The solubility of natural cyclodextrins is very poor and initially this prevented cyclodextrins from becoming effective complexing agents. In the late 1960s, it was discovered that chemical substitutions at the 2-, 3-, and 6-hydroxyl sites would greatly increase solubility. The degree of chemical substitution and the nature of the groups used for substitution determine the final maximum concentration of cyclodextrin in an aqueous medium. Most chemically modified cyclodextrins are able to achieve a 50% (w/v) concentration in water.. Cavity size is the major determinant as to which cyclodextrin is used in complexation. "Fit" is critical to achieving good incorporation of cyclodextrins. α-Cyclodextrins have small cavities that are not capable of accepting many molecules. γ-Cyclodextrins have much larger cavities than many molecules to be incorporated, and cyclodextrin hydrophobic charges cannot effectively interact to facilitate complexation. The cavity diameter of β-cyclodextrins has been ...
In vitro studies of α-amylase degradation of α-, β- and γ-cyclodextrins and 2-hydroxypropyl-β- and -γ-cyclodextrins were investigated spectrophotometrically by measuring the formation of reducing sugars, the reaction products of α-amylase degradation. This was done to evaluate potential degradation and thereby biological conversion of the cyclodextrins if dosed orally, as the intestinal tract contains α-amylase for digestive purposes. The results demonstrated that only γ- and 2-hydroxypropyl-γ-cyclodextrins can be degraded by α-amylase to a relevant extent, that is, γ- and 2-hydroxypropyl-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 was caused by a correlation between solubility of the additives and the stability of the ...
The aim of present study is to highlight the effects of β-cyclodextrin (BCD) and hydroxypropyl-β-cyclodextrin (HBCD) and also the effect of their concentrations and methods of inclusion complexation on solubility and antibacterial activity of trimethoprim [TMP] by inclusion complex formation. The inclusion complexes of TMP were prepared by solvent evaporation, spray drying, kneading and physical mixture methods in 1:1 and 1:2 ratios. The inclusion complexes were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), dissolution study and antimicrobial activity by disk diffusion method. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) results proved formation of inclusion complex of TEM with cyclodextrins. XRD showed decrease in crystanality of TEM after complexation with CDs. The results of saturation solubility study and release study prevailed the more increase in solubility of TMP by HPCD than
TY - JOUR. T1 - Interactions between cyclodextrins and cell-membrane phospholipids. AU - Szejtli, J.. AU - Cserháti, T.. AU - Szögyi, M.. PY - 1986. Y1 - 1986. N2 - The interactions between cyclodextrins (CDs) and selected cell membrane phospholipids, liposomes and human erythrocytes were studied. Non-methylated cyclodextrins did not influence the differential scanning calorimetric behaviour of phospholipids and did not increase the permeability of dipalmitoyl-phosphatidyl-choline liposomes. Dimethyl- and trimethyl- β-CD interacted with the phospholipids but the effect was negligible compared to the effect of valinomycin. Reversed-phase thin-layer chromatography revealed complex formation with dimethyl-β-cyclodextrin, but not with others. The addition of cyclodextrins up to 10-2 mol litre-1 concentration did not modify the active or passive alkali ion transport of human erythrocytes, however, higher concentrations of added β-cyclodextrin especially dimethyl-β-cyclodextrin resulted in ...
Effect of processing variables on dissolution and solubility of piroxicam: Hydroxypropyl-? -cyclodextrin inclusion complexes Abstract.
Formation of maltosyl cyclodextrins from mixtures of maltose and cyclodextrins by reverse reactions of Flavobacterium isoamylase and Klebsiella pullulanase was experimented and it was found that Klebsilla pullulanase produced 50.4 mg maltosyl alpha-cyclodextrin, 35.0 mg maltosyl beta-cyclodextrin and 55.4 mg maltosyl gamma-cyclodextrin per ml of reaction mixture, whereas Flavobacterium isoamylase did not form maltosyl cyclodextrins. Optimum conditions for formation of maltosyl beta-cyclodextrin by Klebsiella pullulanase were pH 4, 50 degrees C reaction temperature and proportion of substrate 100 mg beta-cyclodextrin/600 mg maltose per ml ...
