Ferreira, S.G.; França, F.R.M.; Santos, D.A.; Freitas, L.S.; Alves, P.B.; Araújo, A.A.S.; Cavalcanti, S.C.H.; Nunes, R.S.

    2015-01-01

    Highlights: • Thermal analysis was useful to determine the formation of inclusion complexes by paste and co-precipitation methods. • HS/GC-FID quantitative analysis revealed that the best method of obtaining a CSEO/β-CD complex was the PWE, with the largest inclusion content [78.5%]. • The inclusion complex revealed LC 50 of 23.01 ppm, close to CSEO LC 50 21.5 ppm. - Abstract: The development of β-cyclodextrin (β-CD) complexes is an interesting way for increasing the aqueous solubility of essential oils. The aim of this study was to prepare inclusion complexes of Citrus sinensis essential oil (CSEO) with β-CD using paste complexation (with and without co-solvent) and co-precipitation methods. Additionally, the physicochemical properties of the inclusion complexes using thermal analysis, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy were evaluated. Furthermore, CSEO content (%) and solubility of complexes were measured. The biological activity against the Aedes aegypti Linn. larvae was further evaluated. For comparison purposes, a physical mixture between β-CD and CSEO was prepared and evaluated. Thermal analysis clearly indicated the formation of complexes by paste and co-precipitation methods. The headspace/gas chromatography quantitative analysis showed inclusions contents higher than 50%. On the other hand, the product revealed LC 50 of 23.01 ppm, close to CSEO LC 50 21.5 ppm

  2. Recovery and purification of cholesterol from cholesterol-β-cyclodextrin inclusion complex using ultrasound-assisted extraction.

    Science.gov (United States)

    Li, Yong; Chen, Youliang; Li, Hua

    2017-01-01

    Response surface methodology was used to optimize ultrasound-assisted ethanol extraction (UAE) of cholesterol from cholesterol-β-cyclodextrin (C-β-CD) inclusion complex prepared from duck yolk oil. The best extraction conditions were solvent-solid ratio 10mL/g, ultrasonic power 251W, extraction temperature 56°C and sonication time 36min. Under these conditions, the highest cholesterol extraction yield and cholesterol content obtained 98.12±0.25% and 43.38±0.61mg/g inclusion complex, respectively. As compared with Reflux extraction and Soxhlet extraction, the UAE was more efficient and economical. To increase the purity of crude cholesterol extraction, silica gel column chromatography and crystallization were carried out. Finally, cholesterol was obtained at 95.1% purity, 71.7% recovery and 22.0% yield. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Study of the β-Cyclodextrin Imipramine Hydrochloride Inclusion Complex and Determination of its Stability Constant (K by UV-Visible Spectroscopy

    Directory of Open Access Journals (Sweden)

    Alamdar Ashnagar

    2007-01-01

    Full Text Available In this research, the interactions of imipramine hydrochloride drug with β- cyclodextrin and the stability constant (K of the inclusion complex formed between them were investigated by using UV-visible spectroscopy. Solutions consisting of a known and constant amount of imipramine hydrochloride and varying amounts of β- cyclodextrin were prepared in 0.1 M phosphate buffer (pH 7.4. The final solutions had cyclodextrin concentrations between 0.0011 and 0.0153 M. UV-visible spectra of each solution was taken at λmax= 250 nm. The absorbances at this wavelength were recorded and plotted against cyclodextrin concentrations. From the graph, the concentrations of free and bound imipramine hydrochloride and free β-cyclodextrin were calculated using the Beer-Lambert law. From these data, the stability constant was calculated and a value of K=52.26±11.41 mol-1L was obtained. The magnitude of the stability constant is discussed in terms of the relative sizes and the chemical natures of β-cyclodextrin and imipramine hydrochloride.

  4. Rapid quantification of polycyclic aromatic hydrocarbons in hydroxypropyl-{beta}-cyclodextrin (HPCD) soil extracts by synchronous fluorescence spectroscopy (SFS)

    Energy Technology Data Exchange (ETDEWEB)

    Guoxiong, Hua [School of Biology and Psychology, Institute for Research on Environment and Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Broderick, John [School of Biology and Psychology, Institute for Research on Environment and Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Semple, Kirk T [Department of Environmental Science, Faculty of Science and Technology, University of Lancaster, Lancaster LA1 4YQ (United Kingdom); Killham, Ken [School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom); Singleton, Ian [School of Biology and Psychology, Institute for Research on Environment and Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2007-07-15

    Synchronous fluorescence spectroscopy (SFS) was directly applied to rapidly quantify selected polycyclic aromatic hydrocarbons (PAHs: benzo[a]pyrene and pyrene) in aqueous hydroxypropyl-{beta}-cyclodextrin (HPCD) soil extract solutions from a variety of aged contaminated soils containing four different PAHs. The method was optimized and validated. The results show that SFS can be used to analyse benzo[a]pyrene and pyrene in HPCD based soil extracts with high sensitivity and selectivity. The linear calibration ranges were 4.0 x 10{sup -6}-1.0 x 10{sup -3} mM for benzo[a]pyrene and 6.0 x 10{sup -6}-1.2 x 10{sup -3} mM for pyrene in 10 mM HPCD aqueous solution alone. The detection limits according to the error propagation theory for benzo[a]pyrene and pyrene were 3.9 x 10{sup -6} and 5.4 x 10{sup -6} mM, respectively. A good agreement between SFS and HPLC was reached for both determinations of PAHs in HPCD alone and in soil HPCD extracts. Hence, SFS is a potential means to simplify the present non-exhaustive hydroxypropyl-{beta}-cyclodextrin (HPCD)-based extraction technique for the evaluation of PAH bioavailability in soil. - SFS can be used to rapidly quantify selected PAHs in soil extracts and to simplify the non-exhaustive HPCD-based extraction technique for the evaluation of PAH bioavailability.

  5. Hydroxypropyl-beta-cyclodextrin as non-exhaustive extractant for organochlorine pesticides and polychlorinated biphenyls in muck soil

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Fiona [Centre for Atmospheric Research Experiments, Science and Technology Branch, Environment Canada, 6248 Eighth Line, Egbert, Ontario, L0L 1N0 (Canada); Department of Chemistry, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4 (Canada); Bidleman, Terry F., E-mail: terry.bidleman@ec.gc.c [Centre for Atmospheric Research Experiments, Science and Technology Branch, Environment Canada, 6248 Eighth Line, Egbert, Ontario, L0L 1N0 (Canada)

    2010-05-15

    Hydroxypropyl-beta-cyclodextrin (HPCD) was used as a non-exhaustive extractant for organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) in muck soil. An optimized extraction method was developed which involved using a HPCD to soil mass ratio of 5.8 with a single extraction period of 20 h. An aging experiment was performed by spiking a muck soil with {sup 13}C-labeled OCs and non-labeled PCBs. The soil was extracted with the optimized HPCD method and Soxhlet apparatus with dichloromethane over 550 d periodically. The HPCD extractability of the spiked OCs was greater than of the native OCs. A decreased in HPCD extractability was observed for the spiked OCs after 550 d of aging and their extractability approached those of the natives. The partition coefficient between HPCD and soil (log K{sub CD-Soil}) was negatively correlated with the octanol-water partition coefficient (log K{sub OW}) with r{sup 2} = 0.67 and p < 0.05. - The effect of aging on the extractability of organochlorine chemicals in muck soil was investigated using hydroxypropyl-beta-cyclodextrin as a mild extractant.

  6. Theoretical investigation on the inclusion of TCDD with β-cyclodextrin by performing QM calculations and MD simulations

    International Nuclear Information System (INIS)

    Pan, Wenxiao; Zhang, Dongju; Zhan, Jinhua

    2011-01-01

    Highlights: → We study the inclusion mechanism of TCDD with β-CD by theoretical methods. → Clearly, the formation of inclusion complex is an energetically driven process. → The inclusion complex can be detected by IR and Raman techniques. → The results imply that β-CD may be used as a host molecule to enrich TCDD molecules. - Abstract: The rapid enrichment and detection of trace polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are currently challenging issues in the field of environmental science. In this paper, by performing quantum chemistry (QM) calculations and molecular dynamics (MD) simulations, we studied the inclusion complexation of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a representative PCDD molecule, with β-cyclodextrin (β-CD), one of the widely used compounds in supramolecular chemistry. The calculated results reveal that the stable inclusion complex can be formed in both the gas phase and solvent, which proposes that β-CD may serve as a potential substrate enriching TCDD. The calculated vibrational spectra indicate that the infrared (IR) and Raman spectroscopy may be suitable for the detection of β-CD-modified TCDD. The present theoretical results may be informative to environmental scientists who are devoting themselves to developing effective methods for detection and treatment of POPs.

  7. Preparation, physicochemical characterization and release behavior of the inclusion complex of trans-anethole and β-cyclodextrin.

    Science.gov (United States)

    Zhang, Wenwen; Li, Xinying; Yu, Taocheng; Yuan, Lun; Rao, Gang; Li, Defu; Mu, Changdao

    2015-08-01

    Trans-anethole (AT) has a variety of antimicrobial properties and is widely used as food functional ingredient. However, the applications of AT are limited due to its low water solubility, strong odor and low physicochemical stability. Therefore, the aim of this work was to encapsulate AT with β-cyclodextrin (β-CD) for obtaining inclusion complex by co-precipitation method. The measurements effectively confirmed the formation of inclusion complex between AT and β-CD. The results showed that the inclusion complex presented new solid crystalline phases and was more thermally stable than the physical mixture and β-CD. The phase solubility study showed that the aqueous solubility of AT was increased by being included in β-CD. The calculated stability constant of inclusion complex was 1195M -1 , indicating the strong interaction between AT and β-CD. Furthermore, the release study suggested that β-CD provided the protection for AT against evaporation. The release behavior of AT from the inclusion complex was controlled. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Thermal stability and aggregation of creatine kinase from rabbit skeletal muscle. Effect of 2-hydroxypropyl-beta-cyclodextrin.

    Science.gov (United States)

    Maloletkina, Olga I; Markossian, Kira A; Belousova, Lyubov V; Kleimenov, Sergey Yu; Orlov, Victor N; Makeeva, Valentina F; Kurganov, Boris I

    2010-05-01

    Effect of 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on thermal aggregation of creatine kinase from rabbit skeletal muscle (RMCK) at 48 degrees C has been studied using dynamic light scattering. An increase in the duration of the lag period on the kinetic curves of aggregation, registered as an increment of the light scattering intensity in time, has been observed in the presence of HP-beta-CD. It has been shown that the initial parts of the dependences of the hydrodynamic radius (R(h)) of the protein aggregates on time follow the exponential law. The reciprocal value of parameter t(2R) (t(2R) is the time interval over which the R(h) value is doubled) was used to characterize the rate of aggregation. A 10-fold decrease in the 1/t(2R) value was observed in the presence of 76mM HP-beta-CD. Judging from the data on the kinetics of RMCK inactivation and the data on differential scanning calorimetry of RMCK, HP-beta-CD does not affect the rate of RMCK unfolding.

  9. Electronic structure and driving forces in β-cyclodextrin: Diclofenac inclusion complexes

    International Nuclear Information System (INIS)

    Bogdan, Diana; Morari, C.

    2007-01-01

    We investigate the geometry and electronic structure for complexes of β-cyclodextrin with diclofenac using DFT calculations. The effect of solvent is explicitly taken into account. This investigation allows us to draw meaningful conclusions upon the stability of the complex and the nature of the driving forces leading to the complexation process. In particular we emphasize the role of the water, by pointing out the changes in the solvent's electronic structure for different docking geometries

  10. The effect of (2-hydroxypropyl)-beta-cyclodextrin on rheology of hydrophobically end-capped poly(ethylene glycol) aqueous solutions

    Czech Academy of Sciences Publication Activity Database

    Horský, Jiří; Mikešová, Jana; Quadrat, Otakar; Šňupárek, J.

    2004-01-01

    Roč. 48, č. 1 (2004), s. 23-38 ISSN 0148-6055 R&D Projects: GA ČR GA104/99/0560 Institutional research plan: CEZ:AV0Z4050913 Keywords : (2-hydroxypropyl)-beta-cyclodextrin * hydrophobized PEG * rheology Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.525, year: 2004

  11. Improved thermal stability of polylactic acid (PLA) composite film via PLA-β-cyclodextrin-inclusion complex systems.

    Science.gov (United States)

    Byun, Youngjae; Rodriguez, Katia; Han, Jung H; Kim, Young Teck

    2015-11-01

    The effects of the incorporation of PLA-β-cyclodextrin-inclusion complex (IC) and β-cyclodextrin (β-CD) on biopolyester PLA films were investigated. Thermal stability, surface morphology, barrier, and mechanical properties of the films were measured at varying IC (1, 3, 5, and 7%) and β-CD (1 and 5%) concentrations. The PLA-IC-composite films (IC-PLA-CFs) showed uniform morphological structure, while samples containing β-CD (β-CD-PLA-CFs) showed high agglomeration of β-CD due to poor interfacial interaction between β-CD and PLA moieties. According to the thermal property analysis, the 5% IC-PLA-CFs showed 6.6 times lower dimensional changes (6.5%) at the temperature range of 20-80°C than that of pure PLA film (43.0%). The increase of IC or β-CD content in the PLA-composite films shifted the glass transition and crystallization temperature to higher temperature regions. The crystallinity of both composite films improved by increasing IC or β-CD content. Both composite films had higher oxygen and water vapor permeability as IC or β-CD content increased in comparison to pure PLA film. All the composite films had less flexibility and lower tensile strength than the pure PLA film. In conclusion, this study shows that the IC technique is valuable to improve the thermal expansion stability of PLA-based films. Published by Elsevier B.V.

  12. Molecular printboards: monolayers of beta-cyclodextrins on silicon oxide surfaces

    NARCIS (Netherlands)

    Onclin, S.; Mulder, A.; Huskens, Jurriaan; Ravoo, B.J.; Reinhoudt, David

    2004-01-01

    Monolayers of β-cyclodextrin host molecules have been prepared on SiO2 surfaces. An ordered and stable cyano-terminated monolayer was modified in three consecutive surface reactions. First, the cyanide groups were reduced to their corresponding free amines using Red Al as a reducing agent. Second,

  13. Sorption of Ochratoxin A from aqueous solutions using beta-cyclodextrin-polyurethane polymer

    Science.gov (United States)

    The ability of a cyclodextrin-polyurethane polymer to remove ochratoxin A from aqueous solutions, including wine, was examined by batch rebinding assays and equilibrium sorption isotherms. The results were fit to two parameter models. Freundlich analysis of the sorption isotherm indicates the polyme...

  14. Solid-state flurbiprofen and methyl-β-cyclodextrin inclusion complexes prepared using a single-step, organic solvent-free supercritical fluid process.

    Science.gov (United States)

    Rudrangi, Shashi Ravi Suman; Kaialy, Waseem; Ghori, Muhammad U; Trivedi, Vivek; Snowden, Martin J; Alexander, Bruce David

    2016-07-01

    The aim of this study was to enhance the apparent solubility and dissolution properties of flurbiprofen through inclusion complexation with cyclodextrins. Especially, the efficacy of supercritical fluid technology as a preparative technique for the preparation of flurbiprofen-methyl-β-cyclodextrin inclusion complexes was evaluated. The complexes were prepared by supercritical carbon dioxide processing and were evaluated by solubility, differential scanning calorimetry, X-ray powder diffraction, scanning electron microscopy, practical yield, drug content estimation and in vitro dissolution studies. Computational molecular docking studies were conducted to study the possibility of molecular arrangement of inclusion complexes between flurbiprofen and methyl-β-cyclodextrin. The studies support the formation of stable molecular inclusion complexes between the drug and cyclodextrin in a 1:1 stoichiometry. In vitro dissolution studies showed that the dissolution properties of flurbiprofen were significantly enhanced by the binary mixtures prepared by supercritical carbon dioxide processing. The amount of flurbiprofen dissolved into solution alone was very low with 1.11±0.09% dissolving at the end of 60min, while the binary mixtures processed by supercritical carbon dioxide at 45°C and 200bar released 99.39±2.34% of the drug at the end of 30min. All the binary mixtures processed by supercritical carbon dioxide at 45°C exhibited a drug release of more than 80% within the first 10min irrespective of the pressure employed. The study demonstrated the single step, organic solvent-free supercritical carbon dioxide process as a promising approach for the preparation of inclusion complexes between flurbiprofen and methyl-β-cyclodextrin in solid-state. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Interaction Mode between Inclusion Complex of Vitamin K3 with γ- Cyclodextrin and Herring-Sperm DNA.

    Science.gov (United States)

    Tang, Yan; Cai, Li; Xue, Kang; Wang, Chunling; Xiong, Xiaoli

    2016-05-03

    Methods including spectroscopy, electronic chemistry and thermodynamics were used to study the inclusion effect between γ-cyclodextrin (CD) and vitamin K3(K3), as well as the interaction mode between herring-sperm DNA (hsDNA) and γ-CD-K3 inclusion complex. The results from ultraviolet spectroscopic method indicated that VK3 and γ-CD formed 1:1 inclusion complex, with the inclusion constant Kf = 1.02 × 10(4) L/mol, which is based on Benesi-Hildebrand's viewpoint. The outcomes from the probe method and Scatchard methods suggested that the interaction mode between γ-CD-K3 and DNA was a mixture mode, which included intercalation and electrostatic binding effects. The binding constants were K (θ)25°C = 2.16 × 10(4) L/mol, and K(θ)37°C = 1.06 × 10(4) L/mol. The thermodynamic functions of the interaction between γ-CD-K3 and DNA were ΔrHm(θ) = -2.74 × 10(4) J/mol, ΔrSm(θ) = 174.74 J·mol(-1)K(-1), therefore, both ΔrHm(θ) (enthalpy) and ΔrSm(θ) (entropy) worked as driven forces in this action.

  16. FT-Raman and FT-IR studies of 1:2.5 piroxicam: β-cyclodextrin inclusion compound

    Science.gov (United States)

    Bertoluzza, A.; Rossi, M.; Taddei, P.; Redenti, E.; Zanol, M.; Ventura, P.

    1999-05-01

    The FT-Raman and FT-IR spectra of amorphous 1:2.5 piroxicam (P): β-cyclodextrin (βCD) inclusion compound (PβCD) are presented and discussed in comparison with the spectra of the three main modifications of piroxicam (α,β and monohydrate). In the 1700-1200 cm -1 FT-Raman spectrum of 1:2.5 PβCD inclusion compound the bands of βCD are weak and covered by those stronger of piroxicam, differently from the FT-IR spectrum where the bands of βCD are stronger, so covering a large part of the spectrum. Typical FT-Raman marker bands are assigned for the characterization of the three modifications of piroxicam. The FT-Raman spectrum of 1:2.5 PβCD inclusion compound predominantly shows the bands at about 1465 and 1400 cm -1 of the monohydrate, indicating that piroxicam assumes the zwitterionic structure stabilized by interaction with βCD via electrostatic and hydrogen bonds. The dipolar character of 1:2.5 PβCD inclusion compound improves the solubility and the dissolution rate of piroxicam and thus its rate of absorption.

  17. Properties of cyclodextrins. V. Inclusion isotherm and kinetics of inclusion of benzoic acid and m-chlorobenzoic acid on b-E 25 cyclodextrin-epichlorohydrin resin

    NARCIS (Netherlands)

    Wiedenhof, N.; Trieling, R.G.

    1971-01-01

    The previous paper showed that b-E 25 resins have an affinity for aromatic compds., e.g. BZOH and m-ClC6H4CO2H; mainly the undissocd. acids are involved. The isothermal inclusion of undissocd. BZOH is described by a Langmuir isotherm, but that of m-ClC6H4CO2H follows a Freundlich isotherm. The

  18. Supra-molecular inclusion complexation of ionic liquid 1-butyl-3-methylimidazolium octylsulphate with α- and β-cyclodextrins

    Science.gov (United States)

    Banjare, Manoj Kumar; Behera, Kamalakanta; Satnami, Manmohan L.; Pandey, Siddharth; Ghosh, Kallol K.

    2017-12-01

    Host-guest complexation between ionic liquid (IL) 1-butyl-3-methylimidazolium octylsulphate [Bmim][OS] and cyclodextrins (α- and β- CDs) have been studied. Surface tension, conductivity measurements revealed the formation of 1:1 (M) stoichiometry for inclusion complexes (ICs) and further confirmed by UV-Visible and FT-IR results. The nature of the complexes has been established using interfacial and thermodynamic parameters. The aggregation number, Stern-Volmer constants, association constants were obtained from fluorescence quenching and Benesi-Hildebrand methods. The critical micelle concentration (cmc) and association constants of [Bmim][OS] are higher for β-CD as compared to α-CD. FT-IR spectra indicated that CDs and [Bmim][OS] could from ICs with stoichiometry 1:1 (M).

  19. Poly-dopamine-beta-cyclodextrin: A novel nanobiopolymer towards sensing of some amino acids at physiological pH

    International Nuclear Information System (INIS)

    Hasanzadeh, Mohammad; Sadeghi, Sattar; Bageri, Leyla; Mokhtarzadeh, Ahad; Karimzadeh, Ayub; Shadjou, Nasrin; Mahboob, Soltanali

    2016-01-01

    A novel nanobiopolymer film was electrodeposited on the surface of glassy carbon through cyclic voltammetry from dopamine, β-cyclodextrin, and phosphate buffer solution in physiological pH (7.40). The electrochemical behavior of polydopamine-Beta-cyclodextrin modified glassy carbon electrode was investigated for electro-oxidation and determination of some amino acids (L-Cysteine, L-Tyrosine, L-Glycine, and L-Phenylalanine). The modified electrode was applied for selected amino acid detection at physiological pH using cyclic voltammetry, differential pulse voltammetry and chronoamperometry, chronocoulometery. The linear concentration range of the proposed sensor for the L-Glycine, L-Cysteine, L-Tyrosine, and L-Phenylalanine were 0.2–70, 0.06–0.2, 0.01–0.1, and 0.2–10 μM, while low limit of quantifications were 0.2, 0.06, 0.01, and 0.2 μM, respectively. The modified electrode shows many advantages as an amino acid sensor such as simple preparation method without using any specific electron transfer mediator or specific reagent, good sensitivity, short response time, and long term stability. - Highlights: • A novel biopolymer film with entitled PDA-β-CD was electrodeposited on the GCE. • Synergetic effect of β-CD and GQD on the electrical signal amplifications was investigated. • The performance of β-CD-GQD-GCE towards electrochemical sensing of some amino acids was investigated.

  20. Poly-dopamine-beta-cyclodextrin: A novel nanobiopolymer towards sensing of some amino acids at physiological pH

    Energy Technology Data Exchange (ETDEWEB)

    Hasanzadeh, Mohammad, E-mail: mhmmd_hasanzadeh@yahoo.com [Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz 51664 (Iran, Islamic Republic of); Pharmaceutical Analysis Research Center, Tabriz University of Medical Sciences, Tabriz 51664 (Iran, Islamic Republic of); Sadeghi, Sattar [Department of Biochemistry, Higher Education Institute of Rab-Rashid, Tabriz (Iran, Islamic Republic of); Bageri, Leyla [Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz 51664 (Iran, Islamic Republic of); Mokhtarzadeh, Ahad [School of Medicine, Gonabad University of Medical Sciences, Gonabad (Iran, Islamic Republic of); Department of Biochemistry, Higher Education Institute of Rab-Rashid, Tabriz (Iran, Islamic Republic of); Karimzadeh, Ayub [Department of Biochemistry, Higher Education Institute of Rab-Rashid, Tabriz (Iran, Islamic Republic of); Shadjou, Nasrin [Department of Nanochemistry, Nano Technology Research Center, Urmia University, Urmia 57154 (Iran, Islamic Republic of); Department of Nano Technology, Faculty of Science, Urmia University, Urmia 57154 (Iran, Islamic Republic of); Mahboob, Soltanali [Department of Biochemistry, Higher Education Institute of Rab-Rashid, Tabriz (Iran, Islamic Republic of)

    2016-12-01

    A novel nanobiopolymer film was electrodeposited on the surface of glassy carbon through cyclic voltammetry from dopamine, β-cyclodextrin, and phosphate buffer solution in physiological pH (7.40). The electrochemical behavior of polydopamine-Beta-cyclodextrin modified glassy carbon electrode was investigated for electro-oxidation and determination of some amino acids (L-Cysteine, L-Tyrosine, L-Glycine, and L-Phenylalanine). The modified electrode was applied for selected amino acid detection at physiological pH using cyclic voltammetry, differential pulse voltammetry and chronoamperometry, chronocoulometery. The linear concentration range of the proposed sensor for the L-Glycine, L-Cysteine, L-Tyrosine, and L-Phenylalanine were 0.2–70, 0.06–0.2, 0.01–0.1, and 0.2–10 μM, while low limit of quantifications were 0.2, 0.06, 0.01, and 0.2 μM, respectively. The modified electrode shows many advantages as an amino acid sensor such as simple preparation method without using any specific electron transfer mediator or specific reagent, good sensitivity, short response time, and long term stability. - Highlights: • A novel biopolymer film with entitled PDA-β-CD was electrodeposited on the GCE. • Synergetic effect of β-CD and GQD on the electrical signal amplifications was investigated. • The performance of β-CD-GQD-GCE towards electrochemical sensing of some amino acids was investigated.

  1. Genistein in 1:1 Inclusion Complexes with Ramified Cyclodextrins: Theoretical, Physicochemical and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Corina Danciu

    2014-01-01

    Full Text Available Genistein is one of the most studied phytocompound in the class of isoflavones, presenting a notable estrogenic activity and in vitro and/or in vivo benefits in different types of cancer such as those of the bladder, kidney, lung, pancreatic, skin and endometrial cancer. A big inconvenience for drug development is low water solubility, which can be solved by using hydrophilic cyclodextrins. The aim of this study is to theoretically analyze, based on the interaction energy, the possibility of a complex formation between genistein (Gen and three different ramified cyclodextrins (CD, using a 1:1 molar ratio Gen:CD. Theoretical data were correlated with a screening of both in vitro and in vivo activity. Proliferation of different human cancer cell lines, antimicrobial activity and angiogenesis behavior was analyzed in order to see if complexation has a beneficial effect for any of the above mentioned activities and if so, which of the three CDs is the most suitable for the incorporation of genistein, and which may lead to future improved pharmaceutical formulations. Results showed antiproliferative activity with different IC50 values for all tested cell lines, remarkable antimicrobial activity on Bacillus subtilis and antiangiogenic activity as revealed by CAM assay. Differences regarding the intensity of the activity for pure and the three Gen complexes were noticed as explained in the text. The data represent a proof that the three CDs can be used for furtherer research towards practical use in the pharmaceutical and medical field.

  2. Determination of trace platinum by supramolecular catalytic kinetic spectrofluorimetry of {beta}-cyclodextrin-platinum-KBrO{sub 3}-salicylaldehyde furfuralhydrazone

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Bo; Zhang, Ning; Chen, Zhen-Zhen; Kong, Qing-Cheng [Shandong Normal University, College of Chemistry, Chemical Engineering and Materials Science, Jinan (China)

    2006-02-01

    A supramolecular catalytic kinetic spectrofluorimetric method was developed for the determination of platinum(IV) and the possible mechanism of catalytic reaction was discussed. The method was based on the fluorescence-enhancing reaction of salicylaldehyde furfuralhydrazone (SAFH) with potassium bromate, which was catalysed by platinum(IV) in a water-ethanol medium. {beta}-Cyclodextrin ({beta}-CD) obviously sensitized the determination at pH 5.20 and 25 C. Under optimum conditions, the {beta}-CD-platinum-KBrO{sub 3}-SAFH supramolecular kinetic catalytic reaction system had excitation and emission maxima at 372 and 461 nm, respectively. The linear range of this method was 0.60-180 ng ml{sup -1} with a relative standard deviation of 1.2%, and the detection limit was 0.18 ng ml{sup -1}. Investigation of the mechanism and the effects of interferences is presented. The proposed method was applied successfully to determine trace platinum(IV) in the chemotherapeutic drug cisplatin and serum from patients with satisfactory results. (orig.)

  3. Inclusion complex and nanoclusters of cyclodextrin to increase the solubility and efficacy of albendazole.

    Science.gov (United States)

    Pacheco, P A; Rodrigues, L N C; Ferreira, J F S; Gomes, A C P; Veríssimo, C J; Louvandini, H; Costa, R L D; Katiki, L M

    2018-03-01

    Albendazole (ABZ), a benzimidazole widely used to control gastrointestinal parasites, is poorly soluble in water, resulting in variable and incomplete bioavailability. This has favored the appearance ABZ-resistant nematodes and, consequently, an increase in its clinical ineffectiveness. Among the pharmaceutical techniques developed to increase drug efficacy, cyclodextrins (CDs) and other polymers have been extensively used with water-insoluble pharmaceutical drugs to increase their solubility and availability. Our objective was to prepare ABZ formulations, including β-cyclodextrin (βCD) or hydroxypropyl-β-cyclodextrin (HPβCD), associated or not to the water-soluble polymer polyvinylpyrrolidone (PVP). These formulations had their solubility and anthelmintic effect both evaluated in vitro. Also, their anthelmintic efficacy was evaluated in lambs naturally infected with gastrointestinal nematodes (GIN) through the fecal egg count (FEC) reduction test. In vitro, the complex ABZ/HPβCD had higher solubility than ABZ/βCD. The addition of PVP to the complexes increased solubility and dissolution rates more effectively for ABZ/HPβCD than for ABZ/βCD. In vivo, 48 lambs naturally infected with GIN were divided into six experimental groups: control, ABZ, ABZ/βCD, ABZ/βCD-PVP, ABZ/HPβCD, and ABZ/HPβCD-PVP. Each treated animal received 10 mg/kg of body weight (based on the ABZ dose) for three consecutive days. After 10 days of the last administered dose, treatment efficacy was calculated. The efficacy values were as follows: ABZ (70.33%), ABZ/βCD (85.33%), ABZ/βCD-PVP (82.86%), ABZ/HPβCD (78.37%), and ABZ/HPβCD-PVP (43.79%). In vitro, ABZ/HPβCD and ABZ/HPβCD-PVP had high solubility and dissolution rates. In vivo, although the efficacies of ABZ/βCD, ABZ/βCD-PVP, and ABZ/HPβCD increased slightly when compared to pure ABZ, this increase was not significant (P > 0.05).

  4. Selectively Modified Cyclodextrins as Artificial Glycosidases

    DEFF Research Database (Denmark)

    Bjerre, Jeannette; Bols, Mikael

    2008-01-01

    I proceedingen beskrives forfatterens og gruppens arbejde med at skabe kunstige glycosidaser baseret på beta-cyclodextrin. Vha. selektiv modificering af 1-2 alkohol-grupper på den primære rand af beta-cyclodextrin, er syntetiseret en række kunstige glycosidaser. Disse cyclodextrin-baserede glycos...

  5. Linkage of α-cyclodextrin-terminated poly(dimethylsiloxanes by inclusion of quasi bifunctional ferrocene

    Directory of Open Access Journals (Sweden)

    Helmut Ritter

    2013-07-01

    Full Text Available We report the noncovalent linkage of terminally substituted oligo(dimethylsiloxanes bearing α-cyclodextrins (α-CD as host end groups for the cyclopentadienyl rings of ferrocene. This double complexation of unsubstituted ferrocene leads to a supramolecuar formation of the siloxane strands. Structural characterization was performed by the use of 1H NMR and IR spectroscopy and by mass spectrometry. Electron microscopy studies and dynamic light scattering measurements show a significant decrease of the derivative size after the complexation with ferrocene. In addition, further evidence for the successful complexation of the end groups was verified by the shifts of the protons in the 1H NMR spectra and in the correlation signals of the 2D ROESY NMR spectra.

  6. New Electrochemically-Modified Carbon Paste Inclusion β-Cyclodextrin and Carbon Nanotubes Sensors for Quantification of Dorzolamide Hydrochloride

    Directory of Open Access Journals (Sweden)

    Nawal Ahmad Alarfaj

    2016-12-01

    Full Text Available The present article introduces a new approach to fabricate carbon paste sensors, including carbon paste, modified carbon paste inclusion β-cyclodextrin, and carbon nanotubes for the quantification of dorzolamide hydrochloride (DRZ. This study is mainly based on the construction of three different carbon paste sensors by the incorporation of DRZ with phosphotungstic acid (PTA to form dorzolamide-phosphotungstate (DRZ-PT as an electroactive material in the presence of the solvent mediator ortho-nitrophenyloctyl ether (o-NPOE. The fabricated conventional carbon paste sensor (sensor I, as well as the other modified carbon paste sensors using β-cyclodextrin (sensor II and carbon nanotubes (sensor III, have been investigated. The sensors displayed Nernstian responses of 55.4 ± 0.6, 56.4 ± 0.4 and 58.1 ± 0.2 mV·decade−1 over concentration ranges of 1.0 × 10−5–1.0 × 10−2, 1.0 × 10−6–1.0 × 10−2, and 5.0 × 10−8–1.0 × 10−2 mol·L−1 with lower detection limits of 5.0 × 10−6, 5.0 × 10−7, and 2.5 × 10−9 mol·L−1 for sensors I, II, and III, respectively. The critical performance of the developed sensors was checked with respect to the effect of various parameters, including pH, selectivity, response time, linear concentration relationship, lifespan, etc. Method validation was applied according to the international conference on harmonisation of technical requirements for registration of pharmaceuticals for human use ICH guidelines. The developed sensors were employed for the determination of DRZ in its bulk and dosage forms, as well as bio-samples. The observed data were statistically analyzed and compared with those obtained from other published methods.

  7. Evidence of the Disassembly of α-Cyclodextrin-octylamine Inclusion Compounds Conjugated to Gold Nanoparticles via Thermal and Photothermal Effects

    Directory of Open Access Journals (Sweden)

    Nataly Silva

    2016-10-01

    Full Text Available Cyclodextrin (CD molecules form inclusion compounds (ICs, generating dimers that are capable of encapsulating molecules derived from long-chain hydrocarbons. The aim of this study is to evaluate the structural changes experienced by ICs in solution with increasing temperatures. For this, a nuclear magnetic resonance (1H-NMR titration was performed to determinate the stoichiometric α-cyclodextrin (α-CD:octylamine (OA 2:1 and binding constant (k = 2.16 M−2 of ICs. Solution samples of α-CD-OA ICs conjugated with gold nanoparticles (AuNPs were prepared, and 1H-NMR spectra at different temperatures were recorded. Comparatively, 1H-NMR spectra of the sample irradiated with a laser with tunable wavelengths, with plasmons of conjugated AuNPs, were recorded. In this work, we present evidence of the disassembly of ICs conjugated with AuNPs. Thermal studies demonstrated that, at 114 °C, there are reversible rearrangements of the host and guests in the ICs in a solid state. Migration movements of the guest molecules from the CD cavity were monitored via temperature-dependent 1H-NMR, and were verified comparing the chemical shifts of octylamine dissolved in deuterated dimethylsulfoxide (DMSO-d6 with the OA molecule included in α-CD dissolved in the same solvent. It was observed that, at 117 °C, OA exited the α-CD cavity. CD IC dimer disassembly was also observed when the sample was irradiated with green laser light.

  8. Effect of O-methyl-.beta.-cyclodextrin-modified magnetic nanoparticles on the uptake and extracellular level of L-glutamate in brain nerve terminals

    Czech Academy of Sciences Publication Activity Database

    Horák, Daniel; Beneš, Milan J.; Procházková, Zuzana; Trchová, Miroslava; Borysov, A.; Pastukhov, A.; Paliienko, K.; Borisova, T.

    2017-01-01

    Roč. 149, 1 January (2017), s. 64-71 ISSN 0927-7765 R&D Projects: GA ČR(CZ) GC16-01128J; GA MŠk(CZ) LQ1604; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61389013 Keywords : glutamate * cholesterol * O-methyl-beta-cyclodextrin Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.887, year: 2016

  9. Inhalable Andrographolide-β-cyclodextrin Inclusion Complexes for Treatment of Staphylococcus aureus Pneumonia by Regulating Immune Responses.

    Science.gov (United States)

    Zhang, Tongtong; Zhu, Lifei; Li, Miao; Hu, Yuzhen; Zhang, Erfeng; Jiang, Qingcheng; Han, Guang; Jin, Yiguang

    2017-05-01

    Bacterial pneumonia is a serious disease with high mortality if no appropriate and immediate therapy is available. Andrographolide (AG) is an anti-inflammatory agent extracted from a traditional Chinese herb andrographis paniculata. Oral AG tablets and pills are clinically applied for treatment of upper respiratory tract infections. However, the low solubility and bioavailability of AG lead to high doses and long-term therapy. Here we developed an andrographolide-β-cyclodextrin inclusion complex (AG-β-CD) for inhalation therapy of Staphylococcus aureus pneumonia. AG-β-CD was identified with X-ray diffraction and FT-IR. Surprisingly, both AG-β-CD and AG showed little in vitro anti-S. aureus activity. However, pulmonary delivery of AG, AG-β-CD, or penicillin had significant anti-S. aureus pneumonia effects. Leukocytes, neutrophils, white blood cells, total proteins, TNF-α, IL-6, NF-κB p65 expression, and bacterial colonies in the bronchoalveolar lavage fluids were detected. Pulmonary delivery of AG and AG-β-CD led to bacterial inhibition and inflammation alleviation by regulating immune responses, while penicillin only killed bacteria without significant immune regulation. Moreover, the antipneumonia activity of AG-β-CD was much higher than that of AG, probably resulting from locally accelerated AG dissolution due to β-CD inclusion. The aerodynamic diameter of AG-β-CD powders was 2.03 μm, suitable for pulmonary delivery. Inhalable AG-β-CD is a promising antibacterial and anti-inflammatory medicine for the treatment of S. aureus pneumonia by regulating immune responses, and the effect is enhanced by β-CD inclusion. AG and its formulations might be potent weapons against the resistant bacterial pneumonia due to their specific mechanism in the future.

  10. DSC, X-ray and FTIR studies of a gemfibrozil/dimethyl-β-cyclodextrin inclusion complex produced by co-grinding.

    Science.gov (United States)

    Aigner, Z; Berkesi, O; Farkas, G; Szabó-Révész, P

    2012-01-05

    The steps of formation of an inclusion complex produced by the co-grinding of gemfibrozil and dimethyl-β-cyclodextrin were investigated by differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD) and Fourier transform infrared (FTIR) spectroscopy with curve-fitting analysis. The endothermic peak at 59.25°C reflecting the melting of gemfibrozil progressively disappeared from the DSC curves of the products on increase of the duration of co-grinding. The crystallinity of the samples too gradually decreased, and after 35min of co-grinding the product was totally amorphous. Up to this co-grinding time, XRPD and FTIR investigations indicated a linear correlation between the cyclodextrin complexation and the co-grinding time. After co-grinding for 30min, the ratio of complex formation did not increase. These studies demonstrated that co-grinding is a suitable method for the complexation of gemfibrozil with dimethyl-β-cyclodextrin. XRPD analysis revealed the amorphous state of the gemfibrozil-dimethyl-β-cyclodextrin product. FTIR spectroscopy with curve-fitting analysis may be useful as a semiquantitative analytical method for discriminating the molecular and amorphous states of gemfibrozil. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Formation of nanoparticles by cooperative inclusion between (S-camptothecin-modified dextrans and β-cyclodextrin polymers

    Directory of Open Access Journals (Sweden)

    Thorbjørn Terndrup Nielsen

    2015-01-01

    Full Text Available Novel (S-camptothecin–dextran polymers were obtained by “click” grafting of azide-modified (S-camptothecin and alkyne-modified dextrans. Two series based on 10 kDa and 70 kDa dextrans were prepared with a degree of substitution of (S-camptothecin between 3.1 and 10.2%. The binding properties with β-cyclodextrin and β-cyclodextrin polymers were measured by isothermal titration calorimetry and fluorescence spectroscopy, showing no binding with β-cyclodextrin but high binding with β-cyclodextrin polymers. In aqueous solution nanoparticles were formed from association between the (S-camptothecin–dextran polymers and the β-cyclodextrin polymers.

  12. Preparation and tribological properties of inclusion complex of β-cyclodextrin/dialkyl pentasulfide as additive in PEG-600 aqueous solution

    International Nuclear Information System (INIS)

    Guan, Jiju; Xu, Xuefeng; Li, Gan; Peng, Wei

    2014-01-01

    The inclusion complex of β-cyclodextrin (β-CD) and dialkyl pentasulfide (DPS), in which DPS was incorporated into β-CD cavities, was prepared by a co-precipitation method. The tribological properties of the complex used as lubricant additive in PEG 600 aqueous solution were investigated by a four-ball tester. The complex exhibited better tribological properties than β-CD under different loads, and also showed better anti-friction performance than DPS in the latter half of the test duration. The tribological action mechanism of the complex on a steel surface was studied according to the X-ray photoelectron spectroscopy (XPS) analyses. The β-CD molecules of the complexes were decomposed into various molecular fragments and the DPS molecules were released under the friction condition. It revealed that thiolate and ferrous sulfide (FeS) films formed by DPS played a major role, and iron alkoxide and carbon deposition films formed by the friction fragments of β-CD mainly exhibited anti-friction property on FeS-to-FeS interface. The interactions among different films led to the formation of a mixed boundary lubrication film.

  13. Inkjet printing of antiviral PCL nanoparticles and anticancer cyclodextrin inclusion complexes on bioadhesive film for cervical administration.

    Science.gov (United States)

    Varan, Cem; Wickström, Henrika; Sandler, Niklas; Aktaş, Yeşim; Bilensoy, Erem

    2017-10-15

    Personalized medicine is an important treatment approach for diseases like cancer with high intrasubject variability. In this framework, printing is one of the most promising methods since it permits dose and geometry adjustment of the final product. With this study, a combination product consisting of anticancer (paclitaxel) and antiviral (cidofovir) drugs was manufactured by inkjet printing onto adhesive film for local treatment of cervical cancers as a result of HPV infection. Furthermore, solubility problem of paclitaxel was overcome by maintaining this poorly soluble drug in a cyclodextrin inclusion complex and release of cidofovir was controlled by encapsulation in polycaprolactone nanoparticles. In vitro characterization studies of printed film formulations were performed and cell culture studies showed that drug loaded film formulation was effective on human cervical adenocarcinoma cells. Our study suggests that inkjet printing technology can be utilized in the development of antiviral/anticancer combination dosage forms for mucosal application. The drug amount in the delivery system can be accurately controlled and modified. Moreover, prolonged drug release time can be obtained. Printing of anticancer and antiviral drugs on film seem to be a potential approach for HPV-related cervical cancer treatment and a good candidate for further studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Fast-Dissolving, Prolonged Release, and Antibacterial Cyclodextrin/Limonene-Inclusion Complex Nanofibrous Webs via Polymer-Free Electrospinning.

    Science.gov (United States)

    Aytac, Zeynep; Yildiz, Zehra Irem; Kayaci-Senirmak, Fatma; San Keskin, Nalan Oya; Kusku, Semran Ipek; Durgun, Engin; Tekinay, Turgay; Uyar, Tamer

    2016-10-05

    We have proposed a new strategy for preparing free-standing nanofibrous webs from an inclusion complex (IC) of a well-known flavor/fragrance compound (limonene) with three modified cyclodextrins (HPβCD, MβCD, and HPγCD) via electrospinning (CD/limonene-IC-NFs) without using a polymeric matrix. The experimental and computational modeling studies proved that the stoichiometry of the complexes was 1:1 for CD/limonene systems. MβCD/limonene-IC-NF released much more limonene at 37, 50, and 75 °C than HPβCD/limonene-IC-NF and HPγCD/limonene-IC-NF because of the greater amount of preserved limonene. Moreover, MβCD/limonene-IC-NF has released only 25% (w/w) of its limonene, whereas HPβCD/limonene-IC-NF and HPγCD/limonene-IC-NF released 51 and 88% (w/w) of their limonene in 100 days, respectively. CD/limonene-IC-NFs exhibited high antibacterial activity against E. coli and S. aureus. The water solubility of limonene increased significantly and CD/limonene-IC-NFs were dissolved in water in a few seconds. In brief, CD/limonene-IC-NFs with fast-dissolving character enhanced the thermal stability and prolonged the shelf life along with antibacterial properties could be quite applicable in food and oral care applications.

  15. Effect of preparation processes and structural insight into the supermolecular system: Bisacodyl and β-cyclodextrin inclusion complex

    International Nuclear Information System (INIS)

    Li, Shanshan; Zhai, Yuanming; Yan, Jin; Wang, Lili; Xu, Kailin; Li, Hui

    2016-01-01

    In this study, β-cyclodextrin (β-CD) and bisacodyl were chosen as model host and guest molecule to explore the effect of preparation processes on the physicochemical properties of inclusion complexes (ICs) and to gain an insight into the structure of ICs. The influence of temperature and pH on complexation was studied by multiple temperature–pH phase solubility analysis. The most favorable conformation was predicted by molecular modeling using AutoDock. "1H nuclear magnetic resonance and rotating frame nuclear Overhauser effect spectroscopy further confirmed the structure. Moreover, bisacodyl·β-CD ICs in solid state were successfully prepared via three different procedures (co-crystallization, co-evaporation, and co-grinding) and fully characterized by several solid-state techniques, namely, Fourier transform infrared spectroscopy, X-ray powder diffraction, thermogravimetric analysis, differential scanning calorimetry, solid-state NMR spectroscopy, and scanning electron microscopy. It was found that acid solution and low temperature were unfavorable for formation of bisacodyl·β-CD. The pyridine moiety was suggested to be enclosed in the hydrophobic cavity of β-CD. The complexes prepared using co-crystallization showed properties similar to those prepared using co-evaporation. Moreover, ICs obtained by co-evaporation and co-grinding had higher loading efficiency, water solubility, and dissolution rate than ICs obtained by co-crystallization. - Highlights: • The structure of inclusion complex-bisacodyl·β-CD was determined. • Thermodynamic behaviors of complexation under different conditions were discussed. • Products from three different preparation methods were systemically compared. • Co-crystallization and co-evaporation produced similar complexes. • Co-evaporation and co-grinding had better effects than co-crystallization.

  16. Effect of preparation processes and structural insight into the supermolecular system: Bisacodyl and β-cyclodextrin inclusion complex

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shanshan [College of Chemical Engineering, Sichuan University, Chengdu 610065 (China); Zhai, Yuanming [Analytical and Testing Center, Sichuan University, Chengdu 610064 (China); Yan, Jin; Wang, Lili; Xu, Kailin [College of Chemical Engineering, Sichuan University, Chengdu 610065 (China); Li, Hui, E-mail: lihuilab@sina.com [College of Chemical Engineering, Sichuan University, Chengdu 610065 (China)

    2016-01-01

    In this study, β-cyclodextrin (β-CD) and bisacodyl were chosen as model host and guest molecule to explore the effect of preparation processes on the physicochemical properties of inclusion complexes (ICs) and to gain an insight into the structure of ICs. The influence of temperature and pH on complexation was studied by multiple temperature–pH phase solubility analysis. The most favorable conformation was predicted by molecular modeling using AutoDock. {sup 1}H nuclear magnetic resonance and rotating frame nuclear Overhauser effect spectroscopy further confirmed the structure. Moreover, bisacodyl·β-CD ICs in solid state were successfully prepared via three different procedures (co-crystallization, co-evaporation, and co-grinding) and fully characterized by several solid-state techniques, namely, Fourier transform infrared spectroscopy, X-ray powder diffraction, thermogravimetric analysis, differential scanning calorimetry, solid-state NMR spectroscopy, and scanning electron microscopy. It was found that acid solution and low temperature were unfavorable for formation of bisacodyl·β-CD. The pyridine moiety was suggested to be enclosed in the hydrophobic cavity of β-CD. The complexes prepared using co-crystallization showed properties similar to those prepared using co-evaporation. Moreover, ICs obtained by co-evaporation and co-grinding had higher loading efficiency, water solubility, and dissolution rate than ICs obtained by co-crystallization. - Highlights: • The structure of inclusion complex-bisacodyl·β-CD was determined. • Thermodynamic behaviors of complexation under different conditions were discussed. • Products from three different preparation methods were systemically compared. • Co-crystallization and co-evaporation produced similar complexes. • Co-evaporation and co-grinding had better effects than co-crystallization.

  17. Synthesis and characterization of polyurethanes derived from cyclodextrins and poli (ethyleneglycol)

    International Nuclear Information System (INIS)

    Araujo, Marcia V.G. de; Vieira, Joao V.F.; Zawadzki, Sonia F.

    2011-01-01

    Cyclodextrins are natural cyclic oligosaccharides that have the ability to form inclusion complexes with various chemical species. In this work, the polymers with beta-cyclodextrin (BCD) or hydroxypropyl-beta-cyclodextrin (HPBCD) were synthesized from the reaction with poly (ethylene) glycol (PEG400, PEG1500, PEG4000) and diisocyanate, toluene 2,4 and 3,6 (TDI) in a solution of dimethylformamide (DMF). The polymers were characterized by infrared Fourier transform spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The encapsulation capacity was evaluated by calorimetric method of discoloration of the alkaline solution of phenolphthalein. FTIR analysis revealed that assignments confirmed the formation of urethane linkages. TGA was evidenced by the mass loss in three stages and the evaluation results by XRD showed a crosslinking process. The evaluation of the encapsulation capacity of the units of the cyclodextrin crosslinked polymer showed that encapsulation increased proportionally to the mass of polymer used. (author)

  18. [Effect of β-cyclodextrin inclusion complex on transport of major components of Xiangfu Siwu decoction essential oil in Caco-2 cell monolayer model].

    Science.gov (United States)

    Xi, Jun-zuan; Qian, Da-wei; Duan, Jin-ao; Liu, Pei; Zhu, Yue; Zhu, Zhen-hua; Zhang, Li

    2015-08-01

    Although the essential oil of Xiangfu Siwu decoction (XFSWD) has strong pharmacological activity, its special physical and chemical properties restrict the clinical application and curative effect. In this paper, Xiangfu Siwu decoction essential oil (XFS-WO) was prepared by forming inclusion complex with β-cyclodextrin (β-CD). The present study is to investigate the effect of β-CD inclusion complex on the transport of major components of XFSWO using Caco-2 cell monolayer model, thus to research the effect of this formation on the absorption of drugs with low solubility and high permeability, which belong to class 2 in biopharmaceutics classification system. A sensitive and rapid UPLC-MS/MS method was developed for simultaneous quantification of senkyunolide A, 3-n-butylphthalide, Z-ligustilide, dehydrocostus lactone and α-cyperone, which are active compounds in XFSWO. The transport parameters were analyzed and compared in free oil and its β-CD inclusion complex. The result revealed that the formation of XFSWO/β-CD inclusion complex has significantly increased the transportation and absorption of major active ingredients than free oil. Accordingly, it can be speculated that cyclodextrin inclusion complex can improve bioavailability of poorly water-soluble drugs. Above all these mentioned researches, it provided foundation and basis for physiological disposition and pharmaceutical study of XFSWD.

  19. Characterization of aspartame-cyclodextrin complexation.

    Science.gov (United States)

    Sohajda, Tamás; Béni, Szabolcs; Varga, Erzsébet; Iványi, Róbert; Rácz, Akos; Szente, Lajos; Noszál, Béla

    2009-12-05

    The inclusion complex formation of aspartame (guest) and various cyclodextrins (host) were examined using 1H NMR titration and capillary electrophoresis. Initially the protonation constants of aspartame were determined by NMR-pH titration with in situ pH measurement to yield log K1=7.83 and log K2=2.96. Based on these values the stability of the complexes formed by aspartame and 21 different cyclodextrins (CDs) were studied at pH 2.5, pH 5.2 and pH 9.0 values where aspartame exists predominantly in monocationic, zwitterionic and monoanionic form, respectively. The host cyclodextrin derivatives differed in various sidechains, degree of substitution, charge and purity so that the effect of these properties could be examined systematically. Concerning size, the seven-membered beta-cyclodextrin and its derivatives have been found to be the most suitable host molecules for complexation. Highest stability was observed for the acetylated derivative with a degree of substitution of 7. The purity of the CD enhanced the complexation while the degree of substitution did not provide obvious consequences. Finally, geometric aspects of the inclusion complex were assessed by 2D ROESY NMR and molecular modelling which proved that the guest's aromatic ring enters the wider end of the host cavity.

  20. From guest to ligand - A study on the competing interactions of antitumor drug resveratrol with {beta}-cyclodextrin and bovine serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xudong [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong Province 252059 (China); Department of Clinical Laboratory, Liaocheng People' s Hospital, Liaocheng, Shandong Province 252000 (China); Li, Hui [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong Province 252059 (China); Liu, Min, E-mail: liumin_panpan@163.com [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong Province 252059 (China); Li, Guangqian; Li, Linwei [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong Province 252059 (China); Sun, Dezhi, E-mail: sundezhisdz@163.com [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong Province 252059 (China)

    2011-07-10

    Graphical abstract: Thermodynamic behavior of the interaction between bovine serum albumin and antitumor drug resveratrol delivered by {beta}-cyclodextrin in buffer solutions (pH 7.40) have been investigated by ITC combined with UV, FS and circular dichroism at 298.15 K. The results indicated that the affinity of resveratrol with the host ({beta}-cyclodextrin) was evidently weaker than that of the drug with the both classes of binding sites on the protein molecule. Highlights: {yields} Supramolecular complex of a drug with BSA could form in aqueous medium. {yields} A set of thermodynamic parameters were determined. {yields} Affinity of the drug to {beta}-CD is weaker than that of it to the protein. {yields} The molecular conformation of BSA was (slightly) changed by the drug. - Abstract: Interaction between bovine serum albumin (BSA) and resveratrol (RES) included by {beta}-cyclodextrin ({beta}-CD) in Tris-HCl aqueous buffer solutions (pH 7.4) has been investigated by isothermal titration calorimetry (ITC) combined with ultraviolet, fluorescence and circular dichroism spectra analyses. The results indicate that there are two classes of ligand binding sites. The first class of binding is mainly driven by enthalpy, while the second one is driven by both enthalpy and entropy. The secondary structure of BSA in the aqueous system was slightly changed with addition of the drug. Thermodynamic parameters, i.e., equilibrium constants, standard enthalpy changes and the entropy effects for the binding process of RES with BSA were calculated based on the calorimetric data. In fact, due to the poor solubility of RES in aqueous buffer medium, these parameters could not be determined by the employed experimental method without the existence of the CD.

  1. Optimization of Microencapsulation of Fish Oil with Gum Arabic/Casein/Beta-Cyclodextrin Mixtures by Spray Drying.

    Science.gov (United States)

    Li, Junjie; Xiong, Shanbai; Wang, Fang; Regenstein, Joe M; Liu, Ru

    2015-07-01

    Fish oil was encapsulated with gum arabic/casein/beta-cyclodextrin mixtures using spray drying. The processing parameters (solids concentration of the barrier solutions, ratio of oil to barrier materials, emulsifying temperature, and air inlet temperature) were optimized based on emulsion viscosity, emulsion stability, encapsulation efficiency, and yield. A suitable viscosity and high emulsion stability could increase encapsulation efficiency and yield. Encapsulation efficiency and yield were significantly affected by all the 4 parameters. Based on the results of orthogonal experiments, encapsulation efficiency and yield reached a maximum of 79.6% and 55.6%, respectively, at the optimal condition: solids concentration of 35%, ratios of oil to barrier materials of 3:7, emulsifying temperature of 55 °C, and air inlet temperature of 220 °C. Scanning electron microscopy analysis showed that fish oil microcapsules were nearly spherical with a smooth surface with droplet size ranging from 1 to 10 μm. © 2015 Institute of Food Technologists®

  2. Polymer-free nanofibers from vanillin/cyclodextrin inclusion complexes: high thermal stability, enhanced solubility and antioxidant property.

    Science.gov (United States)

    Celebioglu, Asli; Kayaci-Senirmak, Fatma; İpek, Semran; Durgun, Engin; Uyar, Tamer

    2016-07-13

    Vanillin/cyclodextrin inclusion complex nanofibers (vanillin/CD-IC NFs) were successfully obtained from three modified CD types (HPβCD, HPγCD and MβCD) in three different solvent systems (water, DMF and DMAc) via an electrospinning technique without using a carrier polymeric matrix. Vanillin/CD-IC NFs with uniform and bead-free fiber morphology were successfully produced and their free-standing nanofibrous webs were obtained. The polymer-free CD/vanillin-IC-NFs allow us to accomplish a much higher vanillin loading (∼12%, w/w) when compared to electrospun polymeric nanofibers containing CD/vanillin-IC (∼5%, w/w). Vanillin has a volatile nature yet, after electrospinning, a significant amount of vanillin was preserved due to complex formation depending on the CD types. Maximum preservation of vanillin was observed for vanillin/MβCD-IC NFs which is up to ∼85% w/w, besides, a considerable amount of vanillin (∼75% w/w) was also preserved for vanillin/HPβCD-IC NFs and vanillin/HPγCD-IC NFs. Phase solubility studies suggested a 1 : 1 molar complexation tendency between guest vanillin and host CD molecules. Molecular modelling studies and experimental findings revealed that vanillin : CD complexation was strongest for MβCD when compared to HPβCD and HPγCD in vanillin/CD-IC NFs. For vanillin/CD-IC NFs, water solubility and the antioxidant property of vanillin was improved significantly owing to inclusion complexation. In brief, polymer-free vanillin/CD-IC NFs are capable of incorporating a much higher loading of vanillin and effectively preserve volatile vanillin. Hence, encapsulation of volatile active agents such as flavor, fragrance and essential oils in electrospun polymer-free CD-IC NFs may have potential for food related applications by integrating the particularly large surface area of NFs with the non-toxic nature of CD and inclusion complexation benefits, such as high temperature stability, improved water solubility and an enhanced

  3. Direct administration of 2-Hydroxypropyl-Beta-Cyclodextrin into guinea pig cochleae: Effects on physiological and histological measurements.