0083] In some embodiments, the cyclodextrin derivative is present in a pharmaceutical composition or unit dosage form of the present invention in a concentration of about 0.1 mg/mL to about 1000 mg/mL, about 0.1 mg/mL to about 700 mg/mL, about 0.1 mg/mL to about 500 mg/mL, about 0.1 mg/mL to about 250 mg/mL, about 0.1 mg/mL to about 200 mg/mL, about 0.1 mg/mL to about 150 mg/mL, about 0.1 mg/mL to about 100 mg/mL, about 0.1 mg/mL to about 50 mg/mL, about 1 mg/mL to about 1000 mg/mL, about 1 mg/mL to about 700 mg/mL, about 1 mg/mL to about 500 mg/mL, about 1 mg/mL to about 250 mg/mL, about 1 mg/mL to about 200 mg/mL, about 1 mg/mL to about 150 mg/mL, about 1 mg/mL to about 100 mg/mL, about 1 mg/mL to about 50 mg/mL, about 10 mg/mL to about 1000 mg/mL, about 10 mg/mL to about 700 mg/mL, about 10 mg/mL to about 500 mg/mL, about 10 mg/mL to about 250 mg/mL, about 10 mg/mL to about 200 mg/mL, about 10 mg/mL to about 150 mg/mL, about 10 mg/mL to about 100 mg/mL, about 10 mg/mL to about 50 mg/mL, about ...
A stable composition for removing unwanted molecules from a surface comprises low-degree of substitution cyclodextrin derivatives. The compositions are suitable for capturing unwanted molecules from inanimate surfaces, including fabrics, including carpets, and household surfaces such as countertops, dishes, floors, garbage cans, ceilings, walls, carpet padding, air filters, and the like, and from animate surfaces, including skin, hair, and the like. The compositions can further comprise cyclodextrin-compatible and -incompatible materials, and other optional ingredients.
A cyclodextrin-based chiral stationary phase (CD-CSP) is one of the most widely applied CSPs due to its powerful enantioseparation ability. In this study, a facile method was developed to prepare a CD-CSP via carboxyl methyl β-cyclodextrin (CD-COOH) and diazo-resin (DR). Monodisperse silica particles were sy
en] PURPOSE: Ro 28-2653 (RO) is a synthetic inhibitor of matrix metalloproteinases (MMPs), which is potentially effective against bronchial remodeling. Given that this molecule has very poor aqueous solubility, different cyclodextrins (CDs) have been tested to increase its solubility. The aim of this study was to prepare and to characterize inclusion complexes between RO and CDs, in order to develop nebulizable solutions. METHODS: The complex formation was investigated by phase solubility studies. (1)H-NMR spectroscopy and molecular modeling studies were carried out to elucidate the structure of the inclusion complex between RO and dimethyl-beta-CD (DIMEB). Nebulizable solutions of RO were developed with CDs and a stability study was performed over 9 months. RESULTS: The phase solubility studies showed that beta-CD and its derivatives form a 1:2 complex with RO, whereas gamma-CD includes RO with a 1:1 stoichiometry and a weak stability constant. T-ROESY spectra showed that DIMEB is able to ...
Cyclodextrins (sometimes called cycloamyloses) are a family of compounds made up of sugar molecules bound together in a ring (cyclic oligosaccharides). Cyclodextrins are produced from starch by enzymatic conversion. They are used in food, pharmaceutical, drug delivery, and chemical industries, as well as agriculture and environmental engineering. α-Cyclodextrin is a soluble dietary fiber used as an ingredient in commercial food products. Cyclodextrins are composed of 5 or more α-D-glucopyranoside units linked 1->4, as in amylose (a fragment of starch). The largest cyclodextrin contains 32 1,4-anhydroglucopyranoside units, while as a poorly characterized mixture, at least 150-membered cyclic oligosaccharides are also known. Typical cyclodextrins contain a number of glucose monomers ranging from six to eight units in a ring, creating a cone shape: α (alpha)-cyclodextrin: 6-membered sugar ring molecule β (beta)-cyclodextrin: 7-membered sugar ring molecule γ (gamma)-cyclodextrin: 8-membered ...
Inclusion of drug molecules in cyclodextrins can significantly improve various aspects of their performance and has resulted in the use of cyclodextrins (CDs) for a wide variety of pharmaceutical applications. Consequently, the cyclodextrin inclusion of drugs has received great interest in the pharmaceutical and chemical fields. For this study the inclusion of nine pharmaceutical drugs with CDs was investigated in the solid state. The objectives of the study were i.) the preparation, ii.) determination of the chemical composition, iii.) analysis of thermal behaviour and iv.) investigation of the solid state features of the complexes. Ultraviolet spectrophotometry, elemental analysis and thermogravimetric analysis were the principal techniques used for determination of composition. Hot stage microscopy, differential scanning calorimetry and thermogravimetric analysis were the principal techniques used for the analysis of thermal behaviour. Single crystal x-ray diffraction and x-ray powder ...
This study reports the formation of solid vanillin/cyclodextrin inclusion complexes (vanillin/CD ICs) with the aim to enhance the thermal stability and sustained release of vanillin by inclusion complexation. The solid vanillin/CD ICs with three types of CDs (α-CD, β-CD, and γ-CD) were prepared using the freeze-drying method; in addition, a coprecipitation method was also used in the case of γ-CD. The presence of vanillin in CD ICs was confirmed by FTIR and (1)H NMR studies. Moreover, (1)H NMR study elucidated that the complexation stoichiometry for both vanillin/β-CD IC and vanillin/γ-CD IC was a 1:1 molar ratio, whereas it was 0.625:1 for vanillin/α-CD IC. XRD studies have shown channel-type arrangement for CD molecules, and no diffraction peak for free vanillin was observed for vanillin/β-CD IC and vanillin/γ-CD IC, indicating that complete inclusion complexation was successfully achieved for these CD ICs. In the case of vanillin/α-CD IC, the sample was mostly amorphous and some uncomplexed
TY - JOUR. T1 - Thermodynamics of inclusion complex formation of β-cyclodextrin with a variety of surfactants differing in the nature of headgroup. AU - Benk, Mária. AU - Király, Zoltán. PY - 2012/11/1. Y1 - 2012/11/1. N2 - 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 vant Hoff enthalpy were additionally calculated.. AB - The inclusion ...
1A47: Engineering of cyclodextrin product specificity and pH optima of the thermostable cyclodextrin glycosyltransferase from Thermoanaerobacterium thermosulfurigenes EM1.
1A47: Engineering of cyclodextrin product specificity and pH optima of the thermostable cyclodextrin glycosyltransferase from Thermoanaerobacterium thermosulfurigenes EM1.
0131]Pharmaceutical compositions of the present invention comprise a therapeutically effective amount of iron from one or more iron-containing compounds, and/or one or more compounds or agents selected from the group consisting of vitamin supplements, erythropoietin stimulating agents, erythropoietin, pharmaceutically acceptable carriers, transdermal permeabilizing agents, and cyclodextrins. As used herein and in the claims, the term "cyclodextrin" refers to any of a family of cyclic oligosaccharides. Cyclodextrins, also sometimes called cycloamyloses, are composed of, but are not necessarily limited to, five or more D-glucopyranoside units, connected by α-(1,4) glycosidic linkages, as in amylose. Cyclodextrins having as many as 32 1,4-glucopyranoside units have been well characterized. Cyclic oligosaccharides as large as 150 units have been identified. Typically, cyclodextrins contain, but are not necessarily limited to, six to eight glucopyranoside units in a ring, commonly termed ...
We report the effect of native cyclodextrins (alpha, beta, and gamma) and selected derivatives in modulating the self-assembly of the nonionic surfactant polyoxyethylene cholesteryl ether (ChEO(10)) and its mixtures with triethylene glycol monododecyl ether (C12EO3), which form wormlike micelles. Cyclodextrins (CDs) generally induce micellar breakup through a host-guest interaction with surfactants; instead, we show that a constructive effect, leading to gel formation, is obtained with specific CDs and that the widely invoked host-guest interaction may not be the only key to the association. When added to wormlike micelles of ChEO(10) and C12EO3, native beta-CD, 2-hydroxyethyl-beta-CD (HEBCD), and a sulfated sodium salt of beta-CD (SULFBCD) induce a substantial increase of the viscoelasticity, while methylated CDs rupture the micelles, leading to a loss of the viscosity, and the other CDs studied (native alpha- and gamma- and hydroxypropylated CDs) show a weak interaction. Most remarkably, the ...