    Directory of Open Access Journals (Sweden)

    J T Lichtenhan

    Full Text Available 2-Hydroxypropyl-Beta-Cyclodextrin (HPβCD can be used to treat Niemann-Pick type C disease, Alzheimer's disease, and atherosclerosis. But, a consequence is that HPβCD can cause hearing loss. HPβCD was recently found to be toxic to outer hair cells (OHCs in the organ of Corti. Previous studies on the chronic effects of in vivo HPβCD toxicity did not know the intra-cochlear concentration of HPβCD and attributed variable effects on OHCs to indirect drug delivery to the cochlea. We studied the acute effects of known HPβCD concentrations administered directly into intact guinea pig cochleae. Our novel approach injected solutions through pipette sealed into scala tympani in the cochlear apex. Solutions were driven along the length of the cochlear spiral toward the cochlear aqueduct in the base. This method ensured that therapeutic levels were achieved throughout the cochlea, including those regions tuned to mid to low frequencies and code speech vowels and background noise. A wide variety of measurements were made. Results were compared to measurements from ears treated with the HPβCD analog methyl-β-cyclodextrin (MβCD, salicylate that is well known to attenuate the gain of the cochlear amplifier, and injection of artificial perilymph alone (controls. Histological data showed that OHCs appeared normal after treatment with a low dose of HPβCD, and physiological data was consistent with attenuation of cochlear amplifier gain and disruption of non-linearity associated with transferring acoustic sound into neural excitation, an origin of distortion products that are commonly used to objectively assess hearing and hearing loss. A high dose of HPβCD caused sporadic OHC losses and markedly affected all physiologic measurements. MβCD caused virulent destruction of OHCs and physiologic responses. Toxicity of HPβCD to OHC along the cochlear length is variable even when a known intra-cochlear concentration is administered, at least for the duration

  4. Gold nanoparticles interacting with β-cyclodextrin-phenylethylamine inclusion complex: a ternary system for photothermal drug release.

    Science.gov (United States)

    Sierpe, Rodrigo; Lang, Erika; Jara, Paul; Guerrero, Ariel R; Chornik, Boris; Kogan, Marcelo J; Yutronic, Nicolás

    2015-07-22

    We report the synthesis of a 1:1 β-cyclodextrin-phenylethylamine (βCD-PhEA) inclusion complex (IC) and the adhesion of gold nanoparticles (AuNPs) onto microcrystals of this complex, which forms a ternary system. The formation of the IC was confirmed by powder X-ray diffraction and NMR analyses ((1)H and ROESY). The stability constant of the IC (760 M(-1)) was determined using the phase solubility method. The adhesion of AuNPs was obtained using the magnetron sputtering technique, and the presence of AuNPs was confirmed using UV-vis spectroscopy (surface plasmon resonance effect), which showed an absorbance at 533 nm. The powder X-ray diffractograms of βCD-PhEA were similar to those of the crystals decorated with AuNPs. A comparison of the one- and two-dimensional NMR spectra of the IC with and without AuNPs suggests partial displacement of the guest to the outside of the βCD due to attraction toward AuNPs, a characteristic tropism effect. The size, morphology, and distribution of the AuNPs were analyzed using TEM and SEM. The average size of the AuNPs was 14 nm. Changes in the IR and Raman spectra were attributed to the formation of the complex and to the specific interactions of this group with the AuNPs. Laser irradiation assays show that the ternary system βCD-PhEA-AuNPs in solution enables the release of the guest.

  5. Ionic cluster size distributions of swollen nafion/sulfated beta-cyclodextrin membranes characterized by nuclear magnetic resonance cryoporometry.

    Science.gov (United States)

    Jeon, Jae-Deok; Kwak, Seung-Yeop

    2007-08-16

    Nafion/sb-CD membranes were prepared by mixing 5 wt% Nafion solution with H+-form sulfated beta-cyclodextrin (sb-CD), and their water uptakes, ion exchange capacities (IECs), and ionic cluster size distributions were measured. Gravimetric and thermogravimetric measurements showed that the water uptake of the membranes increased with increases in their sb-CD content. The IECs of the membrane were measured with acid-base titration and found to increase with increases in the sb-CD content, reaching 0.96 mequiv/g for NC5 ("NCx" denotes a Nafion/sb-CD composite membrane containing x wt% of sb-CD). The cluster-correlation peaks and ionic cluster size distributions of the water-swollen membranes were determined using small-angle X-ray scattering (SAXS) and 1H nuclear magnetic resonance (NMR) cryoporometry, respectively. The SAXS experiments confirmed that increases in the sb-CD content of the membranes shifted the maximum SAXS peaks to lower angles, indicating an increase in the cluster correlation peak. NMR cryoporometry is based on the theory of the melting point depression, Delta Tm, of a liquid confined within a pore, which is dependent on the pore diameter. The melting point depression was determined by analyzing the variation of the NMR signal intensity with temperature. Our analysis of the intensity-temperature (IT) curves showed that the ionic cluster size distribution gradually became broader with increases in the membrane sb-CD content due to the increased water content, indicating an increase in the ionic cluster size. This result indicates that the presence of sb-CD with its many sulfonic acid sites in the Nafion membranes results in increases in the ionic cluster size as well as in the water uptake and the IEC. We conclude that NMR cryoporometry provides a method for determining the ionic cluster size on the nanometer scale in an aqueous environment, which cannot be obtained using other methods.

  6. Liposome-encapsulated EF24-HP{beta}CD inclusion complex: a preformulation study and biodistribution in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Agashe, H; Lagisetty, P; Sahoo, K; Bourne, D [University of Oklahoma Health Sciences Center, Department of Pharmaceutical Sciences (United States); Grady, B [School of Chemical, Biological and Materials Engineering (United States); Awasthi, V [University of Oklahoma Health Sciences Center, Department of Pharmaceutical Sciences (United States)

    2011-06-15

    3,5-Bis(2-fluorobenzylidene)-4-piperidone (EF24) is an anti-proliferative diphenyldifluoroketone analog of curcumin with more potent activity. The authors describe a liposome preparation of EF24 using a 'drug-in-CD-in liposome' approach. An aqueous solution of EF24 and hydroxypropyl-{beta}-cyclodextrin (HP{beta}CD) inclusion complex (IC) was used to prepare EF24 liposomes. The liposome size was reduced by a combination of multiple freeze-thaw cycles. Co-encapsulation of glutathione inside the liposomes conferred them with the capability of labeling with imageable radionuclide Tc-99m. Phase solubility analysis of EF24-HP{beta}CD mixture provided k{sub 1:1} value of 9.9 M{sup -1}. The enhanced aqueous solubility of EF24 (from 1.64 to 13.8 mg/mL) due to the presence of HP{beta}CD helped in the liposome preparation. About 19% of the EF24 IC was encapsulated inside the liposomes (320.5 {+-} 2.6 nm) by dehydration-rehydration technique. With extrusion technique, the size of 177 {+-} 6.5 nm was obtained without any effect on encapsulation efficiency. The EF24-liposomes were evaluated for anti-proliferative activity in lung adenocarcinoma H441 and prostate cancer PC-3 cells. The EF24-liposomes demonstrated anti-proliferative activity superior to that of plain EF24 at 10 {mu}M dose. When injected in rats, the Tc-99m-labeled EF24-liposomes cleared from blood with an {alpha}-t{sub 1/2} of 21.4 min and {beta}-t{sub 1/2} of 397 min. Tissue radioactivity counting upon necropsy showed that the majority of clearance was due to the uptake in liver and spleen. The results suggest that using 'drug-in-CD-in liposome' approach is a feasible strategy to formulate an effective parenteral preparation of EF24. In vitro studies show that the liposomal EF24 remains anti-proliferative, while presenting an opportunity to image its biodistribution.

  7. Liposome-encapsulated EF24-HP{beta}CD inclusion complex: a preformulation study and biodistribution in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Agashe, H.; Lagisetty, P.; Sahoo, K.; Bourne, D. [University of Oklahoma Health Sciences Center, Department of Pharmaceutical Sciences (United States); Grady, B. [School of Chemical, Biological and Materials Engineering (United States); Awasthi, V., E-mail: vawasthi@ouhsc.edu [University of Oklahoma Health Sciences Center, Department of Pharmaceutical Sciences (United States)

    2011-06-15

    3,5-Bis(2-fluorobenzylidene)-4-piperidone (EF24) is an anti-proliferative diphenyldifluoroketone analog of curcumin with more potent activity. The authors describe a liposome preparation of EF24 using a 'drug-in-CD-in liposome' approach. An aqueous solution of EF24 and hydroxypropyl-{beta}-cyclodextrin (HP{beta}CD) inclusion complex (IC) was used to prepare EF24 liposomes. The liposome size was reduced by a combination of multiple freeze-thaw cycles. Co-encapsulation of glutathione inside the liposomes conferred them with the capability of labeling with imageable radionuclide Tc-99m. Phase solubility analysis of EF24-HP{beta}CD mixture provided k{sub 1:1} value of 9.9 M{sup -1}. The enhanced aqueous solubility of EF24 (from 1.64 to 13.8 mg/mL) due to the presence of HP{beta}CD helped in the liposome preparation. About 19% of the EF24 IC was encapsulated inside the liposomes (320.5 {+-} 2.6 nm) by dehydration-rehydration technique. With extrusion technique, the size of 177 {+-} 6.5 nm was obtained without any effect on encapsulation efficiency. The EF24-liposomes were evaluated for anti-proliferative activity in lung adenocarcinoma H441 and prostate cancer PC-3 cells. The EF24-liposomes demonstrated anti-proliferative activity superior to that of plain EF24 at 10 {mu}M dose. When injected in rats, the Tc-99m-labeled EF24-liposomes cleared from blood with an {alpha}-t{sub 1/2} of 21.4 min and {beta}-t{sub 1/2} of 397 min. Tissue radioactivity counting upon necropsy showed that the majority of clearance was due to the uptake in liver and spleen. The results suggest that using 'drug-in-CD-in liposome' approach is a feasible strategy to formulate an effective parenteral preparation of EF24. In vitro studies show that the liposomal EF24 remains anti-proliferative, while presenting an opportunity to image its biodistribution.

  8. Amphiphilic cyclodextrin nanoparticles.

    Science.gov (United States)

    Varan, Gamze; Varan, Cem; Erdoğar, Nazlı; Hıncal, A Atilla; Bilensoy, Erem

    2017-10-15

    Cyclodextrins are cyclic oligosaccharides obtained by enzymatic digestion of starch. The α-, β- and γ- cyclodextrins contain respectively 6, 7 and 8 glucopyranose units, with primary and secondary hydroxyl groups located on the narrow and wider rims of a truncated cone shape structure. Such structure is that of a hydrophobic inner cavity with a hydrophilic outer surface allowing to interact with a wide range of molecules like ions, protein and oligonucleotides to form inclusion complexes. Many cyclodextrin applications in the pharmaceutical area have been widely described in the literature due to their low toxicity and low immunogenicity. The most important is to increase the solubility of hydrophobic drugs in water. Chemically modified cyclodextrin derivatives have been synthesized to enhance their properties and more specifically their pharmacological activity. Among these, amphiphilic derivatives were designed to build organized molecular structures, through selfassembling systems or by incorporation in lipid membranes, expected to improve the vectorization in the organism of the drug-containing cyclodextrin cavities. These derivatives can form a variety of supramolecular structures such as micelles, vesicles and nanoparticles. The purpose of this review is to summarize applications of amphiphilic cyclodextrins in different areas of drug delivery, particularly in protein and peptide drug delivery and gene delivery. The article highlights important amphiphilic cyclodextrin applications in the design of novel delivery systems like nanoparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. A water-soluble, mucoadhesive quaternary ammonium chitosan-methyl-β-cyclodextrin conjugate forming inclusion complexes with dexamethasone.

    Science.gov (United States)

    Piras, Anna Maria; Zambito, Ylenia; Burgalassi, Susi; Monti, Daniela; Tampucci, Silvia; Terreni, Eleonora; Fabiano, Angela; Balzano, Federica; Uccello-Barretta, Gloria; Chetoni, Patrizia

    2018-03-30

    The ocular bioavailability of lipophilic drugs, such as dexamethasone, depends on both drug water solubility and mucoadhesion/permeation. Cyclodextrins and chitosan are frequently employed to either improve drug solubility or prolong drug contact onto mucosae, respectively. Although the covalent conjugation of cyclodextrin and chitosan brings to mucoadhesive drug complexes, their water solubility is restricted to acidic pHs. This paper describes a straightforward grafting of methyl-β-cyclodextrin (MCD) on quaternary ammonium chitosan (QA-Ch60), mediated by hexamethylene diisocyanate. The resulting product is a water-soluble chitosan derivative, having a 10-atom long spacer between the quaternized chitosan and the cyclodextrin. The derivative is capable of complexing the model drug dexamethasone and stable complexes were also observed for the lyophilized products. Furthermore, the conjugate preserves the mucoadhesive properties typical of quaternized chitosan and its safety as solubilizing excipient for ophthalmic applications was preliminary assessed by in vitro cytotoxicity evaluations. Taken as a whole, the observed features appear promising for future processing of the developed product into 3D solid forms, such as controlled drug delivery systems, films or drug eluting medical devices.

  10. The Synthesis of N-Acetyllactosamine Functionalized Dendrimers, and the Functionalization of Silica Surfaces Using Tunable Dendrons and beta-Cyclodextrins

    Science.gov (United States)

    Ennist, Jessica Helen

    Galectin-3 is beta-galactoside binding protein which is found in many healthy cells. In cancer, the galectin-3/tumor-associated Thomsen-Friedenreich antigen (TF antigen) interaction has been implicated in heterotypic and homotypic cellular adhesion and apoptotic signaling pathways. However, a stronger mechanistic understanding of the role of galectin-3 in these processes is needed. N-acetyllactosamine (LacNAc) is a non-native ligand for galectin-3 which binds with comparable affinity to the TF antigen and therefore an important ligand to study galectin-3 mediated processes. To study galectin-3 mediated homotypic cellular aggregation, four generations of polyamidoamine (PAMAM) dendrimers were functionalized with N-acetyllactosamine using a four-step chemoenzymatic route. The enzymatic step controlled the regiochemistry of the galactose addition to N-acetylglucosamine functionalized dendrimers using a recombinant beta-1,4-Galactosyltransferase-/UDP-4'-Gal Epimerase Fusion Protein (lgtB-galE). Homotypic cellular aggregation, which is promoted by the presence of galectin-3 as it binds to glycosides at the cell surface, was studied using HT-1080 fibrosarcoma, A549 lung, and DU-145 prostate cancer cell lines. In the presence of small LacNAc functionalized PAMAM dendrimers, galectin-3 induced cancer cellular aggregation was inhibited. However, the larger glycodendrimers induced homotypic cellular aggregation. Additionally, novel poly(aryl ether) dendronized silica surfaces designed for reversible adsorbtion of targeted analytes were synthesized, and characterization using X-ray Photoelectron Spectroscopy (XPS) was performed. Using a Cu(I) mediated cycloaddition "click" reaction, beta-cyclodextrin was appended to dendronized surfaces via triazole formation and also to a non-dendronized surface for comparison purposes. First generation G(1) dendrons have more than 6 times greater capacity to adsorb targeted analytes than slides functionalized with monomeric beta-cyclodextrin

  11. Investigation of six-membered carbocyclic compounds as a molecular switch block of room temperature phosphorescence in nondeoxygenated {beta}-cyclodextrin solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Hairong; Wei Yansheng; Jin Weijun; Liu Changsong

    2003-05-07

    An aerated aqueous solution, intense room temperature phosphorescence (RTP) of nitrogen heterocyclic compounds (NHCs) and polyaromatic hydrocarbons (PAHs) can be observed when micro amounts of six-membered carbocyclic compounds (6-MCCs) are introduced in {beta}-cyclodextrin ({beta}-CD) solution. In order to find the predominating factors of the enhanced phosphorescence observed with this novel approach, 22 typical phosphors of NHCs and PAHs were carefully screened and served as model compounds. The role of the inner heavy atom, the substituent group and the host-guest molecules space-matching on the RTP of different phosphors were investigated. The results demonstrated that the enhancement effects of cyclohexane, bromocyclohexane and cyclohexanol for the RTP of NHCs and PAHs have precedence over traditional halide alkanes such as 1,2-dibromoethane (DBE), exhibiting an obvious sequence as following: cyclohexane > bromocyclohexane > cyclohexanol. This new approach compared with other RTP methods is simple, convenient and fast.

  12. Studying anti-oxidative properties of inclusion complexes of α-lipoic acid with γ-cyclodextrin in single living fission yeast by confocal Raman microspectroscopy

    Science.gov (United States)

    Noothalapati, Hemanth; Ikarashi, Ryo; Iwasaki, Keita; Nishida, Tatsuro; Kaino, Tomohiro; Yoshikiyo, Keisuke; Terao, Keiji; Nakata, Daisuke; Ikuta, Naoko; Ando, Masahiro; Hamaguchi, Hiro-o.; Kawamukai, Makoto; Yamamoto, Tatsuyuki

    2018-05-01

    α-lipoic acid (ALA) is an essential cofactor for many enzyme complexes in aerobic metabolism, especially in mitochondria of eukaryotic cells where respiration takes place. It also has excellent anti-oxidative properties. The acid has two stereo-isomers, R- and S- lipoic acid (R-LA and S-LA), but only the R-LA has biological significance and is exclusively produced in our body. A mutant strain of fission yeast, Δdps1, cannot synthesize coenzyme Q10, which is essential during yeast respiration, leading to oxidative stress. Therefore, it shows growth delay in the minimal medium. We studied anti-oxidant properties of ALA in its free form and their inclusion complexes with γ-cyclodextrin using this mutant yeast model. Both free forms R- and S-LA as well as 1:1 inclusion complexes with γ-cyclodextrin recovered growth of Δdps1 depending on the concentration and form. However, it has no effect on the growth of wild type fission yeast strain at all. Raman microspectroscopy was employed to understand the anti-oxidant property at the molecular level. A sensitive Raman band at 1602 cm-1 was monitored with and without addition of ALAs. It was found that 0.5 mM and 1.0 mM concentrations of ALAs had similar effect in both free and inclusion forms. At 2.5 mM ALAs, free forms inhibited the growth while inclusion complexes helped in recovered. 5.0 mM ALA showed inhibitory effect irrespective of form. Our results suggest that the Raman band at 1602 cm-1 is a good measure of oxidative stress in fission yeast.

  13. Use of cyclodextrins as a cosmetic delivery system for fragrance materials: linalool and benzyl acetate.

    Science.gov (United States)

    Numanoğlu, Ulya; Sen, Tangül; Tarimci, Nilüfer; Kartal, Murat; Koo, Otilia M Y; Onyüksel, Hayat

    2007-10-19

    The aim of this study was to increase the stability and water solubility of fragrance materials, to provide controlled release of these compounds, and to convert these substances from liquid to powder form by preparing their inclusion complexes with cyclodextrins (CDs). For this purpose, linalool and benzyl acetate were chosen as the fragrance materials. The use of beta-cyclodextrin (beta CD) and 2-hydroxypropyl-beta-cyclodextrin (2-HP beta CD) for increasing the solubility of these 2 fragrance materials was studied. Linalool and benzyl acetate gave a B-type diagram with beta CD, whereas they gave an A(L)-type diagram with 2-HP beta CD. Therefore, complexes of fragrance materials with 2-HP beta CD at 1:1 and 1:2 molar ratios (guest:host) were prepared. The formation of inclusion complexes was confirmed using proton nuclear magnetic resonance ((1)H-NMR) spectroscopy and circular dichroism spectroscopy. The results of the solubility studies showed that preparing the inclusion complex with 2-HP beta CD at a 1:1 molar ratio increased the solubility of linalool 5.9-fold and that of benzyl acetate 4.2-fold, whereas the complexes at a 1:2 molar ratio increased the solubility 6.4- and 4.5-fold for linalool and benzyl acetate, respectively. The stability and in vitro release studies were performed on the gel formulations prepared using uncomplexed fragrance materials or inclusion complexes of fragrance materials at a 1:1 molar ratio. It was observed that the volatility of both fragrance materials was decreased by preparing the inclusion complexes with 2-HP beta CD. Also, in vitro release data indicated that controlled release of fragrances could be possible if inclusion complexes were prepared.

  14. Cyclodextrins in drug carrier systems.

    Science.gov (United States)

    Uekama, K; Otagiri, M

    1987-01-01

    One of the important characteristics of cyclodextrins is the formation of an inclusion complex with a variety of drug molecules in solution and in the solid state. As a consequence of intensive basic research, exhaustive toxic studies, and realization of industrial production during the past decade, there seem to be no more barriers for the practical application of natural cyclodextrins in the biomedical field. Recently, a number of cyclodextrin derivatives and cyclodextrin polymers have been prepared to obtain better inclusion abilities than parent cyclodextrins. The natural cyclodextrins and their synthetic derivatives have been successfully utilized to improve various drug properties, such as solubility, dissolution and release rates, stability, or bioavailability. In addition, the enhancement of drug activity, selective transfer, or the reduction of side effects has been achieved by means of inclusion complexation. The drug-cyclodextrin complex is generally formed outside of the body and, after administration, it dissociates, releasing the drug into the organism in a fast and nearly uniform manner. In the biomedical application of cyclodextrins, therefore, particular attention should be directed to the magnitude of the stability constant of the inclusion complex. In the case of parenteral application, a rather limited amount of work has been done because the cyclodextrins in the drug carrier systems have to be more effectively designed to compete with various biological components in the circulatory system. However, the works published thus far apparently indicate that the inclusion phenomena of cyclodextrin analogs may allow the rational design of drug formulation and that the combination of molecular encapsulation with other carrier systems will become a very effective and valuable method for the development of a new drug delivery system in the near future.

  15. Conformational Change in the Mechanism of Inclusion of Ketoprofen in β-Cyclodextrin: NMR Spectroscopy, Ab Initio Calculations, Molecular Dynamics Simulations, and Photoreactivity.

    Science.gov (United States)

    Guzzo, T; Mandaliti, W; Nepravishta, R; Aramini, A; Bodo, E; Daidone, I; Allegretti, M; Topai, A; Paci, M

    2016-10-11

    Inclusion of drugs in cyclodextrins (CDs) is a recognized tool for modifying several properties such as solubility, stability, bioavailability, and so on. The photoreactive behavior of the β-CD/ketoprofen (KP) complex upon UV exposure showed a significant increase in photodecarboxylation, whereas the secondary degradation products by hydroxylation of the benzophenone moiety were inhibited. The results may account for an improvement of KP photophysical properties upon inclusion, thus better fostering its topical use. To correlate the structural details of the inclusion with these results, an NMR spectroscopic study of KP upon inclusion in β-CD was performed. Effects of the magnetically anisotropic centers of KP, changing their orientations upon inclusion and giving chemical shift variations, were specifically correlated with the results of the molecular dynamic simulations and ab initio calculations. In the large variety of papers focusing on the structural analysis of β-CD complexes, this work represents one of the few examples in which a detailed analysis of these simultaneous upfield-downfield NMR shifts of the same aromatic molecule upon inclusion is reported. Interestingly, the results demonstrate that the observed upfield and downfield shifts upon inclusion are not related to any direct magnetic role of β-CD. The conformational change of KP upon the inclusion process consists of a slight reduction in the angle between the two phenyl rings and in a remarkable reduction in the mobility of the carboxyl group, the latter being one of the main contributions to the NMR resonance shifts. These structural details help in understanding the features of the inclusion complex and, eventually, the driving force for its formation.

  16. Investigation of interaction of vanillin with Alpha, Beta and Gamma-cyclodextrin as drug delivery carriers: brief report

    Directory of Open Access Journals (Sweden)

    Batoolalsadat Mousavi Fard

    2015-05-01

    Methods: All theoretical calculations were performed on a Intel® Core™ i5 Processors computer at Kerman University using Gaussian 09 program package (Gaussian, Inc., Wallingford, USA in a three month period (February 2014 to May 2014. Starting geometries were generated employing GaussView software, version 5 (Gaussian, Inc., Wallingford, USA and then the resulting coordinates were optimized using density functional theory (DFT calculations. The natural bond orbital method (NBO program, under Gaussian 09 program package was carried out to study charge transfer energy associated with the intermolecular interactions. The quantum theory of atoms in molecules was applied for DFT results to get insight in the nature of interaction existing in the investigated systems. The calculations were carried out with AIM2000 program and AIMAll 14.10.27 package (Todd A. Keith, TK Gristmill software, Overland Park KS, USA to find and characterize bond critical points. Results: The vanillin molecule is adsorbed on the surface of carriers by hydrogen bonding between its oxygen atom and hydrogen atoms of cyclodextrin. The hydrogen of -OH group on the cyclodextrin can form hydrogen bond to the oxygen atom of carbonyl group of vanillin molecule. This study indicates a decrease of total energy with increasing surface of cyclodextrin. So gamma-cyclodextrin and its complex with the maximum surface in between carriers have the highest stabilities. The gamma-cyclodextrin shows the strongest interaction with vanillin. In all complexes of vanillin-cyclodextrin, the direction of charge transfer is from drug to carrier. Conclusion: Due to the high solubility of gamma-cyclodxtrin and its stronger interaction with the molecule vanillin, it can be the best option as drug carrier.

  17. Effect of cyclodextrin complexation on the aqueous solubility and solubility/dose ratio of praziquantel.

    Science.gov (United States)

    Maragos, Stratos; Archontaki, Helen; Macheras, Panos; Valsami, Georgia

    2009-01-01

    Praziquantel (PZQ), the primary drug of choice in the treatment of schistosomiasis, is a highly lipophilic drug that possesses high permeability and low aqueous solubility and is, therefore, classified as a Class II drug according to the Biopharmaceutics Classification System (BCS). In this work, beta-cyclodextrin (beta-CD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) were used in order to determine whether increasing the aqueous solubility of a drug by complexation with CDs, a BCS-Class II compound like PZQ could behave as BCS-Class I (highly soluble/highly permeable) drug. Phase solubility and the kneading and lyophilization techniques were used for inclusion complex preparation; solubility was determined by UV spectroscopy. The ability of the water soluble polymer polyvinylpyrolidone (PVP) to increase the complexation and solubilization efficiency of beta-CD and HP-beta-CD for PZQ was examined. Results showed significant improvement of PZQ solubility in the presence of both cyclodextrins but no additional effect in the presence of PVP. The solubility/dose ratios values of PZQ-cyclodextrin complexes calculated considering the low (150 mg) and the high dose (600 mg) of PZQ, used in practice, indicate that PZQ complexation with CDs may result in drug dosage forms that would behave as a BCS-Class I depending on the administered dose.

  18. Caracterização físico-química de complexos de insulina: dimetil-beta-ciclodextrina e insulina: hidroxipropil-beta-ciclodextrina e avaliação da influência do tipo de complexo na produção de microesferas biodegradáveis Physico-chemical caracterization of insulin: dimethyl-beta-cyclodextrin and insulin:hydroxypropil-beta-cyclodextrin complexes and evaluation of the kind of complexes on the biodegradable microspheres preparation

    Directory of Open Access Journals (Sweden)

    Viviane Conceição Fernandes

    2007-12-01

    Full Text Available A etapa principal na ativação e ligação da insulina ao seu receptor é a dissociação dos hexâmeros do hormônio, normalmente presente nas preparações farmacêuticas, para a forma monomérica bioativa. A utilização de diferentes ciclodextrinas (CDs como adjuvantes em formulações contendo insulina vem sendo explorada e os estudos realizados demonstram que estas substâncias podem aumentar a absorção da insulina principalmente por diminuírem sua capacidade de formar dímeros e hexâmeros em meio aquoso. No presente trabalho, complexos de insulina:hidroxipropil-beta-ciclodextrina (INS:HP-beta-CD e insulina:dimetil-beta-ciclodextrina (INS:DM-beta-CD foram caracterizados utilizando técnicas de titulação calorimétrica isotérmica e espalhamento dinâmico de luz. Por meio da titulação calorimétrica foram determinados os parâmetros termodinâmicos de interação entre a insulina e as CDs utilizadas, sugerindo que o mecanismo de complexação ocorre com aumento de entropia para ambos os sistemas. Os experimentos de espalhamento dinâmico de luz não indicaram diminuição do diâmetro hidrodinâmico das espécies moleculares de insulina após a complexação com as CDs. Os complexos INS:HP-beta-CD e INS:DM-beta-CD foram encapsulados em microesferas (MEs de PLGA 50:50. A caracterização das MEs obtidas revelou aumento considerável na taxa de encapsulamento de insulina quando complexada com as CDs sem que ocorresse diferença significativa no diâmetro das partículas em função da complexação.The main stage in the linking and activation of the specific receptors by the insulin is the dissociation of this peptide hexamers, normally present in pharmaceutical formulations, in the monomeric active form. Because of this, the use of different cyclodextrins as adjuvants in the formulations containing insulin has been explored and the realized studies have demonstrated that the cyclodextrins can increase the absorption of the insulin

  19. Ascorbyl Tetraisopalmitate Inclusion into Υ-Cyclodextrin and Mesoporous SBA-15: Preparation, Characterization and In Vitro Release Study

    Directory of Open Access Journals (Sweden)

    Maria Bastianini

    2017-07-01

    Full Text Available Ascorbic acid or vitamin C is a strong antioxidant widely used in cosmetic and food fields. This vitamin is very unstable and rapidly undergoes degradation. In order to solve this problem and to obtain a stable ascorbic acid, Nikkol Group has developed ascorbyltetraisopalmitate (VC-IP. This raw material is an oil phase, already well-known and employed in the cosmetic market. The objective of this study is to obtain VC-IP in micro-powder form, in order to produce a new raw material that is easily dispersible in oil and water phases and useful for make-up and color cosmetic applications. Various types of drug carriers were studied and considered in order to support VC-IP and obtain the conversion in powder. Υ-cyclodextrin and mesoporous silica SBA-15 were chosen as the best candidates. A white powder of supported VC-IP was obtained with each carrier (VC-IP@cyclodextrin, VC-IP@SBA-15. The systems underwent physicochemical characterization and in vitro release tests were carried out. Based on the conducted study, it can be concluded that by supporting VC-IP on Υ-cyclodextrin and SBA-15, it is feasible to obtain a new raw material in powder form. The two carriers possess different release profiles, adding the possibility to finely tune the release of the active component in smart formulations.

  20. Interaction of hydroxypropyl-beta-cyclodextrin with peptides, studied by reversed-phase thin-layer chromatography

    Czech Academy of Sciences Publication Activity Database

    Gere-Pászti, E.; Cserháti, T.; Forgács, E.; Deyl, Zdeněk; Mikšík, Ivan; Eckhardt, Adam; Illés, Z.

    2005-01-01

    Roč. 28, č. 16 (2005), s. 2619-2632 ISSN 1082-6076 Grant - others:CZ-HU(CZ) Cooperation program Institutional research plan: CEZ:AV0Z50110509 Keywords : cyclodextrin * peptides * nonlinear map Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.814, year: 2005

  1. Beta-Cyclodextrin Duplexes That Are Connected through Two Disulfide Bonds: Potent Hosts for the Complexation of Organic Molecules

    Czech Academy of Sciences Publication Activity Database

    Grishina, Anastasia; Stanchev, Stancho; Kumprecht, Lukáš; Buděšínský, Miloš; Pojarová, Michaela; Dušek, Michal; Rumlová, Michaela; Křížová, Ivana; Rulíšek, Lubomír; Kraus, Tomáš

    2012-01-01

    Roč. 18, č. 39 (2012), s. 12292-12304 ISSN 0947-6539 Grant - others:AV ČR(CZ) M200550904 Institutional support: RVO:61388963 ; RVO:68378271 Keywords : cucurbiturils * cyclodextrins * duplexes * host-guest systems * sulfur Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.831, year: 2012

  2. A thermogravimetric analysis (TGA) method developed for estimating the stoichiometric ratio of solid-state {alpha}-cyclodextrin-based inclusion complexes

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yuxiang; Wang, Jinpeng; Bashari, Mohanad; Hu, Xiuting [The State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122 (China); Feng, Tao [School of Perfume and Aroma Technology, Shanghai Institute of Technology, Shanghai 201418 (China); Xu, Xueming [The State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122 (China); Jin, Zhengyu, E-mail: jinlab2008@yahoo.com [The State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122 (China); Tian, Yaoqi, E-mail: yqtian@jiangnan.edu.cn [The State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122 (China)

    2012-08-10

    Highlights: Black-Right-Pointing-Pointer We develop a TGA method for the measurement of the stoichiometric ratio. Black-Right-Pointing-Pointer A series of formulas are deduced to calculate the stoichiometric ratio. Black-Right-Pointing-Pointer Four {alpha}-CD-based inclusion complexes were successfully prepared. Black-Right-Pointing-Pointer The developed method is applicable. - Abstract: An approach mainly based on thermogravimetric analysis (TGA) was developed to evaluate the stoichiometric ratio (SR, guest to host) of the guest-{alpha}-cyclodextrin (Guest-{alpha}-CD) inclusion complexes (4-cresol-{alpha}-CD, benzyl alcohol-{alpha}-CD, ferrocene-{alpha}-CD and decanoic acid-{alpha}-CD). The present data obtained from Fourier transform-infrared (FT-IR) spectroscopy showed that all the {alpha}-CD-based inclusion complexes were successfully prepared in a solid-state form. The stoichiometric ratios of {alpha}-CD to the relative guests (4-cresol, benzyl alcohol, ferrocene and decanoic acid) determined by the developed method were 1:1, 1:2, 2:1 and 1:2, respectively. These SR data were well demonstrated by the previously reported X-ray diffraction (XRD) method and the NMR confirmatory experiments, except the SR of decanoic acid with a larger size and longer chain was not consistent. It is, therefore, suggested that the TGA-based method is applicable to follow the stoichiometric ratio of the polycrystalline {alpha}-CD-based inclusion complexes with smaller and shorter chain guests.

  3. A thermogravimetric analysis (TGA) method developed for estimating the stoichiometric ratio of solid-state α-cyclodextrin-based inclusion complexes

    International Nuclear Information System (INIS)

    Bai, Yuxiang; Wang, Jinpeng; Bashari, Mohanad; Hu, Xiuting; Feng, Tao; Xu, Xueming; Jin, Zhengyu; Tian, Yaoqi

    2012-01-01

    Highlights: ► We develop a TGA method for the measurement of the stoichiometric ratio. ► A series of formulas are deduced to calculate the stoichiometric ratio. ► Four α-CD-based inclusion complexes were successfully prepared. ► The developed method is applicable. - Abstract: An approach mainly based on thermogravimetric analysis (TGA) was developed to evaluate the stoichiometric ratio (SR, guest to host) of the guest–α-cyclodextrin (Guest-α-CD) inclusion complexes (4-cresol-α-CD, benzyl alcohol-α-CD, ferrocene-α-CD and decanoic acid-α-CD). The present data obtained from Fourier transform-infrared (FT-IR) spectroscopy showed that all the α-CD-based inclusion complexes were successfully prepared in a solid-state form. The stoichiometric ratios of α-CD to the relative guests (4-cresol, benzyl alcohol, ferrocene and decanoic acid) determined by the developed method were 1:1, 1:2, 2:1 and 1:2, respectively. These SR data were well demonstrated by the previously reported X-ray diffraction (XRD) method and the NMR confirmatory experiments, except the SR of decanoic acid with a larger size and longer chain was not consistent. It is, therefore, suggested that the TGA-based method is applicable to follow the stoichiometric ratio of the polycrystalline α-CD-based inclusion complexes with smaller and shorter chain guests.

  4. Chiral separation of synthetic vicinal diol compounds by capillary zone electrophoresis with borate buffer and beta-cyclodextrin as buffer additive.

    Science.gov (United States)

    Zhao, Yan; Yang, Xingbin; Jiang, Ru; Sun, Xiaoli; Liu, Wenmin; Zhang, Shengyong

    2006-05-01

    The investigation on capillary electrophoretic enantioseparation of six synthetic compounds containing vicinal diol groups has been undertaken to acquire the optimum conditions using native beta-cyclodextrin (beta-CD) as chiral selector and borate as a background electrolyte. The separation was carried out in an uncoated capillary (58.5 cm x 75 microm i.d., effective length 48.5 cm) and the effects of several important factors were investigated in detail. The results showed that beta-CD as a chiral selector exhibited good enantioselectivity and that the enantioseparation was greatly influenced by the structure of the diols, the borate concentration and the buffer pH. The optimum performance was obtained for the chiral vicinal diols under the conditions of 200 mM borate buffer of pH 9.8 containing 1.7% beta-CD at an applied voltage of 15 kV and a capillary temperature of 20 degrees C. Under the conditions, four diols were baseline separated with fast analysis time and the good theoretical plate numbers (above 10 x 10(4)) and favorable migration-time reproducibilities (RSDs below 3.0%) were obtained. The separation results were satisfactory.

  5. The influence of dissolved H2O content in supercritical carbon dioxide to the inclusion complexes formation of ketoprofen/β-cyclodextrin

    Science.gov (United States)

    Goenawan, Joshua; Trisanti, P. N.; Sumarno

    2015-12-01

    This work studies the relation between dissolved H2O content in supercritical carbon dioxide (SC-CO2) with the formation of ketoprofen (KP)/β-cyclodextrin(CD) inclusion complexes. The process involves a physical mixture of these two compounds into contact with the supercritical carbon dioxide which had been previously saturated with H2O over a certain duration. The pressure used for saturation process is 130 bar and saturation temperature was ranged between 30 °C to 50 °C. The inclusion process was achieved by keeping it for 2 hours at 160 bar and 200 bar with inclusion temperature of 50 °C. The results enable us to suggest explanations for the inclusion formation. The inclusion complexes can be formed by contacting the dissolved H2O in SC-CO2 to the physical mixture of KP and CD. An increase in the temperature of saturation process resulted in an increase of dissolved H2O content in the supercritical carbon dioxide. The increasing levels of this water soluble resulted an increase in the inclusion complexes that has been formed. The formation of inclusion complexes includes the water molecules enhancing the emptying of the CD cavities and being replaced by KP, towards a more stable energy state. The drug release used for analyzing the dissolution rate of the KP/CD complexes. The results vary from 79,85% to 99,98% after 45 minutes which is above the rate that has been assigned by Farmakope Indonesia at 70% dissolution rate for KP. The use of SC-CO2 offers a new methods for increasing the rate of dissolution of drugs that are hydrophobic such as KP. CO2 used as a supercritical fluid because of its relatively low cost, easily obtainable supercritical conditions, and lack of toxicity. The material samples were characterized by DSC and Spectrophotometer UV-vis technique.

  6. Synthesis, Characterization, In Vitro Evaluation, and Preclinical Profiling of beta-Cyclodextrin Polyrotaxane Families for Use As Potential Niemann-Pick Type C Therapeutics

    Science.gov (United States)

    Collins, Christopher J.

    Niemann-Pick Disease Type C (NPC) is a rare, autosomal recessive genetic disorder featuring a loss of proteins responsible for unesterified cholesterol (UC) trafficking through the late endosomes/lysosomes (LE/LY) of every cell of the body. Disruption of this pathway leads to abnormal accumulation and storage of UC and other lipids. A broad range of visceral and neurological symptoms result from this accumulation exhibiting a variable age of onset and a disease progression that is ultimately fatal. The disease has an incidence of approximately 1 in 120,000 live births and has no known effective treatment. beta-Cyclodextrin (beta-CD) are natural small molecules macrocycles composed of glucose units with a hydrophobic inner cavity and hydrophilic outer rims. beta-CD derivatives have recently been shown to be effective therapeutics for NPC in cellular and animal models. In the mouse model of the disease, beta-CD therapy increases overall lifetime by as much as 50% and slows the progression of neurodegeneration. The progress has led to the initiation of a National Institutes of Health phase I clinical trial. A main drawback of beta-CD administration is the poor pharmacokinetic profile characterized by rapid renal clearance of the drug through the urine. Libraries of beta-CD derivative carrying high molecular weight polyrotaxane (PR) systems have been designed to prevent glomerular filtration of the injected beta-CD dose. An initial family of unmodified beta-CD PRs was synthesized, characterized, and their therapeutic efficacy was tested in NPC fibroblasts. This was followed by screening of PRs consisting of mixed beta-CD derivative threading featuring charged sulfobutylether beta-CD. Finally, we sought to define PR structure-property effects on in vivo pharmacokinetics, biodistribution, toxicity, immunogenicity, and protein hard corona composition. This was accomplished using a family of gadolinium carrying PRs composed of triblock Pluronic co-polymers of varying

  7. Analyses of polycyclic aromatic hydrocarbon (PAH) and chiral-PAH analogues-methyl-β-cyclodextrin guest-host inclusion complexes by fluorescence spectrophotometry and multivariate regression analysis.

    Science.gov (United States)

    Greene, LaVana; Elzey, Brianda; Franklin, Mariah; Fakayode, Sayo O

    2017-03-05

    The negative health impact of polycyclic aromatic hydrocarbons (PAHs) and differences in pharmacological activity of enantiomers of chiral molecules in humans highlights the need for analysis of PAHs and their chiral analogue molecules in humans. Herein, the first use of cyclodextrin guest-host inclusion complexation, fluorescence spectrophotometry, and chemometric approach to PAH (anthracene) and chiral-PAH analogue derivatives (1-(9-anthryl)-2,2,2-triflouroethanol (TFE)) analyses are reported. The binding constants (K b ), stoichiometry (n), and thermodynamic properties (Gibbs free energy (ΔG), enthalpy (ΔH), and entropy (ΔS)) of anthracene and enantiomers of TFE-methyl-β-cyclodextrin (Me-β-CD) guest-host complexes were also determined. Chemometric partial-least-square (PLS) regression analysis of emission spectra data of Me-β-CD-guest-host inclusion complexes was used for the determination of anthracene and TFE enantiomer concentrations in Me-β-CD-guest-host inclusion complex samples. The values of calculated K b and negative ΔG suggest the thermodynamic favorability of anthracene-Me-β-CD and enantiomeric of TFE-Me-β-CD inclusion complexation reactions. However, anthracene-Me-β-CD and enantiomer TFE-Me-β-CD inclusion complexations showed notable differences in the binding affinity behaviors and thermodynamic properties. The PLS regression analysis resulted in square-correlation-coefficients of 0.997530 or better and a low LOD of 3.81×10 -7 M for anthracene and 3.48×10 -8 M for TFE enantiomers at physiological conditions. Most importantly, PLS regression accurately determined the anthracene and TFE enantiomer concentrations with an average low error of 2.31% for anthracene, 4.44% for R-TFE and 3.60% for S-TFE. The results of the study are highly significant because of its high sensitivity and accuracy for analysis of PAH and chiral PAH analogue derivatives without the need of an expensive chiral column, enantiomeric resolution, or use of a polarized

  8. Electrochemical quantification of the thermodynamic equilibrium constant of the tenoxicam-β-cyclodextrin inclusion complex formed on the surface of a poly-β cyclodextrin-modified carbon paste electrode

    International Nuclear Information System (INIS)

    Guzmán-Hernández, D.S.; Palomar-Pardavé, M.; Rojas-Hernández, A.; Corona-Avendaño, S.; Romero-Romo, M.; Ramírez-Silva, M.T.

    2014-01-01

    Graphical abstract: - Highlights: • A carbon paste electrode (CPE) was modified with a β-CD polymer. • Tenoxicam oxidation on the CPE/poly-β-CD was adsorption controlled. • Influence of pH, scan rate, angular velocity and concentration was evaluated. • Fittings of i-E plots were done considering an irreversible surface reaction. • Electrochemical evaluation of the surface inclusion constant is presented. - Abstract: In this work it is shown that when a carbon paste electrode, CPE, is modified with a β-cyclodextrin polymer, the tenoxicam oxidation becomes an adsorption controlled process due to formation of a surface inclusion complex with the β-CD molecules comprising the surface of the polymer. It was found that such surface inclusion complex can be formed independently of the tenoxicam predominant species, Tenox’, in the aqueous solution namely: H 2 Tenox + , HTenox or Tenox − , depending on the solution pH. The electrochemical quantification of the thermodynamic constant of the equilibrium Tenox’ + β-CD (polymer) = Tenox’-β-CD (polymer) was estimated as log K incl. = 4.26 ± 0.01. Furthermore, from the analyses of the experimental voltammograms according with Laviron's equation for an irreversible surface reaction [E. Laviron, J. Electroanal. Chem. 52 (1974) 355-393] it is shown that the surface concentration, Γ R , of tenoxicam increases as its concentration in solution does, reaching a maximum value of 1.51 × 10 −10 mol cm −2 at 64 μM

  9. Methylated β-Cyclodextrins

    DEFF Research Database (Denmark)

    Schönbeck, Jens Christian Sidney; Westh, Peter; Madsen, Jens Christian

    2011-01-01

    The complexation of 6 bile salts with various methylated β-cyclodextrins was studied to elucidate how the degree and pattern of substitution affects the binding. The structures of the CDs were determined by mass spectrometry and NMR techniques, and the structures of the inclusion complexes were...

  10. The effects of cyclodextrins on drug release from fatty suppository bases : III. Application of cyclodextrin derivatives

    NARCIS (Netherlands)

    Frijlink, H.W.; Paiotti, S.; Eissens, Anko; Lerk, C.F.

    1992-01-01

    The complexation of both n-butyl-4-aminobenzoate and diazepam with dimethyl-beta-cyclodextrin and hydroxypropyl-beta-cyclodextrin, respectively, was studied. Solid complexes were prepared by freeze-drying. The complexes were incorporated in fatty suppositories and drug release was studied, both in

  11. Experimental and Theoretical Investigations on the Supermolecular Structure of Isoliquiritigenin and 6-O-α-D-Maltosyl-β-cyclodextrin Inclusion Complex

    Directory of Open Access Journals (Sweden)

    Bin Li

    2015-08-01

    Full Text Available Isoliquiritigenin (ILTG possesses many pharmacological properties. However, its poor solubility and stability in water hinders its wide applications. The solubility of bioactive compounds can often be enhanced through preparation and delivery of various cyclodextrin (CD inclusion complexes. The 6-O-α-D-maltosyl-β-CD (G2-β-CD, as one of the newest developments of CDs, has high aqueous solubility and low toxicity, especially stable inclusion characteristics with bioactive compounds. In this work, we for the first time construct and characterize the supermolecular structure of ILTG/G2-β-CD by scanning electron microscopy (SEM, ultraviolet-visible spectroscopy (UV, Fourier transform infrared spectroscopy (FT-IR, and X-ray diffractometry (XRD. The solubility of ILTG in water at 25 °C rises from 0.003 to 0.717 mg/mL by the encapsulation with G2-β-CD. Our experimental observations on the presence of the ILTG/G2-β-CD inclusion complex are further supported by the ONIOM(our Own N-layer Integrated Orbital molecular Mechanics-based QM/MM (Quantum Mechanics/Molecular Mechanics calculations, typically substantiating these supermolecular characteristics, such as detailed structural assignments, preferred binding orientations, selectivity, solvent effects, interaction energies and forces of the ILTG/G2-β-CD inclusion complex. Our results have elucidated how ILTG interacts with G2-β-CD, demonstrating the primary host-guest interactions between ILTG and G2-β-CD, characterized by hydrogen bonds, hydrophobic interactions, electrostatic forces, and conformational effects, are favored for the formation of the ILTG/G2-β-CD inclusion.

  12. CYCLODEXTRINS - FIELFS OF APPLICATION. PART II

    Directory of Open Access Journals (Sweden)

    Gh. Duca

    2012-12-01

    Full Text Available This paper represents an analysis of potential and current applications of cyclodextrins as biologically active substances in medicine. The main applications described here include use of cyclodextrins as agents that form inclusion complexes with endogenous substances (membrane lipids, cellular cholesterol, agents that form inclusion complexes with exogenous substances with their man role as guest molecules (sugammadex, FBCx, agents that block endogenous and exogenous macromolecules (ion channels, anthrax toxin, α-hemolysin, and agents which activity is based on the chemical nature of them and of their derivatives (cyclodextrin polysulphate derivatives. The fi rst classifi cation for medically important biological activity of cyclodextrins has been proposed.

  13. Selective discrimination of cyclodextrin diols using cyclic sulfates

    DEFF Research Database (Denmark)

    Petrillo, Marta; Marinescu, Lavinia; Rousseau, Cyril

    2009-01-01

    A method for selective monofunctionalition of readily available cyclodextrin diols (2(A-F),3(A-F),6(B,C,E,F)-hexadeca-O-benzyl-alpha-cyclodextrin and 2(A-G),3(A-G),6(B,C,E-G)-nonadeca-O-benzyl-beta-cyclodextrin) by regioselective nucleophilic opening of their cyclic sulfates is presented. Although...

  14. A novel multi-tiered experimental approach unfolding the mechanisms behind cyclodextrin-vitamin inclusion complexes for enhanced vitamin solubility and stability.

    Science.gov (United States)

    Braithwaite, Miles C; Kumar, Pradeep; Choonara, Yahya E; du Toit, Lisa C; Tomar, Lomas K; Tyagi, Charu; Pillay, Viness

    2017-10-30

    This study was conducted to provide a mechanistic account for understanding the synthesis, characterization and solubility phenomena of vitamin complexes with cyclodextrins (CD) for enhanced solubility and stability employing experimental and in silico molecular modeling strategies. New geometric, molecular and energetic analyses were pursued to explicate experimentally derived cholecalciferol complexes. Various CD molecules (α-, β-, γ-, and hydroxypropyl β-) were complexed with three vitamins: cholecalciferol, ascorbic acid and α-tocopherol. The Inclusion Efficiency (IE%) was computed for each CD-vitamin complex. The highest IE% achieved for a cholecalciferol complex was for 'βCDD 3 -8', after utilizing a unique CD:cholecalciferol molar synthesis ratio of 2.5:1, never before reported as successful. 2HPβCD-cholecalciferol, γCD-cholecalciferol and α-tocopherol inclusion complexes (IC's) reached maximal IE% with a CD:vitamin molar ratio of 5:1. The results demonstrate that IE%, thermal stability, concentration, carrier solubility, molecular mechanics and intended release profile are key factors to consider when synthesizing vitamin-CD complexes. Phase-solubility data provided insights into the design of formulations with IC's that may provide analogous oral vitamin release profiles even when hydrophobic and hydrophilic vitamins are co-incorporated. Static lattice atomistic simulations were able to validate experimentally derived cholecalciferol IE phenomena and are invaluable parameters when approaching formulation strategies using CD's for improved solubility and efficacy of vitamins. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Inclusion complexes of cefuroxime axetil with β-cyclodextrin: Physicochemical characterization, molecular modeling and effect of l-arginine on complexation

    Directory of Open Access Journals (Sweden)

    Sarika Sapte

    2016-10-01

    Full Text Available The inclusion complexes of poorly water-soluble cephalosporin, cefuroxime axetil (CFA, were prepared with β-cyclodextrin (βCD with or without addition of l-arginine (ARG to improve its physicochemical properties. We also investigated the effect of ARG on complexation efficiency (CE of βCD towards CFA in an aqueous medium through phase solubility behaviour according to Higuchi and Connors. Although phase solubility studies showed AL (linear type of solubility curve in presence and absence of ARG, the CE and association constant (Ks of βCD towards CFA were significantly promoted in presence of ARG, justifying its use as a ternary component. The solid systems of CFA with βCD were obtained by spray drying technique with or without incorporation of ARG and characterized by differential scanning calorimetry (DSC, X-ray powder diffractometry (XRPD, scanning electron microscopy (SEM, and saturation solubility and dissolution studies. The molecular modeling studies provided a better insight into geometry and inclusion mode of CFA inside βCD cavity. The solubility and dissolution rate of CFA were significantly improved upon complexation with βCD as compared to CFA alone. However, ternary system incorporated with ARG performed better than binary system in physicochemical evaluation. In conclusion, ARG could be exploited as a ternary component to improve the physicochemical properties of CFA via βCD complexation.

  16. Investigation into reactions of starch with monochloro triazinyl- {beta} Cyclodextrin and Application of their Products in Textile Sizing

    Energy Technology Data Exchange (ETDEWEB)

    Hebeish, A; Higazy, A; El- Shafei, A; Sharaf, S [National Research Center, Textile Research Division, Dokki, Cairo (Egypt)

    2005-07-01

    Chemical modification of starch and hydrolyzed starches through their reaction with reactive cyclodextrin (RCD), namely, monochloro triazinyl-B cyclodextrin was investigated under a variety of conditions. Results obtained signify that the reaction is favoured in alkaline rather than in acidic media and in shorter than larger liquor ratios. Maximization of the reaction could also be achieved at 40 degree C for 60 minutes. Of the several alkaline catalysts used NaOH proved to be the best when used at a concentration of 10 g/1. Reaction of starch and hydrolyzed starches with RCD is determined by concentration of the latter. It brings about polymeric products the apparent viscosity of which depends on both the extent of reaction, expressed as nitrogen percent, and degree of acid hydrolysis prior to the modification. Evidence for involvement of starch and RCD by chemical bonding is evidenced by FTIR analysis. Furthermore the newly synthesized starch based polymeric products were applied to light cotton fabric and evaluation of the sized materials through monitoring size add-on, size removal and strength properties of the fabric made.

  17. Insights on novel particulate self-assembled drug delivery beads based on partial inclusion complexes between triglycerides and cyclodextrins.

    Science.gov (United States)

    Aburahma, Mona Hassan

    2016-09-01

    Most of the newly designed drug molecules are lipophilic in nature and often encounter erratic absorption and low bioavailability after oral administration. Finding ways to enhance the absorption and bioavailability of these lipophilic drugs is one of the major challenges that face pharmaceutical industry nowadays. In view of that, the purpose of this review is to shed some light on a novel particulate self-assembling system named "beads" than can act as a safe carrier for delivering lipophilic drugs. The beads are prepared simply by mixing oils with cyclodextrin (CD) aqueous solution in mild conditions. A unique interaction between oil components and CD molecules occurs to form in situ surface-active complexes which are prerequisites for beads formation. This review mainly focuses on the fundamentals of beads preparation through reviewing present, yet scarce, literature. The key methods used for beads characterization are discussed in details. Also, the potential mechanisms by which beads increase the bioavailability of lipophilic drugs are illustrated. Finally, the related research areas that needs to be addressed in future for optimizing this promising delivery system are briefly outlined.

  18. Effect of inclusion of hydroxycinnamic and chlorogenic acids from green coffee bean in β-cyclodextrin on their interactions with whey, egg white and soy protein isolates.

    Science.gov (United States)

    Budryn, Grażyna; Pałecz, Bartłomiej; Rachwał-Rosiak, Danuta; Oracz, Joanna; Zaczyńska, Donata; Belica, Sylwia; Navarro-González, Inmaculada; Meseguer, Josefina María Vegara; Pérez-Sánchez, Horacio

    2015-02-01

    The aim of the study was to characterise the interactions of hydroxycinnamic and chlorogenic acids (CHAs) from green coffee, with isolates of proteins from egg white (EWP), whey (WPC) and soy (SPI), depending on pH and temperature. The binding degree was determined by liquid chromatography coupled to a diode array detector and an ultrahigh resolution hybrid quadruple-time-of-flight mass spectrometer with ESI source (LC-QTOF-MS/MS). As a result of binding, the concentration of CHAs in proteins ranged from 9.44-12.2, 11.8-13.1 and 12.1-14.4g/100g for SPI, WPC and EWP, respectively. Thermodynamic parameters of protein-ligand interactions were determined by isothermal titration calorimetry (ITC) and energetics of interactions at the atomic level by molecular modelling. The amount of CHAs released during proteolytic digestion was in the range 0.33-2.67g/100g. Inclusion of CHAs with β-cyclodextrin strongly limited these interactions to a level of 0.03-0.06g/100g. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Core-shell nanofibers of curcumin/cyclodextrin inclusion complex and polylactic acid: Enhanced water solubility and slow release of curcumin.

    Science.gov (United States)

    Aytac, Zeynep; Uyar, Tamer

    2017-02-25

    Core-shell nanofibers were designed via electrospinning using inclusion complex (IC) of model hydrophobic drug (curcumin, CUR) with cyclodextrin (CD) in the core and polymer (polylactic acid, PLA) in the shell (cCUR/HPβCD-IC-sPLA-NF). CD-IC of CUR and HPβCD was formed at 1:2 molar ratio. The successful formation of core-shell nanofibers was revealed by TEM and CLSM images. cCUR/HPβCD-IC-sPLA-NF released CUR slowly but much more in total than PLA-CUR-NF at pH 1 and pH 7.4 due to the restriction of CUR in the core of nanofibers and solubility improvement shown in phase solubility diagram, respectively. Improved antioxidant activity of cCUR/HPβCD-IC-sPLA-NF in methanol:water (1:1) is related with the solubility enhancement achieved in water based system. The slow reaction of cCUR/HPβCD-IC-sPLA-NF in methanol is associated with the shell inhibiting the quick release of CUR. On the other hand, cCUR/HPβCD-IC-sPLA-NF exhibited slightly higher rate of antioxidant activity than PLA-CUR-NF in methanol:water (1:1) owing to the enhanced solubility. To conclude, slow release of CUR was achieved by core-shell nanofiber structure and inclusion complexation of CUR with HPβCD provides high solubility. Briefly, electrospinning of core-shell nanofibers with CD-IC core could offer slow release of drugs as well as solubility enhancement for hydrophobic drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Complexation thermodynamics of modified cyclodextrins

    DEFF Research Database (Denmark)

    Schönbeck, Jens Christian Sidney; Westh, Peter; Holm, Rene

    2014-01-01

    Inclusion complexes between two bile salts and a range of differently methylated β-cyclodextrins were studied in an attempt to rationalize the complexation thermodynamics of modified cyclodextrins. Calorimetric titrations at a range of temperatures provided precise values of the enthalpies (ΔH......°), entropies (ΔS°), and heat capacities (ΔCp) of complexation, while molecular dynamics simulations assisted the interpretation of the obtained thermodynamic parameters. As previously observed for several types of modified cyclodextrins, the substituents at the rims of the cyclodextrin induced large changes......° and then a strong decrease when the degree of substitution exceeded some threshold. Exactly the same trend was observed for ΔCp. The dehydration of nonpolar surface, as quantified by the simulations, can to a large extent explain the variation in the thermodynamic parameters. The methyl substituents form additional...

  1. Preparation and in-vitro characterization of Risperidone-cyclodextrin inclusion complexes as a potential injectable product

    Directory of Open Access Journals (Sweden)

    D Shukla

    2009-12-01

    Full Text Available "n  "n Background and the purpose of the study: This investigation deals with risperidone cyclodextrin (CD complexation for parenteral administration to improve its aqueous solubility which would be beneficial over immediate and sustained release formulations available in market especially for agitated and non-cooperative psychotic patients. "nMethods: The phase solubility study of the drug with β-CD, hydroxypropyl (HP-β-CD and γ-CD was conducted and CDs with higher stability constants were selected for complexation. The complexes of Risperidone with β-CD and HP-β-CD were prepared by precipitation and vacuum drying methods, respectively. Fourier transform-infrared, X-ray diffraction and differential scanning calorimetry techniques were used for characterization of complexes. Drug precipitation study of complex's solution in water for injection and 100 ml of 0.1 M pH 7.4 phosphate buffer saline and stability study in accelerated condition were also carried out. "nResults: The stability constants of the CD were in the following order: β-CD (341.953±11.87 M-1 > HP-β-CD (170.817± 5.93 M-1 > γ-CD (93.716 ± 3.25 M-1. CDs with high stability constants were selected to prepare the drug CD complex. The complexation efficiencies of β-CD and HP-β-CD were 95.23 ± 2.27% and 97.59 ±1.97%, respectively. Both types of CDs exhibited complexation at 1:2 molar stoichiometric ratio. The drug precipitation study indicated complete solubility (100% drug dissolution without a trace of precipitate within 5 mins. The complexes were found to be stable for a period of 3 months under accelerated stability conditions. Major conclusion:Stable complexes of risperidone were successfully formulated using both β-CD and HP-β-CD by simple and highly efficient methods of complexation for parenteral administration.

  2. Enhanced phytoremediation potential of polychlorinated biphenyl contaminated soil from e-waste recycling area in the presence of randomly methylated-{beta}-cyclodextrins

    Energy Technology Data Exchange (ETDEWEB)

    Shen Chaofeng [Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029 (China); MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310029 (China); Tang Xianjin; Cheema, Sardar Alam; Zhang Congkai; Khan, Muhammad Imran; Liang Fang; Chen Xincai; Zhu Youfeng [Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029 (China); Lin Qi, E-mail: linqi@zju.edu.cn [Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029 (China); Chen, Yingxu [Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029 (China)

    2009-12-30

    The crude recycling of electronic and electric waste (e-waste) is now creating soil pollution problems with organic compounds such as polychlorinated biphenyls (PCBs). The present study aimed to compare the phytoremediation potential of four plant species (rice, alfalfa, ryegrass and tall fescue) for PCBs contaminated soil from Taizhou city, one of the largest e-waste recycling centers in China. In addition, the enhanced effects of randomly methylated-{beta}-cyclodextrins (RAMEB) on PCBs phytoremediation potential were evaluated. Higher PCBs removal percentages of 25.6-28.5% in rhizosphere soil were observed after 120 days, compared with those of the non-rhizosphere (10.4-16.9%) and unplanted controls (7.3%). The average PCBs removal percentages of four plant species increased from 26.9% to 37.1% in the rhizosphere soil with addition of RAMEB. Meanwhile, relatively high microbial counts and dehydrogenase activity were detected in planted soils and a stimulatory effect by RAMEB addition was found. The present study indicated that all the plant candidates were feasible for phytoremediation of PCBs contaminated soil from the e-waste recycling area, and tall fescue with RAMEB amendment seemed as a promising remediation strategy. High PCBs removal percentage was due to the increased PCBs bioavailability as well as biostimulation of microbial communities after plantation and RAMEB addition.

  3. Cyclodextrin Controlled Release of Poorly Water-Soluble Drugs from Hydrogels

    DEFF Research Database (Denmark)

    Woldum, Henriette Sie; Madsen, Flemming; Larsen, Kim Lambertsen

    2008-01-01

    The effect of 2-hydroxypropyl- -cyclodextrin and -cyclodextrin on the release of ibuprofen, ketoprofen and prednisolone was studied. Stability constants calculated for inclusion complexes show size dependence for complexes with both cyclodextrins. Hydrogels were prepared by ultraviolet irradiation...... and release of each model drug was studied. For drugs formulated using cyclodextrins an increase in the achievable concentration and in the release from hydrogels was obtained due to increased solubility, although the solubility of all -cyclodextrin complexes was limited. The load also was increased...

  4. Encapsulation and release of the hypnotic agent zolpidem from biodegradable polymer microparticles containing hydroxypropyl-beta-cyclodextrin.

    Science.gov (United States)

    Trapani, Giuseppe; Lopedota, Angela; Boghetich, Giancarlo; Latrofa, Andrea; Franco, Massimo; Sanna, Enrico; Liso, Gaetano

    2003-12-11

    The goal of this study was to design a prolonged release system of the hypnotic agent zolpidem (ZP) useful for the treatment of insomnia. In this work, ZP alone or in the presence of HP-beta-CD was encapsulated in microparticles constituted by poly(DL-lactide) (PDLLA) and poly(DL-lactide-co-glycolide) (PLGA) and the drug release from these systems was evaluated. ZP alone-loaded microparticles were prepared by the classical O/W emulsion-solvent evaporation method. Conversely, ZP/HP-beta-CD containing microparticles were prepared by the W/O/W emulsion-solvent evaporation method following two different procedures (i.e. A and B). Following procedure A, the previously produced ZP/HP-beta-CD solid complex was added to the water phase of primary emulsion. In the procedure B, HP-beta-CD was added to the aqueous phase and ZP to the organic phase. The resulting microparticles were characterized about morphology, size, encapsulation efficiency and release rates. FT-IR, X-ray, and DSC results suggest the drug is in an essentially amorphous state within the microparticles. The release profiles of ZP from microparticles were in general biphasic, being characterized by an initial burst effect and a subsequent slow ZP release. It resulted that co-encapsulating ZP with or without HP-beta-CD in PDLLA and PLGA the drug release from the corresponding microparticles was protracted. Moreover, in a preliminary pharmacological screening, the ataxic activity in rats was investigated and it was found that intragastric administration of the ZP/HP-beta-CD/PLGA microparticles prepared according to procedure B produced the same ataxic induction time as the one induced by the currently used formulation Stilnox. Interestingly moreover, there was a longer ataxic lasting and a lower intensity of ataxia produced by the ZP/HP-beta-CD/PLGA-B-formulation already after 60 min following the administration. However, a need for further pharmacokinetic and pharmacodynamic studies resulted to fully evaluate

  5. A study of salt effects on the complexation between beta-cyclodextrins and bile salts based on the Hofmeister series

    DEFF Research Database (Denmark)

    Holm, Rene; Schonbeck, Christian; Somprasirt, Pitchayanun

    2014-01-01

    bound drug molecules. The influence of Hofmeister ions on the binding constants of complexes between CDs (β-CD and hydroxypropylated β-CD) and bile salts (glycocholate and glycochenodeoxycholate) were examined by isothermal titration calorimetry. The chaotropic anions tended to weaken these inclusion...

  6. Molecular Modeling and Physicochemical Properties of Supramolecular Complexes of Limonene with α- and β-Cyclodextrins.

    Science.gov (United States)

    Dos Passos Menezes, Paula; Dos Santos, Polliana Barbosa Pereira; Dória, Grace Anne Azevedo; de Sousa, Bruna Maria Hipólito; Serafini, Mairim Russo; Nunes, Paula Santos; Quintans-Júnior, Lucindo José; de Matos, Iara Lisboa; Alves, Péricles Barreto; Bezerra, Daniel Pereira; Mendonça Júnior, Francisco Jaime Bezerra; da Silva, Gabriel Francisco; de Aquino, Thiago Mendonça; de Souza Bento, Edson; Scotti, Marcus Tullius; Scotti, Luciana; de Souza Araujo, Adriano Antunes

    2017-02-01

    This study evaluated three different methods for the formation of an inclusion complex between alpha- and beta-cyclodextrin (α- and β-CD) and limonene (LIM) with the goal of improving the physicochemical properties of limonene. The study samples were prepared through physical mixing (PM), paste complexation (PC), and slurry complexation (SC) methods in the molar ratio of 1:1 (cyclodextrin:limonene). The complexes prepared were evaluated with thermogravimetry/derivate thermogravimetry, infrared spectroscopy, X-ray diffraction, complexation efficiency through gas chromatography/mass spectrometry analyses, molecular modeling, and nuclear magnetic resonance. The results showed that the physical mixing procedure did not produce complexation, but the paste and slurry methods produced inclusion complexes, which demonstrated interactions outside of the cavity of the CDs. However, the paste obtained with β-cyclodextrin did not demonstrate complexation in the gas chromatographic technique because, after extraction, most of the limonene was either surface-adsorbed by β-cyclodextrin or volatilized during the procedure. We conclude that paste complexation and slurry complexation are effective and economic methods to improve the physicochemical character of limonene and could have important applications in pharmacological activities in terms of an increase in solubility.

  7. A facile and flexible process of β-cyclodextrin grafted on Fe3O4 magnetic nanoparticles and host-guest inclusion studies

    International Nuclear Information System (INIS)

    Zhu Jie; He Jiang; Du Xiaoyan; Lu Ruihua; Huang Lizhen; Ge Xia

    2011-01-01

    In this study, a kind of novel surface-functionalized magnetic nanoparticles was fabricated by the Fe 3 O 4 nanoparticles surface modification with mono-6-deoxy-6-(p-tolylsulfonyl)-cyclodextrin (6-TsO-β-CD), which were employed to interact with uric acid and their behavior was investigated by electrochemical methods. The architecture has been characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA), which confirmed that cyclodextrins have been effectively functionalized on the surface of Fe 3 O 4 nanoparticles. The analyses of vibration sample magnetometer (VSM) verified that the nanoparticles owned good magnetic property. The grafted β-cyclodextrin on the Fe3O4 nanoparticles contributed to as a modified electrode for detecting uric acid with cyclic voltammograms. Electrochemical results revealed that the new materials could exhibit excellent molecules recognition ability and show high electrochemical response. The new nanoparticles simultaneously had unique properties of magnetic nanoparticles and cyclodextrins through combining their individual distinct advantages.

  8. Chiral high-performance liquid chromatographic analysis of fluoxetine and norfluoxetine in rabbit plasma, urine, and vitreous humor using an acetylated beta-cyclodextrin column.

    Science.gov (United States)

    Yee, L; Wong, S H; Skrinska, V A

    2000-10-01

    Fluoxetine (Prozac) is a potent selective serotonin reuptake inhibitor used for the treatment of major depression. Both fluoxetine (F) and its demethylated metabolite, norfluoxetine (NF), are racemic. S-Fluoxetine (SF) and S-norfluoxetine (SNF) are more potent inhibitors of serotonin reuptake than R-fluoxetine (RF) and R-norfluoxetine (RNF). Quantitation of individual enantiomers may provide a greater understanding of pharmacokinetic properties. The objective of this study was to perform a limited chiral selectivity study using rabbit plasma, urine, and vitreous humor analyzed by a solid-phase extraction protocol and a newly developed chiral analysis with an acetylated beta-cyclodextrin (CD) column. Liquid chromatographic parameters for CD were as follows: a mobile phase composition of methanol/0.3% triethylamine buffer, pH 5.6, (30:70), a flow rate of 1 mL/min, detection at 214 nm, and a temperature of 40 degrees C. Elution order was SNF, SF, RNF, and RF with capacity factors of 6, 7, 8, and 9, respectively. The corresponding resolution factors were as follows: R1,2 = 0.8, R2,3 = 1.2, and R3,4 = 0.9. The conditions for solid-phase extraction were optimized for Varian Bond Elut Certify columns. Following sample application, the column was rinsed with water, acetic acid, and then with methanol. Drug enantiomers were eluted with methylene chloride, isopropanol, and ammonium hydroxide (78:20:2). After extract evaporation, the extract residue was reconstituted for high-performance liquid chromatographic analysis. To investigate chiral pharmacology, a biodistribution study was performed by administering 2 mg/kg of F to five rabbits. Blood, urine, and vitreous specimens were collected. Plasma samples collected 45 min postinjection showed nearly equal concentrations of RF and SE After 24 h, the only metabolite detected in plasma was RNF. Drugs were not detectable in vitreous humor. Urine concentrations of SNF, SF, RNF, and RF were 51, 76, 34, and 8 microg/L, respectively

  9. Inclusion of fluorophores in cyclodextrins: a closer look at the fluorometric determination of association constants by linear and nonlinear fitting procedures

    Science.gov (United States)

    Hutterer, Rudi

    2018-01-01

    The author discusses methods for the fluorometric determination of affinity constants by linear and nonlinear fitting methods. This is outlined in particular for the interaction between cyclodextrins and several anesthetic drugs including benzocaine. Special emphasis is given to the limitations of certain fits, and the impact of such studies on enzyme-substrate interactions are demonstrated. Both the experimental part and methods of analysis are well suited for students in an advanced lab.

  10. Study of vitamin A derivative complexation in natural and modified cyclodextrins

    International Nuclear Information System (INIS)

    Weisse, Sandrine

    1999-01-01

    This research thesis reports a test of solubilisation and stabilisation of retinol, a highly hydrophobic and unsteady molecule, by natural or modified cyclodextrins. The author first recalls retinol physical-chemical characteristics, and then evokes the different techniques (other than cyclodextrins) used to modify these characteristics. Then, the author addresses the complexes of inclusion of retinol in cyclodextrins, and the associated characterization techniques [fr

  11. Novel Method to Quantitatively Study Inclusive Association of Cyclodextrin Polymer%定量研究环糊精聚合物包合作用的新方法

    Institute of Scientific and Technical Information of China (English)

    于恒达; 刘建佳; 李莉; 郭旭虹; 王杰

    2012-01-01

    通过聚合物接枝改性的方法制备了β-环糊精改性聚丙烯酸(PAAβCDen)和丹磺酰基团改性聚丙烯酸(PAADSen),并用二维氢核磁、流变学、紫外-可见分光光度法等方法对接枝于聚合物上的环糊精主客体相互作用进行了定量研究。结果表明:接枝于聚丙烯酸链上的β-环糊精和丹磺酰基团之间能够形成主客体包合结构,从而使PAAβCDen和PAADSen之间产生交联,并且首次采用紫外-可见分光光度法测得接枝于不同聚合物链上环糊精基团和丹磺酰基团之间的结合常数为(27.5±3)L/mol,远小于自由状态下β-环糊精与丹酰胺之间的结合常数((103±5)L/mol)。%Both β-cyclodextrin(PAAβCDen) and dansyl modified poly(acrylic acid)s(PAADSen) were synthesized respectively by polymer grafting reaction.The inclusive association between PAAβCDen and PAADSen was studied quantitatively by 2D 1H-NMR,rheology and UV-Vis spectroscopy.The results showed that the crosslinking between PAAβCDen and PAADSen was formed by host-guest interaction between β-cyclodextrin and dansyl substituents.The association constant between β-cyclodextrin and dansyl substituents in PAA was determined as(27.5±3) L/mol for the first time,which was much smaller than that of free β-cyclodextrin with dansyl amide((103±5) L/mol).

  12. Inclusion Complex of Zerumbone with Hydroxypropyl-β-Cyclodextrin Induces Apoptosis in Liver Hepatocellular HepG2 Cells via Caspase 8/BID Cleavage Switch and Modulating Bcl2/Bax Ratio

    Directory of Open Access Journals (Sweden)

    Nabilah Muhammad Nadzri

    2013-01-01

    Full Text Available Zerumbone (ZER isolated from Zingiber zerumbet was previously encapsulated with hydroxypropyl-β-cyclodextrin (HPβCD to enhance ZER’s solubility in water, thus making it highly tolerable in the human body. The anticancer effects of this new ZER-HPβCD inclusion complex via apoptosis cell death were assessed in this study for the first time in liver hepatocellular cells, HepG2. Apoptosis was ascertained by morphological study, nuclear stain, and sub-G1 cell population accumulation with G2/M arrest. Further investigations showed the release of cytochrome c and loss of mitochondrial membrane potential, proving mitochondrial dysfunction upon the ZER-HPβCD treatment as well as modulating proapoptotic and anti-apototic Bcl-2 family members. A significant increase in caspase 3/7, caspase 9, and caspase 8 was detected with the depletion of BID cleaved by caspase 8. Collectively, these results prove that a highly soluble inclusion complex of ZER-HPβCD could be a promising anticancer agent for the treatment of hepatocellular carcinoma in humans.

  13. Molecular insight into the inclusion of the dietary plant flavonol fisetin and its chromophore within a chemically modified γ-cyclodextrin: Multi-spectroscopic, molecular docking and solubility studies.

    Science.gov (United States)

    Pahari, Biswapathik; Chakraborty, Sandipan; Sengupta, Pradeep K

    2018-09-15

    We explored the encapsulation of dietary plant flavonols fisetin and its chromophore 3-hydroxyflavone, within 2-hydroxypropyl-γ-cyclodextrin (HPγ-CDx) nano-cavity in aqueous solution using multi-spectroscopic approaches and molecular docking. Upon addition of HPγ-CDx, dramatic changes occur in the intrinsic 'two color' fluorescence behavior of the fluorophores. This is manifested by significant increase in the steady state fluorescence intensities, anisotropies, average fluorescence lifetimes and rotational correlation times. Furthermore, in the CDx environment, intrinsically achiral flavonols exhibit prominent induced circular dichroism bands. These findings indicate that the flavonol molecules spontaneously enter the relatively hydrophobic, chiral environment of the HPγ-CDx nano-cavities. Molecular docking computations corroborate the spectroscopic findings, and predict selectivity in orientation of the encapsulated flavonols. HPγ-CDx inclusion increases the aqueous solubility of individual flavonols ∼100-1000 times. The present study demonstrates that the hydroxypropyl substituent in γ-CDx controls the inclusion mode of the flavonols, leading to their enhanced solubilization and altered spectral signatures. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Comparative studies of the influence of cyclodextrins on the stability of the sunscreen agent, 2-ethylhexyl-p-methoxycinnamate.

    Science.gov (United States)

    Scalia, Santo; Casolari, Alberto; Iaconinoto, Antonietta; Simeoni, Silvia

    2002-11-07

    The effects of beta-cyclodextrin (beta-CD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the base-catalyzed degradation and light-induced decomposition of the sunscreen agent, trans-2-ethylhexyl-p-methoxycinnamate (trans-EHMC) were investigated. Reversed-phase liquid chromatography was used to study the interaction between natural and modified cyclodextrins, added to the mobile phase, and the sunscreen. Among the available cyclodextrins (beta-CD, HP-beta-CD, hydroxypropyl-alpha-cyclodextrin and hydroxypropyl-gamma-cyclodextrin), only HP-beta-CD and beta-CD produced a significant decrease in the chromatographic retention of trans-EHMC. The complexation of the sunscreen agent with HP-beta-CD and beta-CD was confirmed by thermal analysis and nuclear magnetic resonance spectroscopy. beta-CD depressed the decomposition of trans-EHMC in alkaline solutions more effectively than HP-beta-CD. Moreover, the irradiation-induced degradation of the sunscreen agent in emulsion vehicles was reduced by complexation with beta-CD (the extent of degradation was 26.1% for the complex compared to 35.8% for free trans-EHMC) whereas HP-beta-CD had no significant effect. Therefore, the complex of beta-CD with trans-EHMC enhances the chemical- and photo-stability of the sunscreen agent. Moreover, it limits adverse interactions of the UV filter with other formulation ingredients.

  15. Exploring inclusion complexes of ionic liquids with α- and β- cyclodextrin by NMR, IR, mass, density, viscosity, surface tension and conductance study

    Science.gov (United States)

    Barman, Biraj Kumar; Rajbanshi, Biplab; Yasmin, Ananya; Roy, Mahendra Nath

    2018-05-01

    The formation of the host-guest inclusion complexes of ionic liquids namely [BMIm]Cl and [HMIm]Cl with α-CD and β-CD were studied by means of physicochemical and spectroscopic methods. Conductivity and surface tension study were in good agreement with the 1H NMR and FT-IR studies which confirm the formation of the inclusion complexes. The Density and viscosity study also supported the formation of the ICs. Further the stoichiometry was determined 1:1 for each case and the association constants and thermodynamic parameters derived supported the most feasible formation of the [BMIm]Cl- β-CD inclusion complex.

  16. Comparative study of 2-hydroxy propyl beta cyclodextrin and calixarene as ionophores in potentiometric ion-selective electrodes for neostigmine bromide.

    Science.gov (United States)

    El-Kosasy, Amira M; Nebsen, Marianne; Abd El-Rahman, Mohamed K; Salem, Maissa Y; El-Bardicy, Mohamed G

    2011-08-15

    Three novel neostigmine bromide (NEO) selective electrodes were investigated with 2-nitrophenyl octyl ether as a plasticiser in a polymeric matrix of polyvinyl chloride (PVC). Sensor 1 was fabricated using tetrakis(4-chlorophenyl)borate (TpClPB) as an anionic exchanger without incorporation of an ionophore. Sensor 2 used 2-hydroxy propyl β-cyclodextrin as an ionophore while sensor 3 was constructed using 4-sulfocalix-8-arene as an ionophore. Linear responses of NEO within the concentration ranges of 10(-5) to 10(-2), 10(-6) to 10(-2) and 10(-7) to 10(-2) mol L(-1) were obtained using sensors 1, 2 and 3, respectively. Nernstian slopes of 51.6 ± 0.8, 52.9 ± 0.6 and 58.6 ± 0.4 mV/decade over the pH range of 4-9 were observed. The selectivity coefficients of the developed sensors indicated excellent selectivity for NEO. The utility of 2-hydroxy propyl β-cyclodextrin and 4-sulfocalix[8]arene as ionophores had a significant influence on increasing the membrane sensitivity and selectivity of sensors 2 and 3 compared to sensor 1. The proposed sensors displayed useful analytical characteristics for the determination of NEO in bulk powder, different pharmaceutical formulations, and biological fluids (plasma and cerebrospinal fluid (CSF)) and in the presence of its degradation product (3-hydroxyphenyltrimethyl ammonium bromide) and thus could be used for stability-indicating methods. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Aspectos biofarmacêuticos da formulação de medicamentos para neonatos: fundamentos da complexação de indometacina com hidroxipropil-beta-ciclodextrina para tratamento oral do fechamento do canal arterial Biopharmaceutical aspects of drug formulation for neonatology: rational for indomethacin's complexation with hydroxypropyl-beta-cyclodextrin to treat patent ductus arteriosus

    Directory of Open Access Journals (Sweden)

    Ana Cristina Ribeiro Rama

    2005-09-01

    Full Text Available A terapêutica farmacológica em recém-nascidos confronta-se, por um lado, com um organismo sujeito a marcadas alterações biológicas, resultantes da composição orgânica e da maturação funcional, que decorre a diferentes graus em crianças com a mesma idade, determinando modificações no perfil farmacocinético e farmacodinâmico e, por outro lado, com a necessidade efetiva da utilização de fármacos. Para dar resposta à necessidade de tratamento destes doentes, recorre-se à utilização de medicamentos "off label", sendo esta uma prática com um elevado risco de segurança e de eficácia, na ausência de informação acerca da estabilidade, solubilidade e biodisponibilidade. Considerou-se, assim, que a utilização de derivados das ciclodextrinas altamente solúveis em água seria uma alternativa para a formulação de preparações líquidas aquosas de fármacos fracamente solúveis, aliada à melhoria de biodisponibilidade e de segurança. Esta revisão pretende fundamentar a possibilidade de recurso à complexação de indometacina com hidroxipropil-beta-ciclodextrina, com o objetivo de melhorar as características de biodisponibilidade e de segurança e permitir a administração por via oral para o tratamento farmacológico do fechamento do canal arterial em prematuros ou em recém-nascidos com esta patologia.Pharmacological therapy for newborns is faced on one hand, with an organism characterized by biological differences and functional immaturity with various grades of evolution for the same age, implying changes on the pharmacokinetic and pharmacodinamic medicine profiles. On the other hand, there is the effective need for pharmacotherapy. The "off label" use of medicines is therefore the only thing left to do, having in mind the risk of using therapeutic agents not studied for this special group of people. On this context it has been considered the use of cyclodextrin derivatives like hydroxypropyl-beta-cyclodextrin as an

  18. Self-assembly of cyclodextrins

    DEFF Research Database (Denmark)

    Fülöp, Z.; Kurkov, S.V.; Nielsen, T.T.

    2012-01-01

    The design of functional cyclodextrin (CD) nanoparticles is a developing area in the field of nanomedicine. CDs can not only help in the formation of drug carriers but also increase the local concentration of drugs at the site of action. CD monomers form aggregates by self-assembly, a tendency...... that increases upon formation of inclusion complexes with lipophilic drugs. However, the stability of such aggregates is not sufficient for parenteral administration. In this review CD polymers and CD containing nanoparticles are categorized, with focus on self-assembled CD nanoparticles. It is described how...

  19. (13)C and (15)N solid-state NMR studies on albendazole and cyclodextrin albendazole complexes.

    Science.gov (United States)

    Ferreira, M João G; García, A; Leonardi, D; Salomon, Claudio J; Lamas, M Celina; Nunes, Teresa G

    2015-06-05

    (13)C and (15)N solid-state nuclear magnetic resonance (NMR) spectra were recorded from albendazole (ABZ) and from ABZ:β-cyclodextrin, ABZ:methyl-β-cyclodextrin, ABZ:hydroxypropyl-β-cyclodextrin and ABZ:citrate-β-cyclodextrin, which were prepared by the spray-drying technique. ABZ signals were typical of a crystalline solid for the pure drug and of an amorphous compound obtained from ABZ:cyclodextrin samples. Relevant spectral differences were correlated with chemical interaction between ABZ and cyclodextrins. The number and type of complexes revealed a strong dependence on the cyclodextrin group substituent. Solid-state NMR data were consistent with the presence of stable inclusion complexes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. A Comparative Study of the Inclusion Complexes of 2-[5'-benzylidene-2'-phenyl-4'-oxo-1', 3'-thiazolidine]-1, 3-benzothiazole and 2-[5'-(p-N,N-dimethylamino- benzylidene-2'-phenyl-4'-oxo-1', 3'-thiazolidine]-1, 3-benzothiazole withβ-Cyclodextrin

    Directory of Open Access Journals (Sweden)

    S. Panda

    2011-01-01

    Full Text Available The compounds 2-[5'-benzylidene-2'-phenyl-4'-oxo-1', 3'-thiazolidine]-1, 3-benzothiazole and 2-[5'-(p-N,N-dimethylamino- benzylidene-2'-phenyl-4'-oxo-1', 3'-thiazolidine]-1, 3-benzothiazole have been synthesized in their purest forms starting from 2-aminobenzothiazole. The inclusion complexes of the above compounds have been prepared with β-cyclodextrin to increase their solubility and bioaccessibility in polar medium. The formation of inclusion complexes have been ascertained by study of spectral characteristic before and after inclusion complex formation. The stability of inclusion complexes and nature of interaction between the host and guest are known from the determination of thermodynamic parameters. Further the antibacterial and antifungal activities of the compounds are determined which is found to increase significantly after inclusion complex formation

  1. Direct site-directed photocoupling of proteins onto surfaces coated with β-cyclodextrins

    DEFF Research Database (Denmark)

    Städe, Lars W; Wimmer, Reinhard; Stensballe, Allan

    2010-01-01

    . Insertion of pBpa was verified by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectroscopy. A molecular dynamic simulation, with water as solvent, showed high solvent accessibility of the pBpa benzophenone group in N27pBpa-cutinase mutant. The formation of an inclusion......A method called Dock'n'Flash was developed to offer site-specific capture and direct UVA-induced photocoupling of recombinant proteins. The method involves the tagging of recombinant proteins with photoreactive p-benzoyl-L-phenylalanine (pBpa) by genetic engineering. The photoreactive pBpa tag...... is used for affinity capture of the recombinant protein by beta-cyclodextrin (beta-CD), which provides hydrogen atoms to be abstracted in the photocoupling process. To exemplify the method, a recombinant, folded, and active N27pBpa mutant of cutinase from Fusarium solani pisi was produced in E. coli...

  2. Cyclodextrin-Catalyzed Organic Synthesis: Reactions, Mechanisms, and Applications

    Directory of Open Access Journals (Sweden)

    Chang Cai Bai

    2017-09-01

    Full Text Available Cyclodextrins are well-known macrocyclic oligosaccharides that consist of α-(1,4 linked glucose units and have been widely used as artificial enzymes, chiral separators, chemical sensors, and drug excipients, owing to their hydrophobic and chiral interiors. Due to their remarkable inclusion capabilities with small organic molecules, more recent interests focus on organic reactions catalyzed by cyclodextrins. This contribution outlines the current progress in cyclodextrin-catalyzed organic reactions. Particular emphases are given to the organic reaction mechanisms and their applications. In the end, the future directions of research in this field are proposed.

  3. Cooperation between two ClpB isoforms enhances the recovery of the recombinant {beta}-galactosidase from inclusion bodies

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Izabela [Department of Biochemistry, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk (Poland); Zolkiewski, Michal [Department of Biochemistry, Kansas State University, Manhattan, KS 66506 (United States); Kedzierska-Mieszkowska, Sabina, E-mail: kedzie@biotech.ug.gda.pl [Department of Biochemistry, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk (Poland)

    2012-10-05

    Highlights: Black-Right-Pointing-Pointer An important role of synergistic cooperation between the two ClpB isoforms. Black-Right-Pointing-Pointer Both ClpB isoforms are associated with IBs of {beta}-galactosidase. Black-Right-Pointing-Pointer ClpB is a key chaperone in IB protein release. -- Abstract: Bacterial ClpB is a molecular chaperone that solubilizes and reactivates aggregated proteins in cooperation with the DnaK chaperone system. The mechanism of protein disaggregation mediated by ClpB is linked to translocation of substrates through the central channel within the ring-hexameric structure of ClpB. Two isoforms of ClpB are produced in vivo: the full-length ClpB95 and the truncated ClpB80 (ClpB{Delta}N), which does not contain the N-terminal domain. The functional specificity of the two ClpB isoforms and the biological role of the N-terminal domain are still not fully understood. Recently, it has been demonstrated that ClpB may achieve its full potential as an aggregate-reactivating chaperone through the functional interaction and synergistic cooperation of its two isoforms. It has been found that the most efficient resolubilization and reactivation of stress-aggregated proteins occurred in the presence of both ClpB95 and ClpB80. In this work, we asked if the two ClpB isoforms functionally cooperate in the solubilization and reactivation of proteins from insoluble inclusion bodies (IBs) in Escherichia coli cells. Using the model {beta}-galactosidase fusion protein (VP1LAC), we found that solubilization and reactivation of enzymes entrapped in IBs occurred more efficiently in the presence of ClpB95 with ClpB80 than with either ClpB95 or ClpB80 alone. The two isoforms of ClpB chaperone acting together enhanced the solubility and enzymatic activity of {beta}-galactosidase sequestered into IBs. Both ClpB isoforms were associated with IBs of {beta}-galactosidase, what demonstrates their affinity to this type of aggregates. These results demonstrate a synergistic

  4. The effects of cyclodextrins on the disposition of intravenously injected drugs in the rat

    NARCIS (Netherlands)

    Frijlink, H W; Franssen, E J; Eissens, Anko; Oosting, Roelof; Lerk, C F; Meijer, D K

    Naproxen and flurbiprofen form complexes with hydroxypropyl-beta-cyclodextrin; with stability constants of 2207 and 12515 M-1, respectively. However, only small fractions of the drug remain complexed when the drug-cyclodextrin complex is added to plasma in vitro. This result can be explained by

  5. Selectivity and stoichiometry boosting of beta-cyclodextrin in cationic/anionic surfactant systems: when host-guest equilibrium meets biased aggregation equilibrium.

    Science.gov (United States)

    Jiang, Lingxiang; Yu, Caifang; Deng, Manli; Jin, Changwen; Wang, Yilin; Yan, Yun; Huang, Jianbin

    2010-02-18

    Cationic surfactant/anionic surfactant/beta-CD ternary aqueous systems provide a platform for the coexistence of the host-guest (beta-CD/surfactant) equilibrium and the biased aggregation (monomeric/aggregated surfactants) equilibrium. We report here that the interplay between the two equilibria dominates the systems as follows. (1) The biased aggregation equilibrium imposes an apparent selectivity on the host-guest equilibrium, namely, beta-CD has to always selectively bind the major surfactant (molar fraction > 0.5) even if binding constants of beta-CD to the pair of surfactants are quite similar. (2) In return, the host-guest equilibrium amplifies the bias of the aggregation equilibrium, that is, the selective binding partly removes the major surfactant from the aggregates and leaves the aggregate composition approaching the electroneutral mixing stoichiometry. (3) This composition variation enhances electrostatic attractions between oppositely charged surfactant head groups, thus resulting in less-curved aggregates. In particular, the present apparent host-guest selectivity is of remarkably high values, and the selectivity stems from the bias of the aggregation equilibrium rather than the difference in binding constants. Moreover, beta-CD is defined as a "stoichiometry booster" for the whole class of cationic/anionic surfactant systems, which provides an additional degree of freedom to directly adjust aggregate compositions of the systems. The stoichiometry boosting of the compositions can in turn affect or even determine microstructures and macroproperties of the systems.

  6. Inclusion of 5-[4-(1-dodecanoylpyridinium)]-10,15,20-triphenylporphine in supramolecular aggregates of cationic amphiphilic cyclodextrins: physicochemical characterization of the complexes and strengthening of the antimicrobial photosensitizing activity.

    Science.gov (United States)

    Ferro, Stefania; Jori, Giulio; Sortino, Salvatore; Stancanelli, Rosanna; Nikolov, Peter; Tognon, Giuseppe; Ricchelli, Fernanda; Mazzaglia, Antonino

    2009-09-14

    Recent findings suggest that visible light-promoted photooxidative processes mediated by sensitizers of appropriate chemical structure could represent a useful tool for properly addressing the problem of the increasing occurrence of infectious diseases caused by multiantibiotic-resistant microbial pathogens. The monocationic meso-substituted porphyrin 5-[4-(1-dodecanoylpyridinium)]-10,15,20-triphenyl-porphine (TDPyP) complexed into supramolecular aggregates of cationic amphiphilic beta-cyclodextrin (SC(6)NH(2)) (mean diameter = 20 nm) appeared to be endowed with favorable properties to act as a photosensitizing agent, including a very high quantum yield (Phi(Delta) = 0.90) for the generation of the highly reactive oxygen species, singlet oxygen ((1)O(2)). Although the yield of (1)O(2) generation was comparable to that obtained after TDPyP incorporation into cationic unilamellar liposomes of N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTAP) SC(6)NH(2)-bound TDPyP was more active than DOTAP-bound TDPyP in photosensitizing the inactivation of the Gram-positive methicillin-resistant bacterium Staphylococcus aureus (MRSA). At variance with DOTAP-bound TDPyP, photoactivated SC(6)NH(2)-bound TDPyP was efficient also in photokilling Gram-negative bacterial pathogens, such as Escherichia coli . These observations are in agreement with the well-known photobactericidal effect of positively charged porphyrin derivatives, which can be markedly enhanced after incorporation into carriers with multiple positive charges. In addition, transmission electron microscopy studies revealed that potentiation of the TDPyP-mediated photobactericidal effect by incorporation into SC(6)NH(2) is a consequence of the carrier's ability to promote an efficient crossing of the very tightly organized three-dimensional architecture of the bacterial outer wall by the embedded porphyrin so that a prompt interaction between the short-lived photogenerated (1)O(2) and the nearby

  7. Gas-liquid partitioning of halogenated volatile organic compounds in aqueous cyclodextrin solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ondo, Daniel; Barankova, Eva [Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Dohnal, Vladimir, E-mail: dohnalv@vscht.cz [Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic)

    2011-08-15

    Highlights: > Binding of halogenated VOCs with cyclodextrins examined through g-l partitioning. > Complex stabilities reflect host-guest size matching and hydrophobic interaction. > Presence of halogens in the guest molecule stabilizes the binding. > Thermodynamic origin of the binding varies greatly among the systems studied. > Results obey the guest-CD global enthalpy-entropy compensation relationship. - Abstract: Gas-liquid partitioning coefficients (K{sub GL}) were measured for halogenated volatile organic compounds (VOCs), namely 1-chlorobutane, methoxyflurane, pentafluoropropan-1-ol, heptafluorobutan-1-ol, {alpha},{alpha},{alpha}-trifluorotoluene, and toluene in aqueous solutions of natural {alpha}-, {beta}-, and {gamma}-cyclodextrins (CDs) at temperatures from (273.35 to 326.35) K employing the techniques of headspace gas chromatography and inert gas stripping. The binding constants of the 1:1 inclusion complex formation between the VOCs and CDs were evaluated from the depression of the VOCs volatility as a function of CD concentration. The host-guest size matching and the hydrophobic interaction concept were used to rationalize the observed widely different affinity of the VOC-CD pairs to form the inclusion complex. The enthalpic and entropic component of the standard Gibbs free energy of complex formation as derived from the temperature dependence of the binding constant indicate the thermodynamic origin of the binding to vary greatly among the systems studied, but follow the global enthalpy-entropy compensation relationships reported previously in the literature.

  8. Post monitoring of a cyclodextrin remeditated chlorinated solvent contaminated aquifer

    Science.gov (United States)

    Blanford, W. J.

    2006-12-01

    Hydroxypropyl-â-cyclodextrin (HPâCD) has been tested successfully in the laboratory and in the field for enhanced flushing of low-polarity contaminants from aquifers. The cyclodextrin molecule forms a toroidal structure, which has a hydrophobic cavity. Within this cavity, organic compounds of appropriate shape and size can form inclusion complexes, which is the basis for the use of cyclodextrin in groundwater remediation. The hydrophilic exterior of the molecule makes cyclodextrin highly water-soluble. The solubility of cyclodextrins can be further enhanced by adding functional groups, such as hydroxypropyl groups, to the cyclodextrin core. The aqueous solubility of HPâCD exceeds 950 g/L. These high solubilities are advantageous for field applications because they permit relatively high concentrations of the flushing agent. In order for cyclodextrin to become a feasible remediative alternative, it must be demonstrate a short term resistance to biodegradation during field application, but ultimately biodegrade so as not to pose a long term presence in the aquifer. The potential for degradation of cyclodextrin as well as changes in the chlorinated solvents and groundwater geochemistry were examined during the post monitoring of a field demonstration in a shallow aquifer at Little Creek Naval Amphibious Base in Virginia. It was found that a portion of the cyclodextrin remaining in the aquifer after the cessation of field activities biodegraded during the 425 days of post monitoring. This degradation also led to the degradation of the chlorinated solvents trichloroethylene and 1,1-trichloroethane through both biological and chemical processes. The aquifer remained anaerobic with average dissolved oxygen levels below 0.5 mg/L. Dissolved nitrate and sulfate concentrations within the cyclodextrin plume decreased due their being used as terminal electron acceptors during the degradation of the cyclodextrin. The concentrations of total iron at the field site showed no

  9. Investigation of Cyclodextrin-Based Nanosponges for Solubility and Bioavailability Enhancement of Rilpivirine.

    Science.gov (United States)

    Rao, Monica R P; Chaudhari, Jagruti; Trotta, Francesco; Caldera, Fabrizio

    2018-06-04

    Rilpivrine is BCS class II drug used for treatment of HIV infection. The drug has low aqueous solubility (0.0166 mg/ml) and dissolution rate leading to low bioavailability (32%). Aim of this work was to enhance solubility and dissolution of rilpivirine using beta-cyclodextrin-based nanosponges. These nanosponges are biocompatible nanoporous particles having high loading capacity to form supramolecular inclusion and non-inclusion complexes with hydrophilic and lipophilic drugs for solubility enhancement. Beta-cyclodextrin was crosslinked with carbonyl diimidazole and pyromellitic dianhydride to prepare nanosponges. The nanosponges were loaded with rilpivirine by solvent evaporation method. Binary and ternary complexes of drug with β-CD, HP-β-CD, nanosponges, and tocopherol polyethylene glycol succinate were prepared and characterized by phase solubility, saturation solubility in different media, in vitro dissolution, and in vivo pharmacokinetics. Spectral analysis by Fourier transform infrared spectroscopy, powder X-ray diffraction, and differential scanning calorimetry was performed. Results obtained from spectral characterization confirmed inclusion complexation. Phase solubility studies indicated stable complex formation. Saturation solubility was found to be 10-13-folds higher with ternary complexes in distilled water and 12-14-fold higher in 0.1 N HCl. Solubility enhancement was evident in biorelevant media. Molecular modeling studies revealed possible mode of entrapment of rilpivirine within β-CD cavities. A 3-fold increase in dissolution with ternary complexes was observed. Animal studies revealed nearly 2-fold increase in oral bioavailability of rilpivirine. It was inferred that electronic interactions, hydrogen bonding, and van der Waals forces are involved in the supramolecular interactions.

  10. Phase solubility, 1H NMR and molecular modelling studies of bupivacaine hydrochloride complexation with different cyclodextrin derivates

    Science.gov (United States)

    Jug, Mario; Mennini, Natascia; Melani, Fabrizio; Maestrelli, Francesca; Mura, Paola

    2010-11-01

    A novel method, which simultaneously exploits experimental (NMR) and theoretically calculated data obtained by a molecular modelling technique, was proposed, to obtain deeper insight into inclusion geometry and possible stereoselective binding of bupivacaine hydrochloride with selected cyclodextrin derivatives. Sulphobuthylether-β-cyclodextrin and water soluble polymeric β-cyclodextrin demonstrated to be the best complexing agents for the drug, resulting in formation of the most stable inclusion complexes with the highest increase in aqueous drug solubility. The drug-carrier binding modes with these cyclodextrins and phenomena which may be directly related to the higher stability and better aqueous solubility of complexes formed were discussed in details.

  11. Cyclodextrin Aldehydes are Oxidase Mimics

    DEFF Research Database (Denmark)

    Fenger, Thomas Hauch; Bjerre, Jeannette; Bols, Mikael

    2009-01-01

    Cyclodextrins containing 6-aldehyde groups were found to catalyse oxidation of aminophenols in the presence of hydrogen peroxide. The catalysis followed Michaelis-Menten kinetics and is related to the catalysis previously observed with cyclodextrin ketones. A range of different cyclodextrin aldeh...

  12. Cyclodextrin-insulin complex encapsulated polymethacrylic acid based nanoparticles for oral insulin delivery.

    Science.gov (United States)

    Sajeesh, S; Sharma, Chandra P

    2006-11-15

    Present investigation was aimed at developing an oral insulin delivery system based on hydroxypropyl beta cyclodextrin-insulin (HPbetaCD-I) complex encapsulated polymethacrylic acid-chitosan-polyether (polyethylene glycol-polypropylene glycol copolymer) (PMCP) nanoparticles. Nanoparticles were prepared by the free radical polymerization of methacrylic acid in presence of chitosan and polyether in a solvent/surfactant free medium. Dynamic light scattering (DLS) experiment was conducted with particles dispersed in phosphate buffer (pH 7.4) and size distribution curve was observed in the range of 500-800 nm. HPbetaCD was used to prepare non-covalent inclusion complex with insulin and complex was analyzed by Fourier transform infrared (FTIR) and fluorescence spectroscopic studies. HPbetaCD complexed insulin was encapsulated into PMCP nanoparticles by diffusion filling method and their in vitro release profile was evaluated at acidic/alkaline pH. PMCP nanoparticles displayed good insulin encapsulation efficiency and release profile was largely dependent on the pH of the medium. Enzyme linked immunosorbent assay (ELISA) study demonstrated that insulin encapsulated inside the particles was biologically active. Trypsin inhibitory effect of PMCP nanoparticles was evaluated using N-alpha-benzoyl-L-arginine ethyl ester (BAEE) and casein as substrates. Mucoadhesive studies of PMCP nanoparticles were conducted using freshly excised rat intestinal mucosa and the particles were found fairly adhesive. From the preliminary studies, cyclodextrin complexed insulin encapsulated mucoadhesive nanoparticles appear to be a good candidate for oral insulin delivery.

  13. Host-Guest Inclusion Complexes between Amlodipine Enantiomers in Biphasic Recognition Chiral Extraction System using Tartaric Acid and β-Cyclodextrin Derivatives as Positive Confirmation Using of their Enantioselective Extraction

    OpenAIRE

    AZZAM, Khaldun; ABDALLAH, Hassan; HALIM, Hairul; AHMAD, Maizatul; SHAIBAH, Hassan

    2015-01-01

    The current work reports an extended theoretical study from our previous experimental work for the enantioselective extraction of amlodipine enantiomers in a biphasic recognition chiral extraction system (BRCES) consisting of hydrophobic D-diisopropyl tartrate dissolved in organic phase (n-decanol) and hydrophilic hydroxypropyl-?-cyclodextrin (HP-?-CD) in aqueous phase (acetate buffer) which preferentially recognize the R-enantiomer and S-enantiomer, respectively. The calculations were simula...

  14. Electrospun Fibers of Cyclodextrins and Poly(cyclodextrins

    Directory of Open Access Journals (Sweden)

    Alejandro Costoya

    2017-02-01

    Full Text Available Cyclodextrins (CDs can endow electrospun fibers with outstanding performance characteristics that rely on their ability to form inclusion complexes. The inclusion complexes can be blended with electrospinnable polymers or used themselves as main components of electrospun nanofibers. In general, the presence of CDs promotes drug release in aqueous media, but they may also play other roles such as protection of the drug against adverse agents during and after electrospinning, and retention of volatile fragrances or therapeutic agents to be slowly released to the environment. Moreover, fibers prepared with empty CDs appear particularly suitable for affinity separation. The interest for CD-containing nanofibers is exponentially increasing as the scope of applications is widening. The aim of this review is to provide an overview of the state-of-the-art on CD-containing electrospun mats. The information has been classified into three main sections: (i fibers of mixtures of CDs and polymers, including polypseudorotaxanes and post-functionalization; (ii fibers of polymer-free CDs; and (iii fibers of CD-based polymers (namely, polycyclodextrins. Processing conditions and applications are analyzed, including possibilities of development of stimuli-responsive fibers.

  15. Lanthanide-cyclodextrin complexes as probes for elucidating optical purity by NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wenzel, T.J.; Bogyo, M.S.; Lebeau, E.L. (Bates College, Lewiston, ME (United States))

    1994-06-01

    A multidentate ligand is bonded to cyclodextrins by the reaction of diethylenetriaminepentaacetic dianhydride with 6-mono- and 2-mono(ethylenediamine) derivatives of cyclodextrin. Adding Dy(III) to the cyclodextrin derivatives enhances the enantiomeric resolution in the [sup 1]H NMR spectra of carbionoxamine maleate, doxylamine succinate, pheniramine maleate, propranolol hydrochloride, and tryptophan. The enhancement is more pronounced with the secondary derivative. The Dy(III)-induced shifts can be used to elucidate the geometry of cyclodextrin-substrate inclusion complexes. Lanthanide-induced shifts are reported for complexes of aspartame, tryptophan, propranolol, and 1-anilino-8-naphthalenesulfonate with cyclodextrins, and the relative magnitudes of the shifts agree with previously reported structures of the complexes. 37 refs., 9 figs., 5 tabs.

  16. Influence of lipophilicity on drug-cyclodextrin interactions: A calorimetric study

    Energy Technology Data Exchange (ETDEWEB)

    Waters, Laura J., E-mail: l.waters@hud.ac.uk [School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH (United Kingdom); Bedford, Susan; Parkes, Gareth M.B. [School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH (United Kingdom); Mitchell, J.C. [Medway Sciences, School of Science, University of Greenwich at Medway, Chatham Maritime, Kent ME4 4TB (United Kingdom)

    2010-11-20

    This study presents a systematic investigation of the interaction of three functionally related drugs, ibuprofen, ketoprofen and flurbiprofen, with two distinct forms of cyclodextrin at three specific temperatures, 298, 303 and 310 K using isothermal titration calorimetry (ITC). Although all three pharmaceutical compounds have similar pKa values, they exhibit widely differing lipophilicities. While previous authors have presented data regarding the binding of flurbiprofen and ibuprofen with {beta}-cyclodextrin, this is the first report of the interaction of all three drug substances with {beta}-cyclodextrin and 2-(hydroxypropyl)-{beta}-cyclodextrin at controlled pH and temperature. For all scenarios, the associated changes in Gibbs free energy, enthalpy and entropy are presented alongside the stoichiometry and binding constants concerned. In all cases the binding was found to occur at a 1:1 ratio with an associated negative enthalpy and Gibbs free energy with the formation of the complex enthalpically, rather than entropically driven. The data further demonstrates a clear relationship between the thermodynamic behaviour and log P of the drug molecules. This work confirms the suitability of ITC to determine thermodynamic data for drug-cyclodextrin complex formations and provides an insight into the selection of appropriate cyclodextrins for bespoke pharmaceutical formulations.

  17. Relation between structure and organisation properties of new amphiphilic cyclodextrins

    International Nuclear Information System (INIS)

    Moutard, Stephane

    2003-01-01

    Since a number of years, special attention and efforts have been made to prepare amphiphilic cyclodextrins (CDs) with the objective to use them to obtain supramolecular assemblies as such or in the presence of preformed lipidic structures. The aim of these investigation is in both cases to combine the size specificity of cyclodextrins for guests and the transport properties of phospho-lipidic structures. The final objects could be of importance to transport or target biologically relevant molecules such as drugs using new galenic formulations. In a first step, a new family of amphiphilic CDs was prepared from a pure phospholipids (DMPE) onto cyclodextrins or methylated derivatives through a spacing arm. The afforded compounds (phospholipidyl-cyclodextrins) were fully characterized by high field NMR and high resolution mass spectrometry. The methylated derivatives were shown to self-organize in water with low CMC to form fluctuating micellar fibers retaining the inclusion capacity of the cyclodextrin cavities. The interactions of these compounds with membrane systems were investigated as black films using X-ray reflectivity and by evaluation of their detergent power towards model DMPC liposomes. Their ability to cross over the Blood Brain Barrier was evidenced by a new approach making use of novel immuno-enzymatic assays. In a second step, a new class of amphiphilic cyclodextrins was considered (peptidolipidyl-cyclodextrins). Although they are structurally similar to phospholipidyl-CDs, their preparation overcomes the tedious steps of the later and lead to a considerable versatility in terms of the number of possible molecules to be prepared. Moreover, the stability problems encountered with phospholipids are avoided. Several examples have been prepared, fully characterized and their organization properties investigated by the determination of CMC and by deuterium NMR on a pure and homogeneous mixed peptidolipidyl-CD / DMPC lamellar phase. This novel class of

  18. Synthesis of polyrotaxanes from acetyl-β-cyclodextrin

    Science.gov (United States)

    Ristić, I. S.; Nikolić, L.; Nikolić, V.; Ilić, D.; Budinski-Simendić, J.

    2011-12-01

    Polyrotaxanes are intermediary products in the synthesis of topological gels. They are created by inclusion complex formation of hydrophobic linear macromolecules with cyclodextrins or their derivatives. Then, pairs of cyclodextrin molecules with covalently linkage were practically forming the nodes of the semi-flexible polymer network. Such gels are called topological gels and they can absorb huge quantities of water due to the net flexibility allowing the poly(ethylene oxide) chains to slide through the cyclodextrin cavities, without being pulled out altogether. For polyrotaxane formation poly(ethylene oxide) was used like linear macromolecules. There are hydroxyl groups at poly(ethylene oxide) chains, whereby the linking of the voluminous molecules should be made. To avoid the reaction of cyclodextrin OH groups with stoppers, they should be protected by, e.g., acetylation. In this work, the acetylation of the OH groups of β-cyclodextrin was performed by acetic acid anhydride with iodine as the catalyst. The acetylation reaction was assessed by the FTIR and HPLC method. By the HPLC analysis was found that the acetylation was completed in 20 minutes. Inserting of poly(ethylene oxide) with 4000 g/mol molecule mass into acetyl-β-cyclodextrin with 2:1 poly(ethylene oxide) monomer unit to acetyl-β-cyclodextrin ratio was also monitored by FTIR, and it was found that the process was completed in 12 h at the temperature of 10°C. If the process is performed at temperatures above 10°C, or for periods longer than 12 hours, the process of uncontrolled hydrolysis of acetate groups was initiated.

  19. [Pharmaceutical application of cyclodextrins as multi-functional drug carriers].

    Science.gov (United States)

    Uekama, Kaneto

    2004-12-01

    Owing to the increasingly globalized nature of the cyclodextrin (CyD)-related science and technology, development of the CyD-based pharmaceutical formulation is rapidly progressing. The pharmaceutically useful CyDs are classified into hydrophilic, hydrophobic, and ionic derivatives. Because of the multi-functional characteristics and bioadaptability, these CyDs are capable of alleviating the undesirable properties of drug molecules through the formation of inclusion complexes or the form of CyD/drug conjugates. This review outlines the current application of CyDs in drug delivery and pharmaceutical formulation, focusing on the following evidences. 1) The hydrophilic CyDs enhance the rate and extent of bioavailability of poorly water-soluble drugs. 2) The amorphous CyDs such as 2-hydroxypropyl-beta-CyD are useful for inhibition of polymorphic transition and crystallization rates of drugs during storage. 3) The delayed release formulation can be obtained by the use of enteric type CyDs such as O-carboxymethyl-O-ethyl-beta-CyD. 4) The hydrophobic CyDs are useful for modification of the release site and/or time profile of water-soluble drugs with prolonged therapeutic effects. 5) The branched CyDs are particularly effective in inhibiting the adsorption to hydrophobic surface of containers and aggregation of polypeptide and protein drugs. 6) The combined use of different CyDs and/or pharmaceutical additives can serve as more functional drug carriers, improving efficacy and reducing side effects. 7) The CyD/drug conjugates may provide a versatile means for the constructions of not only colonic delivery system but also site-specific drug release system, including gene delivery. On the basis of the above-mentioned knowledge, the advantages and limitations of CyDs in the design of advanced dosage forms will be discussed.

  20. Host-Guest Inclusion Complexes between Amlodipine Enantiomers in the Biphasic Recognition Chiral Extraction System using Tartaric Acid and β-Cyclodextrin Derivatives as Positive Confirmation by using their Enantioselective Extraction.

    Science.gov (United States)

    Al Azzam, Khaldun M; Abdallah, Hassan H; Halim, Hairul N Abdul; Ahmad, Maizatul Akmam; Shaibah, Hassan

    2015-01-01

    The current work reports an extended theoretical study from our previous experimental work for the enantioselective extraction of amlodipine enantiomers in a biphasic recognition chiral extraction system (BRCES) consisting of hydrophobic D-diisopropyl tartrate dissolved in organic phase (n-decanol) and hydrophilic hydroxypropyl-β-cyclodextrin (HP-β-CD) in aqueous phase (acetate buffer) which preferentially recognize the R-enantiomer and S-enantiomer, respectively. The calculations were simulated using a semi-empirical PM3 method as a part of the Gaussian09 software package and were used to optimize the structures of the hosts, guests, and host-guest complexes in the gas phase without any restrictions. It was found that HP-β-CD has the strongest recognition ability among the three β-CD derivatives studied, namely HP-β-CD, hydroxyethyl-β-cyclodextrin (HE-β-CD), and methylated-β-cyclodextrin (Me-β-CD), due to the large interaction energies (Ecomp = -14.3025 kcal/ mol), while D-diisopropyl tartrate has the strongest ability among the four tartaric acid derivatives studied namely; L-diisopropyl tartrate, D-diisopropyl tartrate, L-diethyl tartrate, and D-diethyl tartrate (Ecomp = -5.9964 kcal/ mol). The computational calculations for the enantioselective partitioning of amlodipine enantiomers rationalized the reasons for the different behaviors for this extraction. The present theoretical results may be informative to scientists who are devoting themselves to developing models for their experimental parts or for enhancing the hydrophobic drug solubility in drug delivery systems.

  1. Host-Guest Inclusion Complexes between Amlodipine Enantiomers in the Biphasic Recognition Chiral Extraction System using Tartaric Acid and β-Cyclodextrin Derivatives as Positive Confirmation by using their Enantioselective Extraction

    Science.gov (United States)

    Al Azzam, Khaldun M.; Abdallah, Hassan H.; Halim, Hairul N. Abdul; Ahmad, Maizatul Akmam; Shaibah, Hassan

    2015-01-01

    The current work reports an extended theoretical study from our previous experimental work for the enantioselective extraction of amlodipine enantiomers in a biphasic recognition chiral extraction system (BRCES) consisting of hydrophobic D-diisopropyl tartrate dissolved in organic phase (n-decanol) and hydrophilic hydroxypropyl-β-cyclodextrin (HP-β-CD) in aqueous phase (acetate buffer) which preferentially recognize the R-enantiomer and S-enantiomer, respectively. The calculations were simulated using a semi-empirical PM3 method as a part of the Gaussian09 software package and were used to optimize the structures of the hosts, guests, and host-guest complexes in the gas phase without any restrictions. It was found that HP-β-CD has the strongest recognition ability among the three β-CD derivatives studied, namely HP-β-CD, hydroxyethyl-β-cyclodextrin (HE-β-CD), and methylated-β-cyclodextrin (Me-β-CD), due to the large interaction energies (Ecomp = −14.3025 kcal/ mol), while D-diisopropyl tartrate has the strongest ability among the four tartaric acid derivatives studied namely; L-diisopropyl tartrate, D-diisopropyl tartrate, L-diethyl tartrate, and D-diethyl tartrate (Ecomp = −5.9964 kcal/ mol). The computational calculations for the enantioselective partitioning of amlodipine enantiomers rationalized the reasons for the different behaviors for this extraction. The present theoretical results may be informative to scientists who are devoting themselves to developing models for their experimental parts or for enhancing the hydrophobic drug solubility in drug delivery systems. PMID:26839848

  2. Preparation and Disinfection Effect on Trichomonas Vaginalis of Dihydroartemisinin Hydroxypropyl-β-cyclodextrin Inclusion Complex%双氢青蒿素包合物的制备及对阴道毛滴虫的杀灭作用考察

    Institute of Scientific and Technical Information of China (English)

    张丽娟; 吴常伟; 钟家亮; 孙宝清; 魏秋芬

    2011-01-01

    Objective: To prepare the water-soluble dihydroartemisinin hydroxypropyl-β-cyclodextrin inclusion complex and study its disinfection effect against trichomonas vaginalis by MTT Assay. Method: The ultrasound method has been used to prepare the inclusion complex. The UV and powder X-ray diffraction (PXRD) techniques have been used to identify the complex. The MTT assay has been applied to study the disinfection effect against trichomonas vaginalis. Result: The complex has been validated by UV and PXRD.There was significant difference in the disinfection effect against trichomonas vaginalis between the inclusion complex and dihydroartemisin (P < 0. 05 ). Conclusion: The dihydroartemisinin hydroxypropyl-β-cyclodextrin inclusion complex can significantly improve the disinfection effect against Trichomonas vaginalis.%目的:制备双氢青蒿素-羟丙基-β-环糊精(HP-β-CD)包合物,并考察其对阴道毛滴虫的杀灭作用.方法:超声法制备双氢青蒿素HP-β-CD包合物.以紫外分光光度法和粉末 X 射线衍射分析法鉴定包合物的制备结果,MTT法考察双氢青蒿素的HP-β-CD包合物时阴道毛滴虫的杀灭作用.结果:紫外分光光度法与粉末X射线衍射分析均表明双氢青蒿素与 HP-β-CD 形成了包合物,双氢青蒿素被包含后,对阴道毛滴虫的杀灭作用与包合前有显著差异(P<0.05).结论:双氢青蒿素-HP-β-CD 包合物显著提高了双氢青蒿素的杀灭阴道毛滴虫的作用.