Branched cyclodextrins are produced by the pyrolysis of cyclodextrins. The temperature range is 135 C. to 220 C. using equipment suitable for making British gum and other starch dextrins.
where [P]0 denotes the initial concentration of IBU and [CD]0 denotes that of CDs. F and F0 are the fluorescence intensities of IBU in the presence and absence of CDs, respectively. K is a formation constant, k is the instrument constant and Q is the fluorescence quantum yield of the inclusion complex. If the curve of 1/(F-F0) versus 1/[CD]0 exhibits good linearity, it implies that inclusion complexes with a stoichiometry of 1:1 are formed. B. Effect of the types of CDs β-CDs have the hydrophilic outer surface and a hydrophobic internal cavity. The inclusion interaction of β-CDs and the guest molecules is affected by the size of the internal cavity and hydrophilic, hydrophobic characters of the host. It is generally believed that dipole-dipole, electrostatic, van der Walls forces, hydrogen bonding, hydrophobic interaction, and the release of distortion energy of CD ring upon guest binding cooperatively govern the stability of an inclusion complex. The effect of HP-β-CD concentration on the ...
The preparation and characterization of a supramolecular host-guest inclusion complex between a fluorescent indolizinyl-pyridinium salt and β-cyclodextrin is reported. The formation of the inclusion complex was investigated by ESI-MS experiments, transmission electron microscopy, Jobs plot investigations an
Equilibrium constants and standard enthalpies have been measured calorimetrically for the formation of complexes of α-and β-cyclodextrins with substituted phenols in aqueous solutions at 298.15 K. The study includes variation of the size and shape of the phenol, the size and degree of methylation of the cyclodextrin, and the effects of pH and ionic strength. Substituent effects were measured for p-chloro-, p-bromo-, p-methyl-, p-hydroxy-, p-nitro- and m-nitrophenols. The effects of ionization were studied with m- and p-nitrophenolate ions. The effects of methyl substitutions of β-cyclodextrin were investigated with nitrophenol and nitrophenolate ions complexing with heptakis(2,6-di-O-methyl)-β-cyclodextrin and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin. All of the effects studied show a substantial amount of entropic-enthalpic compensation, such that free energy effects are relatively small in comparison to enthalpic and/or entropie effects, but there was no simple relationship between the
The interactions of trimethoprim, sulphadiazine and sulphamethoxazole with natural (alpha-, beta-, gamma-) and amorphous (RAMEB) or crystalline (DIMEB) methylated beta-cyclodextrins were investigated both in aqueous solution (using phase-solubility analysis) and in the solid state (using DSC supported by X-ray analysis). In particular, DSC studies enabled determination of the relative degree of crystallinity of each drug in its physical and ground mixtures with the different cyclodextrins on the basis of the variation of its heat of fusion in comparison with that of the pure drug. In all cases, the host cavity size was a prevalent factor for the inclusion complexation in liquid state. On the contrary, it had a negligible effect on solid-state interactions in terms of drug amorphization. DIMEB and RAMEB exhibited similar performances in aqueous solution, showing that the presence of methyl-groups improved the complexing and solubilizing properties of beta-cyclodextrin. However, DSC studies ...
Maniruzzaman, Mohammed, Ross, Steven A., Dey, Tumpa, Nair, Arun, Snowden, Martin J. and Douroumis, Dennis (2017) A quality by design (QbD) twin-screw extrusion wet granulation approach for processing water insoluble drugs. International Journal of Pharmaceutics, 526 (1-2). pp. 496-505. ISSN 0378-5173 (doi:10.1016/j.ijpharm.2017.05.020) Snowden, Martin J. (2016) Colloidal microgels - untapped potential? Journal of Nanomedicine and Nanotechnology, 7 (4). pp. 1-2. ISSN 2157-7439 (Online) (doi:10.4172/2157-7439.1000e142) Rudrangi, Shashi Ravi Suman, Kaialy, Waseem, Ghori, Muhammad U., Trivedi, Vivek, Alexander, Bruce David and Snowden, Martin J. (2016) Solid-state flurbiprofen and methyl-β-cyclodextrin inclusion complexes prepared using a single-step, organic solvent-free supercritical fluid process. European Journal of Pharmaceutics and Biopharmaceutics, 104. pp. 164-170. ISSN 0939-6411 (doi:10.1016/j.ejpb.2016.04.024) Ehiwe, Tracy O., Alexander, Bruce D, Mitchell, John C., Snowden, Martin J. and ...