  3. Dioxin sensing which uses fluorescent cyclodextrin; Keikosei shikurodekisutorin wo mochiita daiokishin senshingu

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, F. [Akita Univ., Akita (Japan)

    2000-05-01

    Environmental hormones are called pluricausal endocrine disrupting chemical substances (endocrine disrupters) that are deemed to disrupt effects of vital hormones and give influence to homeostasis of in vivo environment. Today, 70,000 to 80,000 kinds of chemical substances are used in the world, and about 70 kinds among them are suspected of being environmental hormones. The present authors have clarified that a host with fluorescent residue chemically bonded to cyclodextrin responses at a high sensitivity to bile acids having a steroid skeleton. In this paper, dioxin sensing that uses fluorescent cyclodextrin is described. Florescent sensing of a dansyl group or anthranyl ground modified cyclodextrin having somewhat different molecular sizes; and sensing of hetero-2 substituted-dansyl-tosyl, modified {beta}-, cyclodextrin are examined. (NEDO)

  4. Intestinal Permeability of β-Lapachone and Its Cyclodextrin Complexes and Physical Mixtures.

    Science.gov (United States)

    Mangas-Sanjuan, Victor; Gutiérrez-Nieto, Jorge; Echezarreta-López, Magdalena; González-Álvarez, Isabel; González-Álvarez, Marta; Casabó, Vicente-Germán; Bermejo, Marival; Landin, Mariana

    2016-12-01

    β-Lapachone (βLAP) is a promising, poorly soluble, antitumoral drug. βLAP combination with cyclodextrins (CDs) improves its solubility and dissolution but there is not enough information about the impact of cyclodextrins on βLAP intestinal permeability. The objectives of this work were to characterize βLAP intestinal permeability and to elucidate cyclodextrins effect on the dissolution properties and on the intestinal permeability. The final goal was to evaluate CDs influence on the oral absorption of βLAP. Binary systems (physical mixtures and inclusion complexes) including βLAP and CDs (β-cyclodextrin: βCD, random-methyl-β-cyclodextrin: RMβCD and sulfobutylether-β-cyclodextrin: SBEβCD) have been prepared and analysed by differential scanning calorimetry. βLAP (and its combinations with CDs) absorption rate coefficients and effective permeability values have been determined in vitro in MDCK or MDCK-Mdr1 monolayers and in situ in rat by a closed loop perfusion technique. DSC results confirmed the formation of the inclusion complexes. βLAP-CDs inclusion complexes improve drug solubility and dissolution rate in comparison with physical mixtures. βLAP presented a high permeability value which can provide complete oral absorption. Its oral absorption is limited by its low solubility and dissolution rate. Cyclodextrin (both as physical mixtures and inclusion complexes) showed a positive effect on the intestinal permeability of βLAP. Complexation with CDs does not reduce βLAP intestinal permeability in spite of the potential negative effect of the reduction in free fraction of the drug. The use of RMβCD or SBEβCD inclusion complexes could benefit βLAP oral absorption by enhancing its solubility, dissolution rate and permeability.

  5. In vitro investigations of α-amylase mediated hydrolysis of cyclodextrins in the presence of ibuprofen, flurbiprofen, or benzo[a]pyrene

    DEFF Research Database (Denmark)

    Riisager, Ludmilla Lumholdt; Holm, R.; Jørgensen, E. B.

    2012-01-01

    -γ-cyclodextrins have different biopharmaceutical behaviours than the other evaluated cyclodextrins. The rate of degradation was affected by the addition of the inclusion complex forming additives flurbiprofen, ibuprofen and benzo[a]pyrene. This effect between the degradation dynamics and the included additives...

  6. Capping of Silybin with β-Cyclodextrin Influences its Binding with Bovine Serum Albumin: A Study by Fluorescence Spectroscopy and Molecular Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, Sudha; Sowrirajan, Chandrasekaran; Dhanaraj, Premnath; Enoch, Israel V. M. V. [Karunya Univ., Tamil Nadu (India)

    2014-07-15

    The association of silybin with β-cyclodextrin and its influence on silybin's binding with bovine serum albumin are reported. The stoichiometry, binding constant, and the structure of silybin-β-cyclodextrin inclusion complex are reported. The titrations of silybin with bovine serum albumin in the absence and presence of β-cyclodextrin are carried out and the differences in binding strengths are discussed. Molecular modeling is used to optimize the sites and mode of binding of silybin with bovine serum albumin. Forster resonance energy transfer is calculated and the proximity of interacting molecules is reported in the presence and absence of β-cyclodextrin.

  7. Capping of Silybin with β-Cyclodextrin Influences its Binding with Bovine Serum Albumin: A Study by Fluorescence Spectroscopy and Molecular Modeling

    International Nuclear Information System (INIS)

    Natesan, Sudha; Sowrirajan, Chandrasekaran; Dhanaraj, Premnath; Enoch, Israel V. M. V.

    2014-01-01

    The association of silybin with β-cyclodextrin and its influence on silybin's binding with bovine serum albumin are reported. The stoichiometry, binding constant, and the structure of silybin-β-cyclodextrin inclusion complex are reported. The titrations of silybin with bovine serum albumin in the absence and presence of β-cyclodextrin are carried out and the differences in binding strengths are discussed. Molecular modeling is used to optimize the sites and mode of binding of silybin with bovine serum albumin. Forster resonance energy transfer is calculated and the proximity of interacting molecules is reported in the presence and absence of β-cyclodextrin

  8. Supramolecular structure of glibenclamide and β-cyclodextrins complexes.

    Science.gov (United States)

    Lucio, David; Irache, Juan Manuel; Font, María; Martínez-Ohárriz, María Cristina

    2017-09-15

    Glibenclamide is an antidiabetic drug showing low bioavailability as consequence of its low solubility. To solve this drawback, the interaction with cyclodextrins has been proposed. The formation of GB-βCDs inclusion complexes was carried out using different methods, βCD derivatives and drug-to-cyclodextrin ratios. The structures of the corresponding complexes have been studied by molecular modelling, X-ray diffraction and differential thermal analysis. The dissolution behavior of inclusion complexes has been compared to that of pure GB. Dimeric inclusion complexes were obtained with different CD disposals, head-to-head for βCD and head-to-tail for HPβCD and RMβCD. Amorphous inclusion complexes were obtained by employing methods of freeze-drying or coevaporation in ammonia-water. However, crystalline structures were formed by kneading and coevaporation in ethanol/water in the case of GB-βCD complexes. The arrangement of these structures depended on the GB:βCD ratio, yielding cage type structures for 1:3 and 1:5 ratios and channel-type structures for higher GB contents. The amount of GB released and its dissolution rate was considerably increased by the use of amorphous inclusion complexes; whereas, slower GB release rates were found from crystalline inclusion complexes formed by kneading or coevaporation in ethanol/water. In addition, it was found that the porous structure strongly conditioned the GB dissolution rate from crystalline products. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Promising applications in drug delivery systems of a novel β-cyclodextrin derivative obtained by green synthesis.

    Science.gov (United States)

    García, Agustina; Leonardi, Darío; Lamas, María C

    2016-01-15

    An efficient and green method has been developed for the synthesis of succinyl-β-cyclodextrin in aqueous media obtaining very good yield. Acidic groups have been introduced in the synthesized carrier molecule to improve the guest-host affinity. To evaluate the suitability of the novel excipient focused to develop oral dosage forms, albendazole, a BSC class II compound, was chosen as a model drug. The β-cyclodextrin derivative and the inclusion complex were thoroughly characterized in solution and solid state by phase solubility studies, FT-IR spectroscopy, SEM, XRD, ESI-MS, DSC, 1D (1)H NMR, 1D (13)C NMR, selective 1D TOCSY, 2D COSY, 2D HSQC, 2D HMBC and ROESY NMR spectroscopy. Phase solubility studies indicated that both of them β-cyclodextrin and succinyl-β-cyclodextrin formed 1:1 inclusion complexes with albendazole, and the stability constants were 68M(-1) (β-cyclodextrin), 437M(-1) (succinyl-β-cyclodextrin), respectively. Water solubility and dissolution rate of albendazole were significantly improved in complex forms. Thus, the succinyl-β-cyclodextrin derivative could be a promising excipient to design oral dosage forms. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Sugar-Decorated Sugar Vesicles : Lectin-Carbohydrate Recognition at the Surface of Cyclodextrin Vesicles

    NARCIS (Netherlands)

    Voskuhl, Jens; Stuart, Marc C. A.; Ravoo, Bart Jan

    2010-01-01

    An artificial glycocalix self-assembles when unilamellar bilayer vesicles of amphiphilic beta-cyclodextrins are decorated with maltose and lactose by host-guest interactions. To this end, maltose and lactose were conjugated with adamantane through a tetra(ethyleneglycol) spacer. Both

  11. The evolution of cyclodextrin glucanotransferase product specificity

    NARCIS (Netherlands)

    Kelly, Ronan M.; Dijkhuizen, Lubbert; Leemhuis, Hans

    Cyclodextrin glucanotransferases (CGTases) have attracted major interest from industry due to their unique capacity of forming large quantities of cyclic alpha-(1,4)-linked oligosaccharides (cyclodextrins) from starch. CGTases produce a mixture of cyclodextrins from starch consisting of 6 (alpha), 7

  12. Influence of the substitution of β-cyclodextrins by cationic groups on the complexation of organic anions

    International Nuclear Information System (INIS)

    Hbaieb, S.; Kalfat, R.; Chevalier, Y.; Amdouni, N.; Parrot-Lopez, H.

    2008-01-01

    The inclusion complexation of the organic anion, dansyl-acid, by cationic derivatives of β-cyclodextrin has been investigated. A series of cationic β-cyclodextrins with various positive charge has been synthesized by selective functionalization of the primary face of β-cyclodextrin with amino groups. The complexes were of the 1:1 stoichiometry; the stability constants (K 11 ) have been evaluated from UV-Vis measurements by application of the Benesi-Hildebrand equation. The presence of amino groups increased the complexation ability. β-cyclodextrin fully substituted at the primary face with amino groups showed the strongest inclusion binding ability towards the dansyl-acid guest. The enhanced complexation for anions was ascribed to the cationic amino groups. A simple thermodynamic model of the electrostatic contribution to the complexation is presented

  13. Thermal degradation features of peppermint oil in a binary system with Β- cyclodextrin

    Directory of Open Access Journals (Sweden)

    I. A. Omelchenko

    2016-04-01

    Full Text Available Aim. One of the most promising ways of changing physical and chemical properties of the active pharmaceutical ingredient is an encapsulation on a molecular level with the use of cyclodextrins. This makes it possible to create products with the desired activity and controlled distribution in the body. Methods and results. We have studied the thermal decomposition of peppermint oil in binary systems with β-cyclodextrin. It has been found that the thermal degradation of mechanical mixture and inclusion complex of the «host-guest» with the composition of 1:1 passes through different mechanisms. Conclusions. It is shown that the given data of thermal stability are useful for the identification of an inclusion complex «β-CD – peppermint oil» and assessing its complexation, and for the development of technology of medicinal forms of supramolecular complex of β-cyclodextrin and peppermint oil

  14. Enthalpy of solution of α- and β-cyclodextrin in water and in some organic solvents

    International Nuclear Information System (INIS)

    Belica, Sylwia; Sadowska, Monika; Stępniak, Artur; Graca, Anna; Pałecz, Bartłomiej

    2014-01-01

    Highlights: • A great influence of crystalline water on the energetic of dissolving compounds. • The strongest interaction between β-cyclodextrin and DMSO. • The enthalpic pair interaction coefficient, h βCD-EtOH , obtained is positive. • Predominating effects of the partial dehydration of the molecules – βCD-EtOH. -- Abstract: The calorimetric measurements of solution enthalpy of α-cyclodextrin, β-cyclodextrin in water (H 2 O), dimetyloformamid (DMF), dimethyl sulfoxide (DMSO) and aqueous ethanol solutions (H 2 O + EtOH) at 298.15 K were made. The experimental results were used to calculate the enthalpic coefficients of the interactions between cyclodextrin and ethanol molecules in water based on McMillan–Mayer’s model. The results were compared with literature data and with hydrodynamic radii of cyclodextrin in examined solvents and with donor numbers of these solvents. In order to check, if the inclusion complex formation between the solvent with the highest enthalpy of solution and cyclodextrin has happened, the calorimetric isothermal titration measurements were made and the results were interpreted

  15. Synthesis of Some Trifluoromethylated Cyclodextrin Derivatives and Analysis of Their Properties as Artificial Glycosidases and Oxidases

    DEFF Research Database (Denmark)

    Bjerre, Jeannette; Fenger, Thomas Hauch; Marinescu, Lavinia Georgeta

    2007-01-01

    Cyclodextrin derivatives containing trifluoromethyl groups at C6 of the A and D rings were synthesized for the purpose of creating artificial enzymes. The compounds were synthesized by perbenzylation of beta-cyclodextrin followed by selective A,D-debenzylation according to Sinaÿ. Subsequent...... deprotected. The trifluoromethylated alcohols were found to be weak artificial enzymes catalysing hydrolysis of nitrophenyl glycosides at neutral pH with a kcat/kuncat of up to 56. It is proposed that this catalysis is analogues to the catalysis performed by related cyanohydrins. The trifluoro ketones were...

  16. Effect of cyclodextrins on pH-induced conformational transition of poly(methacrylic acid)

    Czech Academy of Sciences Publication Activity Database

    Horský, Jiří; Podešva, Jiří; Walterová, Zuzana

    2011-01-01

    Roč. 65, č. 6 (2011), s. 847-854 ISSN 0366-6352 R&D Projects: GA ČR GA202/09/2078 Institutional research plan: CEZ:AV0Z40500505 Keywords : cyclodextrins * inclusion complexes * polyelectrolytes Subject RIV: BO - Biophysics Impact factor: 1.096, year: 2011

  17. Cyclodextrin-modified nanodiamond for the sensitive fluorometric determination of doxorubicin in urine based on its differential affinity towards β/γ-cyclodextrins.

    Science.gov (United States)

    Laura Soriano, M; Carrillo-Carrion, Carolina; Ruiz-Palomero, Celia; Valcárcel, Miguel

    2018-01-15

    The manuscript reports on the preparation of β-cyclodextrin-modified nanodiamonds (βCD-ND) for the extraction and preconcentration of the fluorescent anticancer drug doxorubicin (DOX) from biological samples. The inclusion of DOX into the cavities of β- and γ-cyclodextrin (CD) confirms their utility for selective extraction and elution of the drug based on its good fit to the cyclodextrin cavity. Although both larger cyclodextrins (βCD and γCD) accommodate DOX, DOX clearly prefers the bigger γCD cavities. Dispersive micro solid-phase extraction using βCD-ND as sorbent enables the inclusion complexation of DOX. The elution of DOX from βCD-ND cavities occurs with a basic solution of γCD containing 10% acetonitrile owing to the preferential affinity (i.e. optimal fit) of DOX into the larger γCD cavity. DOX is quantified by monitoring its intrinsic fluorescence (exc/em = 475/595 nm). The method can determine DOX in urine with a limit of detection of 18 ng·mL -1 . Recoveries (93.2% and 94.0%) and precision (RSDs of 5.9% and 4.7%) at 100 and 400 ng·mL -1 DOX levels in urine are satisfactory. The matrix effect is negligible even when working with undiluted urine samples. Graphical abstract Nanodiamonds functionalized with β-cyclodextrin (βCD-ND) were used as sorbent for the determination of nanomolar levels of doxorubicin (DOX). It is based on host:guest interactions ruled by different stabilities of DOX within cyclodextrin (CD) cavity-size: βCD/γCD.

  18. Cyclodextrin derivatives with cyanohydrin and carboxylate groups as artificial glycosidases

    DEFF Research Database (Denmark)

    Bols, Mikael; Ortega-Caballero, Fernando

    2006-01-01

    Two cyclodextrin derivatives (1 and 2) were prepared in an attempt to create glycosidase mimics with a general acid catalyst and a nucleophilic carboxylate group. The catalysts 1 and 2 were found to catalyse the hydrolysis of 4-nitrophenyl beta-D-glucopyranoside at pH 8.0, but rapidly underwent...... decomposition with loss of hydrogen cyanide to convert the cyanohydrin to the corresponding aldehyde. The initial rate of the catalysis shows that the cyanohydrin group in these molecules functions as a good catalyst, but that the carboxylate has no positive effect. The decomposition product aldehydes display...

  19. Spectral and theoretical study on complexation of sulfamethoxazole with β- and HPβ-cyclodextrins in binary and ternary systems

    Science.gov (United States)

    Varghese, Beena; Suliman, FakhrEldin O.; Al-Hajri, Aalia; Al Bishri, Nahed Surur S.; Al-Rwashda, Nathir

    2018-02-01

    The inclusion complexes of sulfamethoxazole (SMX) with β-cyclodextrin (βCD) and (2-hydroxypropyl) β-cyclodextrin (HPβCD) were prepared. Fluorescence spectroscopy and electrospray mass spectrometry, ESI-MS, were used to investigate and characterize the inclusion complexation of SMX with cyclodextrins in solutions. Whereas in the solid state the complexes were characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD) and Raman techniques. Enhanced twisted intramolecular charge transfer (TICT), emission as well as local excited (LE) bands were observed upon addition of HPβCD indicate that SMX enters deeper into the cyclodextrins cavity. The stoichiometries and association constants of these complexes have been determined by monitoring the fluorescence data. The effect of presence of ternary components like arginine and cysteine on the complexation efficiency of SMX with cyclodextrins was investigated. Molecular Dynamic simulations were also performed to shed an atomistic insight into the complexation mechanism. The results obtained showed that complexes of SMX with both cyclodextrins are stabilized in aqueous media by strong hydrogen bonding interactions.

  20. Preparation and characterization of thermal-responsive non-woven poly (propylene) materials grafted with N-isopropylacrylamide/β-cyclodextrin

    DEFF Research Database (Denmark)

    Amiri, Setareh; Zadhoush, Ali; Mallakpour, Shadpour

    2013-01-01

    A temperature-sensitive hydrogel was successfully grafted on the surface of non-woven poly(propylene) materials. This was carried out by the application of unmodified β-cyclodextrin and N-isopropylacrylamide monomer in order to develop new functional hydrogels for textile science and technology......(N-isopropylacrylamide) and β-cyclodextrin components on the surface of the textile. Unmodified β-cyclodextrin content was estimated by the use of elemental analysis to be 97 µg/cm2. The water uptake measurements and differential scanning calorimetry analyses showed that the hydrogel maintained its temperature...... of smart textiles which possess the temperature-sensitive property of poly(N-isopropylacrylamide) and the ability of inclusion complex formation with guest molecules due to the presence of unmodified β-cyclodextrin in the hydrogel network....

  1. Complexation and sensing behavior of dansyl-appended cyclodextrins and cyclodextrin dimers with bile salts

    NARCIS (Netherlands)

    Jong, de M.R.; Berthault, P.; Hoek, van A.; Visser, A.J.W.G.; Huskens, J.; Reinhoudt, D.N.

    2002-01-01

    The dansyl-modified cyclodextrin derivatives 2 and 3 form complexes with the steroidal bile salts. The selectivity of the monomeric derivative 3 is similar to that of native g-cyclodextrin. All binding constants with 3 are lowered compared to g-cyclodextrin because of the competition for the cavity

  2. Complexation and sensing behavior of dansyl-appended cyclodextrins and cyclodextrin dimers with bile salts

    NARCIS (Netherlands)

    de Jong, M.R.; Berthault, Patrick; van Hoek, Arie; Visser, Antonie J.W.G.; Huskens, Jurriaan; Reinhoudt, David

    2002-01-01

    The dansyl-modified cyclodextrin derivatives 2 and 3 form complexes with the steroidal bile salts. The selectivity of the monomeric derivative 3 is similar to that of native β-cyclodextrin. All binding constants with 3 are lowered compared to β-cyclodextrin because of the competition for the cavity

  3. Interactions between 4-thiothymidine and water-soluble cyclodextrins: Evidence for supramolecular structures in aqueous solutions

    OpenAIRE

    Rizzi, Vito; Matera, Sergio; Semeraro, Paola; Fini, Paola; Cosma, Pinalysa

    2016-01-01

    Since several years the inclusion of organic compounds (guests) within the hydrophobic cavity (host) of cyclodextrins (CDs) has been the subject of many investigations. Interestingly, the formation of inclusion complexes could affect the properties of the guest molecules and, for example, the influence of the delivery system can be a method to improve/change the photochemical behavior of the guest. In particular, very recent studies have shown the protective role of CDs preventing the degrada...

  4. Cellular Interaction and Tumoral Penetration Properties of Cyclodextrin Nanoparticles on 3D Breast Tumor Model

    Directory of Open Access Journals (Sweden)

    Gamze Varan

    2018-01-01

    Full Text Available Amphiphilic cyclodextrins are biocompatible oligosaccharides that can be used for drug delivery especially for the delivery of drugs with solubility problems thanks to their unique molecular structures. In this paper, Paclitaxel was used as a model anticancer drug to determine the inclusion complex properties of amphiphilic cyclodextrins with different surface charge. Paclitaxel-loaded cyclodextrin nanoparticles were characterized in terms of mean particle diameter, zeta potential, encapsulation efficacy, drug release profile and cell culture studies. It was determined that the nanoparticles prepared from the inclusion complex according to characterization studies have a longer release profile than the conventionally prepared nanoparticles. In order to mimic the tumor microenvironment, breast cancer cells and healthy fibroblast cells were used in 3-dimensional (3D cell culture studies. It was determined that the activities of nanoparticles prepared by conventional methods behave differently in 2-dimensional (2D and 3D cell cultures. In addition, it was observed that the nanoparticles prepared from the inclusion complex have a stronger anti-tumoral activity in the 3D multicellular tumor model than the drug solution. Furthermore, polycationic amphiphilic cyclodextrin nanoparticles can diffuse and penetrate through multilayer cells in a 3D tumor model, which is crucial for an eventual antitumor effect.

  5. Development of Orodispersible Tablets of Candesartan Cilexetil-β-cyclodextrin Complex

    Directory of Open Access Journals (Sweden)

    Maddukuri Sravya

    2013-01-01

    Full Text Available The aim of this study was to investigate the use of inclusion complexation technique employing β-cyclodextrin in improving the dissolution profile of candesartan cilexetil, a BCS class-II drug, and to formulate the inclusion complex into orodispersible tablets. The inclusion complexes were formed by physical mixing, kneading, coevaporation, and lyophilisation methods. Inclusion complexes were characterized by FTIR, DSC, XRD, NMR, and mass spectral studies. Inclusion complexes prepared using kneading, and lyophilisation techniques in the molar ratio 1 : 5 with β-cyclodextrin were used for formulating orodispersible tablets by direct compression with different superdisintegrants like croscarmellose sodium, crospovidone, sodium starch glycolate, and low substituted hydroxypropyl cellulose in varying concentrations. The directly compressible powder was evaluated for precompression parameters, and the prepared orodispersible tablets were evaluated for postcompression parameters. Drug-excipient compatibility studies showed no interaction, and characterization proved the formation of inclusion complex. In vitro disintegration time was found to be within 3 minutes, and all the formulations showed complete drug release of 100% within 20 minutes. The optimized formulation was found to be stable after 6 months and showed no significant change in drug content. This work proved β-cyclodextrins to be effective solubilizing agent in improving the solubility of poorly water soluble drugs.

  6. Cyclodextrins in Asymmetric and Stereospecific Synthesis

    Directory of Open Access Journals (Sweden)

    Fliur Macaev

    2015-09-01

    Full Text Available Since their discovery, cyclodextrins have widely been used as green and easily available alternatives to promoters or catalysts of different chemical reactions in water. This review covers the research and application of cyclodextrins and their derivatives in asymmetric and stereospecific syntheses, with their division into three main groups: (1 cyclodextrins promoting asymmetric and stereospecific catalysis in water; (2 cyclodextrins’ complexes with transition metals as asymmetric and stereospecific catalysts; and (3 cyclodextrins’ non-metallic derivatives as asymmetric and stereospecific catalysts. The scope of this review is to systematize existing information on the contribution of cyclodextrins to asymmetric and stereospecific synthesis and, thus, to facilitate further development in this direction.

  7. Cyclodextrins: A Weapon in the Fight Against Antimicrobial Resistance

    Science.gov (United States)

    Wong, Chew Ee; Dolzhenko, Anton V.; Lee, Sui Mae; Young, David James

    Antimicrobial resistance poses one of the most serious global challenges of our age. Cyclodextrins (CDs) are widely utilized excipients in formulations because of their solubilizing properties, low toxicity, and low inflammatory response. This review summarizes recent investigations of antimicrobial agents involving CDs and CD-based antimicrobial materials. CDs have been employed for antimicrobial applications either through formation of inclusion complexes or by chemical modification of their hydroxyl groups to tailor pharmaceutically active compounds. Applications of these CD inclusion complexes include drug delivery, antimicrobial coatings on materials (e.g., biomedical devices and implants) and antimicrobial dressings that help to prevent wound infections. There are relatively limited studies of chemically modified CDs with antimicrobial activity. The mechanism of action of antimicrobial CD inclusion complexes and derivatives needs further elucidation, but activity of CDs and their derivatives is often associated with their interaction with bacterial cell membranes.

  8. Modulating Pluronics micellar rupture with cyclodextrins and drugs: effect of pH and temperature

    International Nuclear Information System (INIS)

    Valero, M; Dreiss, C A

    2014-01-01

    Micelles of the triblock copolymer Pluronic F127 can encapsulate drugs with various chemical structures and their architecture has been studied by small-angle neutron scattering (SANS). Interaction with a derivative of β-cyclodextrin, namely, heptakis(2,6-di-O- methyl)-β-cyclodextrin (DIMEB), induces a complete break-up of the micelles, providing a mechanism for drug release. In the presence of drugs partitioned within the micelles, competitive interactions between polymer, drug and cyclodextrin lead to a modulation of the micellar rupture, depending on the nature of the drug and the exact composition of the ternary system. These interactions can be further adjusted by temperature and pH. While the most widely accepted mechanism for the interaction between Pluronics and cyclodextrins is through polypseudorotaxane (PR) formation, involving the threading of β-CD on the polymer backbone, time-resolved SANS experiments show that de-micellisation takes place in less than 100 ms, thus unambiguously ruling out an inclusion complex between the cyclodextrin and the polymer chains

  9. Pyrolysis characteristics and kinetics of β-cyclodextrin and its two derivatives

    Directory of Open Access Journals (Sweden)

    Zhu Guangyong

    2015-12-01

    Full Text Available β-cyclodextrin (β-CD and its derivatives have been widely used to prepare inclusion complexes. However, systematic research on their thermal stabilities, pyrolysis characteristics and kinetics has rarely been reported. In this paper, thermogravimetric analysis was employed to investigate β-cyclodextrin and its two derivatives, 2-Hydroxypropyl-β-cyclodextrin (HP-β-CD and monochlorotriazinyl-β-cyclodextrin (MCT-β-CD. The pyrolysis characteristics and kinetic parameters were obtained. The results show that three stages can be distinguished during the heating process of the above three samples. The temperature of initial decomposition of HP-β-CD (309.5°C is higher than that of β-CD (297.8°C, while the temperature of initial decomposition of MCT-β-CD (231.4°C is lower than that of β-CD. For the three cyclodextrins, the thermal stability in descending order is HP-β-CD, β-CD and MCT-HP-β-CD. The activation energy values are 350.6, 303.3 and 113.9 KJ/mol, and the pre-exponential factor values are 1.11×1031, 1.37×1026 and 1.39×1010 for β-CD, HP-β-CD and MCT-β-CD respectively.

  10. Synergistic radical scavenging potency of curcumin-in-β-cyclodextrin-in-nanomagnetoliposomes

    Energy Technology Data Exchange (ETDEWEB)

    Aadinath, W.; Bhushani, Anu; Anandharamakrishnan, C., E-mail: anandhram@cftri.res.in

    2016-07-01

    Curcumin is a highly potent nutraceutical associated with various health benefits. However, its hydrophobic nature affects its bioavailability and bioactivity, and limits nutraceutical applications. Drug-in-cyclodextrin-in-liposome has the ability to mask the hydrophobic nature of drug and achieve better encapsulation. Also, encapsulating iron oxide nanoparticles (IONPs) within liposomes endow additional beneficial functionalities of IONPs. In the present study, curcumin-β-cyclodextrin inclusion complex (IC) and IONPs were co-encapsulated within liposomes (curcumin-in-β-cyclodextrin-in-nanomagnetoliposomes) to achieve the synergistic antioxidant potential of curcumin and IONPs. IC of curcumin-β-cyclodextrin was prepared by a simple rapid method and successful inclusion was confirmed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). Mean diameter of IONPs was found to be 180 nm and X-ray diffraction pattern confirmed the formation of hematite nanoparticles. Band gap energy calculated using absorption spectra was 2.25 eV, which falls in close proximity with the theoretically calculated values of hematite. Mean diameter of curcumin-in-β-cyclodextrin-in-nanomagnetoliposomes was 67 nm and encapsulation efficiency of curcumin was found to be 71%. Further, the co-encapsulated particles possessed significantly low IC{sub 50} value (64.7791 μg/ml, p < 0.01) compared to conventional curcumin liposome and IONPs, indicating its synergistically enhanced radical scavenging property. - Highlights: • Curcumin-in-β-cyclodextrin-in-nanomagnetoliposomes (mean diameter, 67 nm) has been prepared. • Encapsulation efficiency of curcumin was found to be 71%. • IONPs in the nano-carrier play dual role of targeted delivery and radical scavenging activities. • Conjunction of IONPs and curcumin into the liposomes increases the radical scavenging activity.

  11. Characterization of pioglitazone cyclodextrin complexes: Molecular modeling to in vivo evaluation

    Directory of Open Access Journals (Sweden)

    Dinesh M Bramhane

    2016-01-01

    Full Text Available Aims: The objective of present study was to study the influence of different β-cyclodextrin derivatives and different methods of complexation on aqueous solubility and consequent translation in in vivo performance of Pioglitazone (PE. Material and Methods: Three cyclodextrins: β-cyclodextrin (BCD, hydroxypropyl-β-cyclodextrin (HPBCD and Sulfobutylether-7-β-cyclodextrin (SBEBCD were employed in preparation of 1:1 Pioglitazone complexes by three methods viz. co-grinding, kneading and co-evaporation. Complexation was confirmed by phase solubility, proton NMR, Fourier Transform Infrared spectroscopy, Differential Scanning Calorimetry (DSC and X-Ray diffraction (XRD. Mode of complexation was investigated by molecular dynamic studies. Pharmacodynamic study of blood glucose lowering activity of PE complexes was performed in Alloxan induced diabetic rat model. Results: Aqueous solubility of PE was significantly improved in presence of cyclodextrin. Apparent solubility constants were observed to be 254.33 M–1 for BCD-PE, 737.48 M–1 for HPBCD-PE and 5959.06 M–1 for SBEBCD-PE. The in silico predictions of mode of inclusion were in close agreement with the experimental proton NMR observation. DSC and XRD demonstrated complete amorphization of crystalline PE upon inclusion. All complexes exhibited >95% dissolution within 10 min compared to drug powder that showed <40% at the same time. Marked lowering of blood glucose was recorded for all complexes. Conclusion: Complexation of PE with different BCD significantly influenced its aqueous solubility, improved in vitro dissolution and consequently translated into enhanced pharmacodynamic activity in rats

  12. Effect of pH on the complexation of kaempferol-4'-glucoside with three β-cyclodextrin derivatives: isothermal titration calorimetry and spectroscopy study.

    Science.gov (United States)

    Zheng, Yan; Dong, Li-Na; Liu, Min; Chen, Aiju; Feng, Shangcai; Wang, Bingquan; Sun, Dezhi

    2014-01-08

    The utilization of kaempferol and its glycosides in food and pharmaceutical industries could be improved by the formation of inclusion complexes with cyclodextrins at different pH. This study explores the complexation of kaempferol-4'-glucoside with sulfobutyl ether-β-cyclodextrin (SBE-β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), and methylated-β-cyclodextrin (M-β-CD) in phosphate buffer solutions of different pH using isothermal titration calorimetry, UV-vis absorption and proton nuclear magnetic resonance spectroscopy at 298.2 K. Experimental results showed that kaempferol-4'-glucoside binds with the three β- cyclodextrins in the same 1:1 stoichiometry. The rank order of stability constants is SBE-β-CD > HP-β-CD > M-β-CD at the same pH level and pH 6.0 > pH 7.4 > pH 9.0 for the same cyclodextrin. The binding of kaempferol-4'-glucoside with the three β-cyclodextrin derivatives is synergistically driven by enthalpy and entropy at pH 6.0 and enthalpy-driven at pH 7.4 and 9.0. The possible inclusion mode was that in the cavity of β-CD is included the planar benzopyranic-4-one part of the kaempferol-4'-glucoside.

  13. α-Cyclodextrin – Water binary system. New data on dehydration of α-cyclodextrin hexahydrate

    International Nuclear Information System (INIS)

    Manakov, Andrey Yu.; Rodionova, Tatyana V.; Aladko, Lyudmila S.; Villevald, Galina V.; Lipkowski, Janusz S.; Zelenina, Lyudmila N.; Chusova, Tamara P.; Karpova, Tamara D.

    2016-01-01

    Highlights: • The T, x– phase diagram of α-CD – water binary system was studied by DTA and DSC. • PXRD was used to follow structural transformation of α-CD hydrates. • α-CD·6.1H 2 O transforms into α-CD·5.3H 2 O at the temperature ∼355 K in isochoric conditions. • The solid solution on the base of α-CD·6H 2 O Form I is formed within the limits of α-CD·6.1H 2 O – α-CD·2.1H 2 O. - Abstract: Cyclodextrins (CDs) are torous-like macrocycles composed of glucopyranose units. Due to their shapes, they are capable to include a wide variety of organic and inorganic guest molecules with formation of inclusion complexes in solid and liquid state. CDs crystallize from aqueous solution as hydrates (water molecules are located in the cavities and fill intermolecular space). The process of inclusion complex formation is, in fact, a replacement reaction of water molecules by hydrophobic guest molecules. Given the important role of water in the formation of CDs inclusion complexes, and the fact that the main commercial forms of cyclodextrins are the hydrated ones, the study of temperature (T) – composition (x) phase diagram of cyclodextrin – water binary system is of scientific and practical interest. This article reports an experimental study of the T, x – phase diagram of α-cyclodextrin – water binary system under isochoric conditions by differential thermal analysis (DTA) and differential scanning calorimetry (DSC). Powder X-ray diffraction was used to identify the structures of different α-CD hydrates and to follow their phase transformations. It was shown that dehydration processes in isochoric and isobaric (open air) conditions differ significantly. In the temperature range of approximately 351 K–359 K the α-CD hexahydrate of known Form I structure transforms into the α-CD·5.3H 2 O of unknown structural type. It is found that the solid solution on the base of the structure α-CD hexahydrate Form I is formed within the limits of

  14. Cyclodextrin-enhanced biodegradation of phenanthrene

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.-M.; Marlowe, E.M.; Miller-Maier, R.M.; Brusseau, M.L. [University of Arizona, Tuscon, AZ (United States). Dept. of Soil, Water and Environmental Science

    1998-07-01

    The effectiveness of in situ bioremediation in many systems may be constrained by low contaminant bioavailability due to limited aqueous solubility or a large magnitude of sorption. The objective of this research was to evaluate the effect of hydroxypropyl-{beta}-cyclodextrin (HPCD) on phenanthrene solubilization and biodegradation. Results showed that analytical-grade HPCD can significantly increase the apparent solubility of phenanthrene. The increase in apparent solubility had a major impact on the biodegradation rate of phenanthrene. For example, in the presence of 10{sup 5} mg L{sup -1} HPCD, the substrate utilization rate increased from 0.17 mg h{sup -1} to 0.93 mg h{sup -1} while the apparent solubility was increased from 1.3 mg L{sup -1} to 161.3 mg L{sup -1}. As a result, only 0.3% of the phenanthrene remained at the end of a 48 h incubation for the highest concentration of HPCD tested (10{sup 5} mg L{sup -1}). In contrast, 45.2% of the phenanthrene remained in the absence of HPCD. Technical-grade HPCD, which contains the biodegradable impurity propylene glycol, also increased the substrate utilization rate, although to a lesser extent than the analytical-grade HPCD. On the basis of these results, it appears that HPCD can significantly increase the bioavailability, and thereby enhance the biodegradation of phenanthrene. 26 refs., 5 figs.

  15. Cyclodextrin-Based Solid-Gas Clathrates

    NARCIS (Netherlands)

    Pereva, Stiliana; Himitliiska, Tsveta; Spassov, Tony; Stoyanov, S.D.; Arnaudov, L.N.; Dudev, Todor

    2015-01-01

    "Cyclodextrin-gas" clathrates were obtained by crystallization from water solution of α-, β-, and γ-cyclodextrins (CDs) under pressure of the gas to be entrapped into the CD molecules. When the pressure is released, these clathrates are stable at ambient conditions and dissociate at elevated

  16. Comparison of Aqueous and 1-Octanol Solubility as well as Liquid?Liquid Distribution of Acyclovir Derivatives and Their Complexes with Hydroxypropyl-?-Cyclodextrin

    OpenAIRE

    Ko?bia?, Ma?gorzata; Gierycz, Pawe?

    2013-01-01

    The aim of the presented work is the comparison of aqueous and 1-octanol solubilities of different acyclovir derivatives and their hydroxypropyl-?-cyclodextrin inclusion complexes. The solubility measurements were carried out at different temperatures over the range 25?45??C using water, 1-octanol, water saturated with 1-octanol, 1-octanol saturated with water, buffered aqueous solutions (pH?=?5.5 and 7.0) and buffered aqueous solutions containing cyclodextrin as solvents. The aqueous solubil...

  17. Cyclodextrins as excipients in tablet formulations.

    Science.gov (United States)

    Conceição, Jaime; Adeoye, Oluwatomide; Cabral-Marques, Helena Maria; Lobo, José Manuel Sousa

    2018-04-22

    This paper aims to provide a critical review of cyclodextrins as excipients in tablet formulations, highlighting: (i) the principal pharmaceutical applications of cyclodextrins; (ii) the most relevant technological aspects in pharmaceutical formulation development; and (iii) the actual regulatory status of cyclodextrins. Moreover, several illustrative examples are presented. Cyclodextrins can be used as complexing excipients in tablet formulations for low-dose drugs. By contrast, for medium-dose drugs and/or when the complexation efficiency is low, the methods to enhance the complexation efficiency play a key part in reducing the cyclodextrin quantity. In addition, these compounds are used as fillers, disintegrants, binders and multifunctional direct compression excipients of the tablets. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Application of cyclodextrins in antibody microparticles: potentials for antibody protection in spray drying.

    Science.gov (United States)

    Ramezani, Vahid; Vatanara, Alireza; Seyedabadi, Mohammad; Nabi Meibodi, Mohsen; Fanaei, Hamed

    2017-07-01

    Dry powder formulations are extensively used to improve the stability of antibodies. Spray drying is one of important methods for protein drying. This study investigated the effects of trehalose, hydroxypropyl beta cyclodextrin (HPBCD) and beta cyclodextrin (BCD) on the stability and particle properties of spray-dried IgG. D-optimal design was employed for both experimental design and analysis and optimization of the variables. The size and aerodynamic behavior of particles were determined using laser light scattering and glass twin impinger, respectively. In addition, stability, ratio of beta sheets and morphology of antibody were analyzed using size exclusion chromatography, IR spectroscopy and electron microscopy, respectively. Particle properties and antibody stability were significantly improved in the presence of HPBCD. In addition, particle aerodynamic behavior, in terms of fine-particle fraction (FPF), enhanced up to 52.23%. Furthermore, antibody was better preserved not only during spray drying, but also during long-term storage. In contrast, application of BCD resulted in the formation of larger particles. Although trehalose caused inappropriate aerodynamic property, it efficiently decreased antibody aggregation. HPBCD is an efficient excipient for the development of inhalable protein formulations. In this regard, optimal particle property and antibody stability was obtained with proper combination of cyclodextrins and simple sugars, such as trehalose.

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

    Science.gov (United States)

    Topuz, Fuat; Uyar, Tamer

    2017-07-01

    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 13 C 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. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Effects of nanosuspension and inclusion complex techniques on the in vitro protease inhibitory activity of naproxen

    Energy Technology Data Exchange (ETDEWEB)

    Dharmalingam, Senthil Rajan; Chidambaram, Kumarappan; Srinivasan, Ramamurthy; Nadaraju, Shamala, E-mail: dsenthilrajan@yahoo.co.in [School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur (Malaysia)

    2014-01-15

    This study investigated the effects of nanosuspension and inclusion complex techniques on in vitro trypsin inhibitory activity of naproxen—a member of the propionic acid derivatives, which are a group of antipyretic, analgesic, and non-steroidal anti-inflammatory drugs. Nanosuspension and inclusion complex techniques were used to increase the solubility and anti-inflammatory efficacy of naproxen. The evaporative precipitation into aqueous solution (EPAS) technique and the kneading methods were used to prepare the nanosuspension and inclusion complex of naproxen, respectively. We also used an in vitro protease inhibitory assay to investigate the anti-inflammatory effect of modified naproxen formulations. Physiochemical properties of modified naproxen formulations were analyzed using UV, IR spectra, and solubility studies. Beta-cyclodextrin inclusion complex of naproxen was found to have a lower percentage of antitryptic activity than a pure nanosuspension of naproxen did. In conclusion, nanosuspension of naproxen has a greater anti-inflammatory effect than the other two tested formulations. This is because the nanosuspension formulation reduces the particle size of naproxen. Based on these results, the antitryptic activity of naproxen nanosuspension was noteworthy; therefore, this formulation can be used for the management of inflammatory disorders. (author)

  1. Novel ?-cyclodextrin?eosin conjugates

    OpenAIRE

    Benkovics, G?bor; Afonso, Damien; Darcsi, Andr?s; B?ni, Szabolcs; Conoci, Sabrina; Fenyvesi, ?va; Szente, Lajos; Malanga, Milo; Sortino, Salvatore

    2017-01-01

    Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy an...

  2. Hydration Differences Explain the Large Variations in the Complexation Thermodynamics of Modified γ-Cyclodextrins with Bile Salts

    DEFF Research Database (Denmark)

    Køhler, Jonatan; Schönbeck, Jens Christian Sidney; Westh, Peter

    2016-01-01

    The structure and thermodynamics of inclusion complexes of seven different γ-cyclodextrins (γCDs) and three biologically relevant bile salts (BS) were investigated in the present study. Natural γCD and six modified γCDs [two methyl-γCDs, one sulfobutyl ether-γCD (SBEγCD), and three 2-hydroxypropyl...

  3. Host-guest complexes of 2-hydroxypropyl-β-cyclodextrin/β-cyclodextrin and nifedipine: 1H NMR, molecular modeling, and dissolution studies

    Science.gov (United States)

    de Araújo, Márcia Valéria Gaspar; Vieira, João Victor Francisco; da Silva, Caroline W. P.; Barison, Andersson; Andrade, George Ricardo Santana; da Costa, Nivan Bezerra; Barboza, Fernanda Malaquias; Nadal, Jessica Mendes; Novatski, Andressa; Farago, Paulo Vitor; Zawadzki, Sônia Faria

    2017-12-01

    Nifedipine (NIF) is a hydrophobic drug widely used for treating cardiovascular diseases. This calcium channel blocker can present a higher apparent solubility by its inclusion into different cyclodextrins (CDs) as host-guest complexes. This paper focused on the structural investigation and dissolution behavior of inclusion complexes prepared with 2-hydroxypropyl-β-cyclodextrin (HPβCD) or β-cyclodextrin (βCD) and NIF. Drug amorphization was observed for HPβCD/NIF and βCD/NIF inclusion complexes by X-ray diffractometry (XRD). The sharp endothermic peak of NIF was not observed for these both host-guest complexes by differential scanning calorimetry (DSC). These results of XRD and DSC provide evidences of complexation between drug and the investigated CDs. 1H and saturation transfer difference nuclear magnetic resonance studies revealed the enhancement in the signal at 2.27 ppm for HPβCD/NIF and βCD/NIF inclusion complexes that corresponded to the methyl groups of NIF from the non-aromatic ring. This result suggested that non-aromatic ring of NIF was inserted into HPβCD and βCD cavities. Considering the mathematical simulations, it was observed that the inclusion process can occur in the both NH-in or NH-out forms. However, since it was used aqueous medium, it is possible to indicate that the obtained host-guest complexes HPβCD/NIF and βCD/NIF are in NH-in form which corresponded to the previous results obtained by 1H NMR experiments. Dissolution assays demonstrated that NIF inclusion complexes improved the drug release nevertheless without changing its biexponential release behavior. These host-guest complexes can be further used as feasible NIF carriers in solid dosage forms.

  4. Encapsulation of lycopene using spray-drying and molecular inclusion processes

    Directory of Open Access Journals (Sweden)

    Itaciara Larroza Nunes

    2007-09-01

    Full Text Available This study aimed to obtain encapsulated lycopene in a powder form, using either spray-drying or molecular inclusion with beta -cyclodextrin ( beta -CD followed by freeze-drying. The encapsulation efficiency using spray-drying ranged from 94 to 96%, with an average yield of 51%, with microcapsules showing superficial indentations and lack of cracks and breakages. Lycopene- beta -CD complexes were only formed at a molar ratio of 1:4, and irregular structures of different sizes that eventually formed aggregates, similar to those of beta -CD, were observed after freeze-drying. About 50% of the initial lycopene did not form complexes with beta -CD. Lycopene purity increased from 96.4 to 98.1% after spray-drying, whereas lycopene purity decreased from 97.7 to 91.3% after complex formation and freeze-drying. Both the drying processes yielded pale-pink, dry, free-flowing powders.Técnicas de encapsulamento, como "spray-drying" e formação de complexos por inclusão com ciclodextrinas, vêm sendo avaliadas para viabilizar a adição de carotenóides em sistemas hidrofílicos e aumentar a sua estabilidade durante o processamento e estocagem. Portanto, o objetivo do presente trabalho foi obter licopeno encapsulado na forma de pó, utilizando processos de "spray-drying" ou de inclusão molecular com beta -ciclodextrina (CD seguido de liofilização. A eficiência do encapsulamento utilizando "spray-drying" variou de 94 a 96% e o rendimento médio foi de 51%, com as microcápsulas apresentando indentações superficiais, porém sem falhas ou aberturas na superfície. A formação de complexo licopeno- beta -CD ocorreu apenas quando utilizada razão molar de 1:4, e estruturas irregulares de diferentes tamanhos que eventualmente formaram agregados, similares às da beta -CD, foram observadas após liofilização. O licopeno não complexado neste processo ficou em torno de 50%. A pureza do licopeno (% área do all-trans-licopeno aumentou de 96,4 para 98,1% ap

  5. ESR technique for noninvasive way to quantify cyclodextrins effect on cell membranes

    International Nuclear Information System (INIS)

    Grammenos, A.; Mouithys-Mickalad, A.; Guelluy, P.H.; Lismont, M.; Piel, G.; Hoebeke, M.

    2010-01-01

    Research highlights: → ESR: a new tool for cyclodextrins study on living cells. → Cholesterol and phospholipid extraction by Rameb in a dose- and time-dependent way. → Extracted phospholipids and cholesterol form stable aggregates. → ESR spectra show that lipid rafts are damaged by Rameb. → Quantification of the cholesterol extraction on cell membranes in a noninvasive way. -- Abstract: A new way to study the action of cyclodextrin was developed to quantify the damage caused on cell membrane and lipid bilayer. The Electron Spin Resonance (ESR) spectroscopy was used to study the action of Randomly methylated-beta-cyclodextrin (Rameb) on living cells (HCT-116). The relative anisotropy observed in ESR spectrum of nitroxide spin probe (5-DSA and cholestane) is directly related to the rotational mobility of the probe, which can be further correlated with the microviscosity. The use of ESR probes clearly shows a close correlation between cholesterol contained in cells and cellular membrane microviscosity. This study also demonstrates the Rameb ability to extract cholesterol and phospholipids in time- and dose-dependent ways. In addition, ESR spectra enabled to establish that cholesterol is extracted from lipid rafts to form stable aggregates. The present work supports that ESR is an easy, reproducible and noninvasive technique to study the effect of cyclodextrins on cell membranes.

  6. Bioadhesive tablets containing cyclodextrin complex of itraconazole for the treatment of vaginal candidiasis.

    Science.gov (United States)

    Cevher, Erdal; Açma, Ayşe; Sinani, Genada; Aksu, Buket; Zloh, Mire; Mülazımoğlu, Lütfiye

    2014-08-01

    Itraconazole (ITR) is commonly used in the treatment of Candida infections. It has a nephrotoxic effect and low bioavailability in patients who suffer from renal insufficiency, and its poor solubility in water makes ITR largely unavailable. Cyclodextrins (CyDs) are used to form inclusion complexes with drugs to improve their aqueous solubility and to reduce their side effects. In this study, ITR was complexed with γ-cyclodextrin (γ-CyD), hydroxypropyl-β-cyclodextrin (HP-β-CyD), methyl-β-cyclodextrin (Met-β-CyD) and sulphobutyl ether-β-cyclodextrin (SBE7-β-CyD) to increase its water solubility and to reduce the side effects of the drug without decreasing antifungal activity. Complex formation between ITR and CyDs was evaluated using SEM, (1)H NMR and XRD studies. The antifungal activity of the complexes was analyzed on Candida albicans strains, and the susceptibility of the strains was found to be higher for the ITR-SBE7-β-CyD complex than for the complexes that were prepared with other CyDs. Vaginal bioadhesive sustained release tablet formulations were developed using the ITR-SBE7-β-CyD inclusion complex to increase the residence time of ITR in the vagina, thereby boosting the efficacy of the treatment. The swelling, matrix erosion and bioadhesion properties of formulations and the drug release rate of these tablets were analyzed, and the most therapeutically effective vaginal formulation was determined. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. The role of water in the thermodynamics of drug binding to cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Todorova, Niya A. [Center for Advanced Research in Biotechnology, National Institute of Standards and Technology, 9600 Gudelsky Drive, Rockville, MD 20850 (United States); Schwarz, Frederick P. [Center for Advanced Research in Biotechnology, National Institute of Standards and Technology, 9600 Gudelsky Drive, Rockville, MD 20850 (United States)]. E-mail: fred@carb.nist.gov

    2007-07-15

    The thermodynamic parameters, {delta}{sub B} G {sup 0}, {delta}{sub B} H {sup 0}, {delta}{sub B} S {sup 0}, and {delta}{sub B} C {sub p}, of the drugs flurbiprofen (FLP), nabumetone (NAB), and naproxen (NPX) binding to {beta}-cyclodextrin ({beta}CD) and to {gamma}-cyclodextrin ({gamma}CD) in 0.10 M sodium phosphate buffer were determined from isothermal titration calorimetry (ITC) measurements over the temperature range from 293.15 K to 313.15 K. The heat capacity changes for the binding reactions ranged from -(362 {+-} 48) J . mol{sup -1} . K{sup -1} for FLP and -(238 {+-} 90) J . mol{sup -1} . K{sup -1} for NAB binding in the {beta}CD cavity to 0 for FLP and -(25.1 {+-} 9.2) J . mol{sup -1} . K{sup -1} for NPX binding in the larger {gamma}CD cavity, implying that the structure of water is reorganized in the {beta}CD binding reactions but not reorganized in the {gamma}CD binding reactions. Comparison of the fluorescence enhancements of FLP and NAB upon transferring from the aqueous buffer to isopropanol with the maximum fluorescence enhancements observed for their {beta}CD binding reactions indicated that some localized water was retained in the FLP-{beta}CD complex and almost none in the NAB-{beta}CD complex. No fluorescence change occurs with drug binding in the larger {gamma}CD cavity, indicating the retention of the bulk water environment in the drug-{gamma}CD complex. Since the specific drug binding interactions are essentially the same for {beta}CD and {gamma}CD, these differences in the retention of bulk water may account for the enthalpically driven nature of the {beta}CD binding reactions and the entropically driven nature of the {gamma}CD binding reactions.

  8. Effect of Cyclodextrin Complexation of Curcumin on its Solubility and Antiangiogenic and Anti-inflammatory Activity in Rat Colitis Model

    OpenAIRE

    Yadav, Vivek R.; Suresh, Sarasija; Devi, Kshama; Yadav, Seema

    2009-01-01

    The purpose of the study was to prepare and evaluate the anti-inflammatory activity of cyclodextrin (CD) complex of curcumin for the treatment of inflammatory bowel disease (IBD) in colitis-induced rat model. Inclusion complexes of curcumin were prepared by common solvent and kneading methods. These complexes were further evaluated for increase in solubility of poorly soluble curcumin. The inclusion complexes were characterized for enhancement in solubility, in vitro dissolution, surface morp...

  9. Improvement of Aripiprazole Solubility by Complexation with (2-Hydroxy)propyl-β-cyclodextrin Using Spray Drying Technique

    OpenAIRE

    Mihajlovic, Tijana; Kachrimanis, Kyriakos; Graovac, Adrijana; Djuric, Zorica; Ibric, Svetlana

    2012-01-01

    Due to the fact that the number of new poorly soluble active pharmaceutical ingredients is increasing, it is important to investigate the possibilities of improvement of their solubility in order to obtain a final pharmaceutical formulation with enhanced bioavailability. One of the strategies to increase drug solubility is the inclusion of the APIs in cyclodextrins. The aim of this study was to investigate the possibility of aripiprazole solubility improvement by inclusion in (2-hydroxy)propy...

  10. Pharmaceutical Composition of Valsartan: β-Cyclodextrin: Physico–Chemical Characterization and Anti-Hypertensive Evaluation

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Matos Jensen

    2010-06-01

    Full Text Available Valsartan, a water-insoluble drug, is mainly used in the treatment of hypertension albeit with reduced oral bioavailability. The aim of work was to develop a valsartan:β-cyclodextrin (VAL:β-CD pharmaceutical composition in order to improve its water solubility and bioavailability. The VAL:β-CD complexes were prepared by the kneading, solid dispersion and freeze-drying methods, of which the freeze-drying method (FDY was found to be the best to prepare an inclusion complex. A physical mixtyure PM was also prepared. Complexes were characterized by thermal analysis, Fourier transformed- infrared (FTIR spectroscopy, Powder X-ray diffractometry, intrinsic dissolution and NMR (2D-ROESY. Phase-solubility analysis showed AL-type diagrams with β-cyclodextrin (β-CD. Microcalorimetric titrations suggested the formation of 1:1 inclusion complex between VAL and β-CD. The apparent stability constants K1:1 calculated from phase-solubility plots were 165.4 M-1 (298 K, 145.0 M-1 (303 K and 111.3 M-1 (310 K. In vivo experiments in rats showed that reduction in arterial pressure for the FDY complex is better than with valsartan used alone. The better activity of FDY can be attributed to the higher solubility of valsartan after inclusion in the cyclodextrin cavity, as suggest by the intrinsic dissolution studies.

  11. Nuclear magnetic resonance study of naproxen and ibuprofen interaction with β - cyclodextrin in solution

    International Nuclear Information System (INIS)

    Bogdan, M.; Farcas, S.I.; Bojita, M.

    1999-01-01

    Modern biomedical research leads to revealing insights into the molecular activity of many therapeutic molecules. An interesting activity at the organ or cellular level, however, is not sufficient to turn a molecule into an usable drug. Problems such as limited solubility or stability can make impossible to transpose interesting in vitro properties of an experimental compound to an in vivo situation. Various physico - chemical methods have been used to improve aqueous solubility of poorly soluble drugs and to increase the life of unstable drugs, such as adjustment of pH of the aqueous solution, the complexation of drugs with various cyclodextrins and the formation of gels or emulsions. In this paper, we report a 1 H NMR study of the complex formed between naproxen and ibuprofen with β - cyclodextrin in aqueous medium. Our results confirm that inclusion occurs. Analysis of our data by the continuous variation method shows that the complexes have 1 : 1 stoichiometry. The association constants for the 1 : 1 complexes were calculated at different temperatures by non - linear least squares regression analysis of the observed changes in the chemical shifts of the drugs and β - cyclodextrin 1 H NMR lines as a function of β - cyclodextrin concentration. Thermodynamic parameters were obtained by using the temperature dependence of the association constants. Finally, based on the experimentally obtained data, the most probable structure of the investigated complexes is discussed. (authors)

  12. Piroxicam-β-cyclodextrin: a GI safer piroxicam.

    Science.gov (United States)

    Scarpignato, C

    2013-01-01

    Although NSAIDs are very effective drugs, their use is associated with a broad spectrum of adverse reactions in the liver, kidney, cardiovascular (CV) system, skin and gut. Gastrointestinal (GI) side effects are the most common and constitute a wide clinical spectrum ranging from dyspepsia, heartburn and abdominal discomfort to more serious events such as peptic ulcer with life-threatening complications of bleeding and perforation. The appreciation that CV risk is also increased further complicates the choices of physicians prescribing anti-inflammatory therapy. Despite prevention strategies should be implemented in patients at risk, gastroprotection is often underused and adherence to treatment is generally poor. A more appealing approach would be therefore to develop drugs that are devoid of or have reduced GI toxicity. Gastro- duodenal mucosa possesses many defensive mechanisms and NSAIDs have a deleterious effect on most of them. This results in a mucosa less able to cope with even a reduced acid load. NSAIDs cause gastro-duodenal damage, by two main mechanisms: a physiochemical disruption of the gastric mucosal barrier and systemic inhibition of gastric mucosal protection, through inhibition of cyclooxygenase (COX, PG endoperoxide G/H synthase) activity of the GI mucosa. However, against a background of COX inhibition by anti-inflammatory doses of NSAIDs, their physicochemical properties, in particular their acidity, underlie the topical effect leading to short-term damage. It has been shown that esterification of acidic NSAIDs suppresses their gastrotoxicity without adversely affecting anti-inflammatory activity. Another way to develop NSAIDs with better GI tolerability is to complex these molecules with cyclodextrins (CDs), giving rise to so-called "inclusion complexes" that can have physical, chemical and biological properties very different from either those of the drug or the cyclodextrin. Complexation of NSAIDs with β-cyclodextrin potentially leads to a

  13. Effects of cyclodextrin glycosiltransferase modified starch and cyclodextrins on plasma glucose and lipids metabolism in mice

    Science.gov (United States)

    The potential functional and nutritional benefits of granular starch treated with cyclodextrin glycosyltransferase (CGTase) and the released cyclodextrins (CDs) were explored in in vivo studies. The metabolic effects of diets in the C57BL/6J mouse containing native and enzymatically modified corn st...

  14. A novel preparation of methyl-β-cyclodextrin from dimethyl carbonate and β-cyclodextrin

    DEFF Research Database (Denmark)

    Gan, Yongjiang; Zhang, Yimin; Xiao, Chuanhao

    2011-01-01

    A novel green synthesis process about methyl-β-cyclodextrin has been investigated through the reaction between β-cyclodextrin and dimethyl carbonate by anhydrous potassium carbonate as catalyst in DMF. The influence of experimental factors including the molar ratio of dimethyl carbonate to β-cycl...

  15. NMR Investigation of the complexation of (S-2-isopropyl- 1-(o-nitrophenylsulfonylaziridine with -cyclodextrin

    Directory of Open Access Journals (Sweden)

    Mohamed Z. Sliman

    2014-07-01

    Full Text Available Aziridines are known to undergo hydrolysis in the presence of cyclodextrins, whereas the latter are largely investigated as potential vectors of biologically active compounds. Despite this easy cyclodextrin-induced cleavage of aziridines in aqueous medium, it was of interest to find out a model aziridine derivative that would be sufficiently water-stable and form a stable complex with b-cyclodextrin in aqueous medium, so that it could be used as a reference in future formulations or vectorization work. Among compounds we have investigated, we found out that only (S-2-isopropyl-1-(o-nitrophenylsulfonylaziridine complied with the above-mentioned solubility and stability requirements. NMR studies of the inclusion complex of this derivative with b-cyclodextrin provided useful parameters related to the stoichiometry of the complex and the association constant Ka. The geometry of the complex was assessed by 2D-ROESY experiments, suggesting a deep insertion of the aziridine into the cavity of b-cyclodextrin.

  16. Study on the complexation of isoquercitrin with β-cyclodextrin and its derivatives by spectroscopy

    International Nuclear Information System (INIS)

    Wang Yunlong; Qiao Xiaona; Li Wenchao; Zhou Yehong; Jiao Yong; Yang Cheng; Dong Chuan; Inoue, Yoshihisa; Shuang, Shaomin

    2009-01-01

    The inclusion complexes of isoquercitrin (IQ) with cyclodextrins (CDs) including β-cyclodextrin (β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD) and dimethyl-β-cyclodextrin (DM-β-CD) have been investigated using the methods of steady-state fluorescence, UV-vis absorption and induced circular dichroism. The stoichiometric ratio of the three complexes was found to be 1:1 and the stability constants (K) were estimated from spectrofluorometric titrations, as well as the thermodynamic parameters. Maximum inclusion ability was measured in the case of DM-β-CD due to the increased hydrophobicity of the host cavity, followed by HP-β-CD and β-CD. The effect of pH on the complexation process was also quantitatively assessed. IQ exists in different molecular forms depending on pH and β-CDs were most suitable for inclusion of the neutral form of IQ. The phase-solubility diagrams obtained with β-CD, HP-β-CD and DM-β-CD were all classical A L type. And DM-β-CD provided the best solubility enhancement, 12.3-fold increase compared to 2.8- and 7.5-fold increase for β-CD and HP-β-CD. The apparent stability constants obtained from the solubility data at 25 deg. C were comparable with those obtained from the fluorescence assays. Moreover, 1 H NMR was carried out, which revealed that the IQ favorably inserted into the inner cavity from the chromone part instead of the phenyl part, which was in agreement with molecular modeling studies.

  17. Effect of cyclodextrin complexation of curcumin on its solubility and antiangiogenic and anti-inflammatory activity in rat colitis model.

    Science.gov (United States)

    Yadav, Vivek R; Suresh, Sarasija; Devi, Kshama; Yadav, Seema

    2009-01-01

    The purpose of the study was to prepare and evaluate the anti-inflammatory activity of cyclodextrin (CD) complex of curcumin for the treatment of inflammatory bowel disease (IBD) in colitis-induced rat model. Inclusion complexes of curcumin were prepared by common solvent and kneading methods. These complexes were further evaluated for increase in solubility of poorly soluble curcumin. The inclusion complexes were characterized for enhancement in solubility, in vitro dissolution, surface morphology, infrared, differential scanning calorimetry, and X-ray studies. Solubility, phase solubility, and in vitro dissolution studies showed that curcumin has higher affinity for hydroxypropyl-beta-CD (HPbetaCD) than other CDs. HPbetaCD complex of curcumin was further investigated for its antiangiogenic and anti-inflammatory activity using chick embryo and rat colitis model. HPbetaCD complex of curcumin proved to be a potent angioinhibitory compound, as demonstrated by inhibition of angiogenesis in chorioallantoic membrane assay. Curcumin- and HPbetaCD-treated rats showed a faster weight gain compared to dextran sulfate solution (DSS) controls. Whole colon length appeared to be significantly longer in HPbetaCD-treated rats than pure curcumin and DSS controls. An additional finding in the DSS-treated rats was the predominance of eosinophils in the chronic cell infiltrate. Decreased mast cell numbers in the mucosa of the colon of CD of curcumin- and pure-curcumin-treated rats was observed. This study concluded that the degree of colitis caused by administration of DSS was significantly attenuated by CD of curcumin. Being a nontoxic natural dietary product, curcumin could be useful in the therapeutic strategy for IBD patients.

  18. SPECTROPHOTOMETRIC STUDIES OF SANGUINARINE-Β-CYCLODEXTRIN COMPLEX FORMATION

    Directory of Open Access Journals (Sweden)

    Veaceslav Boldescu

    2008-06-01

    Full Text Available The main aim of this study was to investigate the influence of pH and the presence of hydrophilic polymer polyvinylpyrrolidone on the formation of sanguinarine-β-cyclodextrin (SANG-β-CD inclusion complex. Spectrophotometric studies of the SANG-β-CD systems in the presence and without 0.1 % PVP at the pH 5.0 did not show any evidence of the complex formation. However, the same systems showed several obvious evidences at the pH 8.0: the hyperchromic and the hypochromic effects and the presence of the isosbestic point in the region of 200 – 210 nm. The association constants calculated by three linear methods: Benesi-Hildebrand, Scott and Scatchard, were two times higher for the systems with addition of 0.1% PVP than for the systems without it.

  19. Cyclodextrin-Containing Polymers: Versatile Platforms of Drug Delivery Materials

    Directory of Open Access Journals (Sweden)

    Jeremy D. Heidel

    2012-01-01

    Full Text Available Nanoparticles are being widely explored as potential therapeutics for numerous applications in medicine and have been shown to significantly improve the circulation, biodistribution, efficacy, and safety profiles of multiple classes of drugs. One leading class of nanoparticles involves the use of linear, cyclodextrin-containing polymers (CDPs. As is discussed in this paper, CDPs can incorporate therapeutic payloads into nanoparticles via covalent attachment of prodrug/drug molecules to the polymer (the basis of the Cyclosert platform or by noncovalent inclusion of cationic CDPs to anionic, nucleic acid payloads (the basis of the RONDEL platform. For each of these two approaches, we review the relevant molecular architecture and its rationale, discuss the physicochemical and biological properties of these nanoparticles, and detail the progress of leading drug candidates for each that have achieved clinical evaluation. Finally, we look ahead to potential future directions of investigation and product candidates based upon this technology.

  20. Cyclodextrin-Based [1]Rotaxanes on Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Yanli Zhao

    2012-08-01

    Full Text Available Transformation of mechanically interlocked molecules (e.g., rotaxanes and catenanes into nanoscale materials or devices is an important step towards their real applications. In our current work, an azobenzene-modified β-cyclodextrin (β-CD derivative that can form a self-inclusion complex in aqueous solution was prepared. The self-included β-CD derivative was then functionalized onto a gold nanoparticle (AuNP surface via a ligand-exchange reaction in aqueous solution, leading to the formation of AuNP-[1]rotaxane hybrids. Corresponding non-self-included β-CD derivative functionalized AuNPs were also developed in a DMF/H2O mixture solution for control experiments. These hybrids were fully characterized by UV-vis and circular dichroism spectroscopies, together with transmission electron microscopy (TEM. The competitive binding behavior of the hybrids with an adamantane dimer was investigated.

  1. Cyclodextrins

    DEFF Research Database (Denmark)

    Stojanov, Mladen; Nielsen, Hanne Mørck; Larsen, Kim Lambertsen

    2012-01-01

    in the phase solubility studies explaining the difference in the association constants between the two methods. Due to very low signal to noise ratio, no information was extracted for bromhexine/γ-CD solutions from the ITC measurements. The effect on cellular viability of the CDs ranked β- > α- > SBE-β- > γ...

  2. Models of pesticides inside cavities of molecular dimensions. A role of the guest inclusion in the dechlorination process

    Czech Academy of Sciences Publication Activity Database

    Hromadová, Magdaléna; Pospíšil, Lubomír; Fanelli, N.; Giannarelli, S.

    2005-01-01

    Roč. 21, č. 5 (2005), s. 1923-1930 ISSN 0743-7463 R&D Projects: GA ČR(CZ) GP203/02/P082; GA ČR(CZ) GA203/03/0821 Grant - others:GA MŠk(CZ) 1P04OCD31.001 Institutional research plan: CEZ:AV0Z40400503 Keywords : beta-cyclodextrin * electrochemical reduction * gamma-cyclodextrin * alpha-cyclodextrin Subject RIV: CG - Electrochemistry Impact factor: 3.705, year: 2005

  3. Structure–efficiency relationships of cyclodextrin scavengers in the hydrolytic degradation of organophosphorus compounds

    Directory of Open Access Journals (Sweden)

    Sophie Letort

    2017-03-01

    Full Text Available New derivatives of cyclodextrins were prepared in order to determine the relative importance of the structural key elements involved in the degradation of organophosphorus nerve agents. To avoid a competitive inclusion between the organophosphorus substrate and the iodosobenzoate group, responsible for its degradation, the latter group had to be covalently bound to the cyclodextrin scaffold. Although the presence of the α nucleophile iodosobenzoate was a determinant in the hydrolysis process, an imidazole group was added to get a synergistic effect towards the degradation of the agents. The degradation efficiency was found to be dependent on the relative position of the heterocycle towards the reactive group as well as on the nature of the organophosphorus derivative.

  4. Novel β-cyclodextrin-eosin conjugates.

    Science.gov (United States)

    Benkovics, Gábor; Afonso, Damien; Darcsi, András; Béni, Szabolcs; Conoci, Sabrina; Fenyvesi, Éva; Szente, Lajos; Malanga, Milo; Sortino, Salvatore

    2017-01-01

    Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin-EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin-EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

  5. Cyclodextrins in delivery systems: Applications

    Directory of Open Access Journals (Sweden)

    Gaurav Tiwari

    2010-01-01

    Full Text Available Cyclodextrins (CDs are a family of cyclic oligosaccharides with a hydrophilic outer surface and a lipophilic central cavity. CD molecules are relatively large with a number of hydrogen donors and acceptors and, thus in general, they do not permeate lipophilic membranes. In the pharmaceutical industry, CDs have mainly been used as complexing agents to increase aqueous solubility of poorly soluble drugs and to increase their bioavailability and stability. CDs are used in pharmaceutical applications for numerous purposes, including improving the bioavailability of drugs. Current CD-based therapeutics is described and possible future applications are discussed. CD-containing polymers are reviewed and their use in drug delivery is presented. Of specific interest is the use of CD-containing polymers to provide unique capabilities for the delivery of nucleic acids. Studies in both humans and animals have shown that CDs can be used to improve drug delivery from almost any type of drug formulation. Currently, there are approximately 30 different pharmaceutical products worldwide containing drug/CD complexes in the market.

  6. Biophysical aspects of cyclodextrin interaction with paraoxon.

    Science.gov (United States)

    Soni, Sunil-Datta; Bhonsle, Jayendra B; Garcia, Gregory E

    2014-03-01

    Cyclodextrins are torus-shaped polymers of glucose that can bind organophosphorous compounds such as nerve agents and pesticides. We demonstrate here that cyclodextrin can bind up to two paraoxon molecules with a K(av) of 6775 M(-1). Molecular modeling shows that the paraoxon appears to bind in polar opposite orientation and have an average binding energy of -89 Kcals/mol. Published 2013. This article is a U.S. Government work and is in the public domain in the USA. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  7. Studies on the complexation of diclofenac sodium with β-cyclodextrin: Influence of method of preparation

    Science.gov (United States)

    Das, Subhraseema; Subuddhi, Usharani

    2015-11-01

    Inclusion complexes of diclofenac sodium (DS) with β-cyclodextrin (β-CD) were prepared in order to improve the solubility, dissolution and oral bioavailability of the poorly water soluble drug. The effect of method of preparation of the DS/β-CD inclusion complexes (ICs) was investigated. The ICs were prepared by microwave irradiation and also by the conventional methods of kneading, co-precipitation and freeze drying. Though freeze drying method is usually referred to as the gold standard among all the conventional methods, its long processing time limits the utility. Microwave irradiation accomplishes the process in a very short span of time and is a more environmentally benign method. Better efficacy of the microwaved inclusion product (MW) was observed in terms of dissolution, antimicrobial activity and antibiofilm properties of the drug. Thus microwave irradiation can be utilized as an improved, time-saving and cost-effective method for the generation of DS/β-CD inclusion complexes.

  8. Properties of cationic monosubstituted tetraalkylammonium cyclodextrin derivatives – their stability, complexation ability in solution or when deposited on solid anionic surface

    Czech Academy of Sciences Publication Activity Database

    Popr, M.; Filippov, Sergey K.; Matushkin, Nikolai; Dian, J.; Jindřich, J.

    2015-01-01

    Roč. 11, February (2015), s. 192-199 ISSN 1860-5397 R&D Projects: GA ČR GAP108/12/0640 Institutional support: RVO:61389013 Keywords : cyclodextrins * inclusion properties * solid surface Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.697, year: 2015

  9. BETA digital beta radiometer

    International Nuclear Information System (INIS)

    Borovikov, N.V.; Kosinov, G.A.; Fedorov, Yu.N.

    1989-01-01

    Portable transportable digital beta radiometer providing for measuring beta-decay radionuclide specific activity in the range from 5x10 -9 up to 10 -6 Cu/kg (Cu/l) with error of ±25% is designed and introduced into commercial production for determination of volume and specific water and food radioactivity. The device specifications are given. Experience in the BETA radiometer application under conditions of the Chernobyl' NPP 30-km zone has shown that it is convenient for measuring specific activity of the order of 10 -8 Cu/kg, and application of a set of different beta detectors gives an opportunity to use it for surface contamination measurement in wide range of the measured value

  10. Cyclodextrin-based nanosponges as drug carriers

    Directory of Open Access Journals (Sweden)

    Francesco Trotta

    2012-11-01

    Full Text Available Cyclodextrin-based nanosponges, which are proposed as a new nanosized delivery system, are innovative cross-linked cyclodextrin polymers nanostructured within a three-dimensional network. This type of cyclodextrin polymer can form porous insoluble nanoparticles with a crystalline or amorphous structure and spherical shape or swelling properties. The polarity and dimension of the polymer mesh can be easily tuned by varying the type of cross-linker and degree of cross-linking. Nanosponge functionalisation for site-specific targeting can be achieved by conjugating various ligands on their surface. They are a safe and biodegradable material with negligible toxicity on cell cultures and are well-tolerated after injection in mice. Cyclodextrin-based nanosponges can form complexes with different types of lipophilic or hydrophilic molecules. The release of the entrapped molecules can be varied by modifying the structure to achieve prolonged release kinetics or a faster release. The nanosponges could be used to improve the aqueous solubility of poorly water-soluble molecules, protect degradable substances, obtain sustained delivery systems or design innovative drug carriers for nanomedicine.

  11. Synthesis of per-6-guanidinylated cyclodextrins

    Czech Academy of Sciences Publication Activity Database

    Kraus, Tomáš; Buděšínský, Miloš; Závada, Jiří

    2006-01-01

    Roč. 47, č. 5 (2006), s. 679-681 ISSN 0040-4039 R&D Projects: GA ČR(CZ) GA203/03/0087; GA ČR(CZ) GP203/01/D082 Institutional research plan: CEZ:AV0Z40550506 Keywords : cyclodextrins * guanidine Subject RIV: CC - Organic Chemistry Impact factor: 2.509, year: 2006

  12. Spectroscopic investigation of the structures of dialkyl tartrates and their cyclodextrin complexes.

    Science.gov (United States)

    Zhang, Peng; Polavarapu, Prasad L

    2007-02-08

    Structures of three dialkyl tartrates, namely, dimethyl tartrate, diethyl tartrate, and diisopropyl tartrate, in CCl4, dimethyl sulfoxide (DMSO)/DMSO-d6, and H2O/D2O solvents have been investigated using vibrational absorption (VA), vibrational circular dichroism (VCD), and optical rotatory dispersion (ORD). VA, VCD, and ORD spectra are found to be dependent on the solvent used. Density functional theory (DFT) calculations are used to interpret the experimental data in CCl4 and DMSO. The trans-COOR conformer with hydrogen bonding between the OH group and the C=O group attached to the same chiral carbon is dominant for dialkyl tartrates both in vacuum and in CCl4. The experimental VA, VCD, and ORD data of dialkyl-D-tartrates in CCl4 correlated well with those predicted for dimethyl-(S,S)-tartrate molecule as both isolated and solvated in CCl4. In DMSO solvent, dialkyl tartrate molecules favor formation of intermolecular hydrogen bonding with DMSO molecules. Clusters of dimethyl-(S,S)-tartrate, with one molecule of dimethyl-(S,S)-tartrate hydrogen bonded to two DMSO molecules, are used for the DFT calculations. A trans-COOR cluster and a trans-H cluster are needed to obtain a reasonable agreement between the predicted and experimental data of dimethyl tartrate in DMSO solvent. VA, VCD, and optical rotations are also measured for dialkyl tartrate-cyclodextrin complexes. It is noted that these properties are barely affected by complexation of dialkyl tartrates with cyclodextrins, indicating weak interaction between tartrates and cyclodextrin. Binding constants of alpha-CD and beta-CD with diethyl L-tartrate in both H2O and DMSO have been determined using isothermal titration calorimetry technique. The smaller binding constants (less than 100) confirmed the weak interaction between tartrates and cyclodextrin in the solution state.

  13. Cyclodextrins improving the physicochemical and pharmacological properties of antidepressant drugs: a patent review.

    Science.gov (United States)

    Diniz, Tâmara Coimbra; Pinto, Tiago Coimbra Costa; Menezes, Paula Dos Passos; Silva, Juliane Cabral; Teles, Roxana Braga de Andrade; Ximenes, Rosana Christine Cavalcanti; Guimarães, Adriana Gibara; Serafini, Mairim Russo; Araújo, Adriano Antunes de Souza; Quintans Júnior, Lucindo José; Almeida, Jackson Roberto Guedes da Silva

    2018-01-01

    Depression is a serious mood disorder and is one of the most common mental illnesses. Despite the availability of several classes of antidepressants, a substantial percentage of patients are unresponsive to these drugs, which have a slow onset of action in addition to producing undesirable side effects. Some scientific evidence suggests that cyclodextrins (CDs) can improve the physicochemical and pharmacological profile of antidepressant drugs (ADDs). The purpose of this paper is to disclose current data technology prospects involving antidepressant drugs and cyclodextrins. Areas covered: We conducted a patent review to evaluate the antidepressive activity of the compounds complexed in CDs, and we analyzed whether these complexes improved their physicochemical properties and pharmacological action. The present review used 8 specialized patent databases for patent research, using the term 'cyclodextrin' combined with 'antidepressive agents' and its related terms. We found 608 patents. In the end, considering the inclusion criteria, 27 patents reporting the benefits of complexation of ADDs with CDs were included. Expert opinion: The use of CDs can be considered an important tool for the optimization of physicochemical and pharmacological properties of ADDs, such as stability, solubility and bioavailability.

  14. Colorimetric detection of riboflavin by silver nanoparticles capped with β-cyclodextrin-grafted citrate.

    Science.gov (United States)

    Ma, Qi; Song, Jinping; Zhang, Sufang; Wang, Meifang; Guo, Yong; Dong, Chuan

    2016-12-01

    β-Cyclodextrin-grafted citrate was used for the first time as a stabilizer and reducer to prepare silver nanoparticles (AgNPs). The as-synthesized AgNPs were further characterized by UV-vis absorption spectroscopy, powder X-ray diffraction spectroscopy, and transmission electron microscopy. The results show that the presence of riboflavin caused severe aggregation of the nanoparticles, thereby inducing a colour change from yellow to red. 1 H NMR further verified the formation of non-inclusion complexes between riboflavin and β-cyclodextrin-grafted citrate. Hydrogen bond was considered the main driving force of the interaction between the riboflavin and external rim of β-cyclodextrin. Based on these observations, the as-synthesized AgNPs were utilized to develop a novel colorimetric sensor for riboflavin detection. This colorimetric probe showed excellent selectivity and high sensitivity for riboflavin with a detection limit of 167nM. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Methoxypropylamino β-cyclodextrin clicked AC regioisomer for enantioseparations in capillary electrophoresis

    International Nuclear Information System (INIS)

    Zhou, Jie; Wang, Yiying; Liu, Yun; Tang, Jian; Tang, Weihua

    2015-01-01

    Highlights: In this paper, we demonstrate: • The click synthesis of a AC regioisomer cationic cyclodextrin (CD) as chiral selector. • The good enantioselectivities (chiral resolution over 5) for acidic racemates. • The strong chiral recognition of new CD by NMR study. • Baseline enantioseparation of some acidic racemates at CD of 0.5 mM. - Abstract: In this work, a novel methoxypropylamino β-cyclodextrin (β-CD) clicked AC regioisomer, 6 A -4-hydroxyethyl-1,2,3-triazolyl-6 C -3-methoxypropylamino β-cyclodextrin (HETz-MPrAMCD), was synthesized via nucleophilic addition and click chemistry. The chiral separation ability of this AC regioisomer cationic CD was evaluated toward 7 ampholytic and 13 acidic racemates by capillary electrophoresis. Dependence of enantioselectivity and resolution on buffer pH (5.5–8.0) and chiral selector concentration (0.5–7.5 mM) was investigated. Enantioselectivities (α ≥ 1.05) could be achieved for most analytes under optimal conditions except dansyl-DL-noreleucine and dansyl-DL-serine. The highest resolutions for 2-chloromandelic acid p-hydroxymandelic acid were 15.6 and 9.7 respectively. The inclusion complexation between HETz-MPrAMCD and each 3-phenyllactic acid enantiomer was also revealed with nuclear magnetic resonance study

  16. Methoxypropylamino β-cyclodextrin clicked AC regioisomer for enantioseparations in capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jie; Wang, Yiying; Liu, Yun; Tang, Jian; Tang, Weihua, E-mail: whtang@mail.njust.edu.cn

    2015-04-08

    Highlights: In this paper, we demonstrate: • The click synthesis of a AC regioisomer cationic cyclodextrin (CD) as chiral selector. • The good enantioselectivities (chiral resolution over 5) for acidic racemates. • The strong chiral recognition of new CD by NMR study. • Baseline enantioseparation of some acidic racemates at CD of 0.5 mM. - Abstract: In this work, a novel methoxypropylamino β-cyclodextrin (β-CD) clicked AC regioisomer, 6{sup A}-4-hydroxyethyl-1,2,3-triazolyl-6{sup C}-3-methoxypropylamino β-cyclodextrin (HETz-MPrAMCD), was synthesized via nucleophilic addition and click chemistry. The chiral separation ability of this AC regioisomer cationic CD was evaluated toward 7 ampholytic and 13 acidic racemates by capillary electrophoresis. Dependence of enantioselectivity and resolution on buffer pH (5.5–8.0) and chiral selector concentration (0.5–7.5 mM) was investigated. Enantioselectivities (α ≥ 1.05) could be achieved for most analytes under optimal conditions except dansyl-DL-noreleucine and dansyl-DL-serine. The highest resolutions for 2-chloromandelic acid p-hydroxymandelic acid were 15.6 and 9.7 respectively. The inclusion complexation between HETz-MPrAMCD and each 3-phenyllactic acid enantiomer was also revealed with nuclear magnetic resonance study.

  17. Cyclodextrin Nanoparticles Bearing 8-Hydroxyquinoline Ligands as Multifunctional Biomaterials.

    Science.gov (United States)

    Oliveri, Valentina; Bellia, Francesco; Vecchio, Graziella

    2017-03-28

    Cyclodextrins are used as building blocks for the development of a host of polymeric biomaterials. The cyclodextrin polymers have found numerous applications as they exhibit unique features such as mechanical properties, stimuli responsiveness and drug loading ability. Notwithstanding the abundance of cyclodextrin polymers studied, metal-chelating polymers based on cyclodextrins have been poorly explored. Herein we report the synthesis and the characterization of the first metal-chelating β-cyclodextrin polymer bearing 8-hydroxyquinoline ligands. The metal ions (Cu 2+ or Zn 2+ ) can modulate the assembly of the polymer nanoparticles. Moreover, the protective activity of the new chelating polymer against self- and metal-induced Aβ aggregation and free radical species are significantly higher than those of the parent compounds. These synergistic effects suggest that the incorporation of hydroxyquinoline moieties into a soluble β-cyclodextrin polymer could represent a promising strategy to design multifunctional biomaterials. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Displacement of Drugs From Cyclodextrin Complexes by Bile Salts

    DEFF Research Database (Denmark)

    Olesen, Niels Erik; Westh, Peter; Holm, Rene

    2016-01-01

    of drug from the cyclodextrin cavity by bile salts present in the small intestine. As bile salts in the intestine are present at concentrations above the critical micelle concentration, an understanding of the interaction between cyclodextrins and bile salts at such supramicellar concentrations (SMC......) is required for a better biopharmaceutical understanding of the release mechanism from orally dosed cyclodextrin complexes. To address this, experiments were conducted by isothermal titration calorimetry to determine how various b-cyclodextrins and bile salt interacts at SMC. Combined analysis of the current...... results and earlier data demonstrated that direct interactions between bile salt micelles and cyclodextrin were negligible. From this knowledge, an extended form of the UCD was suggested to describe the concentration of cyclodextrins to achieve full drug solubilization in the intestine where bile salts...

  19. Nootkatone encapsulation by cyclodextrins: Effect on water solubility and photostability.

    Science.gov (United States)

    Kfoury, Miriana; Landy, David; Ruellan, Steven; Auezova, Lizette; Greige-Gerges, Hélène; Fourmentin, Sophie

    2017-12-01

    Nootkatone (NO) is a sesquiterpenoid volatile flavor, used in foods, cosmetics and pharmaceuticals, possessing also insect repellent activity. Its application is limited because of its low aqueous solubility and stability; this could be resolved by encapsulation in cyclodextrins (CDs). This study evaluated the encapsulation of NO by CDs using phase solubility studies, Isothermal Titration Calorimetry, Nuclear Magnetic Resonance spectroscopy and molecular modeling. Solid CD/NO inclusion complex was prepared and characterized for encapsulation efficiency and loading capacity using UV-Visible. Thermal properties were investigated by thermogravimetric-differential thermal analysis and release studies were performed using multiple headspace extraction. Formation constants (K f ) proved the formation of stable inclusion complexes. NO aqueous solubility, photo- and thermal stability were enhanced and the release could be insured from solid complex in aqueous solution. This suggests that CDs are promising carrier to improve NO properties and, consequently, to enlarge its use in foods, cosmetics, pharmaceuticals and agrochemicals preparations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Effect of ?-cyclodextrin on Rheological Properties of some Viscosity Modifiers

    OpenAIRE

    Rao, G. Chandra Sekhara; Ramadevi, K.; Sirisha, K.

    2014-01-01

    Cyclodextrins are a group of novel excipients, extensively used in the present pharmaceutical industry. Sometimes they show significant interactions with other conventional additives used in the formulation of dosage forms. The effect of β-cyclodextrin on the rheological properties of aqueous solutions of some selected viscosity modifiers was studied in the present work. β-cyclodextrin showed two different types of effects on the rheology of the selected polymers. In case of natural polymers ...

  1. Mistura com excesso enantiomérico de 50% (S75-R25 de bupivacaína complexada com ciclodextrinas e anestesia por via subaracnóidea em ratos Mezcla con exceso enantiomérico de 50% (S75-R25 de bupivacaina con complejo de ciclodextrinas y anestesia por vía subaracnoidea en ratones Complexation of 50% enantiomeric excess (S75-R25 bupivacaine with cyclodextrins and spinal block anesthesia in rats

    Directory of Open Access Journals (Sweden)

    Daniele Ribeiro de Araujo

    2006-10-01

    concentraciones de HP-beta-CD y la temperatura. Fueron determinadas las constantes de afinidad (K por la HP-beta-CD y los parámetros termodinámicos para los complejos. Los bloqueos motor y sensitivo fueron evaluados en ratones, a través de la administración subaracnoidea de las formulaciones en la concentración clínica de 0,5%. RESULTADOS: La formación de complejos de inclusión se observó a través del aumento de la solubilidad acuosa del AL bajo diferentes temperaturas y concentraciones de HP-beta-CD. Las pruebas in vivo mostraron que S50-R50HP-beta-CD y S75-R25HP-beta-CD redujeron la latencia (p BACKGROUND AND OBJECTIVES: In order to prolong the action and reduce systemic toxicity, formulations of local anesthetic (LA complexed with cyclodextrins (CD have been developed. This study determined the physical-chemical characterization and evaluated the effects of inclusion complexes of racemic bupivacaine (S50-R50 and 50% enantiomeric excess (S75-R25 bupivacaine with hydroxypropil-beta-cyclodextrin (HP-beta-CD in rats, and comparing them with the solutions currently used in the clinical practice. METHODS: Inclusion complexation of S75-R25 with HP-beta-CD (equimolar ratio 1:1 was characterized by phase-solubility studies varying the concentrations of HP-beta-CD and the temperature. Affinity constants (K for HP-beta-CD and the thermodynamic parameters for complexation were determined. Motor and sensitive anesthesias were evaluated through the subarachnoid administration of the formulations in the concentration of 0.5%. RESULTS: Inclusion complexation was observed through the increase in aqueous solubility of LA in different temperatures and concentrations of HP-beta-CD. The in vivo tests demonstrated that S50-R50HP-beta-CD and S75-R25HP-beta-CD reduced latency (p < 0.001 without changing the recovery time of the motor block, time for maximal effect, and total effect of the drugs. Besides, both formulations increased the intensity (1.5 times, p < 0.001 and prolonged the

  2. In vitro photobiochemical characterization of sulfobutylether-β-cyclodextrin formulation of bufexamac.

    Science.gov (United States)

    Seto, Yoshiki; Ochi, Masanori; Igarashi, Naoko; Inoue, Ryo; Oishi, Ami; Toida, Toshihiko; Yamada, Shizuo; Onoue, Satomi

    2011-06-01

    The present study aimed to modulate the photoreactivity of bufexamac, with a focus on photostability and phototoxicity, by forming an inclusion complex with sulfobutylether-β-cyclodextrin (SBECD). The photobiochemical properties of bufexamac were evaluated by reactive oxygen species (ROS) assay and using in vitro photogenotoxic assessment tools. To assess the inclusion properties of SBECD complex with bufexamac, a UV absorption spectroscopic study was also carried out. The influence of SBECD on the photoreactivity of bufexamac was analyzed by ROS assay and photostability test. From the photobiochemical data, superoxide generation from irradiated bufexamac indicated its photoreactivity; however, the photogenotoxic risk of bufexamac was negligible owing to low DNA-binding affinity and DNA-photocleaving activity. SBECD complex of bufexamac was formed, and the association constant of the complex was calculated to be 620M(-1). On the basis of the photochemical data on bufexamac co-existing with SBECD, ROS generation from irradiated bufexamac (200μM) was inhibited by SBECD at concentrations of over 20μM. The degradation constant of bufexamac in SBECD was decreased ca. 30% compared with that of bufexamac, suggesting improvement of its photostability. The phototoxic risk of bufexamac might be attenuated by SBECD complexation, and cyclodextrin inclusion complexes might be a useful approach for modulating the phototoxicity of drugs. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Application of cyclodextrins in textile processes;Aplicacao de ciclodextrinas em processos texteis

    Energy Technology Data Exchange (ETDEWEB)

    Andreaus, Juergen; Dalmolin, Mara C.; Oliveira Junior, Iguatemy B. de; Barcellos, Ivonete O., E-mail: jandr@furb.b [Universidade Regional de Blumenau, SC (Brazil). Dept. de Quimica

    2010-07-01

    Cyclodextrins (CDs) are water soluble cyclic sugars with a hydrophobic nanometric cavity that permits the formation of host/guest inclusion complexes with a large variety of molecules, alternating their physical-chemical properties. In the present review CD research related to the processing of textiles is revised and discussed. CDs may function as encapsulating, dispersing and levelling agents in the dyeing and washing of textiles. Furthermore they may be anchored to polymers and textile fibers in order to impart special properties such as odor reduction, UV protection or for the controlled release of perfumes, aromas, mosquito repellents or substances with therapeutical effects. (author)

  4. Antimicrobial coatings on polyethylene terephthalate based on curcumin/cyclodextrin complex embedded in a multilayer polyelectrolyte architecture.

    Science.gov (United States)

    Shlar, Ilya; Droby, Samir; Rodov, Victor

    2018-04-01

    Bacterial contamination is a growing concern worldwide. The aim of this work was to develop an antimicrobial coating based on curcumin-cyclodextrin inclusion complex and using polyethylene terephthalate (PET) film as a support matrix. After a pre-treatment aimed to provide sufficient electric charge to the PET surface, it was electrostatically coated with repeated multilayers comprising alternately deposited positively-charged poly-l-lysine (PLL) and negatively-charged poly-l-glutamic acid (PLGA) and carboxymethyl-β-cyclodextrin (CMBCD). The coatings had an architecture (PLL-PLGA) 6 -(PLL-PLGA-PLL-CMBCD) n , with the number of repeated multilayers n varying from 5 to 20. The CMBCD molecules were either covalently cross-linked using carbodiimide crosslinker chemistry or left unbound. The surface morphology, structure and elemental composition of the coatings were analysed by scanning electron microscopy and energy dispersive x-ray spectroscopy. To impart antimicrobial properties to the coatings they were loaded with a natural phenolic compound curcumin forming inclusion complexes with β-cyclodextrin. The non-cross-linked coatings showed bactericidal activity towards Escherichia coli in the dark, and this activity was further enhanced upon illumination with white light. Curcumin was released from the non-cross-linked coatings into an aqueous medium in the form of cyclodextrin inclusion complex. After the cross-linking, the coating lost its dark antimicrobial activity but retained the photodynamic properties. Stabilized cross-linked curcumin-loaded coatings can serve a basis for developing photoactivated antimicrobial surfaces controlling bacterial contamination and spread. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Cyclodextrin promotes atherosclerosis regression via macrophage reprogramming

    DEFF Research Database (Denmark)

    Zimmer, Sebastian; Grebe, Alena; Bakke, Siril S

    2016-01-01

    -containing lipoproteins in the subendothelial space causes a local overabundance of free cholesterol. Because cholesterol accumulation and deposition of cholesterol crystals (CCs) trigger a complex inflammatory response, we tested the efficacy of the cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (CD), a compound...... of CD as well as for augmented reverse cholesterol transport. Because CD treatment in humans is safe and CD beneficially affects key mechanisms of atherogenesis, it may therefore be used clinically to prevent or treat human atherosclerosis....

  6. Transfer action of cyclodextrin glycosyltransferase on starch

    Energy Technology Data Exchange (ETDEWEB)

    Kitahata, S; Okada, S [Osaka City Technical Research Inst. (Japan)

    1975-11-01

    The transglycosylation reaction of the cyclodextrin glycosyltransferase from Bacillus megaterium (No. 5 enzyme) and Bacillus macerans (BMA) were examined. No.5 enzyme was more efficient in transglycosylation reaction than BMA in the every acceptor employed in the present study. The order of the efficient acceptors for No. 5 enzyme was maltose (G2), glucose (G1), maltotriose (G3) and sucrose (GF). On the other hand, that found for BMA was G1, G2, GF and G3. The transglycosylation products to glucose formed by the action of No. 5 enzyme on starch were G2, G3, maltotetraose (G4), maltopentaose (G5), maltohexaose (G6) and maltoheptaose (G7) in the order of their quantities, while, in the case of BMA, they were G2, G3, G5, G7 = G4 and G6. The larger transglycosylation products to sucrose formed by the action of No. 5 enzyme on starch were maltosylfructose. On the other hand, that formed by the action of BMA was maltoheptaosylfructose. It was suggested that cyclodextrin glycosyltransferase could transfer the glucosyl residues to an acceptor directly from starch, as well as through cyclodextrin.

  7. Compatibility of hydroxypropyl-β-cyclodextrin with algal toxicity bioassays

    International Nuclear Information System (INIS)

    Fai, Patricia Bi; Grant, Alastair; Reid, Brian J.

    2009-01-01

    Numerous reports have indicated that hydrophobic organic compound bioaccessibility in sediment and soil can be determined by extraction using aqueous hydroxypropyl-β-cyclodextrin (HPCD) solutions. This study establishes the compatibility of HPCD with Selenastrum capricornutum and assesses whether its presence influences the toxicity of reference toxicants. Algal growth inhibition (72 h) showed no significant (P > 0.05) difference at HPCD concentrations up to and including 20 mM. HPCD presence did not influence the toxicity of the inorganic reference toxicant (ZnSO 4 ), with IC50 values of 0.82 μM and 0.85 μM, in the presence and absence of HPCD (20 mM), respectively. However, HPCD presence (20 mM) reduced the toxicity of 2,4-dichlorophenol and the herbicides diuron and isoproturon. These reductions were attributed to inclusion complex formation between the toxicants and the HPCD cavity. Liberation of complexed toxicants, by sample manipulation prior to toxicity assessment, is proposed to provide a sensitive, high throughput, bioassay that reflects compound bioaccessibility. - Compatibility of the biomimetic HPCD extraction method with algal cell growth inhibition bioassays to assess toxicity of reference toxicants and environmental relevant herbicides

  8. Enrichment and sensitive detection of polyphenolic compounds via β-cyclodextrin functionalized fluorescent gold nanorods

    International Nuclear Information System (INIS)

    Luo, Jinmei; Zhang, Jiahui; Lin, Jianxing; Wang, Jinhui; Yang, Peihui

    2015-01-01

    We report on a simple and rapid method for the enrichment of polyphenolic compounds (pPhCs) by means of gold nanorods whose surface was functionalized with a monolayer of β-cyclodextrin (β-CD-AuNRs) via thiol chemistry. Enrichment is based on the formation of inclusion complexes between pPhCs and β-cyclodextrin through hydrophobic interactions and hydrogen bonding. Fourier transform infrared spectroscopy, mass spectrometry, and transmission electron microscopy were applied to confirm the inclusion of the pPhCs. Moreover, binding leads to a quenching of the red fluorescence of the AuNRs. This effect can be applied to quantify the polyphenols mangiferin, chrysin, and daphnetin with detection limits at 5 nM, 15 nM, and 20 nM concentrations, respectively. Water samples were spiked with pPhCs, and their extraction by using β-CD-AuNRs gave recoveries ranging from 97.6 to 110.2 %. (author)

  9. International beta-dosimetry symposium. Program and abstracts

    International Nuclear Information System (INIS)

    1983-02-01

    Abstracts of the presentations at the symposium are contained in this volume. Problems associated with beta dosimetry, beta detectors and dosemeters, and current development programs are described. Each abstract has been indexed separately for inclusion in the Energy Data Base

  10. Inclusive pedagogy

    DEFF Research Database (Denmark)

    Korsgaard, Morten Timmermann; Skov Mortensen, Stig

    This article will present a case for a shift in perspective in inclusive education research towards a continentally inspired approach. Drawing on the age old distinction between continental and Anglo-American educational research the aim is to flesh out what a shift to a continental approach...... will entail, and why it might be beneficial to research in inclusive education...

  11. Social inclusion and inclusive education

    Directory of Open Access Journals (Sweden)

    Marsela Robo

    2014-07-01

    In line with global debate on social inclusion and exclusion, the author brings the way this debate has now pervaded both the official and development policy discourse in Albania.Social inclusion is considered as one of the priorities of the current government, with poverty reduction as its main focus, which will be ensured not only through economic development. In the end, the article focuses on the role of education as a very important and useful tool for ensuring social inclusion.Social inclusion through education, in particular through vocational education, considered by the author as the only way towards sustainable development of Albanian society.

  12. Complexation of tauro- and glyco-conjugated bile salts with alpha-cyclodextrin and hydroxypropyl-alpha-cyclodextrin studied by affinity capillary electrophoresis and molecular modelling

    DEFF Research Database (Denmark)

    Holm, Rene; Schönbeck, Jens Christian Sidney; Askjær, Sune

    2011-01-01

    The interaction of the bile salts taurocholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate, and glycochenodeoxycholate present in man, dog, and rat with α-cyclodextrin and 2-hydroxypropyl-α-cyclodextrin was investigated by mobility shift affinity capillary electrop...

  13. Speculative Betas

    OpenAIRE

    Harrison Hong; David Sraer

    2012-01-01

    We provide a model for why high beta assets are more prone to speculative overpricing than low beta ones. When investors disagree about the common factor of cash-flows, high beta assets are more sensitive to this macro-disagreement and experience a greater divergence-of-opinion about their payoffs. Short-sales constraints for some investors such as retail mutual funds result in high beta assets being over-priced. When aggregate disagreement is low, expected return increases with beta due to r...

  14. Fe-Ni Nanoparticles supported on carbon nanotube-co-cyclodextrin polyurethanes for the removal of trichloroethylene in water

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Rui W. M., E-mail: rkrause@uj.ac.za; Mamba, Bhekie B.; Dlamini, Langelihle N.; Durbach, Shane H. [University of Johannesburg, Department of Chemical Technology (South Africa)

    2010-02-15

    Nanoscale bimetallic particles of nickel on iron were supported on carbon nanotubes and then co-polymerized with {beta}-cyclodextrin (CNTs/CD) and the resulting polymers applied to the degradation of pollutants in water. The bimetallic nanoparticles (BMNPs) were first embedded on functionalized carbon nanotubes (f-CNTs) before being copolymerized with beta cyclodextrin ({beta}-CD) and hexamethylene diisocyanate (HMDI) forming a water-insoluble polyurethane. The particle size and distribution of BMNPs were determined by Transmission Electron Microscopy (TEM), and the surface area was determined by using the Brunauer-Emmett-Teller (BET) method. Energy dispersive X-ray spectroscopy (EDXS) was used to confirm the formation of the BMNPs. Degradation of trichloroethylene (TCE) as a model pollutant was studied and more than 98% reduction in TCE was achieved by the polymers. Polymers with the BMNPs maintained their efficiency in degrading TCE after several cycles compared to metal-free polymers. The degradation was monitored by using gas chromatography-mass spectrometry (GC-MS), while the production of chlorides was verified by using ion chromatography (IC). Atomic absorption spectroscopy (AAS) was employed to determine the possible leaching of the BMNPs from the polymer, and confirmed to be extremely low.

  15. Efficient mechanochemical synthesis of regioselective persubstituted cyclodextrins

    Directory of Open Access Journals (Sweden)

    Laszlo Jicsinszky

    2016-11-01

    Full Text Available A number of per-6-substituted cyclodextrin derivative syntheses have been effectively carried out in a planetary ball mill under solvent-free conditions. The preparation of Bridion® and important per-6-amino/thiocyclodextrin intermediates without polar aprotic solvents, a source of byproducts and persistent impurities, could be performed. Isolation and purification processes could also be simplified. Considerably lower alkylthiol/halide ratio were necessary to reach the complete reaction in comparison with thiourea or azide reactions. While the presented mechanochemical syntheses were carried out on the millimolar scale, they are easily scalable.

  16. Effects of modified β-cyclodextrin on thermal stability and conformation of lysozyme

    International Nuclear Information System (INIS)

    Kamiyama, Tadashi; Satoh, Megumi; Tateishi, Takahiro; Nojiri, Tomoaki; Takeuchi, Daisuke; Kimura, Takayoshi

    2012-01-01

    Highlights: ► Effects of cyclodextrin on stability and conformation of lysozyme were clarified. ► The CD influences the hydrophobic interaction of lysozyme by the inclusion. ► The CD relatively destabilized the folded state by stabilizing the unfolded state. ► The destabilization depends on the concentration and the substituent of CD. ► The conformation of lysozyme was more spread at unfolded state by inclusion of CD. - Abstract: Effects of cyclic oligosaccharide cyclodextrin (CD) on stability and conformation of lysozyme were clarified thermodynamically and rheologically by DSC, viscosity, and circular dichroism measurements. The modified β-CD relatively destabilized the folded state of lysozyme by stabilizing the unfolded state due to inclusion of hydrophobic part into the hydrophobic interior of CD. The order of higher destabilization effect was acetyl-β-CD > methyl-β-CD > hydroxypropyl-β-CD. Apparent number of bound CD to unfolded state for methyl-, hydroxypropyl-, and acetyl-β-CD is 6.7 ± 0.7, 4.2 ± 1.1, and 18.6 ± 4.3 and the binding constant is 5.5 ± 0.8, 6.7 ± 2.4, and 4.4 ± 1.2 L mol −1 , respectively. The viscosity for unfolded state was increased with an increase in the each modified β-CD concentration, suggesting that the inclusion of CD on a part of hydrophobic core at unfolded state leads to break the hydrophobic core, then lysozyme would be more spread structure. The substituent of CD can accelerate instability by directly breaking hydrogen bond and/or can restrain instability by increase in hydrophobic interaction. The fact that the each modified CDs has different destabilization effect shows a possibility to control the stability of protein by the substitution of CD.

  17. Biodegradable films containing α-tocopherol/β-cyclodextrin complex

    International Nuclear Information System (INIS)

    Motta, Caroline; Martelli, Silvia M.; Soldi, Valdir; Barreto, Pedro L.M.

    2011-01-01

    The growing environmental concern about pollution and the need to reduce dependence of plastic industry in relation to non-renewable resources has increased the interest of both researchers and industry in the use of biopolymers. In this work β-cyclodextrin/α-tocopherol complexes were prepared and characterized. In order to obtain polymeric active biofilms, the β-cyclodextrin/α-tocopherol complex was incorporated into a polymeric matrix of carboxymethylcellulose. The β-cyclodextrin/α-tocopherol complex was characterized through of X-ray diffraction and thermogravimetric analysis. The physicochemical properties of the films incorporated with the complex were evaluated through mechanical and colorimetric analysis and moisture sorption isotherm. (author)

  18. An Alginate/Cyclodextrin Spray Drying Matrix to Improve Shelf Life and Antioxidant Efficiency of a Blood Orange By-Product Extract Rich in Polyphenols: MMPs Inhibition and Antiglycation Activity in Dysmetabolic Diseases.

    Science.gov (United States)

    Lauro, Maria Rosaria; Crascì, Lucia; Giannone, Virgilio; Ballistreri, Gabriele; Fabroni, Simona; Sansone, Francesca; Rapisarda, Paolo; Panico, Anna Maria; Puglisi, Giovanni

    2017-01-01

    Alginate and β -cyclodextrin were used to produce easily dosable and spray-dried microsystems of a dried blood orange extract with antidysmetabolic properties, obtained from a by-product fluid extract. The spray-dried applied conditions were able to obtain a concentrate dried extract without the loss of AOA and with TPC and TMA values of 35-40% higher than that of the starting material. They were also effective in producing microparticles with 80-100% of encapsulation efficiency. The 2% sodium alginate was capable of improving the extract shelf life , while the beta-cyclodextrin (1 : 1 molar ratio with dried extract) prolonged the extract antioxidant efficiency by 6 hours. The good inhibition effect of the dried extract on the AGE formation and the MMP-2 and MMP-9 activity is presumably due to a synergic effect exerted by both anthocyanin and bioflavonoid extract compounds and was improved by the use of alginate and cyclodextrin.

  19. Inclusive pedagogy

    DEFF Research Database (Denmark)

    Korsgaard, Morten Timmermann; Mortensen, Stig Skov

    of education. The article explores the relationship between Continental and Anglo-American educational theory, and why they seem to have developed in such distinct directions. Beginning with the Anglo-American perspective it is outlined how pedagogy and the so called educational interest became replaced...... and the politicisation of inclusive education, and a positive aim in the form of an argument for a move towards constructing a pedagogical ideal of inclusion....

  20. The solubility-permeability interplay in using cyclodextrins as pharmaceutical solubilizers: mechanistic modeling and application to progesterone.

    Science.gov (United States)

    Dahan, Arik; Miller, Jonathan M; Hoffman, Amnon; Amidon, Gregory E; Amidon, Gordon L

    2010-06-01

    A quasi-equilibrium mass transport analysis has been developed to quantitatively explain the solubility-permeability interplay that exists when using cyclodextrins as pharmaceutical solubilizers. The model considers the effects of cyclodextrins on the membrane permeability (P(m)) as well as the unstirred water layer (UWL) permeability (P(aq)), to predict the overall effective permeability (P(eff)) dependence on cyclodextrin concentration (C(CD)). The analysis reveals that: (1) UWL permeability markedly increases with increasing C(CD) since the effective UWL thickness quickly decreases with increasing C(CD); (2) membrane permeability decreases with increasing C(CD), as a result of the decrease in the free fraction of drug; and (3) since P(aq) increases and P(m) decreases with increasing C(CD), the UWL is effectively eliminated and the overall P(eff) tends toward membrane control, that is, P(eff) approximately P(m) above a critical C(CD). Application of this transport model enabled excellent quantitative prediction of progesterone P(eff) as a function of HP beta CD concentrations in PAMPA assay, Caco-2 transepithelial studies, and in situ rat jejunal-perfusion model. This work demonstrates that when using cyclodextrins as pharmaceutical solubilizers, a trade-off exists between solubility increase and permeability decrease that must not be overlooked; the transport model presented here can aid in striking the appropriate solubility-permeability balance in order to achieve optimal overall absorption. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association

  1. Efficacy and Safety Profile of Diclofenac/Cyclodextrin and Progesterone/Cyclodextrin Formulations: A Review of the Literature Data.

    Science.gov (United States)

    Scavone, Cristina; Bonagura, Angela Colomba; Fiorentino, Sonia; Cimmaruta, Daniela; Cenami, Rosina; Torella, Marco; Fossati, Tiziano; Rossi, Francesco

    2016-06-01

    According to health technology assessment, patients deserve the best medicine. The development of drugs associated with solubility enhancers, such as cyclodextrins, represents a measure taken in order to improve the management of patients. Different drugs, such as estradiol, testosterone, dexamethasone, opioids, non-steroidal anti-inflammatories (NSAIDs; i.e. diclofenac), and progesterone are associated with cyclodextrins. Products containing the association of diclofenac/cyclodextrins are available for subcutaneous, intramuscular, and intravenous administration in doses that range from 25 to 75 mg. Medicinal products containing the association of progesterone/cyclodextrins are indicated for intramuscular and subcutaneous injection at a dose equal to 25 mg. The effects of cyclodextrins have been discussed in the solubility profile and permeability through biological membranes of drug molecules. A literature search was performed in order to give an overview of the pharmacokinetic characteristics, and efficacy and safety profiles of diclofenac/hydroxypropyl-β-cyclodextrin (HPβCD) and progesterone/HPβCD associations. The results of more than 20 clinical studies were reviewed. It was suggested that the new diclofenac/HPβCD formulation gives a rapid and effective response to acute pain and, furthermore, has pharmacokinetic and efficacy/safety profiles comparable to other medicinal products not containing cyclodextrins. One of the principal aspects of these new diclofenac formulations is that in lowering the dose (lower than 50 mg) the drugs could be more tolerable, especially in patients with comorbid conditions. Moreover, results of studies investigating the characteristics of progesterone and cyclodextrins showed that the new formulation (progesterone/HPβCD 25 mg solution) has the same bioavailability as other products containing progesterone. It is more rapidly absorbed and allows the achievement of peak plasma concentrations in a shorter time. Finally, the

  2. Fluorophore appended saccharide cyclophane: self-association, fluorescent properties, heterodimers with cyclodextrins, and cross-linking behavior with peanut agglutinin of dansyl-modified saccharide cyclophane.

    Science.gov (United States)

    Hayashida, Osamu; Hamachi, Itaru

    2004-05-14

    A saccharide cyclophane bearing an environment-sensitive fluorophore (1) was prepared by introducing not only three branches with a terminal galactose residue but also one with a dansyl moiety into a tetraaza[6.1.6.1]paracyclophane skeleton. Self-association behavior of the dansyl-appended saccharide cyclophane was characterized in aqueous media by fluorescence spectroscopy and dynamic light scattering measurements. At least in the concentrations below 1.0 x 10(-5) M, saccharide cyclophane 1 existed in a monomeric state, whereas it tended to form self-aggregated complexes in the higher concentration. Solvent polarity dependency on the emission spectra of 1 was examined by fluorescence spectroscopy. With increasing dioxane contents in dioxane/water solvents, the fluorescence intensity originating from the dansyl moiety of 1 increased along with a concomitant blue shift of the fluorescence maximum (lambda(em)). In the monomeric state of 1 in water, the dansyl moiety of 1 was not fully included into its cyclophane cavity but partially exposed to the bulk aqueous phase. In the higher concentration ranges in an aggregate state, however, the dansyl group of 1 was located in the apolar cyclophane cavity whose microenvironment was equivalent to the polarity of 1-butanol evaluated on the basis of a correlation between lambda(em) and solvent polarity. This indicates an intermolecular inclusion of the dansyl moiety within the cyclophane. When cyclodextrin (CD) was mixed with 1, the dansyl group of 1 was bound to an internal cavity of CD such as gamma-CD, beta-CD, 6-O-alpha-glucosyl-beta-CD, and 6-O-alpha-maltosyl-beta-CD with binding constants of 7.5 x 10(2), 7.8 x 10(2), 7.7 x 10(2), and 6.0 x 10(2) M(-1), respectively. Such a supramolecular assembling of dansyl-modified cyclophane 1 and CDs caused changes of the fluorescence spectra as well as appearance of induced CD bands in aqueous media. Furthermore, saccharide cyclophane 1 was selectively bound to peanut agglutinin

  3. In-vitro dissolution rate and molecular docking studies of cabergoline drug with β-cyclodextrin

    Science.gov (United States)

    Shanmuga priya, Arumugam; Balakrishnan, Suganya bharathi; Veerakanellore, Giri Babu; Stalin, Thambusamy

    2018-05-01

    The physicochemical properties and dissolution profile of cabergoline drug (CAB) with β-cyclodextrin (β-CD) inclusion complex were investigated by the UV spectroscopy. The inclusion complex has used to calculate the stability constant and gives the stoichiometry molar ratio is 1:1 between CAB and β-CD. The phase solubility diagram and the aqueous solubility of CAB (60%) was found to be enhanced by β-CD. In addition, the phase solubility profile of CAB with β-CD was classified as AL-type. Binary systems of CAB with β-CD were prepared by Physical mixture, Kneading and solvent evaporation methods. The solid-state properties of the inclusion complex were characterized by Fourier transformation-infrared spectroscopy, Differential scanning calorimetry, Powder X-ray diffractometric patterns and Scanning electron microscopic techniques. Theoretically, β-CD and CAB inclusion complex obtained by molecular docking studies, it is in good correlation with the results obtained through experimental methods using the Schrödinger software program. In-vitro dissolution profiles of the inclusion complexes were carried out and obvious increase in dissolution rate was observed when compared with pure CAB drug and the complexes.

  4. Grape Preservation Using Chitosan Combined with β-Cyclodextrin

    Directory of Open Access Journals (Sweden)

    Yu Youwei

    2013-01-01

    Full Text Available The effect of 1% chitosan combined with 2% β-cyclodextrin to the preservation of fresh grapes under ambient temperature was investigated. The results indicated that the hydrogen bond formed between the hydroxyl group of β-cyclodextrin and the amidogen or hydroxyl group of chitosan and the crystal form of chitosan was also changed when cyclodextrin was doped into chitosan coating. The compound coating could prolong the shelf life of grapes, maintain lower respiration rate and higher activities of superoxide dismutase, peroxidase, and catalase during storage time, and restrain weight loss and malonaldehyde content increase. Coating grapes with chitosan + β-cyclodextrin was a good method in postharvested grape preservation.

  5. Disintegrating Tablets Using β-Cyclodextrin and Superdisintegrants

    African Journals Online (AJOL)

    RST) using β- cyclodextrin (CD) and different superdisintegrants to enhance their solubility. Methods: A total of 15 FDT formulations of RST were prepared using three different techniques. The FDTs were evaluated for micromeritic properties, ...

  6. Photophysical and photoprototropic characteristics of phenothiazine in aqueous and β-cyclodextrin media

    Energy Technology Data Exchange (ETDEWEB)

    Rajamohan, Rajaram, E-mail: rajmohanau@gmail.com [Department of Chemistry, S.K.P Institute of Technology, Tiruvannamalai 606611 (India); Nayaki, Sundararajulu Kothai [Chemistry Section, FEAT, Annamalai University, Annamalainagar 608002 (India); Sivakumar, Krishnamoorthy [Department of Chemistry, SCSV University, Enathur, Kanchipuram 631561 (India); Swaminathan, Meenakshisundaram [Department of Chemistry, Annamalai University, Annamalainagar 608002 (India)

    2015-12-15

    The photophysical and photoprototropic characteristics of phenothiazine (PTZ) in aqueous and β-cyclodextrin (β-CD) media have been investigated using absorption, steady state and time resolved fluorescence measurements. The absorbance and fluorescence intensities of the neutral and monocationic forms of PTZ are enhanced by the addition of β-cyclodextrin and it is due to the formation of 1:1 inclusion complex. The formation of complex is confirmed by the decay analysis and Job's continuous variation method in the liquid state while FT-IR spectral study and SEM image analysis in the solid state. The peak and pK{sub a}* values of PTZ in aqueous media are higher than in β-CD medium, which reveals that the >NH group of PTZ lies in the β-CD cavity. - Highlights: • Increase in the absorbance and fluorescence intensity of PTZ by the addition of β-CDx is confirmed the complex formation. • Biexponential decay is noticed for PTZ by the addition of β-CDx is due to the formation of inclusion complex. • FT-IR and SEM images analysis confirms complex between PTZ and β-CDx in solid state. • The pK{sub a} and pK{sub a}* values of PTZ in aqueous medium is higher than in β-CDx medium, which reveals that the >NH group of PTZ lies in the β-CDx cavity. • The orientation of the inclusion complex is proposed by PatchDock server.