TY - GEN. T1 - Branching of cyclodextrins with various mono-, di-, and tri-saccharides by Bacillus acidophilus pullulanase.. AU - Madsen, U.. AU - Larsen, Kim Lambertsen. PY - 2002. Y1 - 2002. KW - Bioteknologi. KW - Bioteknologi. M3 - Article in proceeding. BT - Third Nordic Starch network Symposium. PB - Denmark.. ER - ...
Cyclodextrins: Roquette offers a wide range of betacyclodextrins KLEPTOSE® with different characteristics, solubility, water content, compactibility. | Roquette
From the kinetic investigation of the cleavage of the 4-acetoxybenzoate anion (4-ABA) in the presence of three cyclodextrins (Ì-CD, Ý-CD, and Þ-CD) in basic aqueous solution, the results indicate that 4-ABA binds to Ì-CD fairly weakly while no binding is observed between 4-ABA and Ý-CD or Þ-CD. The effects of the three CDs on the kinetics of the aminolysis of 4-ABA by primary amines have been investigated. Rate constants for the nucleophilic attack by free and CD-bound amine are obtained. For Ì-CD, values of the reactivity ratios for the linear amines are low (,1) implying deceleration of the aminolysis reaction due to binding to the CD. In the case of Ý-CD, the reactivity ratios are slightly larger (,1 for both n -alkyl and branched amines), implying modest catalysis. As for Þ-CD, the values of the reactivity ratios are ,2, which also signifies modest catalysis ...
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The photochem. behavior of alkyldeoxybenzoins $PhCOCHPhCH_2CH_2R$ (R = H, Me, Et, hexyl, decyl) has been investigated in isotropic org. solvents, in aq. cyclodextrin solns., and bound to cyclodextrin in the solid state. Norrish type I and type II reactions occur in these media and the product distribution resulting from these primary processes are dependent on the medium. In org. solvents, type I and type II products are obtained in equal amts. In aq. cyclodextrin soln., type II products are formed in large excess. In the solid state, type II products constitute more than 90% of the product distribution. Ratios of products resulting from elimination and cyclization from the type II 1,4-diradical are also altered by the host cyclodextrin. Conformational and super-cage effects have been invoked to rationalize the dramatic alteration of the photobehavior of alkyldeoxybenzoins by cyclodextrin.. ...
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The effect of cyclodextrin complexation on the solubility and photostability of nerolidol as pure compound and as main constituent of cabreuva essential oil
Paracetamol is a sparingly soluble bitter tasting drug. It is widely used as an analgesic and antipyretic. Complexation of drug with different cyclodextrins (?, ? and HP-?-CD) was attempted to improve solubility of Paracetamol. During the drug excipient interaction studies, ?, ? cyclodextrins elicited analytical interference and showed considerable absorbance at ?max (243.5 nm) of Paracetamol while the ones constituting of hydroxypropyl-beta-cyclodextrin (HP-?-CD) did not show any such interference. Therefore, the present study is concentrated on exploring HP-?-CD as complexing agent. Phase solubility studies showed that complexation of Paracetamol/HP-?-CD at molar ratio 1:1 and showed AL type solubility curve. Complexation was done by various methods like physical mixing, kneading and freeze drying and resulting drug complexes were characterized by Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR). The thermograms obtained showed an endothermic peak for
United This invention relates to complexes, or inclusion compounds, to the preparation of the same, and to edible materials incorporating them. A major problem in the production of convenience foods lies in the difficulty of retaining in the food certain flavors and/or aromas, which, although they may be present in minor amounts, are none the less important. In fact, capturing and preserving for subsequent use the fresh delightful flavors and aromas of fresh edible juices, such as those of freshly picked fruits, leaves and vegetables, is virtually impossible with present-day commercial techniques. Dried leaves, blanched and frozen leaves, dehydrated and frozen fruits and fruit juices, and the like, have been and are used as substitutes, but they fall considerably short of providing the true freshness of the untreated natural material. These flavors and aromas, or notes, which are characteristic of many fresh foods, tend to escape, or undergo change, or be lost in some way, before the food is ...