  7. Ca{sup 2+} ion sensing by a piperidin-4-one derivative and the effect of β-cyclodextrin complexation on the sensing

    Energy Technology Data Exchange (ETDEWEB)

    Sumithra, M.; Sivaraj, R.; Selvan, G. Tamil; Selvakumar, P. Mosae; Enoch, Israel V.M.V., E-mail: drisraelenoch@gmail.com

    2017-05-15

    In this paper, we report the turn-on fluorescence based Ca{sup 2+} ion sensing by an anthracene piperidin-4-one derivative. The compound is obtained using a simple two step synthesis. The compound is characterized using NMR and mass spectral methods. The host-guest complex formation of the compound with β-cyclodextrin is prepared and characterized using fluorescence and 2D ROESY spectroscopy. The compound forms the inclusion complex with a 1:1 stoichiometry. The structure of the host-guest complex is proposed. The Ca{sup 2+} ion selectivity of the compound in its free form and cyclodextrin-bound forms are studied. In both the forms, the piperidin-4-one derivative senses Ca{sup 2+} and in the case of the cyclodextrin encapsulated form it shows a better competitive binding of Ca{sup 2+} in the presence of other metal ions. - Highlights: •An anthracene iminoderivative of 3-methyl-2,6-diphenylpiperidin-4-one is synthesized. •The anthracene moiety of the compound is encapsulated by β-Cyclodextrin. •The compound senses Ca{sup 2+} ion both in water and β-CD media. •β-CD molecule does not interrupt the Ca{sup 2+} ion binding.

  8. An electrochemical study in aqueous solutions on the binding of dopamine to a sulfonated cyclodextrin host

    International Nuclear Information System (INIS)

    Hendy, Gillian M.; Breslin, Carmel B.

    2012-01-01

    Highlights: ► DA and Sβ-CD form an Inclusion complex. ► Electrochemical techniques demonstrated this inclusion complex. ► The association constant, K, was computed as 331.3. ► 1:1 stoichiometry for the inclusion complex was deduced from a Job's plot analysis. ► NMR studies confirmed the structural information on the inclusion complex. - Abstract: Clear evidence for the formation of a weak inclusion complex between dopamine (DA) and a sulfonated β-CD host in aqueous solution was obtained using a combination of electrochemical approaches. Using cyclic voltammetry, a distinct increase in the oxidation potential of DA and a reduction in the peak oxidation current were observed on adding an excess concentration of the sulfonated β-CD to the electrolyte solution. Equally, a clear increase in the half-wave oxidation potential of DA was observed in the presence of the sulfonated β-CD using rotating disc voltammetry. The association constant, K, was computed as 331.3 ± 5.8, indicating the formation of a weak inclusion complex, while a 1:1 stoichiometry for the inclusion complex was deduced from a Job's plot analysis. The rate constant for the oxidation of DA was found to decrease on formation of the inclusion complex. This was attributed to higher reorganization energy for the oxidation of the included DA. These changes in the electrochemistry of DA were not observed when an excess of the smaller sulfonated α-CD was added to the electrolyte, indicating that these variations are not connected with simple electrostatic interactions between the protonated DA and the anionic sulfonated groups. It is proposed that the aromatic ring of the DA molecule includes within the cyclodextrin cavity, while the protonated amine group remains outside the cavity, bound electrostatically with the anionic sulfonated groups.

  9. Cyclodextrin-Modified inorganic materials for the construction of nanocarriers.

    Science.gov (United States)

    Cutrone, Giovanna; Casas-Solvas, Juan M; Vargas-Berenguel, Antonio

    2017-10-15

    Inorganic nanoparticles, such as gold, silver, quantum dots and magnetic nanoparticles, offer a promising way to develop multifunctional nanoparticles for biomedical applications. Such nanoparticles have the potential to combine in a single, stable construct various functionalities, simultaneously providing imaging abilities, thermal therapies and the ability to deliver drugs in a targeted fashion. An approach for providing drug loading abilities to these inorganic nanoparticles consists in the modification of their surface with a coating of cyclodextrins, and thereby endowing the nanoparticles with the potential of functioning as drug nanocarriers. This review presents the advances carried out in the preparation of cyclodextrin-contained gold, silver, quantum dot and magnetic nanoparticles as well as their applications as drug nanocarriers. The nanoparticle surface can be modified incorporating cyclodextrin moieties, (i) in situ during the synthesis of the nanoparticles, either using the cyclodextrin as reducing agent or as stabilizer; or (ii) in a post-synthetic stage. The cyclodextrin coating contributes to provide biocompatibility to the nanoparticles and to reduce their cytotoxicity. Cyclodextrin-modified nanoparticles display a multivalent presentation of quasi-hydrophobic cavities that enables, not only drug loading in a non-covalent manner, but also the non-covalent assembly of targeting motifs and optical probes. This paper also provides an overview of some of the reported applications including the in vitro studies and, to a lesser extent, in vivo studies on the drug-loaded nanoparticles behavior. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Thermodynamic study on salt effects on complex formation of α-, β- and γ-cyclodextrins with p-aminobenzoic acid

    International Nuclear Information System (INIS)

    Chibunova, E.S.; Kumeev, R.S.; Terekhova, I.V.

    2015-01-01

    Highlights: • Thermodynamic study on salt effects in CD/pABA complex formation was performed. • Effects of KCl, KH 2 PO 4 and K 2 SO 4 are insignificant and nonspecific. • Specific influence of KBr is caused by the ability of Br − to penetrate into CD cavity. • Coexistence of two complexation equilibria is accompanied by solvent reorganization. - Abstract: The aim of this work was to gain a deeper understanding of salt effects in the inclusion complex formation of cyclodextrins. For this purpose, thermodynamic study of complex formation of α-, β- and γ-cyclodextrins with p-aminobenzoic acid was carried out in water and solutions of KCl, KBr, KH 2 PO 4 and K 2 SO 4 (0.2 mol/kg). Stability constants were calculated from the binding isotherms obtained on the basis of 1 H NMR measurements. Enthalpy and entropy of complex formation were estimated from the van’t Hoff plots. It was found that effects of KCl, KH 2 PO 4 and K 2 SO 4 are insignificant, while the influence of KBr on complex formation of cyclodextrins with p-aminobenzoic acid is more pronounced and results in a decrease of the stability constants. Specific action of Br − is caused by the ability of these anions to penetrate into macrocyclic cavity. Coexistence of two complexation equilibria in KBr solution is accompanied by significant solvent reorganization originated from more intensive dehydration of the interacting species. This results in an increase of the enthalpy and entropy of complex formation. Manifestation of Br − effect was found to be the same in the binding of p-aminobenzoic acid with α-, β- and γ-cyclodextrins.

  11. Molecule-binding dependent assembly of split aptamer and γ-cyclodextrin: A sensitive excimer signaling approach for aptamer biosensors

    International Nuclear Information System (INIS)

    Jin, Fen; Lian, Yan; Li, Jishan; Zheng, Jing; Hu, Yaping; Liu, Jinhua; Huang, Jin; Yang, Ronghua

    2013-01-01

    Graphical abstract: Adenosine-binding aptamer was splitted into two fragments P2 and P3 which labeled pyrene molecules, mainly produce monomer signal. γ-CD cavity brings P2 and P3 in close proximity, allowing for weak excimer emission. In the presence of target, P2 and P3 are expected to bind ATP and form an aptamer/target complex, leads to large increase of the pyrene excimer fluorescence. -- Highlights: •We assembled split aptamer and γ-cyclodextrin fluorescence biosensors for ATP detection. •The biosensor increased quantum yield and emission lifetime of the excimer. •Time-resolved fluorescence is effective for ATP assay in complicated environment. -- Abstract: A highly sensitive and selective fluorescence aptamer biosensors for the determination of adenosine triphosphate (ATP) was developed. Binding of a target with splitting aptamers labeled with pyrene molecules form stable pyrene dimer in the γ-cyclodextrin (γ-CD) cavity, yielding a strong excimer emission. We have found that inclusion of pyrene dimer in γ-cyclodextrin cavity not only exhibits additive increases in quantum yield and emission lifetime of the excimer, but also facilitates target-induced fusion of the splitting aptamers to form the aptamer/target complex. As proof-of-principle, the approach was applied to fluorescence detection of adenosine triphosphate. With an anti-ATP aptamer, the approach exhibits excimer fluorescence response toward ATP with a maximum signal-to-background ratio of 32.1 and remarkably low detection limit of 80 nM ATP in buffer solution. Moreover, due to the additive fluorescence lifetime of excimer induced by γ-cyclodextrin, time-resolved measurements could be conveniently used to detect as low as 0.5 μM ATP in blood serum quantitatively

  12. Cyclodextrin based ternary system of modafinil: Effect of trimethyl chitosan and polyvinylpyrrolidone as complexing agents.

    Science.gov (United States)

    Patel, Parth; Agrawal, Y K; Sarvaiya, Jayrajsinh

    2016-03-01

    Modafinil is an approved drug for the treatment of narcolepsy and have a strong market presence in many countries. The drug is widely consumed for off-label uses and currently listed as a restricted drug. Modafinil has very low water solubility. To enhance the aqueous solubility of modafinil by the formation of a ternary complex with Hydroxypropyl-β-cyclodextrin and two hydrophilic polymers was the main objective of the present study. Pyrrolidone (PVP K30) and a water soluble chitosan derivative, trimethyl chitosan (TMC) were studied by solution state and solid state characterization methods for their discriminatory efficiency in solubility enhancement of modafinil. Phase solubility study depicted the highest complexation efficiency (2.22) of cyclodextrin derivative in the presence of TMC compared to the same in the presence of PVP K30 (0.08) and in the absence of any polymer (0.92). FT-IR analysis of binary and ternary complex expressed comparable contribution of both polymers in formation of inclusion complex. The thermal behaviour of binary and ternary complex, involving individual polymers disclosed the influence of TMC on polymorphism of the drug. DSC study revealed efficiency of TMC to prevent conversion of metastable polymorphic form to stable polymorphic form. Ternary complex, involving TMC enhanced water solubility of the drug 1.5 times more compared to the binary complex of the drug whereas PVP K30 reduced the Solubility. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Enhanced mineralization of diuron using a cyclodextrin-based bioremediation technology.

    Science.gov (United States)

    Villaverde, Jaime; Posada-Baquero, Rosa; Rubio-Bellido, Marina; Laiz, Leonila; Saiz-Jimenez, Cesareo; Sanchez-Trujillo, María A; Morillo, Esmeralda

    2012-10-10

    The phenylurea herbicide diuron [N-(3,4-dichlorophenyl)-N,N-dimethylurea] is widely used in a broad range of herbicide formulations and, consequently, it is frequently detected as a major soil and water contaminant in areas where there is extensive use. Diuron has the unfortunate combination of being strongly adsorbed by soil organic matter particles and, hence, slowly degraded in the environment due to its reduced bioavailability. N-Phenylurea herbicides seem to be biodegraded in soil, but it must be kept in mind that this biotic or abiotic degradation could lead to accumulation of very toxic derived compounds, such as 3,4-dichloroaniline. Research was conducted to find procedures that might result in an increase in the bioavailability of diuron in contaminated soils, through solubility enhancement. For this purpose a double system composed of hydroxypropyl-β-cyclodextrin (HPBCD), which is capable of forming inclusion complexes in solution, and a two-member bacterial consortium formed by the diuron-degrading Arthrobacter sulfonivorans (Arthrobacter sp. N2) and the linuron-degrading Variovorax soli (Variovorax sp. SRS16) was used. This consortium can achieve a complete biodegradation of diuron to CO2 with regard to that observed in the absence of the CD solution, where only a 45% biodegradation was observed. The cyclodextrin-based bioremediation technology here described shows for the first time an almost complete mineralization of diuron in a soil system, in contrast to previous incomplete mineralization based on single or consortium bacterial degradation.

  14. Hartree-Fock and density functional theory study of alpha-cyclodextrin conformers.

    Science.gov (United States)

    Jiménez, Verónica; Alderete, Joel B

    2008-01-31

    Herein, we report the geometry optimization of four conformers of alpha-cyclodextrin (alpha-CD) by means of PM3, HF/STO-3G, HF/3-21G, HF/6-31G(d), B3LYP/6-31G(d), and X3LYP/6-31G(d) calculations. The analysis of several geometrical parameters indicates that all conformers possess bond lengths, angles, and dihedrals that agree fairly well with the crystalline structure of alpha-CD. However, only three of them (1-3) resemble the polar character of CDs and show intramolecular hydrogen-bonding patterns that agree with experimental NMR data. Among them, conformer 3 appears to be the most stable species both in the gas phase and in solution; therefore, it is expected to be the most suitable representative structure for alpha-CD conformation. The purpose of selecting such a species is to identify an appropriate structure to be employed as a starting point for reliable computational studies on complexation phenomena. Our results indicate that the choice of a particular alpha-CD conformer should affect the results of ab initio computational studies on the inclusion complexation with this cyclodextrin since both the direction and the magnitude of the dipole moment depend strongly on the conformation of alpha-CD.

  15. Aplicação de ciclodextrinas em processos têxteis Application of cyclodextrins in textile processes

    Directory of Open Access Journals (Sweden)

    Jürgen Andreaus

    2010-01-01

    Full Text Available Cyclodextrins (CDs are water soluble cyclic sugars with a hydrophobic nanometric cavity that permits the formation of host/guest inclusion complexes with a large variety of molecules, alternating their physical-chemical properties. In the present review CD research related to the processing of textiles is revised and discussed. CDs may function as encapsulating, dispersing and levelling agents in the dyeing and washing of textiles. Furthermore they may be anchored to polymers and textile fibers in order to impart special properties such as odor reduction, UV protection or for the controlled release of perfumes, aromas, mosquito repellents or substances with therapeutical effects.

  16. Dual fluorescence of N-phenylanthranilic acid: Effect of solvents, pH and β-cyclodextrin

    Science.gov (United States)

    Rajendiran, N.; Balasubramanian, T.

    2007-11-01

    Spectral characteristics of N-phenylanthranilic acid (NPAA) have been studied in different solvents, pH and β-cyclodextrin (β-CD) and compared with anthranilic acid (2-aminobenzoic acid, 2ABA). In all solvents a dual fluorescence is observed in NPAA, whereas 2ABA gives single emission. Combining the results observed in the absorption, fluorescence emission and fluorescence excitation spectra, it is found that strong intramolecular hydrogen bonding (IHB) interactions present in NPAA molecule. The inclusion complex of NPAA with β-CD is analysed by UV-vis, fluorimetry, FT-IR, 1H NMR, scanning electron microscope and AM 1 method. The above spectral studies show that NPAA forms a 1:1 inclusion complex with β-CD and COOH group present in the β-CD cavity. A mechanism is proposed to explain the inclusion process.

  17. Chemical Sensors Based on Cyclodextrin Derivatives.

    Science.gov (United States)

    Ogoshi, Tomoki; Harada, Akira

    2008-08-25

    This review focuses on chemical sensors based on cyclodextrin (CD) derivatives. This has been a field of classical interest, and is now of current interest for numerous scientists. First, typical chemical sensors using chromophore appended CDs are mentioned. Various "turn-off" and "turn-on" fluorescent chemical sensors, in which fluorescence intensity was decreased or increased by complexation with guest molecules, respectively, were synthesized. Dye modified CDs and photoactive metal ion-ligand complex appended CDs, metallocyclodextrins, were also applied for chemical sensors. Furthermore, recent novel approaches to chemical sensing systems using supramolecular structures such as CD dimers, trimers and cooperative binding systems of CDs with the other macrocycle [2]rotaxane and supramolecular polymers consisting of CD units are mentioned. New chemical sensors using hybrids of CDs with p-conjugated polymers, peptides, DNA, nanocarbons and nanoparticles are also described in this review.

  18. inclusions revisited

    Directory of Open Access Journals (Sweden)

    S. Migórski

    1995-01-01

    Full Text Available In this paper we confirm the validity of some recent results of Hu, Lakshmikantham, Papageorgiou [4] and Papageorgiou [13] concerning the existence and relaxation for nonlinear evolution inclusions. We fill a gap in the proofs of these results due to the use of incorrect Nagy's compactness embedding theorem.

  19. Increasing solubility of red bell pepper carotenoids by complexation with 2-hydroxypropyl-β-cyclodextrin.

    Science.gov (United States)

    de Lima Petito, Nicolly; da Silva Dias, Daiana; Costa, Valéria Gonçalves; Falcão, Deborah Quintanilha; de Lima Araujo, Kátia Gome

    2016-10-01

    Red bell pepper carotenoids were complexed with 2-hydroxypropyl-β-cyclodextrin (2-HPβCD) in different mass ratios (1:4, 1:6, 1:8 and 1:10) through ultrasonic homogenization in order to increase carotenoid solubility and their use as natural pigment in food. Inclusion complexes, red bell pepper extract and physical mixtures were analyzed by DSC, FT-IR, (1)H NMR and DLS. Solubility assay was performed to identify the effect of complexation on the solubility of carotenoids. From characterization assays, results showed that inclusion process occurred for all tested ratios. Results for water solubility assays demonstrated clear differences between solubility index of inclusion complexes (8.06±2.59-16.55±4.40mg/mL) and physical mixtures (3.53±1.44-7.3±1.88mg/mL), while carotenoid extract was no water soluble, as expected. These results indicated that molecular inclusion of carotenoids in 2-HPβCD was efficient to enhance their solubility in water, enabling application of red bell pepper carotenoid as natural pigment and/or bioactive substances in food. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Beta spectrometry

    International Nuclear Information System (INIS)

    Dryak, P.; Zderadicka, J.; Plch, J.; Kokta, L.; Novotna, P.

    1977-01-01

    For the purpose of beta spectrometry, a semiconductor spectrometer with one Si(Li) detector cooled with liquid nitrogen was designed. Geometrical detection efficiency is about 10% 4 sr. The achieved resolution for 624 keV conversion electrons of sup(137m)Ba is 2.6 keV (FWHM). A program was written in the FORTRAN language for the correction of the deformation of the measured spectra by backscattering in the analysis of continuous beta spectra. The method permits the determination of the maximum energy of the beta spectrum with an accuracy of +-5 keV. (author)

  1. Enhanced oral bioavailability and anticancer efficacy of fisetin by encapsulating as inclusion complex with HPβCD in polymeric nanoparticles.

    Science.gov (United States)

    Kadari, Amrita; Gudem, Sagarika; Kulhari, Hitesh; Bhandi, Murali Mohan; Borkar, Roshan M; Kolapalli, Venkata Ramana Murthy; Sistla, Ramakrishna

    2017-11-01

    Fisetin (FST), a potent anticancer phytoconstituent, exhibits poor aqueous solubility and hence poor bioavailability. The aim of the present study is to improve the oral bioavailability of FST by encapsulating into PLGA NPs (poly-lactide-co-glycolic acid nanoparticles) as a complex of HPβCD (hydroxyl propyl beta cyclodextrin) and to assess its anti-cancer activity against breast cancer cells. FST-HPβCD inclusion complex (FHIC) was prepared and the supramolecular complex formation was characterized by FTIR, DSC, PXRD and 1 H NMR. FHIC encapsulated PLGA nanoparticles (FHIC-PNP) were prepared and were studied for in vitro anticancer activity, cellular uptake, apoptosis and reactive oxygen species generation in MCF-7 human breast cancer cells. Comparative bioavailability of FST was determined after oral administration in C57BL6 mice as pure FST and FHIC-PNP. The results revealed that FHIC-PNP not only enhanced the anti-cancer activity and apoptosis of FST against MCF-7 cells but also improved its oral bioavailability, as demonstrated by increased peak plasma concentration and total drug absorbed.

  2. Translating Inclusion

    DEFF Research Database (Denmark)

    Fallov, Mia Arp; Birk, Rasmus

    2018-01-01

    The purpose of this paper is to explore how practices of translation shape particular paths of inclusion for people living in marginalized residential areas in Denmark. Inclusion, we argue, is not an end-state, but rather something which must be constantly performed. Active citizenship, today......, is not merely a question of participation, but of learning to become active in all spheres of life. The paper draws on empirical examples from a multi-sited field work in 6 different sites of local community work in Denmark, to demonstrate how different dimensions of translation are involved in shaping active...... citizenship. We propose the following different dimensions of translation: translating authority, translating language, translating social problems. The paper takes its theoretical point of departure from assemblage urbanism, arguing that cities are heterogeneous assemblages of socio-material interactions...

  3. Beta Blockers

    Science.gov (United States)

    ... may not work as effectively for people of African heritage and older people, especially when taken without ... conditions/high-blood-pressure/in-depth/beta-blockers/ART-20044522 . Mayo Clinic Footer Legal Conditions and Terms ...

  4. Effect of antioxidant activity of caffeic acid with cyclodextrins using ground mixture method

    Directory of Open Access Journals (Sweden)

    Ryota Shiozawa

    2018-01-01

    Full Text Available In the current study, we prepared a ground mixture (GM of caffeic acid (CA with α-cyclodextrin (αCD and with β-cyclodextrin (βCD, and then comparatively assessed the physicochemical properties and antioxidant capacities of these GMs. Phase solubility diagrams indicated that both CA/αCD and CA/βCD formed a complex at a molar ratio of 1/1. In addition, stability constants suggested that CA was more stable inside the cavity of αCD than inside the cavity of βCD. Results of powder X-ray diffraction (PXRD indicated that the characteristic diffraction peaks of CA and CD disappeared and a halo pattern was produced by the GMs of CA/αCD and CA/βCD (molar ratios = 1/1. Dissolution testing revealed that both GMs had a higher rate of dissolution than CA alone did. Based on the 1H-1H NOESY NMR spectra for the GM of CA/αCD, the vinylene group of the CA molecule appeared to be included from the wider to the narrower rim of the αCD ring. Based on spectra for the GM of CA/βCD, the aromatic ring of the CA molecule appeared to be included from the wider to the narrower rim of the βCD ring. This suggests that the structures of the CA inclusion complexes differed between those involving αCD rings and those involving βCD rings. Results of a DPPH radical-scavenging activity test indicated that the GM of CA/αCD had a higher antioxidant capacity than that of the GM of CA/βCD. The differences in the antioxidant capacities of the GMs of CA/αCD and CA/βCD are presumably due to differences in stability constants and structures of the inclusion complexes.

  5. Formulation and evaluation of mucoadhesive buccal patch of acyclovir utilizing inclusion phenomenon

    Directory of Open Access Journals (Sweden)

    Ankita Saxena

    2011-12-01

    Full Text Available Mucoadhesive buccal patch releasing drug in the oral cavity at a predetermined rate may present distinct advantages over traditional dosage forms, such as tablets, gels and solutions. A buccal patch for systemic administration of acyclovir in the oral cavity was developed using polymers hydroxy propyl methyl cellulose (K4M, hydroxy propyl methyl cellulose (K15M, sodium carboxy methyl cellulose and poly vinyl pyrolidone (K30, plasticizer poly ethylene glycol (400 and a backing membrane of Eudragit (RL100. The films were evaluated in terms of swelling, residence time, mucoadhesion, release, and organoleptic properties. The optimized films showed lower release as compared to controlled drug delivery systems. Hence, an inclusion complex of acyclovir was prepared with hydrophilic polymer hydroxylpropyl beta-cyclodextrin in the molar ratio of 1:1. The inclusion complex was characterized by optical microscopy, FAB mass spectroscopy, and FTIR spectroscopy. Patches formulated with the acyclovir inclusion complex were evaluated along the same lines as those containing acyclovir alone. The in vitro release data revealed a substantial increase from 64.35% to 88.15% in the case of PS I and PS II batches, respectively, confirming the successful use of inclusion complexes for the formulation of buccal patch of acyclovir.Mucoadesivos bucais liberadores de fármacos para a cavidade oral com taxa de liberação pré-determinada podem apresentar distintas vantagens em relação às formas farmacêuticas convencionais como comprimidos, géis e soluções. Neste trabalho, um adesivo bucal para administração sistêmica de aciclovir através da cavidade oral foi desenvolvido empregando-se os polímeros hidroxipropilmetil celulose (K4M, hidroxipropilmetil celulose (K15M, carboximetil celulose sódica e polivinil pirrolidona (K30, polietilenoglicol plastificado (400 e uma membrana suporte de Eudragit (RL100. Os filmes obtidos foram avaliados em termos de

  6. Supramolecular photocatalyst of RGO-cyclodextrin-TiO2

    International Nuclear Information System (INIS)

    Shen, Jianfeng; Li, Na; Ye, Mingxin

    2013-01-01

    Graphical abstract: Supramolecular photocatalyst of RGO-cyclodextrin-TiO 2 was achieved, which showed high photocatalytic activity and adsorption capacity. Highlights: •Supramolecular photocatalyst of RGO-cyclodextrin-TiO 2 was achieved. •β-CD molecules acted as linkers between RGO and monodisperse TiO 2 nanoparticles. •Reduction of GO and preparation of RGO-cyclodextrin-TiO 2 was simultaneous. •The prepared RGO-cyclodextrin-TiO 2 shows high photocatalytic activity and adsorption capacity. -- Abstract: Reduced graphene oxide (RGO)/β-cyclodextrin (β-CD)/titanium oxide (TiO 2 ) supramolecular photocatalyst was synthesized with a one-pot hydrothermal method. The reducing process was accomplished with the attaching of β-CD and generation of TiO 2 . β-CD acted as a linker between RGO and monodisperse TiO 2 nanoparticles. The structure and composition of the hybrid had been characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, thermal gravimetric analysis, X-ray diffraction and Transmission electron microscopy. The as-prepared RGO-CD-TiO 2 showed significant enhanced performance for phenol and Cr (VI) removal, due to the effective transfer of photo-generated electron from TiO2 to RGO and improved absorbance performance of the hybrid

  7. Cyclodextrins in Food Technology and Human Nutrition: Benefits and Limitations.

    Science.gov (United States)

    Fenyvesi, É; Vikmon, M; Szente, L

    2016-09-09

    Cyclodextrins are tasteless, odorless, nondigestible, noncaloric, noncariogenic saccharides, which reduce the digestion of carbohydrates and lipids. They have low glycemic index and decrease the glycemic index of the food. They are either non- or only partly digestible by the enzymes of the human gastrointestinal (GI) tract and fermented by the gut microflora. Based on these properties, cyclodextrins are dietary fibers useful for controlling the body weight and blood lipid profile. They are prebiotics, improve the intestinal microflora by selective proliferation of bifidobacteria. These antiobesity and anti-diabetic effects make them bioactive food supplements and nutraceuticals. In this review, these features are evaluated for α-, β- and γ-cyclodextrins, which are the cyclodextrin variants approved by authorities for food applications. The mechanisms behind these effects are reviewed together with the applications as solubilizers, stabilizers of dietary lipids, such as unsaturated fatty acids, phytosterols, vitamins, flavonoids, carotenoids and other nutraceuticals. The recent applications of cyclodextrins for reducing unwanted components, such as trans-fats, allergens, mycotoxins, acrylamides, bitter compounds, as well as in smart active packaging of foods are also overviewed.

  8. Chiral separation of methoxamine and lobeline in capillary zone electrophoresis using ethylbenzene-deactivated fused-silica capillary columns and cyclodextrins as buffer additives.

    Science.gov (United States)

    Russo, M V

    2002-08-01

    The complete chiral separation of methoxamine and lobeline was achieved by capillary zone electrophoresis on an ethylbenzene-deactivated fused-silica capillary column and with cyclodextrins (CDs) as buffer additives. Among the CDs investigated in this study, i.e. alpha-CD, beta-CD, dimethyl-beta-CD, hydroxypropyl-beta-CD and gamma-CD, all the three beta-type CDs showed chiral recognition on the two drugs investigated. Under the investigated conditions, the baseline chiral separation of methoxamine can be achieved with 90 mM Tris-H3PO4 (pH 2.5) containing 11.5 mM of the three beta-type CDs, with dimethyl-beta-CD giving the best resolution, whereas the baseline chiral separation of lobeline can be realized by using 90 mM Tris-H3PO4 buffer (pH 2.5) containing 5.8 mM dimethyl-beta-CD or 29.5 mM hydroxypropyl-beta-CD.

  9. Stabilization of nanosized titanium dioxide by cyclodextrin polymers and its photocatalytic effect on the degradation of wastewater pollutants.

    Science.gov (United States)

    Agócs, Tamás Zoltán; Puskás, István; Varga, Erzsébet; Molnár, Mónika; Fenyvesi, Éva

    2016-01-01

    Advanced oxidation processes (AOPs) are considered highly competitive water treatment technologies for the removal of organic pollutants. Among AOP techniques, photocatalysis has recently been the most widely studied. Our aims were to investigate how the dispersion of nanosized titanium dioxide (nanoTiO 2 ) applied in photodegradation-based procedures can be stabilized with cyclodextrins in order to obtain a new, more efficient photocatalyst for the purification of waters polluted by xenobiotics applying UV irradiation. During our work, on the one hand, we studied the behavior and stability of nanoTiO 2 in cyclodextrin solutions. On the other hand, we used various monomer and polymer cyclodextrin derivatives, and assessed the options for nanoTiO 2 stabilization in the presence of various salts and tap water on the basis of turbidity tests. The physical stability of nanoTiO 2 dispersions is diminished in the presence of the salts found in tap water (and occurring also in surface waters and ground water) and they are precipitated immediately. This colloidal instability can be improved by cyclodextrin derivatives. Based on the results of our studies we have selected carboxymethyl β-cyclodextrin polymer (CMBCD-P) for stabilization of nanoTiO 2 dispersions. The photocatalytic degradation of methylene blue and ibuprofen as model organic pollutants in various media (distilled water, NaCl solution and tap water) has been studied using nanoTiO 2 as catalyst stabilized by CMBCD-P. CMBCD-P itself showed a catalytic effect on the UV degradation of methylene blue. In addition to enhancing the colloid stability of nanoTiO 2 CMBCD-P showed also synergistic effects in catalyzing the photodecomposition process of the dye. On the other hand, ibuprofen as a model pharmaceutical, a pollutant of emerging concern (EP), was protected by CMBCD-P against the photocatalytic degradation showing that inclusion complex formation can result in opposite effects depending on the structure of the

  10. Stabilization of nanosized titanium dioxide by cyclodextrin polymers and its photocatalytic effect on the degradation of wastewater pollutants

    Directory of Open Access Journals (Sweden)

    Tamás Zoltán Agócs

    2016-12-01

    Full Text Available Advanced oxidation processes (AOPs are considered highly competitive water treatment technologies for the removal of organic pollutants. Among AOP techniques, photocatalysis has recently been the most widely studied. Our aims were to investigate how the dispersion of nanosized titanium dioxide (nanoTiO2 applied in photodegradation-based procedures can be stabilized with cyclodextrins in order to obtain a new, more efficient photocatalyst for the purification of waters polluted by xenobiotics applying UV irradiation. During our work, on the one hand, we studied the behavior and stability of nanoTiO2 in cyclodextrin solutions. On the other hand, we used various monomer and polymer cyclodextrin derivatives, and assessed the options for nanoTiO2 stabilization in the presence of various salts and tap water on the basis of turbidity tests. The physical stability of nanoTiO2 dispersions is diminished in the presence of the salts found in tap water (and occurring also in surface waters and ground water and they are precipitated immediately. This colloidal instability can be improved by cyclodextrin derivatives. Based on the results of our studies we have selected carboxymethyl β-cyclodextrin polymer (CMBCD-P for stabilization of nanoTiO2 dispersions. The photocatalytic degradation of methylene blue and ibuprofen as model organic pollutants in various media (distilled water, NaCl solution and tap water has been studied using nanoTiO2 as catalyst stabilized by CMBCD-P. CMBCD-P itself showed a catalytic effect on the UV degradation of methylene blue. In addition to enhancing the colloid stability of nanoTiO2 CMBCD-P showed also synergistic effects in catalyzing the photodecomposition process of the dye. On the other hand, ibuprofen as a model pharmaceutical, a pollutant of emerging concern (EP, was protected by CMBCD-P against the photocatalytic degradation showing that inclusion complex formation can result in opposite effects depending on the structure

  11. Supramolecular polymeric materials via cyclodextrin-guest interactions.

    Science.gov (United States)

    Harada, Akira; Takashima, Yoshinori; Nakahata, Masaki

    2014-07-15

    CONSPECTUS: Cyclodextrins (CDs) have many attractive functions, including molecular recognition, hydrolysis, catalysis, and polymerization. One of the most important uses of CDs is for the molecular recognition of hydrophobic organic guest molecules in aqueous solutions. CDs are desirable host molecules because they are environmentally benign and offer diverse functions. This Account demonstrates some of the great advances in the development of supramolecular materials through host-guest interactions within the last 10 years. In 1990, we developed topological supramolecular complexes with CDs, polyrotaxane, and CD tubes, and these preparation methods take advantage of self-organization between the CDs and the polymers. The combination of polyrotaxane with αCD forms a hydrogel through the interaction of αCDs with the OH groups on poly(ethylene glycol). We categorized these polyrotaxane chemistries within main chain type complexes. At the same time, we studied the interactions of side chain type supramolecular complexes with CDs. In these systems the guest molecules modified the polymers and selectively formed inclusion complexes with CDs. The systems that used low molecular weight compounds did not show such selectivity with CDs. The multivalency available within the complex cooperatively enhances the selective binding of CD with guest molecules via the polymer side chains, a phenomenon that is analogous to binding patterns observed in antigen-antibody complexes. To incorporate the molecular recognition properties of CDs within the polymer side chains, we first prepared stimuli-responsive sol-gel switching materials through host-guest interactions. We chose azobenzene derivatives for their response to light and ferrocene derivatives for their response to redox conditions. The supramolecular materials were both redox-responsive and self-healing, and these properties resulted from host-guest interactions. These sol-gels with built in switches gave us insight for

  12. In vitro and in vivo studies on the complexes of glipizide with water-soluble β-cyclodextrin-epichlorohydrin polymers.

    Science.gov (United States)

    Nie, Shufang; Zhang, Shu; Pan, Weisan; Liu, Yanli

    2011-05-01

    The purpose of this study was to evaluate the potential of a newly modified cyclodextrin derivative, water-soluble β-cyclodextrin-epichlorohydrin polymer (β-CDP), as an effective drug carrier to enhance the dissolution rate and oral bioavailability of glipizide as a poorly water-soluble model drug. Inclusion complexes of glipizide with β-CDP were prepared by the co-evaporation method and characterized by phase solubility, dissolution, and differential scanning calorimetry. The solubility curve was classified as type A(L), which indicated the formation of 1:1 complex between glipizide and β-CDP. β-CDP had better properties of increasing the aqueous solubility of glipizide compared with HP-β-CD. The dissolution rate of drug from the β-CDP complexes was significantly greater than that of the corresponding physical mixtures indicating that the formation of amorphous complex increased the solubility of glipizide. Moreover, the increment in drug dissolution rate from the glipizide/β-CDP systems was higher than that from the corresponding ones with HP-β-CD, which indicated that β-CDP could provide greater capability of solubilization for poorly soluble drugs. Furthermore, in vivo study revealed that the bioavailability of glipizide was significantly improved by glipizide /β-CDP inclusion complex after oral administration to beagle dogs.

  13. Synthesis and characterization of new polyamino-cyclodextrin materials.

    Science.gov (United States)

    Lo Meo, Paolo; D'Anna, Francesca; Gruttadauria, Michelangelo; Riela, Serena; Noto, Renato

    2012-01-10

    With the aim of the synthesis of chemically modified cyclodextrins bearing polyamine pendant groups, potentially useful as capping agents for the preparation of nanosized metal systems or as auxiliaries for gene transfection, the reaction between the heptakis-(6-iodo)-(6-deoxy)-β-cyclodextrin and various polyamines has been explored. This synthetic approach allows obtaining materials constituted by mixtures of cyclodextrins, having different degrees of substitution, which were satisfactorily characterized by means of various complementary techniques (ESI-MS, NMR, potentiometric titration). The products obtained were successfully subjected to preliminary tests for their binding abilities towards suitable organic guests and as capping agents for the preparation of stable silver nanoparticles. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Equilibrium location for spherical DNA and toroidal cyclodextrin

    Science.gov (United States)

    Sarapat, Pakhapoom; Baowan, Duangkamon; Hill, James M.

    2018-05-01

    Cyclodextrin comprises a ring structure composed of glucose molecules with an ability to form complexes of certain substances within its central cavity. The compound can be utilised for various applications including food, textiles, cosmetics, pharmaceutics, and gene delivery. In gene transfer, the possibility of forming complexes depends upon the interaction energy between cyclodextrin and DNA molecules which here are modelled as a torus and a sphere, respectively. Our proposed model is derived using the continuum approximation together with the Lennard-Jones potential, and the total interaction energy is obtained by integrating over both the spherical and toroidal surfaces. The results suggest that the DNA prefers to be symmetrically situated about 1.2 Å above the centre of the cyclodextrin to minimise its energy. Furthermore, an optimal configuration can be determined for any given size of torus and sphere.

  15. Direct investigation of the vectorization properties of amphiphilic cyclodextrins in phospholipid films.

    Science.gov (United States)

    Javierre, Isabelle; Nedyalkov, Mickael; Petkova, Vera; Benattar, Jean Jacques; Weisse, Sandrine; Auzély-Velty, Rachel; Djedaïni-Pilard, Florence; Perly, Bruno

    2002-10-01

    Recently, new cyclodextrin derivatives were synthesized and shown to exhibit strong amphiphilic properties. In this paper, we study the action of these new amphiphilic cyclodextrins on phospholipids. Mixed phospholipid/cyclodextrin derivative films were prepared and studied using X-ray reflectivity for various phospholipid/cyclodextrin ratios. A molar ratio of 3 provides a highly stable film the molecular structure of which has been investigated in detail. The cholesterol tail of the cyclodextrin molecule was found to be anchored into the phospholipid film. The cyclodextrin moieties exposed to the aqueous medium are prone to the addition of the guest molecule Dosulepin, making them of high interest for drug delivery. For this purpose and as an example of a potential application, this cyclodextrin molecular carrier property is also addressed to this complex film architecture.

  16. SIKLODEKSTRIN GLIKOSIL TRANSFERASE DAN PEMANFAATANNYA DALAM INDUSTRI [Cyclodextrin Glycosyl Transferase and its application in industries

    Directory of Open Access Journals (Sweden)

    Budiasih Wahyuntari

    2005-12-01

    Full Text Available Cyclodextrin glycosyl transferase (CGT-ase is mainly produced by Bacilli. Systematical name of the enzyme is E.C. 2.4.1.19 a-1,4 glucan-4-glycosyl transferase. The enzyme catalyzes hydrolysis of starch intramolecular, and intermolecular transglycosylation of a-1,4, glucan chains. Cyclodextrins are a-1,4 linked cyclic oligosaccharides resulting from enzymatic degradation of starch by cyclodextrin glycosyl transferase through untramolecular transglycosylation. The major cyclodextrins are made up of 6, 7 and 8 glucopyranose units which are known as a-, b-, and y-cyclodextrin. All CGT-ase catalyze three kinds of cyclodextrins, the proportion of the cyclodextrins depends on the enzyme source and reaction conditions. The intermolecular transglycosylation ability of the enzyme has been applied in transfering glycosyl residues into suitable acceptor. Transglycosylation by the enzymes have been tested to improve solubility of some flavonoids and to favor precipitation ci some glycosides.

  17. Curcumin complexation with cyclodextrins by the autoclave process: Method development and characterization of complex formation.

    Science.gov (United States)

    Hagbani, Turki Al; Nazzal, Sami

    2017-03-30

    One approach to enhance curcumin (CUR) aqueous solubility is to use cyclodextrins (CDs) to form inclusion complexes where CUR is encapsulated as a guest molecule within the internal cavity of the water-soluble CD. Several methods have been reported for the complexation of CUR with CDs. Limited information, however, is available on the use of the autoclave process (AU) in complex formation. The aims of this work were therefore to (1) investigate and evaluate the AU cycle as a complex formation method to enhance CUR solubility; (2) compare the efficacy of the AU process with the freeze-drying (FD) and evaporation (EV) processes in complex formation; and (3) confirm CUR stability by characterizing CUR:CD complexes by NMR, Raman spectroscopy, DSC, and XRD. Significant differences were found in the saturation solubility of CUR from its complexes with CD when prepared by the three complexation methods. The AU yielded a complex with expected chemical and physical fingerprints for a CUR:CD inclusion complex that maintained the chemical integrity and stability of CUR and provided the highest solubility of CUR in water. Physical and chemical characterizations of the AU complexes confirmed the encapsulated of CUR inside the CD cavity and the transformation of the crystalline CUR:CD inclusion complex to an amorphous form. It was concluded that the autoclave process with its short processing time could be used as an alternate and efficient methods for drug:CD complexation. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Pharmaceutical applications of cyclodextrins: basic science and product development.

    Science.gov (United States)

    Loftsson, Thorsteinn; Brewster, Marcus E

    2010-11-01

    Drug pipelines are becoming increasingly difficult to formulate. This is punctuated by both retrospective and prospective analyses that show that while 40% of currently marketed drugs are poorly soluble based on the definition of the biopharmaceutical classification system (BCS), about 90% of drugs in development can be characterized as poorly soluble. Although a number of techniques have been suggested for increasing oral bioavailability and for enabling parenteral formulations, cyclodextrins have emerged as a productive approach. This short review is intended to provide both some basic science information as well as data on the ability to develop drugs in cyclodextrin-containing formulations. There are currently a number of marketed products that make use of these functional solubilizing excipients and new product introduction continues to demonstrate their high added value. The ability to predict whether cyclodextrins will be of benefit in creating a dosage form for a particular drug candidate requires a good working knowledge of the properties of cyclodextrins, their mechanism of solubilization and factors that contribute to, or detract from, the biopharmaceutical characteristics of the formed complexes. We provide basic science information as well as data on the development of drugs in cyclodextrin-containing formulations. Cyclodextrins have emerged as an important tool in the formulator's armamentarium to improve apparent solubility and dissolution rate for poorly water-soluble drug candidates. The continued interest and productivity of these materials bode well for future application and their currency as excipients in research, development and drug product marketing. © 2010 The Authors. Journal compilation © 2010 Royal Pharmaceutical Society of Great Britain.

  19. α-Cyclodextrins Polyrotaxane Loading Silver Sulfadiazine

    Directory of Open Access Journals (Sweden)

    Sa Liu

    2018-02-01

    Full Text Available As a drug carrier, polyrotaxane (PR has been used for targeted delivery and sustained release of drugs, whereas silver sulfadiazine (SD-Ag is an emerging antibiotic agent. PR was synthesized by the use of α-cyclodextrin (CD and poly(ethylene glycol (PEG, and a specific antibacterial material (PR-(SD-Ag was then prepared by loading SD-Ag onto PR with different mass ratios. The loading capacity and the encapsulation efficiency were 90% at a mass ratio of 1:1 of PR and SD-Ag. SD-Ag was released stably and slowly within 6 d in vitro, and its cumulative release reached more than 85%. The mechanism of PR loading SD-Ag might be that SD-Ag attached to the edge of α-CD through hydrogen bonding. PR-(SD-Ag showed a higher light stability than SD-Ag and held excellent antibacterial properties against Escherichia coli (E. coli and Staphylococcus aureus (S. aureus.

  20. Cyclodextrin Protects Podocytes in Diabetic Kidney Disease

    Science.gov (United States)

    Merscher-Gomez, Sandra; Guzman, Johanna; Pedigo, Christopher E.; Lehto, Markku; Aguillon-Prada, Robier; Mendez, Armando; Lassenius, Mariann I.; Forsblom, Carol; Yoo, TaeHyun; Villarreal, Rodrigo; Maiguel, Dony; Johnson, Kevin; Goldberg, Ronald; Nair, Viji; Randolph, Ann; Kretzler, Matthias; Nelson, Robert G.; Burke, George W.; Groop, Per-Henrik; Fornoni, Alessia

    2013-01-01

    Diabetic kidney disease (DKD) remains the most common cause of end-stage kidney disease despite multifactorial intervention. We demonstrated that increased cholesterol in association with downregulation of ATP-binding cassette transporter ABCA1 occurs in normal human podocytes exposed to the sera of patients with type 1 diabetes and albuminuria (DKD+) when compared with diabetic patients with normoalbuminuria (DKD−) and similar duration of diabetes and lipid profile. Glomerular downregulation of ABCA1 was confirmed in biopsies from patients with early DKD (n = 70) when compared with normal living donors (n = 32). Induction of cholesterol efflux with cyclodextrin (CD) but not inhibition of cholesterol synthesis with simvastatin prevented podocyte injury observed in vitro after exposure to patient sera. Subcutaneous administration of CD to diabetic BTBR (black and tan, brachiuric) ob/ob mice was safe and reduced albuminuria, mesangial expansion, kidney weight, and cortical cholesterol content. This was followed by an improvement of fasting insulin, blood glucose, body weight, and glucose tolerance in vivo and improved glucose-stimulated insulin release in human islets in vitro. Our data suggest that impaired reverse cholesterol transport characterizes clinical and experimental DKD and negatively influences podocyte function. Treatment with CD is safe and effective in preserving podocyte function in vitro and in vivo and may improve the metabolic control of diabetes. PMID:23835338

  1. Osmotic properties of sulfobutylether and hydroxypropyl cyclodextrins.

    Science.gov (United States)

    Zannou, E A; Streng, W H; Stella, V J

    2001-08-01

    The purpose of this study was to determine the osmolality of sulfobutylether (SBE) and hydroxypropyl (HP) derivatives of cyclodextrins (CDs) via vapor pressure osmometry (VPO) and freezing point depression (FPD). (SBE) and HP-CDs are efficient excipients capable of solubilizing and stabilizing poorly water-soluble drugs in parenteral formulations. (SBE)-CDs have also been used as solubility enhancers and osmotic agents for the sustained release of poorly water-soluble drugs from osmotic pump tablets. The knowledge of the CD's osmolality in solution or inside such tablets would allow one to further characterize the release mechanisms. Experiments were conducted at 37 degrees C with eight types of HP and (SBE)-CDs. The aqueous solutions ranged from 0.005-0.350 mol(-1). Methods were developed to allow the measurement of high osmolalities using a vapor pressure osmometer or a differential scanning calorimeter. The osmolality calculations from the VPO and FPD measurements correlated well. The osmolality of (SBE)-CDs was significantly higher than the osmolality of HP-CDs and increased with the total degree of substitution (TDS). All CDs showed deviations from ideality at high concentrations. Empirical correlations of osmolality with concentration and TDS allowed the prediction of osmolality over a wide concentration range. This study also gave some useful insights into the behavior of CD derivatives in solution.

  2. Cyclodextrin ketones as oxidation catalysts: investigation of bridged derivatives

    DEFF Research Database (Denmark)

    Fenger, Thomas Hauch; Marinescu, Lavinia; Bols, Mikael

    2009-01-01

    A series of alpha-cyclodextrin derivatives containing a 3, 4 or 5 membered ether-linked bridge between the 6A and 6D oxygen atoms, with and without a ketone, were prepared. The synthesis used perbenzylated alpha-cyclodextrin A,D-diol as a starting material upon which O-alkylation and further modi...... derivatives were also made. The 6A,6D-di-O-(propa-2-on-1,3-diyl)-6C,6F-di-O-methyl and di-O-pivaloyl derivatives were also prepared. The new compounds were analysed for catalysis of the oxidation of amines and alcohols....

  3. Construction and Characterization of a Chitosan-Immobilized-Enzyme and β-Cyclodextrin-Included-Ferrocene-Based Electrochemical Biosensor for H2O2 Detection

    Directory of Open Access Journals (Sweden)

    Wenbo Dong

    2017-07-01

    Full Text Available An electrochemical detection biosensor was prepared with the chitosan-immobilized-enzyme (CTS-CAT and β-cyclodextrin-included-ferrocene (β-CD-FE complex for the determination of H2O2. Ferrocene (FE was included in β-cyclodextrin (β-CD to increase its stability. The structure of the β-CD-FE was characterized. The inclusion amount, inclusion rate, and electrochemical properties of inclusion complexes were determined to optimize the reaction conditions for the inclusion. CTS-CAT was prepared by a step-by-step immobilization method, which overcame the disadvantages of the conventional preparation methods. The immobilization conditions were optimized to obtain the desired enzyme activity. CTS-CAT/β-CD-FE composite electrodes were prepared by compositing the CTS-CAT with the β-CD-FE complex on a glassy carbon electrode and used for the electrochemical detection of H2O2. It was found that the CTS-CAT could produce a strong reduction peak current in response to H2O2 and the β-CD-FE could amplify the current signal. The peak current exhibited a linear relationship with the H2O2 concentration in the range of 1.0 × 10−7–6.0 × 10−3 mol/L. Our work provided a novel method for the construction of electrochemical biosensors with a fast response, good stability, high sensitivity, and a wide linear response range based on the composite of chitosan and cyclodextrin.

  4. Determination of poorly fluorescent carbamate pesticides in water, bendiocarb and promecarb, using cyclodextrin nanocavities and related media

    Energy Technology Data Exchange (ETDEWEB)

    Pacioni, Natalia L. [Instituto de Investigaciones en Fisico Quimica de Cordoba (INFIQC), Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Veglia, Alicia V. [Instituto de Investigaciones en Fisico Quimica de Cordoba (INFIQC), Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina)]. E-mail: aveglia@mail.fcq.unc.edu.ar

    2007-01-30

    The effect of native cyclodextrins ({alpha}, {beta}, or {gamma}CD with six, seven and eight glucose units, respectively), hydroxypropyl-{beta}-cyclodextrin (HPCD), chitosan (CHT) and glucose in water solution or water with n-propylamine (PA) as co-solvent upon the UV-vis and fluorescence properties of poorly fluorescent N-methyl carbamates pesticides (C) as bendiocarb (2,2-dimethyl-1,3-benzodioxol-4-ol methylcarbamate, BC) and promecarb (3-methyl-5-(1-methylethyl)phenol methylcarbame, PC) was examined. Fluorescent enhancement was found for both substrates with all CDs in water or PA-water except from PC with {alpha}CD. The addition of CHT increases the fluorescence of BC but decreases the fluorescence of PC, and glucose addition gives in both cases no spectral changes. Host-guest interaction was clearly determined by fluorescence enhancement with {beta}CD and HPCD with a 1:1 stoichiometry for the complexes (C:CD). The values obtained for the association constants (K {sub A}, M{sup -1}) were (6 {+-} 2) x 10{sup 2} and (2.3 {+-} 0.3) x 10{sup 2} for BC:{beta}CD and BC:HPCD complexes, respectively. For PC:{beta}CD and PC:HPCD the values of K {sub A} were (19 {+-} 2) x 10{sup 2} and (21 {+-} 2) x 10{sup 2}, respectively. The ratio of the fluorescence quantum yields for the bound and free substrates ({phi} {sup CCD}/{phi} {sup C}) was in the range 1.74-3.8. The limits of detection (L {sub D}, {mu}g mL{sup -1}) for the best conditions were (0.57 {+-} 0.02) for BC with HPCD and (0.091 {+-} 0.002) for PC with {beta}CD in water. Application to the analysis in pesticide spiked samples of tap water and fruit yields satisfactory apparent recoveries (84-114%), and for the extraction procedure in fruits and a commercial formulation, recoveries were of 81-98% and 104%, respectively. The method is rapid, simple, direct, sensitive and useful for pesticide analysis.

  5. Cyclodextrins as Protective Agents of Protein Aggregation: An Overview.

    Science.gov (United States)

    Oliveri, Valentina; Vecchio, Graziella

    2016-06-06

    Cyclodextrins are extensively used in different fields (e.g., catalysis, chromatography, pharma, supramolecular chemistry, bioorganic chemistry, and bioinorganic chemistry), and their applications have been widely reviewed. Their main application in the field of pharmaceutical is as a drug carrier. This review overviews, for the first time, the use of cyclodextrins and their derivatives as antiaggregant agents in a number of proteins (e.g., amyloid-β, insulin, recombinant human growth hormone, prion protein, transthyretin, and α-synuclein) and some multimeric enzymes. There are many diseases that are correlated to protein misfolding and amyloid formation processes affecting numerous organs and tissues. There are over 30 different amyloid proteins and a number of corresponding diseases. Alzheimer's disease is the most common neurodegenerative disease. Treatment of these diseases is still a goal to reach, and many molecules are studied in this perspective. Cyclodextrins have also been studied, and they show great potential; as such, further studies could be very promising. This review aims to be a stimulus for the design of new cyclodextrin derivatives to obtain multifunctional systems with antiaggregant activity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Synthesis of Mono(perfluoroalkyl) Cyclodextrins via Cross Metathesis

    Czech Academy of Sciences Publication Activity Database

    Řezanka, M.; Eignerová, Barbara; Jindřich, J.; Kotora, M.

    -, č. 32 (2010), s. 6256-6262 ISSN 1434-193X R&D Projects: GA AV ČR KAN200200651 Institutional research plan: CEZ:AV0Z40550506 Keywords : metathesis * cyclodextrins * fluorine * alkylation * amphiphiles Subject RIV: CC - Organic Chemistry Impact factor: 3.206, year: 2010

  7. Cyclodextrin dimers as receptor molecules for steroid sensors

    NARCIS (Netherlands)

    de Jong, M.R.; Engbersen, Johannes F.J.; Huskens, Jurriaan; Reinhoudt, David

    2000-01-01

    The dansyl-modified dimer 9 complexes strongly with the steroidal bile salts. Relative to native -cyclodextrin, the binding of cholate (1 a) and deoxycholate (1 b) salts is especially enhanced. These steroids bind exclusively in a 1:1 fashion. For other bile salts (1 c-1 e) both 1:1 and 1:2

  8. β-Cyclodextrin-curcumin complex inhibit telomerase gene ...

    African Journals Online (AJOL)

    Yomi

    2011-12-21

    Dec 21, 2011 ... have various applications in cancer therapy. But, its low water solubility and bioavailability is possible for poor drug delivery of curcumin. In this study, we prepared β-cyclodextrin-curcumin complex to determine the inhibitory effect of this drug on telomerase gene expression. Curcumin was encapsulated.

  9. Alpha-cyclodextrins reversibly capped with disulfide bonds

    Czech Academy of Sciences Publication Activity Database

    Kumprecht, Lukáš; Buděšínský, Miloš; Bouř, Petr; Kraus, Tomáš

    2010-01-01

    Roč. 34, č. 10 (2010), s. 2254-2260 ISSN 1144-0546 R&D Projects: GA AV ČR IAA400550810 Institutional research plan: CEZ:AV0Z40550506 Keywords : cyclodextrins * disulfide bond * dynamic covalent bond Subject RIV: CC - Organic Chemistry Impact factor: 2.631, year: 2010

  10. Fe-Ni Nanoparticles supported on carbon nanotube-co-cyclodextrin polyurethanes for the removal of trichloroethylene in water

    International Nuclear Information System (INIS)

    Krause, Rui W. M.; Mamba, Bhekie B.; Dlamini, Langelihle N.; Durbach, Shane H.

    2010-01-01

    Nanoscale bimetallic particles of nickel on iron were supported on carbon nanotubes and then co-polymerized with β-cyclodextrin (CNTs/CD) and the resulting polymers applied to the degradation of pollutants in water. The bimetallic nanoparticles (BMNPs) were first embedded on functionalized carbon nanotubes (f-CNTs) before being copolymerized with beta cyclodextrin (β-CD) and hexamethylene diisocyanate (HMDI) forming a water-insoluble polyurethane. The particle size and distribution of BMNPs were determined by Transmission Electron Microscopy (TEM), and the surface area was determined by using the Brunauer-Emmett-Teller (BET) method. Energy dispersive X-ray spectroscopy (EDXS) was used to confirm the formation of the BMNPs. Degradation of trichloroethylene (TCE) as a model pollutant was studied and more than 98% reduction in TCE was achieved by the polymers. Polymers with the BMNPs maintained their efficiency in degrading TCE after several cycles compared to metal-free polymers. The degradation was monitored by using gas chromatography-mass spectrometry (GC-MS), while the production of chlorides was verified by using ion chromatography (IC). Atomic absorption spectroscopy (AAS) was employed to determine the possible leaching of the BMNPs from the polymer, and confirmed to be extremely low.

  11. Spray-Freeze Drying: a Suitable Method for Aerosol Delivery of Antibodies in the Presence of Trehalose and Cyclodextrins.

    Science.gov (United States)

    Pouya, Maryam Amini; Daneshmand, Behnaz; Aghababaie, Shabnam; Faghihi, Homa; Vatanara, Alireza

    2018-05-08

    We aimed to prepare spray-freeze-dried powder of IgG considering physicochemical stability and aerodynamic aspects. Spray-freeze drying (SFD) exposes proteins to various stresses which should be compensated by suitable stabilizers. The competence of cyclodextrins (CDs), namely beta-cyclodextrin (βCD) and hydroxypropyl βCD (HPβCD), at very low concentrations, was investigated in the presence of separate mannitol- and trehalose-based formulations. Spray-freeze-dried preparations were quantified in terms of monomer recovery and conformation by size exclusion chromatography (SEC-HPLC) and Fourier transform infrared (FTIR) spectroscopy, respectively. Differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) were employed to identify the thermal characteristics of powders. Particle morphology was visualized by scanning electron microscopy (SEM). Aerodynamic behavior of powders was checked through an Anderson cascade impactor (ACI). Although all formulations protected antibody from aggregation during the SFD process (aggregation < 1%), mannitol-containing ones failed upon the storage (19.54% in the worst case). Trehalose-HPβCD incomparably preserved the formulation with fine particle fraction (FPF) of 51.29%. Crystallization of mannitol resulted in IgG destabilization upon storage. Although employed concentration of CDs is too low (less than 50:1 molar ratio to protein), they successfully served as stabilizing agents in SFD with perfect improvement in aerosol functionality. Graphical Abstract ᅟ.

  12. Functional electrospun polystyrene nanofibers incorporating α-, β-, and γ-cyclodextrins: comparison of molecular filter performance.

    Science.gov (United States)

    Uyar, Tamer; Havelund, Rasmus; Hacaloglu, Jale; Besenbacher, Flemming; Kingshott, Peter

    2010-09-28

    Electrospinning has been used to successfully create polystyrene (PS) nanofibers containing either of three different types of cyclodextrin (CD); α-CD, β-CD, and γ-CD. These three CDs are chosen because they have different sized cavities that potentially allow for selective inclusion complex (IC) formation with molecules of different size or differences in affinity of IC formation with one type of molecule. The CD containing electrospun PS nanofibers (PS/CD) were initially characterized by scanning electron microscopy (SEM) to determine the uniformity of the fibers and their fiber diameter distributions. X-ray photoelectron spectroscopy (XPS) was used to quantitatively determine the concentration of each CD on the different fiber surfaces. Static time-of-flight secondary ion mass spectrometry (static-ToF-SIMS) showed the presence of each type of CD on the PS nanofibers by the detection of both the CD sodium adduct molecular ions (M + Na+) and lower molecular weight oxygen containing fragment ions. The comparative efficiency of the PS/CD nanofibers/nanoweb for removing phenolphthalein, a model organic compound, from solution was determined by UV-vis spectrometry, and the kinetics of phenolphthalein capture was shown to follow the trend PS/α-CD > PS/β-CD > PS/γ-CD. Direct pyrolysis mass spectrometry (DP-MS) was also performed to ascertain the relative binding strengths of the phenolphthalein for the CD cavities, and the results showed the trend in the interaction strength was β-CD > γ-CD > α-CD. Our results demonstrate that nanofibers produced by electrospinning that incorporate cyclodextrins with different sized cavities can indeed filter organic molecules and can potentially be used for filtration, purification, and/or separation processes.

  13. Complexation induced aggregation and deaggregation of acridine orange with sulfobutylether-β-cyclodextrin.

    Science.gov (United States)

    Sayed, Mhejabeen; Jha, Shruti; Pal, Haridas

    2017-09-13

    The present study reports a contrasting interaction behaviour of a biologically important dye, acridine orange (AOH + ), with a highly water soluble anionic host, based on a β-cyclodextrin (βCD) scaffold, i.e. sulfobutylether-β-cyclodextrin (SBEβCD), in comparison to native βCD. AOH + shows striking modulation in its photophysical properties, representing sequential changes in the modes of interaction with increasing SBEβCD concentration. At lower SBEβCD concentrations, AOH + preferentially binds in dimeric forms at the negatively charged SBEβCD portals, leading to strong fluorescence quenching. At higher SBEβCD concentrations, the dimeric dyes convert to monomeric forms and subsequently undergo both inclusion and exo complex formation with 1 : 1 stoichiometry, resulting in a large fluorescence enhancement. The intriguing observation of sequential fluorescence switch off and switch on for an AOH + -SBEβCD system is clearly facilitated by the presence of butylether chains with SO 3 - end groups at the portals of SBEβCD, providing an additional ion-ion interaction and much enhanced hydrophobic interaction for cationic AOH + compared to the native βCD host. To the best of our knowledge, such fluorescence off/on switching through multistep host-guest binding has not been reported so far in the literature. The present study not only provides a detailed insight into the unique binding interactions of AOH + with the SBEβCD host, but the findings of this study are also expected to be useful in designing supramolecular based drug formulations, drug delivery systems, sensors, and so on.

  14. Redox-Active Carbohydrate-Coated Nanoparticles: Self-Assembly of a Cyclodextrin-Polystyrene Glycopolymer with Tetrazine-Naphthalimide.

    Science.gov (United States)

    Gross, Andrew J; Haddad, Raoudha; Travelet, Christophe; Reynaud, Eric; Audebert, Pierre; Borsali, Redouane; Cosnier, Serge

    2016-11-15

    The controlled self-assembly of precise and well-defined photochemically and electrochemically active carbohydrate-coated nanoparticles offers the exciting prospect of biocompatible catalysts for energy storage/conversion and biolabeling applications. Here an aqueous nanoparticle system has been developed with a versatile outer layer for host-guest molecule encapsulation via β-cyclodextrin inclusion complexes. A β-cyclodextrin-modified polystyrene polymer was first obtained by copper nanopowder click chemistry. The glycopolymer enables self-assembly and controlled encapsulation of tetrazine-naphthalimide, as a model redox-active agent, into nanoparticles via nanoprecipitation. Cyclodextrin host-guest interactions permit encapsulation and internanoparticle cross-linking for the formation of fluorescent compound and clustered self-assemblies with chemically reversible electroactivity in aqueous solution. Light scattering experiments revealed stable particles with hydrodynamic diameters of 138 and 654 nm for nanoparticles prepared with tetrazine, of which 95% of the nanoparticles represent the smaller objects by number. Dynamic light scattering revealed differences as a function of preparation method in terms of size, 3-month stability, polydispersity, radius of gyration, and shape factor. Individual self-assemblies were visualized by atomic force microscopy and fluorescence microscopy and monitored in real-time by nanoparticle tracking analysis. UV-vis and fluorescence spectra provided insight into the optical properties and critical evidence for host-guest encapsulation as evidenced by solvachromatism and enhanced tetrazine uptake. Cyclic voltammetry was used to investigate the electrochemical properties and provided further support for encapsulation and an estimate of the tetrazine loading capacity in tandem with light scattering data.

  15. The hydroxypropyl–β-cyclodextrin complexation of toltrazuril for enhancing bioavailability

    Directory of Open Access Journals (Sweden)

    Zhang L

    2018-03-01

    Full Text Available Li Zhang,1,2,* Mengxi Liu,1,* Chaocheng Lu,1 Dandan Ren,1 Guoqing Fan,1 Chang Liu,1 Mengjiao Liu,1 Gang Shu,1 Guangneng Peng,1 Zhixiang Yuan,1 Zhijun Zhong,1 Wei Zhang,1 Hualin Fu1 1Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; 2Institute of Traditional Chinese Medicine Pharmacology and Toxicology, Sichuan Academy of Chinese Medicine Sciences, Chengdu, Sichuan, China *These authors contributed equally to this work Introduction: Toltrazuril (Tol is used to prevent and combat coccidiosis. However, its low aqueous solubility and poor oral bioavailability limit clinical application. Methods: To overcome the shortcomings, toltrazuril–hydroxypropyl–β-cyclodextrin inclusion complex (Tol-HP-β-CD was prepared and characterized. The comparative plasma disposition kinetics of Tol was analyzed after a single orally administered dose of 10 mg/kg Tol or Tol-HP-β-CD in rabbits. Solution-stirring method was selected to prepare the inclusion complex. Complex formation was characterized by thin-layer chromatography, Fourier transform infrared spectrophotometry, and 1H nuclear magnetic resonance spectroscopy. In plasma profile, plasma samples were collected between 1 and 10 days following administration. Plasma Tol concentrations were determined by high-performance liquid chromatography. Results: In rabbit plasma, the time to peak concentration (Tmax of Tol-HP-β-CD was shorter than that of Tol (12 h vs 24 h. Cmax (19.92±1.02 µg/mL and area under the concentration–time curve (AUC0-∞, 1,176.86±70.26 mg/L h of the Tol-HP-β-CD group significantly increased (p<0.01 than those of the Tol group (Cmax, 8.02±1.04 µg/mL; AUC0-∞, 514.03±66.65 mg/L h. Conclusion: It can be concluded that the Tol-HP-β-CD increased the aqueous solubility and enhanced the oral bioavailability in rabbits. Complexation with HP-β-CD is a feasible way to prepare a rapidly absorbed and more bioavailable Tol

  16. Solubility profiles, hydration and desolvation of curcumin complexed with γ-cyclodextrin and hydroxypropyl-γ-cyclodextrin

    Science.gov (United States)

    Shityakov, Sergey; Salmas, Ramin Ekhteiari; Durdagi, Serdar; Roewer, Norbert; Förster, Carola; Broscheit, Jens

    2017-04-01

    In this study, we investigated curcumin (CUR) solubility profiles and hydration/desolvation effects of this substance formulated with γ-cyclodextrin (γ-CD) and hydroxypropyl-γ-cyclodextrin (HP-γ-CD) excipients. The CUR/HP-γ-CD complex was found to be more stable in solution with the highest apparent stability constant for CUR/HP-γ-CD (Kc = 1.58*104 M-1) as the more soluble form in distilled water. The in silico calculations, including molecular docking, Monte Carlo (MC), and molecular dynamics (MD) simulations, indicated that water molecules play an important role in host-guest complexation mediating the CUR binding to cyclodextrins via hydrogen bond formations. The CUR hydration/desolvation effects contributed to the complex formation by elevating the CUR binding affinity to both CDs. The CUR/HP-γ-CD complex after the CUR hydration was determined with a minimal Gibbs free energy of binding (ΔGbind = -9.93 kcal*mol-1) due to the major hydrophobic (vdW) forces. Overall, the results of this study can aid a development of cyclodextrin-based drug delivery vectors, signifying the importance of water molecules during the formulation processes.

  17. Engineering of factors determining alpha-amylase and cyclodextrin glycosyltransferase specificity in the cyclodextrin glycosyltransferase from Thermoanaerobacterium thermosulfurigenes EM1

    NARCIS (Netherlands)

    Wind, RD; Buitelaar, RM; Dijkhuizen, L

    1998-01-01

    The starch-degrading enzymes alpha-amylase and cyclodextrin glycosyltransferase (CGTase) are functionally and structurally closely related, with CGTases containing two additional domains (called D and E) compared to the three domains of alpha-amylases (A, B and C). Amino acid residue 196

  18. Mechanochemical Preparation of Stable Sub-100 nm γ-Cyclodextrin:Buckminsterfullerene (C60) Nanoparticles by Electrostatic or Steric Stabilization.

    Science.gov (United States)

    Van Guyse, Joachim F R; de la Rosa, Victor R; Hoogenboom, Richard

    2018-02-21

    Buckminster fullerene (C 60 )'s main hurdle to enter the field of biomedicine is its low bioavailability, which results from its extremely low water solubility. A well-known approach to increase the water solubility of C 60 is by complexation with γ-cyclodextrins. However, the formed complexes are not stable in time as they rapidly aggregate and eventually precipitate due to attractive intermolecular forces, a common problem in inclusion complexes of cyclodextrins. In this study we attempt to overcome the attractive intermolecular forces between the complexes by designing custom γ-cyclodextrin (γCD)-based supramolecular hosts for C 60 that inhibit the aggregation found in native γCD-C 60 complexes. The approach entails the introduction of either repulsive electrostatic forces or increased steric hindrance to prevent aggregation, thus enhancing the biomedical application potential of C 60 . These modifications have led to new sub-100 nm nanostructures that show long-term stability in solution. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Host-Guest Complexes of Cyclodextrins and Nanodiamonds as a Strong Non-Covalent Binding Motif for Self-Assembled Nanomaterials.

    Science.gov (United States)

    Schibilla, Frauke; Voskuhl, Jens; Fokina, Natalie A; Dahl, Jeremy E P; Schreiner, Peter R; Ravoo, Bart Jan

    2017-11-13

    We report the inclusion of carboxy- and amine-substituted molecular nanodiamonds (NDs) adamantane, diamantane, and triamantane by β-cyclodextrin and γ-cyclodextrin (β-CD and γ-CD), which have particularly well-suited hydrophobicity and symmetry for an optimal fit of the host and guest molecules. We studied the host-guest interactions in detail and generally observed 1:1 association of the NDs with the larger γ-CD cavity, but observed 1:2 association for the largest ND in the series (triamantane) with β-CD. We found higher binding affinities for carboxy-substituted NDs than for amine-substituted NDs. Additionally, cyclodextrin vesicles (CDVs) were decorated with d-mannose by using adamantane, diamantane, and triamantane as non-covalent anchors, and the resulting vesicles were compared with the lectin concanavalin A in agglutination experiments. Agglutination was directly correlated to the host-guest association: adamantane showed lower agglutination than di- or triamantane with β-CDV and almost no agglutination with γ-CDV, whereas high agglutination was observed for di- and triamantane with γ-CDV. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Cyclodextrin Enhances Corneal Tolerability and Reduces Ocular Toxicity Caused by Diclofenac

    Directory of Open Access Journals (Sweden)

    Hamdy Abdelkader

    2018-01-01

    Full Text Available With advances in refractive surgery and demand for cataract removal and lens replacement, the ocular use of nonsteroidal anti-inflammatory drugs (NSAIDs has increased. One of the most commonly used NSAIDs is diclofenac (Diclo. In this study, cyclodextrins (CDs, α-, β-, γ-, and HP-β-CDs, were investigated with in vitro irritation and in vivo ulceration models in rabbits to reduce Diclo toxicity. Diclo-, α-, β-, γ-, and HP-β-CD inclusion complexes were prepared and characterized and Diclo-CD complexes were evaluated for corneal permeation, red blood cell (RBCs haemolysis, corneal opacity/permeability, and toxicity. Guest- (Diclo- host (CD solid inclusion complexes were formed only with β-, γ-, and HP-β-CDs. Amphipathic properties for Diclo were recorded and this surfactant-like functionality might contribute to the unwanted effects of Diclo on the surface of the eye. Contact angle and spreading coefficients were used to assess Diclo-CDs in solution. Reduction of ocular toxicity 3-fold to16-fold and comparable corneal permeability to free Diclo were recorded only with Diclo-γ-CD and Diclo-HP-β-CD complexes. These two complexes showed faster healing rates without scar formation compared with exposure to the Diclo solution and to untreated groups. This study also highlighted that Diclo-γ-CD and Diclo-HP-β-CD demonstrated fast healing without scar formation.

  1. Encapsulation of lemongrass oil with cyclodextrins by spray drying and its controlled release characteristics.

    Science.gov (United States)

    Phunpee, Sarunya; Ruktanonchai, Uracha Rangsadthong; Yoshii, Hidefumi; Assabumrungrat, Suttichai; Soottitantawat, Apinan

    2017-04-01

    Inclusion of the two isomers of citral (E-citral and Z-citral), components of lemongrass oil, was investigated within the confines of various cyclodextrin (α-CD, β-CD and γ-CD) host molecules. Aqueous complex formation constants for E-citral with α-CD, β-CD and γ-CD were determined to be 123, 185, and 204 L/mol, respectively, whereas Z-citral exhibited stronger affinities (157, 206, and 253 L/mol, respectively). The binding trend γ-CD > β-CD > α-CD is a reflection of the more favorable geometrical accommodation of the citral isomers with increasing cavity size. Encapsulation of lemongrass oil within CDs was undertaken through shaking citral:CD (1:1, 1.5:1, and 2:1 molar ratio) mixtures followed by spray drying. Maximum citral retention occurred at a 1:1 molar ratio with β-CD and α-CD demonstrating the highest levels of total E-citral and Z-citral retention, respectively. Furthermore, the β-CD complex demonstrated the slowest release rate of all inclusion complex powders.

  2. Construction of 6-thioguanine and 6-mercaptopurine carriers based on βcyclodextrins and gold nanoparticles.

    Science.gov (United States)

    Sierpe, R; Noyong, Michael; Simon, Ulrich; Aguayo, D; Huerta, J; Kogan, Marcelo J; Yutronic, N

    2017-12-01

    As a novel strategy to overcome some of the therapeutic disadvantages of 6-thioguanine (TG) and 6-mercaptopurine (MP), we propose the inclusion of these drugs in βcyclodextrin (βCD) to form the complexes βCD-TG and βCD-MP, followed by subsequent interaction with gold nanoparticles (AuNPs), generating the ternary systems: βCD-TG-AuNPs and βCD-MP-AuNPs. This modification increased their solubility and improved their stability, betting by a site-specific transport due to their nanometric dimensions, among other advantages. The formation of the complexes was confirmed using powder X-ray diffraction, thermogravimetric analysis and one and two-dimensional NMR. A theoretical study using DFT and molecular modelling was conducted to obtain the more stable tautomeric species of TG and MP in solution and confirm the proposed inclusion geometries. The deposition of AuNPs onto βCD-TG and βCD-MP via sputtering was confirmed by UV-vis spectroscopy. Subsequently, the ternary systems were characterized by TEM, FE-SEM and EDX to directly observe the deposited AuNPs and evaluate their sizes, size dispersion, and composition. Finally, the in vitro permeability of the ternary systems was studied using parallel artificial membrane permeability assay (PAMPA). Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Enantioseparation of linear and cyclic chiral bis(phenethyl)amines by means of cyclodextrin-modified capillary electrophoresis.

    Science.gov (United States)

    Wedig, M; Thunhorst, M; Laug, S; Decker, M; Lehmann, J; Holzgrabe, U

    2001-09-01

    For two years drugs introduced to the market have had- to be enantiomerically pure. Rapid and cheap methods of high reproducibility must, therefore, be available for evaluation of enantiomeric purity. Within the framework of a larger project dealing with chiral recognition of phenethylamines by means of native and derivatized cyclodextrins it was intended to find capillary electrophoresis methods suitable for separation of the enantiomers of chiral bis(phenethyl)amines and their corresponding cyclic analogues, within 10 min, using small amounts of a chiral selector, to save time and money. Heptakis(2,3-O-diacetyl-6-sulfato)beta-CD was found to be the most promising candidate most often fulfilling these requirements.

  4. β-cyclodextrin functionalized on glass micro-particles: A green catalyst for selective oxidation of toluene to benzaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Tahir, M. Nazir, E-mail: tahir.muhammad_nazir@courrier.uqam.ca [Department of Chemistry and Bioscience, Aalborg University, Frederik Bajers Vej 7H, DK-9220, Aalborg East (Denmark); Department of Chemistry, University of Quebec at Montreal, QC, H3C 3P8 (Canada); Nielsen, Thorbjørn T.; Larsen, Kim L. [Department of Chemistry and Bioscience, Aalborg University, Frederik Bajers Vej 7H, DK-9220, Aalborg East (Denmark)

    2016-12-15

    Highlights: • Functionalization of βCD onto glass micro-particles (GMP-βCD). • Application of GMP-βCD as a green catalyst for the oxidation of toluene. • 82% yield at room temperature. • Repeated use of the catalyst for several cycles. - Abstract: Oxidation of toluene is considered an important process which often requires high temperatures and specific conditions along with heavy-metals based catalysts. In this study, we have developed a green catalyst by functionalizing beta-cyclodextrin onto glass micro-particle surfaces. All surfaces were characterized by X-ray photoelectron spectroscopy and applied to catalyze the selective oxidation of toluene into benzaldehyde (82% yield) at room temperature. The catalyst was stable and could be used repeatedly for several cycles without losing efficiency.

  5. Removal of some organic pollutants in water employing ceramic membranes impregnated with cross-linked silylated dendritic and cyclodextrin polymers.

    Science.gov (United States)

    Allabashi, Roza; Arkas, Michael; Hörmann, Gerold; Tsiourvas, Dimitris

    2007-01-01

    Triethoxysilylated derivatives of poly(propylene imine) dendrimer, polyethylene imine and polyglycerol hyperbranched polymers and beta-cyclodextrin have been synthesized and characterized. These compounds impregnated ceramic membranes made from Al(2)O(3), SiC and TiO(2) and subsequently sol-gel reaction led to their polymerization and chemical bond formation with the ceramic substrates. The resulting organic-inorganic filters were tested for the removal of a variety of organic pollutants from water. They were found to remove of polycyclic aromatic hydrocarbons (up to 99%), of monocyclic aromatic hydrocarbons (up to 93%), trihalogen methanes (up to 81%), pesticides (up to 43%) and methyl-tert-butyl ether (up to 46%).

  6. Organic/inorganic hybrid filters based on dendritic and cyclodextrin "nanosponges" for the removal of organic pollutants from water.

    Science.gov (United States)

    Arkas, Michael; Allabashi, Roza; Tsiourvas, Dimitris; Mattausch, Eva-Maria; Perfler, Reinhard

    2006-04-15

    Long-alkyl chain functionalized poly(propylene imine) dendrimer, poly(ethylene imine) hyperbranched polymer, and beta-cyclodextrin derivatives, which are completely insoluble in water, have the property of encapsulating organic pollutants from water. Ceramic porous filters can be impregnated with these compounds resulting in hybrid organic/ inorganic filter modules. These hybrid filter modules were tested for the effective purification of water, by continuous filtration experiments, employing a variety of water pollutants. It has been established that polycyclic aromatic hydrocarbons (PAHs) can be removed very efficiently (more than 95%), and final concentrations of several ppb (microg/ L) are easily obtained. Representatives of the pollutant group of trihalogen methanes (THMs), monoaromatic hydrocarbons (BTX), and pesticides (simazine) can also be removed (>80%), although the filters are saturated considerably faster in these cases.

  7. Enantioseparation of thalidomide and its hydroxylated metabolites using capillary electrophoresis with various cyclodextrins and their combinations as chiral buffer additives.

    Science.gov (United States)

    Meyring, M; Chankvetadze, B; Blaschke, G

    1999-09-01

    The separation of thalidomide (TD) and its hydroxylated metabolites including their simultaneous enantioseparation was studied in capillary electrophoresis (CE) using four different randomly substituted charged cyclodextrin (CD) derivatives, the combinations of some of them with each other, and beta-CD. TD, as well as two metabolites recently found in incubations of human liver microsomes and human blood, 5-hydroxythalidomide (5-OH-TD) and one of the diastereomeric 5'-hydroxythalidomides (5'-OH-TD), are neutral compounds. Therefore, they were resolved using charged chiral selectors in CE. Two different separation modes (normal polarity and carrier mode) and two different capillaries (fused-silica and polyacrylamide-coated) were tested. Based on the behavior of the individual CDs, their designed combinations were selected in order to improve the separation selectivity and enantioselectivity. Under optimized conditions all three chiral compounds and their enantiomers were resolved simultaneously.

  8. Anaesthetic efficacy of bupivacaine 2-hydroxypropyl-β-cyclodextrin for dental anaesthesia after inferior alveolar nerve block in rats.

    Science.gov (United States)

    Serpe, L; Franz-Montan, M; Santos, C P dos; Silva, C B da; Nolasco, F P; Caldas, C S; Volpato, M C; Paula, E de; Groppo, F C

    2014-05-01

    Bupivacaine is a long-acting local anaesthetic that is widely used in medicine and dentistry. The duration and intensity of its sensory blockade in animal models is increased by its inclusion in complexes with cyclodextrins. The aim of the present study was to evaluate the anaesthetic efficacy of bupivacaine 2-hydroxypropyl-β-cyclodextrin (HPβCD) inclusion complex for dental anaesthesia after inferior alveolar nerve block in rats. Thirty rats were each given an injection close to the mandibular foramen of 0.2ml of one of the following formulations: 0.5% bupivacaine alone; 0.5% bupivacaine with 1:200,000 epinephrine; and 0.5% bupivacaine-HPβCD inclusion complex (bupivacaine-HPβCD). The other sides were used as controls, with either 0.9% saline or anaesthetic-free HPβCD solution being injected. The onset, success, and duration of pulpal anaesthesia were assessed by electrical stimulation ("pulp tester") on inferior molars. Results were analysed using ANOVA (Tukey), log rank, and chi square tests (α=5%). There were no differences among the formulations in onset of anaesthesia (p=0.59) or between the bupivacaine plus epinephrine and bupivacaine plus HPβCD in duration of anaesthesia, but bupivacaine plus epinephrine gave significantly higher values than bupivacaine alone (p=0.007). Bupivacaine plus epinephrine was a better anaesthetic than bupivacaine alone (p=0.02), while Bupi-HPβCD gave intermediate results, and therefore did not differ significantly from the other 2 groups (p=0.18 with bupivacaine alone; and p=0.44 with bupivacaine plus epinephrine). The bupivacaine-HPβCD complex showed similar anaesthetic properties to those of bupivacaine with epinephrine. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  9. Phosphorus-containing cyclodextrins. Characteristics of the synthesis and chemical behaviour

    International Nuclear Information System (INIS)

    Grachev, M K

    2013-01-01

    Published data on the preparation of phosphorus-containing cyclodextrins are summarized. It is demonstrated that some significant features of their synthesis and chemical behaviour are caused by specific supramolecular interactions involving the inner chiral cavity of cyclodextrins capable of incorporating various guests, which often leads to alteration of customary routes of chemical transformations. The possibilities of practical applications of phosphorus-containing cyclodextrins are briefly analyzed. The bibliography includes 89 references

  10. Evaluation of hydroxypropyl-b-cyclodextrin in the treatment of aldicarb poisoning in rats : short communication

    Directory of Open Access Journals (Sweden)

    R.S. Verster

    2004-06-01

    Full Text Available Cyclodextrins are ring-shaped oligosaccharides with a hydrophilic exterior and a hydrophobic interior. The interior cavity is capable of complexing fat-soluble molecules small enough to fit inside. Sprague-Dawley rats were used to evaluate the efficacy of hydroxypropyl-b-cyclodextrin as treatment of aldicarb poisoning in rats. Survival times in the majority of rats dosed with aldicarb and receiving intravenous cyclodextrin were longer compared with the control rats only dosed with aldicarb per os.

  11. A new purity criterion for α- and β-cyclodextrin using partition chromatography on cellulose columns

    NARCIS (Netherlands)

    Lammers, J.N.J.J.

    1967-01-01

    In order to check the purity of a- and b-cyclodextrins with respect to each other partition chromatog. on cellulose columns was used (elution with 42:29:29 BuOH-EtOH-H2O, 0.3 atm. air pressure on the solvent reservoir; 75-90 ml./hr. flow rate). Amts. down to 2.5% a-cyclodextrin (I) in b-cyclodextrin

  12. A combinatorial approach of inclusion complexation and dendrimer synthesization for effective targeting EGFR-TK.

    Science.gov (United States)

    Shende, Pravin; Patil, Sampada; Gaud, R S

    2017-07-01

    The aim of the present study was to use a combinatorial approach of inclusion complexation and dendrimer synthesization of gefitinib using solvent-free technique for targeting EGFR-TK to treat Non-Small-Cell Lung Cancer (NSCLC). The inclusion complex of gefitinib with β-cyclodextrin was prepared by trituration method. This complex encapsulated G4 PAMAM dendrimers were synthesized by Michael addition and amidation reactions using green chemistry and then PEGylated by conjugation reaction. FTIR and DSC confirmed the formation of inclusion complex of gefitinib and β-cyclodextrin and PEGylation of G4 PAMAM dendrimers. Gefitinib showed higher solubility, encapsulation efficiency and controlled release profile from PEGylated dendrimers compared to inclusion complex. The PEGylated dendrimers of inclusion complex of gefitinib were found to reduce hemolytic toxicity and lesser GI 50 value on Human lung cancer cell line A-549 by effective targeting EGFR-TK. A combinatorial approach of inclusion complexation and dendrimer synthesization is one of the alternative advanced approaches to treat NSCLC. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Fast dissolving cyclodextrin complex of piroxicam in solid dispersion part I: influence of β-CD and HPβ-CD on the dissolution rate of piroxicam.

    Science.gov (United States)

    Bouchal, F; Skiba, M; Chaffai, N; Hallouard, F; Fatmi, S; Lahiani-Skiba, M

    2015-01-30

    Sublingual drug delivery is an interesting route for drug having significant hepatic first-pass metabolism or requiring rapid pharmacological effect as for patients suffering from swallowing difficulties, nausea or vomiting. Sublingual absorption could however be limited by the kinetic of drug dissolution. This study evaluated influences of cyclodextrins (β-CD or HP-β-CD) and their different inclusion process (spray-drying or freeze-drying) on the drug dissolution kinetic of solid dispersions in poly(ethylene glycol) (PEG, Mw 6000Da) of piroxicam, used as poor hydrosoluble drug model. A secondary objective was to determine influences of drug dispersion process in PEG (evaporation or melting methods) on the drug dissolution kinetic of piroxicam. Piroxicam solid dispersions containing or not cyclodextrins were characterized by different scanning calorimetry (DSC), Thermogravometry analyser (TGA) and Fourier transform-infrared spectroscopy (FT-IR) spectroscopy. In vitro drug dissolution study of these solid dispersions was then performed. The results demonstrated the high potential and interest of solid dispersions of drug previously included in cyclodextrins for sublingual delivery of hydrophobic drugs. This study also showed the advantages of evaporation method on the melting ones during drug dispersion in PEG. Indeed, drug complexation with cyclodextrins as dispersion by melting prevented the presence in solid dispersions of drug in crystalline form which can represent up to 63%. Moreover, dispersion in PEG by evaporation method gave more porous drug delivery system than with melting methods. This allowed complete (limited at most at 80-90% with melting methods) and quick drug dissolution without rebound effect like with melting ones. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Attached β-cyclodextrin/γ-(2,3-epoxypropoxy) propyl trimethoxysilane to graphene oxide and its application in copper removal.

    Science.gov (United States)

    Yu, Zongxue; Chen, Qi; Lv, Liang; Pan, Yang; Zeng, Guangyong; He, Yi

    2017-05-01

    The environmental applications of graphene oxide and β-cyclodextrin (β-CD) have attracted great attention since their first discovery. Novel nanocomposites were successfully prepared by using an esterification reaction between β-cyclodextrin/γ-(2,3-epoxypropoxy) propyl trimethoxysilane grafted graphene oxide (β-CD/GPTMS/GO). The β-CD/GPTMS/GO nanocomposites were used to remove the Cu 2+ from aqueous solutions. The characteristics of β-CD/GPTMS/GO were detected by scanning electron microscopy (SEM), Fourier transform infrared, X-ray diffraction (XRD), thermogravimetric analysis (TG) and energy dispersive X-ray (EDX). The dispersibility of graphene oxide was excellent due to the addition of β-CD. The adsorption isotherms data obtained at the optimum pH 7 were fitted by Langmuir isotherm model. The excellent adsorption properties of β-CD/GPTMS/GO for Cu 2+ ions could be attributed to the apolar cavity structure of β-CD, the high surface area and abundant functional groups on the surface of GO. The adsorption patterns of β-CD/GPTMS/GO were electrostatic attraction, formation of host-guest inclusion complexes and the ion exchange adsorption. The efficient adsorption of β-CD/GPTMS/GO for Cu 2+ ions suggested that these novel nanocomposites may be ideal candidates for removing other cation pollutants from waste water.

  15. Adsorption of environmental pollutants using magnetic hybrid nanoparticles modified with β-cyclodextrin

    International Nuclear Information System (INIS)

    Wang, Niejun; Zhou, Lilin; Guo, Jun; Ye, Qiquan; Lin, Jin-Ming; Yuan, Jinying

    2014-01-01

    Graft through strategy was utilized to coat magnetic Fe 3 O 4 nanoparticles with poly(glycidyl methacrylate) using ordinary radical polymerization and then β-cyclodextrin was linked onto the surface of nanoparticles. With these nanoparticles modified with cyclodextrin groups, adsorption of two model environmental pollutants, bisphenol A and copper ions, was studied. Host–guest interactions between cyclodextrin and aromatic molecules had a great contribution to the adsorption of bisphenol A, while multiple hydroxyls of cyclodextrin also helped the adsorption of copper ions. These magnetic nanoparticles could be applied in the elimination, enrichment and detection of some environmental pollutants.

  16. Confronting New Demands : Inclusive Growth, Inclusive Trade ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Confronting New Demands : Inclusive Growth, Inclusive Trade. Policymakers, businesspeople and civil society advocates need evidence-based research to react ... understood implications, such as labour standards and intellectual property; ...

  17. New ethanol and propylene glycol free gel formulations containing a minoxidil-methyl-β-cyclodextrin complex as promising tools for alopecia treatment.

    Science.gov (United States)

    Lopedota, Angela; Cutrignelli, Annalisa; Denora, Nunzio; Laquintana, Valentino; Lopalco, Antonio; Selva, Stefano; Ragni, Lorella; Tongiani, Serena; Franco, Massimo

    2015-05-01

    New topical totally aqueous formulations that improve the low water solubility of minoxidil and realize an adequate permeability of drug in the skin are proposed. These formulations are lacking in propylene glycol and alcohol that are the principal irritant ingredients present in minoxidil commercial solutions. In order to enhance poor water solubility of minoxidil randomly methyl-β-cyclodextrin was used, and four hydrogels such as, calcium alginate, sodium alginate, carbopol 934 and hydroxyethylcellulose were utilized to ensure a prolonged time of contact with the scalp. The inclusion complex minoxidil/methyl-β-cyclodextrin with a molar ratio 1:1 was obtained by freeze drying and evaluated by NMR, FT-IR and DSC analysis. An apparent stability constant of formed inclusion complex was calculated by phase solubility diagram and its value was 400 M(-1). The solid inclusion complex was used to prepare gel formulations with similar dose to minoxidil commercial solution. The gels were evaluated for various technological parameters including rheological behavior, in vitro drug release and ex vivo permeation through pig skin. The best performance was observed for the calcium alginate formulation.

  18. Antibiotic resistance patterns and beta-lactamase identification in ...

    African Journals Online (AJOL)

    Children acquire bacteria from their mother during birth,[3,4] and ... Our results revealed high resistance rates to co-trimoxazole (54.0%), penicillin .... the inclusion of a beta-lactamase inhibitor, clavulanic acid. .... Folate pathway inhibitor/.

  19. Inclusion complex and nanoclusters of cyclodextrin to increase the solubility and efficacy of albendazole

    Science.gov (United States)

    Albendazole (ABZ), a benzimidazole widely used to control gastrointestinal parasites is poorly soluble in water, resulting in variable and incomplete bioavailability, which has favored the appearance of parasite resistance and, consequently, clinical ineffectiveness. Among the pharmaceutical techniq...

  20. A heuristic model to quantify the impact of excess cyclodextrin on oral drug absorption from aqueous solution

    DEFF Research Database (Denmark)

    Olesen, Niels Erik; Westh, Peter; Holm, René

    2016-01-01

    , the cyclodextrin concentration in the drug product must be higher than the amount needed to solubilise the compound, due to the displacement of the drug from the cyclodextrin cavity by bile salts in the intestinal lumen. On the other hand, dosing cyclodextrin at View the MathML source>DtotSC is expected to result...... the implication of having excess cyclodextrin in an oral solution....

  1. Insights into the multi-equilibrium, superstructure system based on β-cyclodextrin and a highly water soluble guest.

    Science.gov (United States)

    De Paula, Elgte Elmin B; De Sousa, Frederico B; Da Silva, Júlio César C; Fernandes, Flaviana R; Melo, Maria Norma; Frézard, Frédéric; Grazul, Richard M; Sinisterra, Rubén D; Machado, Flávia C

    2012-12-15

    Pentamidine isethionate (PNT) is an antiprotozoal active in many cases of leishmaniasis, despite the present limitations including high toxicity and parenteral administration. In the present work, a PNT encapsulation strategy into β-cyclodextrin cavity at 1:1 and 2:1 (βCD:PNT) molar ratios was used in order to improve the drug's physical and chemical properties. Combining thermodynamic and structural approaches such as isothermal titration calorimetry (ITC), electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance ((1)H NMR, and ROESY) the inclusion process and the thermodynamics parameters were identified. ITC and ESI-MS experimental data suggest the simultaneous formation of different supramolecular complexes in solution. Moreover, NMR data are in accordance with these results, suggesting a deep inclusion of PNT into the βCD cavity, through correlations observed in 2D ROESY contour maps. The systems were also characterized by FTIR, TG/DTA and SEM. These techniques indicate the formation of inclusion complex in the solid state. In vivo PNT activity was evaluated orally in mice. The inclusion complex showed a significant reduction of parasite load compared to free PNT. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Photoinduced electron transfer within porphyrin-cyclodextrin conjugates

    Czech Academy of Sciences Publication Activity Database

    Lang, Kamil; Král, V.; Kapusta, P.; Kubát, Pavel; Vašek, P.

    2002-01-01

    Roč. 43, - (2002), s. 4919-4922 ISSN 0040-4039 R&D Projects: GA ČR GA203/99/1163; GA ČR GA203/01/0634; GA ČR GA203/02/1483 Institutional research plan: CEZ:AV0Z4032918 Keywords : porphyrin-cyclodextrin * chiral aggregate * quenching Subject RIV: CA - Inorganic Chemistry Impact factor: 2.357, year: 2002

  3. Removal of emerging micropollutants from water using cyclodextrin.

    Science.gov (United States)

    Nagy, Zsuzsanna Magdolna; Molnár, Mónika; Fekete-Kertész, Ildikó; Molnár-Perl, Ibolya; Fenyvesi, Éva; Gruiz, Katalin

    2014-07-01

    Small scale laboratory experiment series were performed to study the suitability of a cyclodextrin-based sorbent (ß-cyclodextrin bead polymer, BCDP) for modelling the removal of micropollutants from drinking water and purified waste water using simulated inflow test solutions containing target analytes (ibuprofen, naproxen, ketoprofen, bisphenol-A, diclofenac, β-estradiol, ethinylestradiol, estriol, cholesterol at 2-6 μg/L level). This work was focused on the preliminary evaluation of BCDP as a sorbent in two different model systems (filtration and fluidization) applied for risk reduction of emerging micropollutants. For comparison different filter systems combined with various sorbents (commercial filter and activated carbon) were applied and evaluated in the filtration experiment series. The spiked test solution (inflow) and the treated outflows were characterized by an integrated methodology including chemical analytical methods gas chromatography-tandem mass spectrometry (GC-MS/MS) and various environmental toxicity tests to determine the efficiency and selectivity of the applied sorbents. Under experimental conditions the cyclodextrin-based filters used for purification of drinking water in most cases were able to absorb more than 90% of the bisphenol-A and of the estrogenic compounds. Both the analytical chemistry and toxicity results showed efficient elimination of these pollutants. Especially the toxicity of the filtrate decreased considerably. Laboratory experiment modelling post-purification of waste water was also performed applying fluidization technology by ß-cyclodextrin bead polymer. The BCDP removed efficiently from the spiked test solution most of the micropollutants, especially the bisphenol-A (94%) and the hormones (87-99%) The results confirmed that the BCDP-containing sorbents provide a good solution to water quality problems and they are able to decrease the load and risk posed by micropollutants to the water systems. Copyright © 2014

  4. β-Cyclodextrin hydrogels for the ocular release of antibacterial thiosemicarbazones.

    Science.gov (United States)

    Glisoni, Romina J; García-Fernández, María J; Pino, Marylú; Gutkind, Gabriel; Moglioni, Albertina G; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Sosnik, Alejandro

    2013-04-02

    Two types of hydrophilic networks with conjugated beta-cyclodextrin (β-CD) were developed with the aim of engineering useful platforms for the localized release of an antimicrobial 5,6-dimethoxy-1-indanone N4-allyl thiosemicarbazone (TSC) in the eye and its potential application in ophthalmic diseases. Poly(2-hydroxyethyl methacrylate) soft contact lenses (SCLs) displaying β-CD, namely pHEMA-co-β-CD, and super-hydrophilic hydrogels (SHHs) of directly cross-linked hydroxypropyl-β-CD were synthesized and characterized regarding their structure (ATR/FT-IR), drug loading capacity, swelling and in vitro release in artificial lacrimal fluid. Incorporation of TSC to the networks was carried out both during polymerization (DP method) and after synthesis (PP method). The first method led to similar drug loads in all the hydrogels, with minor drug loss during the washing steps to remove unreacted monomers, while the second method evidenced the influence of structural parameters on the loading efficiency (proportion of CD units, mesh size, swelling degree). Both systems provided a controlled TSC release for at least two weeks, TSC concentrations (up to 4000μg/g dry hydrogel) being within an optimal therapeutic window for the antimicrobial ocular treatment. Microbiological tests against P. aeruginosa and S. aureus confirmed the ability of TSC-loaded pHEMA-co-β-CD network to inhibit bacterial growth. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Enhancement of solubility of albendazole by complexation with β-cyclodextrin

    International Nuclear Information System (INIS)

    Moriwaki, C.; Costa, G.L.; Ferracini, C.N.; Matioli, G.; Moraes, F.F. de; Zanin, G.M.; Pineda, E.A.G.

    2008-01-01

    A high dosage of albendazole (ABZ) is required for treating systemic helminth infections because of its low solubility. Aiming at increasing ABZ solubility, complexation with beta-cyclodextrin (β-CD) using aqueous and acetic acid solutions as ABZ solubiliser was studied. In aqueous β-CD, complexation increased solubility 53.4 times, giving a complex equilibrium constant of 1266 L mol -1 with a maximum ABZ concentration of 276 μmol L -1 for 16.3 mmol L -1 β-CD. For complexation in 1.05 mol L -1 acetic acid, UV absorbance spectra and 1 H-NMR analysis confirmed complex formation. The UV absorbance of ABZ/acid acetic/β-CD solutions was modeled by the formation of two complexes with molar ratios 1:1 and 1:2 ABZ:β-CD. When neutralized with NaOH these solutions did not form precipitates only for the ABZ:β-CD molar ratios of 1:8 and 1:10, showing that ABZ solubility could be increased 306 times. Results show that high β-CD molar ratios hold ABZ in solution by complexation enhanced by the acetate anion. (author)

  6. Physico-Chemical Properties and Phase Behavior of the Ionic Liquid-β-Cyclodextrin Complexes

    Directory of Open Access Journals (Sweden)

    Michał Wlazło

    2013-08-01

    Full Text Available The solubility of β-cyclodextrin (β-CD in ionic liquids (ILs and the activity coefficients at infinite dilution ( of more than 20 solutes (alkanes, aromatic hydrocarbons, alcohols were measured in four chosen ionic liquids, their mixtures with β-CD, and in the β-CD at high temperatures from 338 to 398 K using the inverse gas chromatography. The intermolecular interactions, inclusion complexes and the possible increasing of the solubility of β-CD in water using the IL are presented. The solubility of β-CD in ten chosen hydrophobic ILs at the temperature T = 423 K was detected. The solid-liquid phase diagrams (SLE of {IL (1 + β-CD (2} binary systems at the high mole fraction of the IL were measured for three systems (1-ethyl-3-methylimidazolium chloride, [EMIM][Cl], 1-ethyl-3-methylimidazolium bromide, [EMIM][Br]; and for 1-butyl-3-methylimidazolium chloride, [BMIM][Cl]. The eutectic points were determined at the high IL concentration for all binary systems. The intermolecular interaction and the possibility of inclusion complexes of the IL and/or solvents with β-CD were discussed. The infrared spectroscopy, IR was used for the description of the intermolecular interactions in the (β-CD + IL systems. It was shown via the activity coefficients at infinite dilution results that the inclusion complexes are dependent on the temperature. The addition of β-CD to the IL does not improve the selectivity of the separation of the aliphatics from aromatics.

  7. Determination of the glass transition temperature of cyclodextrin polymers.

    Science.gov (United States)

    Tabary, Nicolas; Garcia-Fernandez, Maria Jose; Danède, Florence; Descamps, Marc; Martel, Bernard; Willart, Jean-François

    2016-09-05

    The aim of this work was to determine the main physical characteristics of β-cyclodextrin polymers, well known for improving complexation capacities and providing enhanced and sustained release of a large panel of drugs. Two polymers were investigated: a polymer of β-cyclodextrin (polyβ-CD) and a polymer of partially methylated (DS=0.57) β-cyclodextrin (polyMe-β-CD). The physical characterizations were performed by powder X-ray diffraction and differential scanning calorimetry. The results indicate that these polymers are amorphous and that their glass transition is located above the thermal degradation point of the materials preventing their direct observation and thus their full characterization. We could however estimate the virtual glass transition temperatures by mixing the polymers with different plasticizers (trehalose and mannitol) which decreases Tg sufficiently to make the glass transition observable. Extrapolation to zero plasticizer concentration then yield the following Tg values: Tg (polyMe-β-CD)=317°C±5°C and Tg (polyβ-CD)=418°C±6°C. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Studies on inclusion complex as potential systems for enhancement of oral bioavailability of olmesartan medoxomil

    Directory of Open Access Journals (Sweden)

    Hetal Paresh Thakkar

    2012-01-01

    Full Text Available Background: Olmesartan medoxomil (OLM, an anti-hypertensive agent administered orally, has absolute bioavailability of only 26% due to the poor aqueous solubility (7.75 μg/ml. Inclusion complexation with cyclodextrins (CD has been reported to increase the aqueous solubility of various compounds. Aim: The present investigation aimed to enhancing the oral bioavailability of OLM by inclusion complexation with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD. Materials and Methods: The inclusion complexes with HP-β-CD were prepared using two different methods, viz., physical mixture and kneading. The prepared complexes were characterized for various parameters such as drug content, aqueous solubility, dissolution study, in vitro diffusion, intestinal permeability and stability study. The formation of the inclusion complex was confirmed by differential scanning calorimetry, X-ray diffraction, and Fourier transform infrared spectroscopy. Results: The solubility, dissolution, diffusion rate, and intestinal permeability of the prepared complexes were found to be significantly higher than that of the plain drug. Among the two methods used for formation of inclusion complex, KN method gave higher solubility rates and hence is a better method when compared with PM. Conclusion: The approach seems to be promising in improving the oral bioavailability of OLM.

  9. Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

    Directory of Open Access Journals (Sweden)

    Élise Euvrard

    2016-08-01

    Full Text Available In this study, a polymer, prepared by crosslinking cyclodextrin (CD by means of a polycarboxylic acid, was used for the removal of pollutants from spiked solutions and discharge waters from the surface treatment industry. In spiked solutions containing five metals, sixteen polycyclic aromatic hydrocarbons (PAH and three alkylphenols (AP, the material exhibited high adsorption capacities: >99% of Co2+, Ni2+ and Zn2+ were removed, between 65 and 82% of the PAHs, as well as 69 to 90% of the APs. Due to the structure of the polymer and its specific characteristics, such as the presence of carboxylic groups and CD cavities, the adsorption mechanism involves four main interactions: ion exchange, electrostatic interactions and precipitation for metal removal, and inclusion complexes for organics removal. In industrial discharge waters, competition effects appeared, especially because of the presence of calcium at high concentrations, which competed with other pollutants for the adsorption sites of the adsorbent.

  10. Enhanced bioavailability of orally administered flurbiprofen by combined use of hydroxypropyl-cyclodextrin and poly(alkyl-cyanoacrylate) nanoparticles.

    Science.gov (United States)

    Zhao, Xiaoyun; Li, Wei; Luo, Qiuhua; Zhang, Xiangrong

    2014-03-01

    Flurbiprofen was formulated into nanoparticle suspension to improve its oral bioavailability. Hydroxypropyl-β-cyclodextrin inclusion-flurbiprofen complex (HP-β-CD-FP) was prepared, then incorporating this complex into poly(alkyl-cyanoacrylate) (PACA) nanoparticles. HP-β-CD-FP-PACA nanoparticle was prepared by the emulsion solvent polymerization method. The zeta potential was -26.8 mV, the mean volume particle diameter was 134 nm, drug encapsulation efficiency was 53.3 ± 3.6 % and concentration was 1.5 mg/mL. The bioavailability of flurbiprofen from optimized nanoparticles was assessed in male Wistar rats at a dose of 15 mg/kg. As compared to the flurbiprofen suspension, 211.6 % relative bioavailability was observed for flurbiprofen nanoparticles. The reduced particle size and increased surface area may contribute to improve oral bioavailability of flurbiprofen.

  11. Extending the hydrophobic cavity of β-cyclodextrin results in more negative heat capacity changes but reduced binding affinities

    DEFF Research Database (Denmark)

    Schönbeck, Christian; Holm, René; Westh, Peter

    2014-01-01

    The formation of inclusion complexes of hydroxypropylated β-cyclodextrins (CDs) with three bile salts are investigated to shed light on the role played by the hydroxypropyl (HP) substituents. The HP-chains are situated at the rim of the CD and may thus extend the hydrophobic cavity of the CD....... Calorimetric titrations in a broad temperature range and molecular dynamics simulations confirm previous speculations that the HP-chains cause an increase in dehydrated nonpolar surface area upon formation of the complexes. This additional burial of nonpolar surface area, 12–16 Å2 per HP-chain according...... CD (but depend on the type of bile salt). Interestingly, these convergence temperatures are close to what is observed for unfolding of proteins and may be a common feature of hydrophobic dehydration....

  12. Predicting Complexation Thermodynamic Parameters of β-Cyclodextrin with Chiral Guests by Using Swarm Intelligence and Support Vector Machines

    Directory of Open Access Journals (Sweden)

    Luckhana Lawtrakul

    2009-05-01

    Full Text Available The Particle Swarm Optimization (PSO and Support Vector Machines (SVMs approaches are used for predicting the thermodynamic parameters for the 1:1 inclusion complexation of chiral guests with β-cyclodextrin. A PSO is adopted for descriptor selection in the quantitative structure-property relationships (QSPR of a dataset of 74 chiral guests due to its simplicity, speed, and consistency. The modified PSO is then combined with SVMs for its good approximating properties, to generate a QSPR model with the selected features. Linear, polynomial, and Gaussian radial basis functions are used as kernels in SVMs. All models have demonstrated an impressive performance with R2 higher than 0.8.

  13. Photoprocesses of photosensitizing drugs within cyclodextrin cavities.

    Science.gov (United States)

    Monti, Sandra; Sortino, Salvatore

    2002-09-01

    Recently some interest has been focused on the photobehavior of CD-drug inclusion complexes in relation to the problem of the biological photosensitization by drugs. This review is dedicated to the illustration of the mechanistic aspects of the photoprocesses occurring in some non-steroidal anti-inflammatory drugs (NSAIDs), with photosensitising side effects, within CD cavities. It is shown how the photobehavior of the CD-drug associates can help to model the photoreactivity of the drugs in biological sites. The limitations for the use of CDs as protective systems for the clinical administration of photosensitising drugs is also evidenced.

  14. Self-Assembled Monolayers on Gold of β-Cyclodextrin Adsorbates with Different Anchoring Groups

    NARCIS (Netherlands)

    Méndez Ardoy, Alejandro; Steentjes, Tom; Kudernac, Tibor; Huskens, Jurriaan

    2014-01-01

    We designed multivalent β-cyclodextrin-based adsorbates bearing different anchoring groups aiming to yield stable monolayers with improved packing and close contact of the cavity to the gold surface. Toward this end the primary rim of the β-cyclodextrin was decorated with several functional groups,

  15. The effects of cyclodextrins on drug release from fatty suppository bases : I. In vitro observations

    NARCIS (Netherlands)

    Frijlink, H.W.; Eissens, Anko; Schoonen, Adelbert; Lerk, C.F.

    The effect of cyclodextrins on suppository drug release was investigated. Complexes of several lipophilic drugs with β- and/or γ-cyclodextrin were prepared using the coprecipitation method. The formation of true complexes was confirmed by DSC and an 'ether-wash' method. Witepsol H15 suppositories

  16. Limits to Inclusion

    Science.gov (United States)

    Hansen, Janne Hedegaard

    2012-01-01

    In this article, I will argue that a theoretical identification of the limit to inclusion is needed in the conceptual identification of inclusion. On the one hand, inclusion is formulated as a vision that is, in principle, limitless. On the other hand, there seems to be an agreement that inclusion has a limit in the pedagogical practice. However,…

  17. Does the Digestibility of Cyclodextrins Influence the In Vivo Absorption of Benzo[a] pyrene in Rats?

    DEFF Research Database (Denmark)

    Olesen, Niels Erik; Vana, Vasiliki; Holm, Rene

    2016-01-01

    -Cyclodextrin is digestible in contrast to b-cyclodextrins. This could potentially limit the sensitivity toward overdose, which was evaluated using benzo[a] pyrene in this study, in which rats were administered benzo[a] pyrene and different doses of the 2 cyclodextrins. Both cyclodextrins lowered the area under the curve......,000 at the concentration where a significant decrease in the absorption was observed. No difference was observed between the 2 cyclodextrins, so digestibility seemed less important. More interesting was that the decrease in absorption was relatively small when compared with literature values, suggesting that the effect...

  18. Thermodynamics of chiral selectivity in capillary electrophoresis : separation of ibuprofen enantiomers with beta-cyclodextrin

    NARCIS (Netherlands)

    Reijenga, J.C.; Ingelse, B.A.; Everaerts, F.M.

    1997-01-01

    The effect of temperature on the electrophoretic chiral separation of ibuprofen with ß-CD was investigated. Background electrolytes with sodium acetate or formate were chosen because of their constant pK within 0.03 units in the temperature range 25–50°C. Ibuprofen has a temperature independent pK

  19. Characterization of a single-isomer carboxymethyl-beta-cyclodextrin in chiral capillary electrophoresis.

    Science.gov (United States)

    Fejős, Ida; Varga, Erzsébet; Benkovics, Gábor; Malanga, Milo; Sohajda, Tamás; Szemán, Julianna; Béni, Szabolcs

    2017-08-01

    In this work, the synthesis, characterization, and chiral capillary electrophoretic study of heptakis-(2,3-di-O-methyl-6-O-carboxymethyl)-β-CD (HDMCM), a single-isomer carboxymethylated CD, are presented. The pH-dependent and selector concentration-dependent enantiorecognition properties of HDMCM were investigated and discussed herein. The enantioseparation was assessed applying a structurally diverse set of noncharged, basic, and zwitterionic racemates. The increase in the selector concentration and gross negative charge of HDMCM improved the enantioseparation that could be observed in the majority of the cases. HDMCM was also successfully applied as BGE additive in NACE using a methanol-based system in order to prove the separation selectivity features and to highlight the broad applicability of HDMCM. Over 25 racemates showed partial or baseline separation with HDMCM under the conditions investigated, among which optimal enantiomer migration order was found for the four stereoisomers of tadalafil, tapentadol, and dapoxetine, offering the possibility of a chiral CE method development for chiral purity profiling of these drugs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Host-Guest Interaction between Herbicide Oxadiargyl and Hydroxypropyl- β -Cyclodextrin

    Directory of Open Access Journals (Sweden)

    Sofia Benfeito

    2013-01-01

    Full Text Available In the face of a growing human population and increased urbanization, the demand for pesticides will simply rise. Farmers must escalate yields on increasingly fewer farm acres. However, the risks of pesticides, whether real or perceived, may force changes in the way these chemicals are used. Scientists are working toward pest control plans that are environmentally sound, effective, and profitable. In this context the development of new pesticide formulations which may improve application effectiveness, safety, handling, and storage can be pointed out as a solution. As a contribution to the area, the microencapsulation of the herbicide oxadiargyl (OXA in (2-hydroxypropyl-β-cyclodextrin (HP-β-CD was performed. The study was conducted in different aqueous media (ultrapure water and in different pH buffer solutions. In all cases an increment of the oxadiargyl solubility as a function of the HP-β-CD concentration that has been related to the formation of an inclusion complex was verified. UV-Vis and NMR experiments allowed concluding that the stoichiometry of the OXA/HP-β-CD complex formed is 1 : 1. The gathered results can be regarded as an important step for its removal from industrial effluents and/or to increase the stabilizing action, encapsulation, and adsorption in water treatment plants.

  1. Molecular binding thermodynamics of spherical guests by β-cyclodextrins bearing aromatic substituents

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nan; Chen, Yong; Zhang, Ying-Ming; Wang, Li-Hua; Mao, Wen-Zhao; Liu, Yu, E-mail: yuliu@nankai.edu.cn

    2014-01-20

    Graphical abstract: - Highlights: • Different conformation of β-CD derivatives. • Enthalpy gain. • High binding ability. - Abstract: The molecular binding behaviors of two β-cyclodextrin (β-CD) derivatives bearing 1,2,3-triazole moieties, i.e. mono-6-deoxy-6-{4-(8-oxymethylquinolino)[1,2,3]triazolyl}-β-CD (1) and mono-6-deoxy-6-{4-(8-oxymethylnaphthol)[1,2,3]triazolyl}-β-CD (3), and their analogs without 1,2,3-triazole moieties, i.e. mono-6-deoxy-6-(8-oxymethylquinolino)-β-CD (2) and mono-6-deoxy-6-(8-oxymethylnaphthol)-β-CD (4) toward spherical guests (±)-borneol and (±)-camphor were investigated to elucidate how substituent moiety of host affects the binding abilities by 2D NMR as well as microcalorimetric titrations in aqueous phosphate buffer solution (pH 7.20) at 298.15 K. The binding modes of host–guest interactions obtained from 2D NMR displayed that host CDs without triazole moieties gave better induce-fit efficiency between hosts and guests, leading to stronger binding abilities. Thermodynamically, the inclusion complexation was driven by enthalpy with the stoichiometry of 1:1. Another factor contributed to the enhanced binding abilities was the enthalpy gain with the smaller entropy loss.

  2. Optimization of a method for preparing solid complexes of essential clove oil with β-cyclodextrins.

    Science.gov (United States)

    Hernández-Sánchez, Pilar; López-Miranda, Santiago; Guardiola, Lucía; Serrano-Martínez, Ana; Gabaldón, José Antonio; Nuñez-Delicado, Estrella

    2017-01-01

    Clove oil (CO) is an aromatic oily liquid used in the food, cosmetics and pharmaceutical industries for its functional properties. However, its disadvantages of pungent taste, volatility, light sensitivity and poor water solubility can be solved by applying microencapsulation or complexation techniques. Essential CO was successfully solubilized in aqueous solution by forming inclusion complexes with β-cyclodextrins (β-CDs). Moreover, phase solubility studies demonstrated that essential CO also forms insoluble complexes with β-CDs. Based on these results, essential CO-β-CD solid complexes were prepared by the novel approach of microwave irradiation (MWI), followed by three different drying methods: vacuum oven drying (VO), freeze-drying (FD) or spray-drying (SD). FD was the best option for drying the CO-β-CD solid complexes, followed by VO and SD. MWI can be used efficiently to prepare essential CO-β-CD complexes with good yield on an industrial scale. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  3. β-Cyclodextrin functionalised gold nanoclusters as luminescence probes for the ultrasensitive detection of dopamine.

    Science.gov (United States)

    Ban, Rui; Abdel-Halim, E S; Zhang, Jianrong; Zhu, Jun-Jie

    2015-02-21

    A novel luminescence probe based on mono-6-amino-β-cyclodextrin (NH2-β-CD) functionalised gold nanoclusters (β-CD-AuNC) was designed for dopamine (DA) detection. The NH2-β-CD molecules were conjugated onto the surface of 11-mercaptoundecanoic acid capped AuNCs (11-MUA-AuNC) via a carbodiimide coupling reaction. The integrity of the β-CD cavities was preserved on the surface of AuNCs and they retained their capability for molecular DA host-guest recognition. DA could be captured by the β-CD cavities to form an inclusion complex in which the oxidised DA could quench the fluorescence of the β-CD-AuNC probe by electron transfer. The probe could be used to quantify DA in the range of 5-1000 nM with a detection limit of 2 nM. This sensitivity was 1-2 orders of magnitude higher than that in previously reported methods. Interference by both ascorbic acid (AA) and uric acid (UA) was not observed. Therefore, the β-CD-AuNC probe could be directly used to determine the DA content in biological samples without further separation. This strategy was successfully applied to a DA assay in spiked human serum samples and it exhibited remarkable accuracy, sensitivity and selectivity.

  4. Cyclodextrin conjugated magnetic colloidal nanoparticles as a nanocarrier for targeted anticancer drug delivery

    International Nuclear Information System (INIS)

    Banerjee, Shashwat S; Chen, D.-H.

    2008-01-01

    A novel magnetic nanocarrier (CD-GAMNPs) was fabricated for targeted anticancer drug delivery by grafting cyclodextrin (CD) onto gum arabic modified magnetic nanoparticles (GAMNPs) using hexamethylene diisocyanate (HMDI) as a linker. Analyses by transmission electron microscopy (TEM) and dynamic light scattering (DLS) revealed that the product had a mean diameter of 17.1 nm and a mean hydrodynamic diameter of 44.1 nm. The CD grafting was confirmed by Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA) indicated that the amount of CD grafted on the GAMNPs was 16.8 mg g -1 . The study on the loading of anticancer drug all-trans-retinoic acid (retinoic acid) revealed that the newly fabricated magnetic nanocarrier possessed a considerably higher adsorption capability as compared to GAMNPs due to the special hydrophobic cavity structure of CD, which could act as a host-guest complex with retinoic acid. Furthermore, it was found that the complexation of CD-GAMNPs with retinoic acid was exothermic and the presence of a surfactant (sodium dodecyl sulfate) led to the decrease in the inclusion of retinoic acid because the linear structure of sodium dodecyl sulfate made it easier to enter the cavity of CD as compared to less linear retinoic acid. In addition, the in vitro release profile of retinoic acid from CD-GAMNPs was characterized by an initial fast release followed by a delayed release phase

  5. Novel Solid Encapsulation of Ethylene Gas Using Amorphous α-Cyclodextrin and the Release Characteristics.

    Science.gov (United States)

    Ho, Binh T; Bhandari, Bhesh R

    2016-05-04

    This research investigated the encapsulation of ethylene gas into amorphous α-cyclodextrins (α-CDs) at low (LM) and high (HM) moisture contents at 1.0-1.5 MPa for 24-120 h and its controlled release characteristics at 11.2-52.9% relative humidity (RH) for 1-168 h. The inclusion complexes (ICs) were characterized using X-ray diffractometry (XRD), nuclear magnetic resonance spectroscopy (CP-MAS (13)C NMR), and scanning electron microscopy (SEM). Ethylene concentrations in the ICs were from 0.45 to 0.87 mol of ethylene/mol CD and from 0.42 to 0.54 mol of ethylene/mol CD for LM and HM α-CDs, respectively. Ethylene gas released from the encapsulated powder at higher rates with increasing RH. An analysis of release kinetics using Avrami's equation showed that the LM and HM amorphous α-CDs were not associated with significant differences in release constant k and parameter n for any given RH condition. NMR spectra showed the presence of the characteristic carbon-carbon double bond of ethylene gas in the encapsulated α-CD powder.

  6. Fluorinated Chaperone-β-Cyclodextrin Formulations for β-Glucocerebrosidase Activity Enhancement in Neuronopathic Gaucher Disease.

    Science.gov (United States)

    García-Moreno, M Isabel; de la Mata, Mario; Sánchez-Fernández, Elena M; Benito, Juan M; Díaz-Quintana, Antonio; Fustero, Santos; Nanba, Eiji; Higaki, Katsumi; Sánchez-Alcázar, José A; García Fernández, José M; Ortiz Mellet, Carmen

    2017-03-09

    Amphiphilic glycomimetics encompassing a rigid, undistortable nortropane skeleton based on 1,6-anhydro-l-idonojirimycin and a polyfluorinated antenna, when formulated as the corresponding inclusion complexes with β-cyclodextrin (βCD), have been shown to behave as pharmacological chaperones (PCs) that efficiently rescue lysosomal β-glucocerebrosidase mutants associated with the neuronopathic variants of Gaucher disease (GD), including the highly refractory L444P/L444P and L444P/P415R single nucleotide polymorphs, in patient fibroblasts. The body of work here presented includes the design criteria for the PC prototype, the synthesis of a series of candidates, the characterization of the PC:βCD complexes, the determination of the selectivity profiles toward a panel of commercial and human lysosomal glycosidases, the evaluation of the chaperoning activity in type 1 (non-neuronopathic), type 2 (acute neuronopathic), and type 3 (adult neuronopathic) GD fibroblasts, the confirmation of the rescuing mechanism by immunolabeling, and the analysis of the PC:GCase binding mode by docking experiments.

  7. Application of β-cyclodextrin polymers in separation of metal ions

    International Nuclear Information System (INIS)

    Kozlowski, C.A.; Kozlowska, J.

    2006-01-01

    In the present work the competitive transport of Cu(II), Co(II), Ni(II) and Zn(II) ions through the plasticized immobilized membranes was studied. β-cyclodextrin (β-CD) polymers have been used as macrocyclic ligands for separation of metal ions from dilute aqueous solutions by ion exchange methods, i.e. transport across polymer inclusion membranes and ion flotation process. β-CD polymers were prepared by cross-linking β-CD with alkenyl (nonenyl) succinic anhydride derivatives, phtalic and 3-nitrophtalic anhydride in anhydrous N,N-dimethylformamide (DMF) resulting in formation of Polymer A, B or C, respectively. In he case of cooper(II) flotation results obtained with the use of nonylphenol polyoxyethyl glycol ether as an non-anionic surfactant and β-CD polymers as complexation agent, show that the removal of metal decreases with higher molecular mass of β-CD polymers linked by phtalic or 3-nitrophtalic anhydrides. For both derivatives with pH increase the copper(II) removed increase. The highest flotation removal, i.e. 93% is observed for β-CD polymers synthesized at 100 o C with molar ratio CD : NaH : 3-nitrophtalic anhydride equal to 1 : 7 : 7

  8. Antiseptic cyclodextrin-functionalized hydrogels and gauzes for loading and delivery of benzalkonium chloride.

    Science.gov (United States)

    Garcia-Fernandez, Maria José; Brackman, Gilles; Coenye, Tom; Concheiro, Angel; Alvarez-Lorenzo, Carmen

    2013-01-01

    Prevention and management of wound infections receive a lot of attention, since the presence of micro-organisms interferes with the wound-healing process. The aim of this work was to use cyclodextrins (CDs) to endow hydrogels and gauzes with the ability to take up antiseptics and sustain their delivery for several hours. Benzalkonium chloride (BzCl) can form inclusion complexes with cross-linked CDs that regulate the release through an affinity-driven mechanism. Grafting of CDs to cotton gauzes using citric acid as the linker, at 190 °C and for 15 min, led to grafting yields of about 148%, much larger than those obtained at 180 °C or with shorter reaction times. Microbiological tests revealed that the BzCl-loaded networks can inhibit the growth of Staphylococcus epidermidis and Escherichia coli both on agar plates and in liquid medium. Furthermore, the antiseptic-loaded gauzes were able to inhibit biofilm formation by Staphylococcus aureus RN1HG pMV158GFP when applied in early stages of biofilm formation and could reduce the number of living cells in preformed biofilms grown in a chronic wound biofilm model. These findings highlight the role of CDs as main components of hydrogels and gauzes for the efficient delivery of antiseptics.

  9. A study of fluorescence properties of citrinin in β-cyclodextrin aqueous solution and different solvents

    International Nuclear Information System (INIS)

    Zhou Youxiang; Chen Jianbiao; Dong Lina; Lu Liang; Chen Fusheng; Hu Dingjin; Wang Xiaohong

    2012-01-01

    Citrinin (CIT) is a nephrotoxic mycotoxin initially isolated from filamentous fungus Penicilliu citrinum. It was later isolated from several other species, such as Aspergillus and Monascus. It has a conjugated, planar structure that gives it a natural fluorescence ability, which can be used to develop sensitive methods for detecting CIT in food. In this paper, we used the spectrofluorescence technique to study the effects of pH value, β-cyclodextrin (β-CD) and organic solvents on the CIT fluorescence intensity. The results show that lower pH value, aceitc acid, β-CD and acetonitrile can induce a higher fluorescence intensity of CIT, but methanol or H 2 O has a decreasing effect on the fluorescence intensity of CIT. Findings in this study provide a theoretical basis for development of a high sensitivity fluorescence-based trace analysis for CIT detection. - Highlights: ► The effects of pH, solvents and β-CD on the fluorescence of citrinin are analyzed. ► [H] + , acetic acid, β-CD and acetonitrile can induce CIT fluorescence enhancement. ► Methanol and H 2 O can induce CIT fluorescence reduction. ► The 1:1 inclusion complex of CIT/β-CD can form in acidic phosphate solution.

  10. SERS-Based Flavonoid Detection Using Ethylenediamine-β-Cyclodextrin as a Capturing Ligand

    Directory of Open Access Journals (Sweden)

    Jae Min Choi

    2017-01-01

    Full Text Available Ethylenediamine-modified β-cyclodextrin (Et-β-CD was immobilized on aggregated silver nanoparticle (NP-embedded silica NPs (SiO2@Ag@Et-β-CD NPs for the effective detection of flavonoids. Silica NPs were used as the template for embedding silver NPs to create hot spots and enhance surface-enhanced Raman scattering (SERS signals. Et-β-CD was immobilized on Ag NPs to capture flavonoids via host-guest inclusion complex formation, as indicated by enhanced ultraviolet absorption spectra. The resulting SiO2@Ag@Et-β-CD NPs were used as the SERS substrate for detecting flavonoids, such as hesperetin, naringenin, quercetin, and luteolin. In particular, luteolin was detected more strongly in the linear range 10−7 to 10−3 M than various organic molecules, namely ethylene glycol, β-estradiol, isopropyl alcohol, naphthalene, and toluene. In addition, the SERS signal for luteolin captured by the SiO2@Ag@Et-β-CD NPs remained even after repeated washing. These results indicated that the SiO2@Ag@Et-β-CD NPs can be used as a rapid, sensitive, and selective sensor for flavonoids.

  11. Enhanced Solubilization of Fluoranthene by Hydroxypropyl β-Cyclodextrin Oligomer for Bioremediation

    Directory of Open Access Journals (Sweden)

    Kyeong Hui Park

    2018-01-01

    Full Text Available Fluoranthene (FT is a polycyclic aromatic hydrocarbon (PAH, consisting of naphthalene and benzene rings connected by a five-member ring. It is widespread in the environment. The hydrophobicity of FT limits its availability for biological uptake and degradation. In this study, hydroxypropyl β-cyclodextrin oligomers (HP-β-CD-ol were synthesized with epichlorohydrin (EP, while the solubility enhancement of FT by HP-β-CD-ol was investigated in water. The synthesized HP-β-CD-ol was characterized by MALDI-TOF mass spectrometry (MS, 1H NMR, and 13C NMR spectroscopy. The solubility of FT increased 178-fold due to the complex formation with HP-β-CD oligomers. The inclusion complexes of FT/HP-β-CD-ol were analyzed using Fourier-Transform Infrared (FT-IR, Differential Scanning Calorimetry (DSC, Scanning Electron Microscope (SEM, and Nuclear Overhauser Effect Spectroscopy Nuclear magnetic resonance (NOESY NMR spectroscopy. On the basis of these results, HP-β-CD-ol is recommended as a potential solubilizer for the development of PAH removal systems.

  12. Efficacy of albendazole:β-cyclodextrin citrate in the parenteral stage of Trichinella spiralis infection.

    Science.gov (United States)

    Codina, Ana V; García, Agustina; Leonardi, Darío; Vasconi, María D; Di Masso, Ricardo J; Lamas, María C; Hinrichsen, Lucila I

    2015-01-01

    Albendazole-β-cyclodextrin citrate (ABZ:C-β-CD) inclusion complex in vivo antiparasitic activity was evaluated in the parenteral phase of Trichinella spiralis infection in mice. An equimolar complex of ABZ:C-β-CD was prepared by spray-drying and tested in CBi-IGE male mice orally infected with L1 infective larvae. Infected animals were treated with 50 or 30mg/kg albendazole, (ABZ) equivalent amounts of the ABZ:C-β-CD complex and non treated (controls). Mice received a daily dose on days 28, 29 and 30 post-infection. A week later, larval burden and percentage of encysted dead larvae were assessed in the host by counting viable and non-viable larvae in the tongue. Complexation of ABZ with C-β-CD increased the drug dissolution efficiency nearly eightfold. At 37 days p-i, the reduction percentage in muscle larval load was 35% in mice treated with 50mg/kg/day ABZ and 68% in those given the complex. Treatment with the lower dose showed a similar decrease in parasite burden. Treated animals showed a high percentage of nonviable larvae, the proportion being significantly higher in mice receiving the complex than in control animals (72-88% vs. 11%, P=0.0032). These data indicate that ABZ:C-β-CD increases bioavailability and effectiveness of ABZ against encapsulated Trichinella larvae, thus allowing the use of small doses. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Clove essential oil-in-cyclodextrin-in-liposomes in the aqueous and lyophilized states: From laboratory to large scale using a membrane contactor.

    Science.gov (United States)

    Sebaaly, Carine; Charcosset, Catherine; Stainmesse, Serge; Fessi, Hatem; Greige-Gerges, Hélène

    2016-03-15

    This work is dedicated to prepare liposomal dry powder formulations of inclusion complexes of clove essential oil (CEO) and its main component eugenol (Eug). Ethanol injection method and membrane contactor were applied to prepare liposomes at laboratory and large scale, respectively. Various liposomal formulations were tested: (1) free hydroxypropyl-β-cyclodextrin loaded liposomes; (2) drug in hydroxypropyl-β-cyclodextrin in liposomes (DCL); (3) DCL2 obtained by double loading technique, where the drug is added in the organic phase and the inclusion complex in the aqueous phase. Liposomes were characterized for their particle size, polydispersity index, Zeta potential, morphology, encapsulation efficiency of CEO components and Eug loading rate. Reproducible results were obtained with both injection devices. Compared to Eug-loaded liposomes, DCL and DCL2 improved the loading rate of Eug and possessed smaller vesicles size. The DPPH(•) scavenging activity of Eug and CEO was maintained upon incorporation of Eug and CEO into DCL and DCL2. Contrary to DCL2, DCL formulations were stable after 1 month of storage at 4°C and upon reconstitution of the dried lyophilized cakes. Hence, DCL in aqueous and lyophilized forms, are considered as a promising carrier system to preserve volatile and hydrophobic drugs enlarging their application in cosmetic, pharmaceutical and food industries. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Guest-Host Complex Formed between Ascorbic Acid and β-Cyclodextrin Immobilized on the Surface of an Electrode

    Directory of Open Access Journals (Sweden)

    María Teresa Ramírez-Silva

    2014-05-01

    Full Text Available This work deals with the formation of supramolecular complexes between ascorbic acid (AA, the guest, and β-cyclodextrin (β-CD, the host, that was first potentiodynamically immobilized on the surface of a carbon paste electrode (CPE throughout the formation of a β-CD-based conducting polymer (poly-β-CD. With the bare CPE and the β-CD-modified CPE, an electrochemical study was performed to understand the effect of such surface modification on the electrochemical response of the AA. From this study it was shown that on the modified-CPE, the AA was surface-immobilized through formation of an inclusion complex with β-CD, which provoked the adsorption of AA in such a way that this stage became the limiting step for the electrochemical oxidation of AA. Moreover, from the analysis of the experimental voltammetric plots recorded during AA oxidation on the CPE/poly-β-CD electrode surfaces, the Gibbs’ standard free energy of the inclusion complex formed by the oxidation product of AA and β-CD has been determined for the first time, ∆G0inclus = −36.4 kJ/mol.

  15. Beta Emission and Bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-13

    Bremsstrahlung is continuous radiation produced by beta particles decelerating in matter; different beta emitters have different endpoint energies; high-energy betas interacting with high-Z materials will more likely produce bremsstrahlung; depending on the data, sometimes all you can say is that a beta emitter is present.

  16. Social imaginaries and inclusion

    DEFF Research Database (Denmark)

    Hansen, Janne Hedegaard

    2016-01-01

    that inclusion on the one hand may be seen to be about human rights, solidarity, and democracy, and on the other hand, it is about ensuring the cohesion of neoliberal society by means of every person’s obligation to realize one’s potential through learning, development, and education regardless of one’s needs......, the development of inclusive schools and inclusive learning environments will involve both inclusion and exclusion processes. With this starting point, international educational research knowledge about inclusive schools and inclusive learning environments in general will be related to the fundamental dilemma...

  17. Release of β-galactosidase from poloxamine/α-cyclodextrin hydrogels

    Directory of Open Access Journals (Sweden)

    César A. Estévez

    2014-12-01

    Full Text Available All mammals lose their ability to produce lactase (β-galactosidase, the enzyme that cleaves lactose into galactose and glucose, after weaning. The prevalence of lactase deficiency (LD spans from 2 to 15% among northern Europeans, to nearly 100% among Asians. Following lactose consumption, people with LD often experience gastrointestinal symptoms such as abdominal pain, bowel distension, cramps and flatulence, or even systemic problems such as headache, loss of concentration and muscle pain. These symptoms vary depending on the amount of lactose ingested, type of food and degree of intolerance. Although those affected can avoid the uptake of dairy products, in doing so, they lose a readily available source of calcium and protein. In this work, gels obtained by complexation of Tetronic 90R4 with α-cyclodextrin loaded with β-galactosidase are proposed as a way to administer the enzyme immediately before or with the lactose-containing meal. Both molecules are biocompatible, can form gels in situ, and show sustained erosion kinetics in aqueous media. The complex was characterized by FTIR that evidenced an inclusion complex between the polyethylene oxide block and α-cyclodextrin. The release profiles of β-galactosidase from two different matrices (gels and tablets of the in situ hydrogels have been obtained. The influence of the percentage of Tetronic in media of different pH was evaluated. No differences were observed regarding the release rate from the gel matrices at pH 6 (t50 = 105 min. However, in the case of the tablets, the kinetics were faster and they released a greater amount of 90R4 (25%, t50 = 40–50 min. Also, the amount of enzyme released was higher for mixtures with 25% Tetronic. Using suitable mathematical models, the corresponding kinetic parameters have been calculated. In all cases, the release data fit quite well to the Peppas–Sahlin model equation, indicating that the release of β-galactosidase is governed by a

  18. Synergetic skin targeting effect of hydroxypropyl-β-cyclodextrin combined with microemulsion for ketoconazole.

    Science.gov (United States)

    Che, Junxiu; Wu, Zushuai; Shao, Weiyan; Guo, Penghao; Lin, Yuanyuan; Pan, Wenhui; Zeng, Weidong; Zhang, Guoguang; Wu, Chuanbin; Xu, Yuehong

    2015-06-01

    The objective was to develop a ternary skin targeting system for ketoconazole (KET) using a combined strategy of microemulsion (ME) and cyclodextrin (HP-β-CD), i.e., KET-CD-ME, which exploits both virtues of cyclodextrin complex and ME to obtain the synergetic effect. KET-CD-ME was formulated using Labrafil M 1944 CS as oil phase, Solutol HS 15 as surfactant, Transcutol P as cosurfactant, and HP-β-CD solution as aqueous phase. The formulation of KET-CD-ME was optimized and the optimal formulation was characterized in terms of particle size, size distribution, pH value, and viscosity. Long term stability experiment showed that HP-β-CD could increase the physical stability of ternary system and KET chemical stability. Percutaneous permeation of KET from KET-CD-ME in vitro through rat skin was investigated in comparison with KET microemulsion (KET-ME), KET HP-β-CD inclusion solution (KET-CD), KET aqueous suspension, and commercial KET cream; the results showed that the combination of ME with HP-β-CD exhibited significantly synergistic effect on KET deposition within the skin (29.38 ± 1.79 μg/cm(2)) and a slightly synergistic effect on KET penetration through the skin (11.3 μg/cm(2)/h). The enhancement of the combination on skin deposition was further visualized by confocal laser scanning microscope (CLSM). In vitro sensitivity against Candida parapsilosis test indicated that KET-CD-ME enhanced KET antifungal activity mainly owing to the solubilization of HP-β-CD on KET in the ternary system. Moreover, the interactions between HP-β-CD and KET in the ternary system were elucidated through microScale thermophoresis (MST) and 2D (1)H NMR spectroscopy. The profiles from MST confirmed the host-guest interactions of HP-β-CD with KET in the ternary system and a deep insight into the interactions between KET and HP-β-CD were obtained by means of 2D (1)H NMR spectroscopy. The results indicate that the ternary system of ME combination with HP-β-CD may be a promising

  19. Increased Yield of Biotransformation of Androsta-1, 4-Dien-3, 17-Dione from Β-Sitosterol by Using Sulfobutyl Ether-Β-Cyclodextrin Complexation Technique

    Directory of Open Access Journals (Sweden)

    Wang Jingwen

    2016-01-01

    Full Text Available Substrate solubility in steroid biotransformation is critical for enhancing the biotransformation of hydrophobic compounds. In this study, the sulfobutyl ether-β-cyclodextrin (SBE-β-CD complexation technique was used for the biotransformation of β-sitosterol to androsta-1, 4-diene-3, 17-dione with Mycobacterium ATCC25795. The production yield was increased by 26.72%, and the biotransformation course was shortened by 24h using β-sitosterol/SBE-β-CD inclusion complexes as substrates (1.0 g/L. Fourier transform infrared spectroscopy and differential scanning calorimetry indicated that an inclusion complex was formed between SBE-β-CD and β-sitosterol. The complex significantly increased the solubility of β-sitosterol and improved the biotransformation efficiency of the substrate.

  20. Modulation of Cyclodextrin Particle Amphiphilic Properties to Stabilize Pickering Emulsion.

    Science.gov (United States)

    Xi, Yongkang; Luo, Zhigang; Lu, Xuanxuan; Peng, Xichun

    2018-01-10

    Cyclodextrins have been proven to form complexes with linear oil molecules and stabilize emulsions. Amphiphilic properties of cyclodextrin particles were modulated through esterification reaction between β-cyclodextrin (β-CD) and octadecenyl succinic anhydride (ODSA) under alkaline conditions. ODS-β-CD particles with degree of substitution (DS) of 0.003, 0.011, and 0.019 were obtained. The introduced hydrophobic long chain that was linked within β-CD cavity led to the change of ODS-β-CD in terms of morphological structure, surface charge density, size, and contact angle, upon which the properties and stability of the emulsions stabilized by ODS-β-CD were highly dependent. The average diameter of ODS-β-CD particles ranged from 449 to 1484 nm. With the DS increased from 0.003 to 0.019, the contact angle and absolute zeta potential value of these ODS-β-CD particles improved from 25.7° to 47.3° and 48.1 to 62.8 mV, respectively. The cage structure of β-CD crystals was transformed to channel structure, then further to amorphous structure after introduction of the octadecenyl succinylation chain. ODS-β-CD particles exhibited higher emulsifying ability compared to β-CD. The resulting Pickering emulsions formed by ODS-β-CD particles were more stable during storage. This study investigates the ability of these ODS-β-CD particles to stabilize oil-in-water emulsions with respect to their amphiphilic character and structural properties.

  1. An Alginate/Cyclodextrin Spray Drying Matrix to Improve Shelf Life and Antioxidant Efficiency of a Blood Orange By-Product Extract Rich in Polyphenols: MMPs Inhibition and Antiglycation Activity in Dysmetabolic Diseases

    Directory of Open Access Journals (Sweden)

    Maria Rosaria Lauro

    2017-01-01

    Full Text Available Alginate and β-cyclodextrin were used to produce easily dosable and spray-dried microsystems of a dried blood orange extract with antidysmetabolic properties, obtained from a by-product fluid extract. The spray-dried applied conditions were able to obtain a concentrate dried extract without the loss of AOA and with TPC and TMA values of 35–40% higher than that of the starting material. They were also effective in producing microparticles with 80–100% of encapsulation efficiency. The 2% sodium alginate was capable of improving the extract shelf life, while the beta-cyclodextrin (1 : 1 molar ratio with dried extract prolonged the extract antioxidant efficiency by 6 hours. The good inhibition effect of the dried extract on the AGE formation and the MMP-2 and MMP-9 activity is presumably due to a synergic effect exerted by both anthocyanin and bioflavonoid extract compounds and was improved by the use of alginate and cyclodextrin.

  2. Roadmap for Inclusive Innovation

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Roadmap for Inclusive Innovation data set shares the status of action items under the Roadmap for Inclusive Innovation. Each action or project has been assigned...

  3. Teachers becoming inclusive practitioners

    African Journals Online (AJOL)

    , construct their identities in the light of inclusive education, and how they negotiate the tensions and contradictions emerging from the processof becoming inclusive practitioners. Central to this discussion is the understanding that teachers' ...

  4. Delimiting Inclusive Design

    DEFF Research Database (Denmark)

    Herriott, Richard

    2014-01-01

    This paper was written as an answer to the question raised by my PhD dissertation on accessibility through user-centred and Inclusive Design (ID) methods: can Inclusive Design be delimited? The literature on Inclusive Design deals almost entrirely with consumer product design and assistive...

  5. Footstep towards Inclusive Education

    Science.gov (United States)

    Abbas, Faiza; Zafar, Aneeka; Naz, Tayyaba

    2016-01-01

    Inclusive education is a rising trend in the world. The first step towards inclusive education is providing the awareness to the general education teachers. This study focused to investigate the general education teachers of primary and secondary level awareness about the special education and inclusive education. This study is descriptive method…

  6. Inclusion: Conceptualization and measurement

    NARCIS (Netherlands)

    Jansen, W.S.; Otten, S.; Van der Zee, K.I.; Jans, L.

    2014-01-01

    n the present research, we introduced a conceptual framework of inclusion and subsequently used this as a starting point to develop and validate a scale to measure perceptions of inclusion. Departing from existing work on inclusion and complementing this with theoretical insights from optimal

  7. Inclusion : Conceptualization and measurement

    NARCIS (Netherlands)

    Jansen, Wiebren S.; Otten, Sabine; van der Zee, Karen I.; Jans, Lise

    In the present research, we introduced a conceptual framework of inclusion and subsequently used this as a starting point to develop and validate a scale to measure perceptions of inclusion. Departing from existing work on inclusion and complementing this with theoretical insights from optimal

  8. Inclusion: Conceptualization and measurement

    NARCIS (Netherlands)

    Jansens, Wiebren S.; Otten, Sabine; van der Zee, Karen; Jans, Lise

    2014-01-01

    In the present research, we introduced a conceptual framework of inclusion and subsequently used this as a starting point to develop and validate a scale to measure perceptions of inclusion. Departing from existing work on inclusion and complementing this with theoretical insights from optimal

  9. Imprinting of Phenylalanine ethyl ester in cyclodextrin polymers in aqueous solution

    DEFF Research Database (Denmark)

    Detcheva, Anna Hr.; Yu, Donghong; Larsen, Kim Lambertsen

    During the last decades there has been a wide interest of developing molecularly imprinted polymers, which selectively can recognize small molecules. Cyclodextrins offer relatively strong binding site of a wide range of small molecules in water and molecular imprinted polymers of these have...... previously been produced with some success. Nevertheless most molecules of interest for molecular imprinting are too samll to accommodate more than one cyclodextrin per molecule and thus limited selectivity may be expected. In order to improve the selectivity of cyclodextrin based molecular imprinted polymer...

  10. Thermodynamics of the interaction of γ-cyclodextrin and tauro- and glyco-conjugated bile salts

    DEFF Research Database (Denmark)

    Schönbeck, Jens Christian Sidney; Westh, Peter; Holm, René

    2013-01-01

    The structural differences in the interaction between natural γ-cyclodextrin and bile salts common in rat, dog and man was were investigated by 1H-ROESY and 13C NMR and molecular modeling and the thermodynamic parameters of the reaction by isothermal titration calorimetry. The γ-cyclodextrin was ......The structural differences in the interaction between natural γ-cyclodextrin and bile salts common in rat, dog and man was were investigated by 1H-ROESY and 13C NMR and molecular modeling and the thermodynamic parameters of the reaction by isothermal titration calorimetry. The γ...

  11. Cyclodextrin based nanosponges for pharmaceutical use: a review.

    Science.gov (United States)

    Tejashri, Gursalkar; Amrita, Bajaj; Darshana, Jain

    2013-09-01

    Nanosponges are a novel class of hyper-crosslinked polymer based colloidal structures consisting of solid nanoparticles with colloidal sizes and nanosized cavities. These nano-sized colloidal carriers have been recently developed and proposed for drug delivery, since their use can solubilize poorly water-soluble drugs and provide prolonged release as well as improve a drug's bioavailability by modifying the pharmacokinetic parameters of actives. Development of nanosponges as drug delivery systems, with special reference to cyclodextrin based nanosponges, is presented in this article. In the current review, attempts have been made to illustrate the features of cyclodextrin based nanosponges and their applications in pharmaceutical formulations. Special emphasis has been placed on discussing the methods of preparation, characterization techniques and applications of these novel drug delivery carriers for therapeutic purposes. Nanosponges can be referred to as solid porous particles having a capacity to load drugs and other actives into their nanocavity; they can be formulated as oral, parenteral, topical or inhalation dosage forms. Nanosponges offer high drug loading compared to other nanocarriers and are thus suitable for solving issues related to stability, solubility and delayed release of actives. Controlled release of the loaded actives and solubility enhancement of poorly water-soluble drugs are major advantages of nanosponge drug delivery systems.

  12. Synthesis of magnetite nanoparticles-β-cyclodextrin complex

    International Nuclear Information System (INIS)

    Cobos Cruz, L.A.; Martinez Perez, C.A.; Monreal Romero, H.A.; Garcia Casillas, P.E.

    2008-01-01

    In this work, the synthesis and characterization of a magnetite (M) and β-cyclodextrin (CD) complex is presented. The chemical bonding between the magnetite and CD was studied as evidence of host-guest interaction; therefore the CD works like a reactor with the magnetite inside of it, as consequence the growth of the particle is restricted by the electrostatic interaction of M-CD complex. The particle size of the magnetite-cyclodextrin complex (M-CD) decreased 79.1% with 0.5% of CD. The average particle size of the M-CD complex was 10 nm. The saturation magnetization (σ s ) and intrinsic coercivity (H c ) increased 10% and 20%, respectively. In order to understand how the the CD affects the results obtained, the second derivate of remission function was obtained from the ultraviolet-visible spectra (UV-vis). Fourier transform infrared spectroscopy (FTIR) was used to elucidate the interaction between the magnetite and CD. The thermal analysis was measured by thermogravimetric and differential thermal analysis (TGA-DTA). The magnetic properties, intrinsic coercivity (H c ) and the saturation magnetization were determined by vibrating sample magnetometry (VSM); the size and shape of nanoparticles were determined by scanning electron microscopy (SEM). The identification of phases was made by X-ray diffraction

  13. Characterization of inclusion complexes of organic ions with hydrophilic hosts by ion transfer voltammetry with solvent polymeric membranes.

    Science.gov (United States)

    Olmos, José Manuel; Laborda, Eduardo; Ortuño, Joaquín Ángel; Molina, Ángela

    2017-03-01

    The quantitative characterization of inclusion complexes formed in aqueous phase between organic ions and hydrophilic hosts by ion-transfer voltammetry with solvent polymeric membrane ion sensors is studied, both in a theoretical and experimental way. Simple analytical solutions are presented for the determination of the binding constant of the complex from the variation with the host concentration of the electrochemical signal. These solutions are valid for any voltammetric technique and for solvent polymeric membrane ion sensors comprising one polarisable interface (1PI) and also, for the first time, two polarisable interfaces (2PIs). Suitable experimental conditions and data analysis procedures are discussed and applied to the study of the interactions of a common ionic liquid cation (1-octyl-3-metyl-imidazolium) and an ionisable drug (clomipramine) with two hydrophilic cyclodextrins: α-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin. The experimental study is performed via square wave voltammetry with 2PIs and 1PI solvent polymeric membranes and in both cases the electrochemical experiments enable the detection of inclusion complexes and the determination of the corresponding binding constant. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Cyclodextrin Reduces Cholesterol Crystal-Induced Inflammation by Modulating Complement Activation

    DEFF Research Database (Denmark)

    Bakke, Siril S; Aune, Marie H; Niyonzima, Nathalie

    2017-01-01

    Cholesterol crystals (CC) are abundant in atherosclerotic plaques and promote inflammatory responses via the complement system and inflammasome activation. Cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (BCD) is a compound that solubilizes lipophilic substances. Recently we have shown...

  15. Magnetic porous corn starch for the affinity purifi cation of cyclodextrin glucanotransferase produced by Bacillus circulans

    Czech Academy of Sciences Publication Activity Database

    Šafaříková, Miroslava; Horská, Kateřina; Maděrová, Zdeňka; Tonkova, A.; Ivanova-Pashkoulova, V.; Šafařík, Ivo

    2012-01-01

    Roč. 30, č. 1 (2012), s. 96-101 ISSN 1024-2422 Institutional support: RVO:67179843 Keywords : Bacillus circulans * cyclodextrin glucanotransferase * magnetic starch * magnetic separation Subject RIV: EH - Ecology, Behaviour Impact factor: 0.895, year: 2012

  16. INTERACTIONS OF METHYL ORANGE WITH CYCLODEXTRIN/SODIUM-MONTMORILLONITE SYSTEMS PROBED BY UV-VISIBLE SPECTROSCOPY

    Science.gov (United States)

    Clay mineral colloids play important roles in the adsorption of polar organic contaminants in the environment. Similarly, cyclodextrins (CD) can entrap poorly water-soluble organic compounds. A combination of CDs and clay minerals affords great opportunities to investigate simult...

  17. Chemical encapsulation of rocuronium by synthetic cyclodextrin derivatives: reversal of neuromuscular block in anaesthetized Rhesus monkeys.

    NARCIS (Netherlands)

    Boer, H.D. de; Egmond, J. van; Pol, F. van de; Bom, A.; Booij, L.H.D.J.

    2006-01-01

    BACKGROUND: At present, reversal of neuromuscular block induced by steroidal neuromuscular blocking agents (NMBAs) is achieved by administration of cholinesterase inhibitors. Chemical encapsulation of steroidal NMBAs, such as rocuronium, by a cyclodextrin is a new concept in neuromuscular block

  18. Influencing of resorption and side-effects of salicylic acid by complexing with β-cyclodextrin

    International Nuclear Information System (INIS)

    Szejtli, J.; Gerloczy, A.; Sebestyen, G.; Fonagy, A.

    1981-01-01

    After oral administration of 14 C-labelled salicylic acid and its β-cyclodextrin complex to rats, the radioactivity level of the blood reached its maximum during the first 2 h. The blood level obtained with the complex is somewhat but not significantly lower than with free acid. Since the resorption of cyclodextrin is a considerably slower process, it is very likely that the resorption of salicylic acid takes place in the form of free acid after dissociation of the complex. The urinary excretion cumulative curves showed that the free salicylic acid was completely excreted, while about 10% of the salicylic acid administered in the form of complex is lost. The cyclodextrin complex formation increased the pK values of all hydroxybenzoic acids. Direct observations revealed that complex formation decreased the stomach-irritating effect of salicylic acid. The ratio of radioactivity was nearly the same in the organs of animals treated by both free salicylic and cyclodextrin complex. (author)

  19. Effect of β-cyclodextrin on Rheological Properties of some Viscosity Modifiers.

    Science.gov (United States)

    Rao, G Chandra Sekhara; Ramadevi, K; Sirisha, K

    2014-01-01

    Cyclodextrins are a group of novel excipients, extensively used in the present pharmaceutical industry. Sometimes they show significant interactions with other conventional additives used in the formulation of dosage forms. The effect of β-cyclodextrin on the rheological properties of aqueous solutions of some selected viscosity modifiers was studied in the present work. β-cyclodextrin showed two different types of effects on the rheology of the selected polymers. In case of natural polymers like xanthan gum and guar gum, enhanced apparent viscosity was found and in case of semi-synthetic polymers like sodium carboxymethyl cellulose and methyl cellulose, reduction in apparent viscosity was found. β-cyclodextrin was included at 0.5, 1 and 2% w/v concentrations into the polymeric solutions. These findings are useful in the adjustment of concentrations of viscosity modifiers during the formulation of physically stable disperse systems.

  20. Comparative In Vitro Controlled Release Studies on the Chronobiotic Hormone Melatonin from Cyclodextrins-Containing Matrices and Cyclodextrin: Melatonin Complexes.

    Science.gov (United States)

    Vlachou, Marilena; Papamichael, Marianna; Siamidi, Angeliki; Fragouli, Irene; Afroudakis, Pandelis A; Kompogennitaki, Rodanthi; Dotsikas, Yannis

    2017-07-28

    A series of hydrophilic matrix tablets was prepared and tested with respect to their ability to release the hormone melatonin in a controlled manner, in order to alleviate sleep onset and sleep maintenance dysfunctions. Besides the active ingredient, the tablets were comprised of combinations of the following: HPMC K 15M, low viscosity sodium alginate, microcrystalline cellulose (Avicel PH 102), magnesium stearate, and the cyclodextrins, α-CD, β-CD, γ-CD, HP-β-CD, sulfated β-CD, HP-α-CD and HP-γ-CD, and MLT (guest):CD (host) complexes of the above cyclodextrins, in 1:1 ratio. The controlled release studies were conducted in two aqueous dissolution media at pH 1.2 and 7.4. The stoichiometry of the formed complexes was examined by applying the continuous variation method (Job plot), while the stability constants were calculated by monitoring the spectrophotometric properties of free and CD-encapsulated melatonin (UV-Vis). Host-guest interactions were studied by Nuclear Magnetic Resonance (NMR) spectroscopy. The dissolution data suggest that melatonin is released faster from the MLT:CD complexes than from the rest matrix systems. This enhancement in the dissolution rate and the % release of melatonin from the complexes is due to the increased solubility of the MLT:CD complexes.

  1. Separation of hydroxynorketamine stereoisomers using capillary electrophoresis with sulfated β-cyclodextrin and highly sulfated γ-cyclodextrin.

    Science.gov (United States)

    Sandbaumhüter, Friederike A; Theurillat, Regula; Thormann, Wolfgang

    2017-08-01

    The racemic N-methyl-d-aspartate receptor antagonist ketamine is used in anesthesia, analgesia and the treatment of depressive disorders. It is known that interactions of hydroxylated norketamine metabolites and 5,6-dehydronorketamine (DHNK) with the α 7 -nicotinic acetylcholine receptor and the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor are responsible for the antidepressive effects. Ketamine and its first metabolite norketamine are not active on these receptors. As stereoselectivity plays a role in ketamine metabolism, a cationic capillary electrophoresis based method capable of resolving and analyzing the stereoisomers of four hydroxylated norketamine metabolites, norketamine and DHNK was developed. The assay is based on liquid/liquid extraction of the analytes from the biological matrix, electrokinetic sample injection across a buffer plug and analysis of the stereoisomers in a phosphate background electrolyte (BGE) at pH 3 comprising a mixture of sulfated β-cyclodextrin (5 mg/mL) and highly sulfated γ-cyclodextrin (0.1%). The method was used to analyze samples of an in vitro study in which ketamine was incubated with equine liver microsomes and in plasma samples of dogs and horses that were collected after an i.v. bolus injection of racemic ketamine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Egg yolk and glycerol requirements for freezing boar spermatozoa treated with methyl β-cyclodextrin or cholesterol-loaded cyclodextrin.

    Science.gov (United States)

    Blanch, Eva; Tomás, Cristina; Hernández, Marta; Roca, Jordi; Martínez, Emilio A; Vázquez, Juan M; Mocé, Eva

    2014-04-24

    Egg yolk (EY) and glycerol are common constituents of extenders used for sperm cryopreservation. It has been demonstrated that using cholesterol-loaded cyclodextrins (CLC) improves sperm cryosurvival in several species. However, standard freezing extenders might not be the most appropriate for CLC-treated sperm. This study evaluated the EY and glycerol requirements for freezing CLC-treated boar spermatozoa. Semen samples from 34 ejaculates coming from 4 boars were used. Each ejaculate was split into three aliquots: one was used untreated (control), and the other two were treated with 1 mg of CLC or methyl-β-cyclodextrin/120 × 10(6) sperm for 15 min at 22 C prior to cryopreservation. Our results indicated that reducing the concentration of EY was detrimental for sperm viability after thawing (31.57 ± 2 vs. 19.89% ± 2 for 20 and 10% EY, respectively; P semen treated with CLC. On the other hand, it was observed that the traditional concentration of glycerol (3%) was not the appropriate for freezing CLC-treated sperm (61.10 ± 3 vs. 47.87% ± 3 viable sperm for control and CLC-treated sperm, respectively; P extenders for CLC-treated sperm. Nevertheless, additional studies will be needed to evaluate alternative cryoprotectants and to determine the effect of high glycerol concentrations on sperm functionality.

  3. Levered and unlevered Beta

    OpenAIRE

    Fernandez, Pablo

    2003-01-01

    We prove that in a world without leverage cost the relationship between the levered beta ( L) and the unlevered beta ( u) is the No-costs-of-leverage formula: L = u + ( u - d) D (1 - T) / E. We also analyze 6 alternative valuation theories proposed in the literature to estimate the relationship between the levered beta and the unlevered beta (Harris and Pringle (1985), Modigliani and Miller (1963), Damodaran (1994), Myers (1974), Miles and Ezzell (1980), and practitioners) and prove that all ...

  4. Gallic acid/hydroxypropyl-β-cyclodextrin complex: Improving solubility for application on in vitro/ in vivo Candida albicans biofilms.

    Directory of Open Access Journals (Sweden)

    Guilherme Rodrigues Teodoro

    Full Text Available The aim of this study was to increase the solubility of gallic acid (GA for the treatment of Candida albicans biofilm, which is very difficult to treat and requires high drug concentrations. Cyclodextrins (CDs were used for this purpose. Complexes were evaluated by phase-solubility studies, prepared by spray drying and characterized by drug loading, scanning electron microscopy (SEM and differential scanning calorimetry (DSC. The complexes were tested on C. albicans biofilm using in vitro and in vivo models. HPβCD formed soluble inclusion complexes with GA. The percentage of GA in GA/HPβCD was 10.8 ± 0.01%. The SEM and DSC analyses confirmed the formation of inclusion complexes. GA/HPβCD maintained the antimicrobial activity of the pure GA. GA/HPβCD was effective on C. albicans biofilms of 24 and 48h. The in vivo results showed an anti-inflammatory activity of GA/HPβCD with no difference in invading hypha counting among the groups. This study encourages the development of new antifungal agents.

  5. Effect of Cyclodextrin Complexation on the Aqueous Solubility and Solubility/Dose Ratio of Praziquantel

    OpenAIRE

    Maragos, Stratos; Archontaki, Helen; Macheras, Panos; Valsami, Georgia

    2009-01-01

    Praziquantel (PZQ), the primary drug of choice in the treatment of schistosomiasis, is a highly lipophilic drug that possesses high permeability and low aqueous solubility and is, therefore, classified as a Class II drug according to the Biopharmaceutics Classification System (BCS). In this work, β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) were used in order to determine whether increasing the aqueous solubility of a drug by complexation with CDs, a BCS-Class II compound ...

  6. Beta Thalassemia (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Beta Thalassemia KidsHealth / For Parents / Beta Thalassemia What's in this ... Symptoms Diagnosis Treatment Print en español Beta talasemia Thalassemias Thalassemias are a group of blood disorders that ...

  7. Mucoadhesive Cyclodextrin-Modified Thiolated Poly(aspartic acid as a Potential Ophthalmic Drug Delivery System

    Directory of Open Access Journals (Sweden)

    Mária Budai-Szűcs

    2018-02-01

    Full Text Available Thiolated poly(aspartic acid is known as a good mucoadhesive polymer in aqueous ophthalmic formulations. In this paper, cyclodextrin-modified thiolated poly(aspartic acid was synthesized for the incorporation of prednisolone, a lipophilic ophthalmic drug, in an aqueous in situ gellable mucoadhesive solution. This polymer combines the advantages of cyclodextrins and thiolated polymers. The formation of the cyclodextrin-drug complex in the gels was analyzed by X-ray powder diffraction. The ocular applicability of the polymer was characterized by means of physicochemical, rheological and drug diffusion tests. It was established that the chemical bonding of the cyclodextrin molecule did not affect the complexation of prednisolone, while the polymer solution preserved its in situ gellable and good mucoadhesive characteristics. The chemical immobilization of cyclodextrin modified the diffusion profile of prednisolone and prolonged drug release was observed. The combination of free and immobilized cyclodextrins provided the best release profile because the free complex can diffuse rapidly, while the bonded complex ensures a prolonged action.

  8. Effect of methyl-β-cyclodextrin on gene expression in microbial conversion of phytosterol.

    Science.gov (United States)

    Shtratnikova, Victoria Y; Schelkunov, Mikhail I; Dovbnya, Dmitry V; Bragin, Eugeny Y; Donova, Marina V

    2017-06-01

    Modified β-cyclodextrins are widely used for the enhancement of microbial conversions of lipophilic compounds such as steroids. Multiple mechanisms of cyclodextrin-mediated enhancement of phytosterol bioconversion by mycobacteria had previously been shown to include steroid solubilization, alterations in the cell wall permeability for both steroids and nutrients, facilitation of protein leaking, and activity suppression of some steroid-transforming enzymes.In this work, we studied whether cyclodextrins might affect expression of the genes involved in the steroid catabolic pathway. Phytosterol bioconversion with 9α-hydroxy-androst-4-ene-3,17-dione accumulation by Mycobacterium sp. VKM Ac-1817D in the presence of methylated β-cyclodextrin (MCD) was investigated. RNA sequencing of the whole transcriptomes in different combinations of phytosterol and MCD showed a similar expression level of the steroid catabolism genes related to the KstR-regulon and was responsible for side chain and initial steps of steroid core oxidation; whereas, induction levels of the genes related to the KstR2-regulon were attenuated in the presence of MCD in this strain. The data were attenuated with quantitative real-time PCR.The results contribute to the understanding of cyclodextrin effects on microbial steroid conversion and provide a basis for the use of cyclodextrins as expression enhancers for studies of sterol catabolism in actinobacteria.

  9. Influence of lipophilicity on drug-cyclodextrin interactions: A calorimetric study

    International Nuclear Information System (INIS)

    Waters, Laura J.; Bedford, Susan; Parkes, Gareth M.B.; Mitchell, J.C.

    2010-01-01

    This study presents a systematic investigation of the interaction of three functionally related drugs, ibuprofen, ketoprofen and flurbiprofen, with two distinct forms of cyclodextrin at three specific temperatures, 298, 303 and 310 K using isothermal titration calorimetry (ITC). Although all three pharmaceutical compounds have similar pKa values, they exhibit widely differing lipophilicities. While previous authors have presented data regarding the binding of flurbiprofen and ibuprofen with β-cyclodextrin, this is the first report of the interaction of all three drug substances with β-cyclodextrin and 2-(hydroxypropyl)-β-cyclodextrin at controlled pH and temperature. For all scenarios, the associated changes in Gibbs free energy, enthalpy and entropy are presented alongside the stoichiometry and binding constants concerned. In all cases the binding was found to occur at a 1:1 ratio with an associated negative enthalpy and Gibbs free energy with the formation of the complex enthalpically, rather than entropically driven. The data further demonstrates a clear relationship between the thermodynamic behaviour and log P of the drug molecules. This work confirms the suitability of ITC to determine thermodynamic data for drug-cyclodextrin complex formations and provides an insight into the selection of appropriate cyclodextrins for bespoke pharmaceutical formulations.

  10. Foresighting for Inclusive Development

    DEFF Research Database (Denmark)

    Andersen, Allan Dahl; Andersen, Per Dannemand

    2017-01-01

    of policymaking processes affects the actual process with a focus on inclusion, and we discuss how it affects policy effectiveness and innovation system transformation. Our argument is that processes of policymaking must be inclusive to affect and transform innovation systems because a set of distributed actors...... in foresight cases in two emerging economies: Brazil and South Korea. We conclude that better systemic and innovation oriented foresight is needed to enhance inclusive development....

  11. INCLUSIVE EDUCATION IN ITALY

    OpenAIRE

    Voitkāne, Vita

    2017-01-01

    European member States implement Inclusive Education policies thus contributing to a sustainable, inclusive society, although each country is at a different stage in this process. Italy, one of the first countries to launch integrative learning, has set an example since the 1970s, although the quality of inclusive education is unpredictable due to many issues. Authors Cantoni and Panetta (2006) emphasize that, although the culture of integration in Italy exists, much needs to be done to impro...

  12. SUPPORT IN INCLUSIVE EDUCATION

    OpenAIRE

    Belma Čičkušić; Ševala Tulumović; Selma Bakić; Salem Bakić

    2016-01-01

    In order for inclusive class to be successful, associates are of great help to teachers. Besides associates, teachers' specialization can be accomplished through educational seminars on the inclusion topic. However, information about inclusion, working with children with special needs, can also be found in scientific journals that offer more information on methods of working with children with special needs, didactic materials customized according to abilities of children. Aim of ...

  13. Targeted delivery and pH-responsive release of stereoisomeric anti-cancer drugs using β-cyclodextrin assemblied Fe{sub 3}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Congli; Huang, Lizhen; Song, Shengmei; Saif, Bassam; Zhou, Yehong; Dong, Chuan; Shuang, Shaomin, E-mail: smshuang@sxu.edu.cn

    2015-12-01

    Graphical abstract: - Highlights: • β-Cyclodextrin assemblied magnetic Fe{sub 3}O{sub 4} nanoparticles (β-CD-MNPs) with good stability were successfully fabricated. • Stereoisomeric doxorubicin (DOX) and epirubicin (EPI) were used to explore the loading and release performance. • The loading properties of β-CD-MNPs were investigated using the Langmuir and Freundlich adsorption equilibrium models. • {sup 1}H NMR and the computer simulation were used to demonstrate the inclusion position between drug molecules and β-CD. - Abstract: The β-cyclodextrin assemblied magnetic Fe{sub 3}O{sub 4} nanoparticles (β-CD-MNPs) were successfully fabricated via a layer-by-layer method. Possessing an average size 14 nm, good stability and super-paramagnetic response (Ms 64 emu/g), the resultant nanocomposites could be served as a versatile biocompatible platform for selective loading, targeted delivery and pH-responsive release of stereoisomeric doxorubicin (DOX) and epirubicin (EPI). {sup 1}H-nuclear magnetic resonance ({sup 1}H NMR) and the computer simulation further give the evidence that partial anthracene ring of drug molecule is included by β-CD. In addition, non-toxic β-CD-MNPs have excellent biocompatibility on MCF-7 cells, and cellular uptake indicate that different amounts of DOX or EPI can be transported to targeting site and released from the internalized carriers. The results demonstrate that as-prepared β-CD-MNPs could be a very promising vehicle for DOX and EPI.

  14. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward......-looking. This paper introduces a radically different approach to estimating market betas. Using the tools in Bakshi and Madan (2000) and Bakshi, Kapadia and Madan (2003) we employ the information embedded in the prices of individual stock options and index options to compute our forward-looking market beta...

  15. Nuclear Matrix Elements for the $\\beta\\beta$ Decay of the $^{76}$Ge

    CERN Document Server

    Brown, B A; Horoi, M

    2015-01-01

    The nuclear matrix elements for two-neutrino double-beta (2 n$\\beta\\beta$ ) and zero-neutrino double-beta (0 n$\\beta\\beta$) decay of 76 Ge are evaluated in terms of the configuration interaction (CI), quasiparticle random phase approximation (QRPA) and interacting boson model (IBM) methods. We show that the decomposition of the matrix elements in terms of interemediate states in 74 Ge is dominated by ground state of this nucleus. We consider corrections to the CI results that arise from configurations admixtures involving orbitals out-side of the CI configuration space by using results from QRPA, many-body-perturbation theory, and the connections to related observables. The CI two-neutrino matrix element is reduced due to the inclusion of spin-orbit partners, and to many-body correlations connected with Gamow-Teller beta decay. The CI zero-neutrino matrix element for the heavy neutrino is enhanced due to particle-particle correlations that are connected with the odd-even oscillations in the nuclear masse...

  16. Cyclodextrin-grafted barium titanate nanoparticles for improved dispersion and stabilization in water-based systems

    Energy Technology Data Exchange (ETDEWEB)

    Serra-Gómez, R. [Universidad de Navarra, Departamento de Química y Edafología (Spain); Martinez-Tarifa, J. M. [Universidad Carlos III de Madrid, Departamento de Ingeniería Eléctrica (Spain); González-Benito, J. [Universidad Carlos III de Madrid, Departamento de Ciencia e Ingeniería de Materiales e Ingeniería Química, IQMAAB (Spain); González-Gaitano, G., E-mail: gaitano@unav.es [Universidad de Navarra, Departamento de Química y Edafología (Spain)

    2016-01-15

    Ceramic nanoparticles with piezoelectric properties, such as BaTiO{sub 3} (BT), constitute a promising approach in the fields of nanocomposite materials and biomaterials. In the latter case, to be successful in their preparation, the drawback of their fast aggregation and practically null stability in water has to be overcome. The objective of this investigation has been the surface functionalization of BaTiO{sub 3} nanoparticles with cyclodextrins (CDs) as a way to break the aggregation and improve the stability of the nanoparticles in water solution, preventing and minimizing their fast precipitation. As a secondary goal, we have achieved extra-functionality of the nanoparticles, bestowed from the hydrophobic cavity of the macrocycle, which is able to lodge guest molecules that can form inclusion complexes with the oligosaccharide. The nanoparticle functionalization has been fully tracked and characterized, and the cytotoxicity of the modified nanoparticles with fibroblasts and pre-osteoblasts cell lines has been assessed with excellent results in a wide range of concentrations. The modified nanoparticles were found to be suitable for the easy preparation of nanocomposite hydrogels, via dispersion in hydrophilic polymers of typical use in biomedical applications (PEG, Pluronics, and PEO), and further processed in the form of films via water casting, showing very good results in terms of homogeneity in the dispersion of the filler. Likewise, as examples of application and with the aim of exploring a different range of nanocomposites, rhodamine B was included in the macrocycles as a model molecule, and films prepared from a thermoplastic matrix (EVA) via high-energy ball milling have been tested by impedance spectroscopy to discuss their dielectric properties, which indicated that even small modifications in the surface of the nanoparticles generate a different kind of interaction with the polymeric matrix. The CD-modified nanoparticles are thus suitable for easy

  17. Cyclodextrins as drug carriers in Pharmaceutical Technology: The state of the art.

    Science.gov (United States)

    Conceição, Jaime; Adeoye, Oluwatomide; Cabral-Marques, Helena Maria; Lobo, Jose Manuel Sousa

    2017-12-18

    Cyclodextrins (CDs) are versatile excipients with an essential role in drug delivery, as they can form non-covalently bonded inclusion complexes (host-guest complexes) with several drugs either in solution or in the solid state. The main purpose of this publication was to carry out a state of the art of CDs as complexing agents in drug carrier systems. In this way, the history, properties and pharmaceutical applications of the CDs were highlighted with typical examples. The methods to enhance the complexation efficiency (CE) and the CDs applications in solid dosage forms were emphasized in more detail. The main advantages of using these cyclic oligosaccharides are as follows: (1) to enhance solubility/dissolution/ bioavailability of poorly soluble drugs; (2) to enhance drug stability; (3) to modify the drug release site and/or time profile; and (4) to reduce drug side effects (for example, gastric or ocular irritation). These compounds present favorable toxicological profile for human use and therefore there are various medicines containing CDs approved by regulatory authorities worldwide. On the other hand, the major drawback of CDs is the increase in formulation bulk, once the CE is, in general, very low. This aspect is particularly relevant in solid dosage forms and limits the use of CDs to potent drugs. CDs have great potential as drug carriers in Pharmaceutical Technology and can be used by the formulator in order to improve the drug properties such as solubility, bioavailability and stability. Additionally, recent studies have shown that these compounds can be applied as active pharmaceutical ingredients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. Quality Enhancement by Inclusion Complex Formation of Simvastatin Tablets

    Directory of Open Access Journals (Sweden)

    Emőke Rédai

    2013-08-01

    Full Text Available Introduction: Simvastatin is an inhibitor of hydroxy-methyl-glutaryl-coenzyme A reductase, used in the treatment of hypercholesterolemia. To enhance its bioavailability by inclusion complexation, as host molecule randommethyl-β-cyclodextrin had been used. After evaluating the complexes we chose the kneading product in 1:2 molar ratio for incorporation of 10 mg simvastatin tablets. Materials and methods: We prepared homogenous mixtures of the inclusion complex and some excipients. The tablets were prepared by direct compression. The tablets were evaluated in regard to: weight uniformity, thickness, diameter, hardness, friability, disintegration and dissolution profile. Results: Weights are in the range of 196-208 mg, diameter 6.83-6.86 mm, height 3.86-4.01 mm, hardness 78.3-113.1 N, friability 0.75- 1.19 %, disintegration above 15 minutes. The dissolved amounts of simvastatin from the tablets are higher compared to the dissolution of pure simvastatin, but lower than the dissolution of the complex itself. Excipients, like disintegrants and lubricants greatly influence the dissolution properties of the tablets. Conclusions: According to our results, tablets containing inclusion complex of simvastatin exhibit better solubility, according to the dissolved amount of simvastatin, than pure drug alone. Proper physical parameters of the tablets are obtained by application of 5 % Primellose

  19. Monitoring cyclodextrin-polyviologen pseudopolyrotaxanes with the Bradford assay.

    Science.gov (United States)

    Belitsky, Jason M; Nelson, Alshakim; Stoddart, J Fraser

    2006-01-21

    Self-assembled multivalent pseudopolyrotaxanes, composed of lactoside-bearing cyclodextrin (CD) rings threaded on linear polyviologen polymers, have been introduced recently as flexible and dynamic neoglycoconjugates. In the course of this research, it was found that polyviologens are responsive to the Bradford assay, which is traditionally highly selective for proteins. The response of the pseudopolyrotaxanes to the Bradford assay was dependant on, and thus indicative of, the degree of threading of the CD rings onto the polyelectrolyte. The assay was then used to report on the threading and dethreading of native and lactoside-bearing alpha-CD rings onto and off of polyviologen chains, a phenomenon which demonstrates the utility of biochemical assays to address problems unique to supramolecular chemistry.

  20. Synthesis of Randomly Substituted Anionic Cyclodextrins in Ball Milling

    Directory of Open Access Journals (Sweden)

    László Jicsinszky

    2017-03-01

    Full Text Available A number of influencing factors mean that the random substitution of cyclodextrins (CD in solution is difficult to reproduce. Reaction assembly in mechanochemistry reduces the number of these factors. However, lack of water can improve the reaction outcomes by minimizing the reagent’s hydrolysis. High-energy ball milling is an efficient, green and simple method for one-step reactions and usually reduces degradation and byproduct formation. Anionic CD derivatives have successfully been synthesized in the solid state, using a planetary ball mill. Comparison with solution reactions, the solvent-free conditions strongly reduced the reagent hydrolysis and resulted in products of higher degree of substitution (DS with more homogeneous DS distribution. The synthesis of anionic CD derivatives can be effectively performed under mechanochemical activation without significant changes to the substitution pattern but the DS distributions were considerably different from the products of solution syntheses.