The synthesis of a new family of cyclodextrin (CD) analogues is described, This family consists of novel cyclic oligosaccharides built from monosaccharides that possess the same relative but opposite absolute (D- and L-) configurations. The alternation of such D- and L-residues-specifically, D- and L-rhamnose or D- and L-mannose-in a macrocyclic structure results in S-n-type symmetry and, consequently, optical inactivity. The synthesis of these cyclic oligosaccharides was achieved by an economical polycondensation/cycloglycosylation approach that relies on an appropriately-derivatized disaccharide monomer and that avoids the time-consuming, and often low-yielding, stepwise growth of long linear oligosaccharide precursors. In the cases reported, the key precursors are the disaccharide monomers 1-RR and 1-MM, which bear both a glycosyl donor (cyanoethylidene function) and a glycosyl acceptor (trityloxy group). These compounds are able to undergo Tr+-catalyzed polycondensation which, under ...
Cardiovascular disease resulting from atherosclerosis is one of the most common causes of death worldwide. Inflammation plays a crucial role in atherosclerosis and cholesterol crystals are candidate triggers early in the development of the disease.. Scientists from Bonn in Germany together with scientists from Center of Molecular Inflammation Research (CEMIR) in Trondheim and UiO/OUS Rikshospitalet in Oslo, have in a multi-international collaboration published in Science Translational Medicine that cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin dissolve cholesterol crystals and reduces atherosclerotic plaques. This is a promising therapeutic approach for treating atherosclerosis.. Cyclodextrin reprograms the macrophages in an anti-inflammatory manner in addition to increasing cholesterol efflux. The result is prevention of plaque formation and even atherosclerotic plaque regression in mice. Furthermore, biopsies of plaque carotid from humans treated with cyclodextrin showed similar ...
article{0f55d48c-6744-4fed-8c52-9bc57e9a4281, abstract = {The thickening effect of a hydrophobically modified polymer in an aqueous solution is dependent on intermolecular hydrophobic associations, and if the polymer concentration is significantly above the overlap concentration also on chain entanglements. In this investigation we have added different cyclodextrins (CD) in order to decouple hydrophobic polymer-polymer associations via inclusion complex formation with the polymer hydrophobic tails. Both size and hydrophobicity of the cavity of the CD-molecules were found to have an effect on the process. In addition, the influence of chemical structure of the polymer hydrophobic tails was investigated. Either a linear C-14-chain or a more bulky nonylphenol group was used. The viscosity as a function of CD-concentration first decreased strongly, and then attained a constant value. At excess CD the viscosity became virtually the same as in a solution of the unmodified parent polymer, provided that ...
The dielectric properties of alpha and beta cyclodextrin have been investigated in aqueous solutions. Static dielectric constants were measured in water and in mixtures of methyl sulfoxide-water and methanol-water at 25(DEGREES)C. Dielectric constants and losses were measured for water solutions onl.... Full description. ...
Novel multifunctional cyclodextrin-based nanocarriers for drug encapsulation and delivery as a strategy to overcome current therapeutic drawbacks ...
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TY - JOUR. T1 - Thermodynamic study of the discrimination between uridine and thymidine derivatives by hydrophobic, stacking, and intercalating interactions. AU - Rekharsky, M. V.. AU - Nakamura, Asao. AU - Hembury, G. A.. AU - Inoue, Y.. PY - 2001/3. Y1 - 2001/3. N2 - Thermodynamic parameters for the complexation reactions of uridine/thymidine nucleobases and related compounds, with hosts of differing binding modes and properties (natural cyclodextrins, 5,10,15,20-tetrakis (1-methlpyridinium-4-yl) porphyrin tetrachloride and bis-intercaland macrocycle) have been determined by titration microcalorimetry and/or fluorometry, in an aqueous buffer. For each of these hosts the effect of the 5-methyl group on the binding affinities was investigated. Although the affinities of uridine and thymidine towards cyclodextrins and 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin tetrachloride are very similar, the intercalation of these compounds into the bis-intercaland macrocycle has been shown to ...
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Darunavir, a protease inhibitor most widely used in the treatment of HIV infection, was complexed with β-cyclodextrin due to the low solubility in water and its poor bioavailability. This research describes the study the long-term stability of the complex darunavir: β-cyclodextrin which was kept in a climatic chamber for 24 months at 30°C ± 2°C and 75 % UR ± 5 %. The samples were analyzed using LC-MS, 250 mm × 4.6 mm CN Luna column, water + 0.1 % glacial acetic acid: acetonitrile + 0.1 % glacial acetic acid 60:40 (v/v) as mobile phase, flow rate of 1.0 mL min-1, UV detection at 268 nm and ambient room temperature (25°C) before the start of study and thereafter 3, 6, 9, 12, 18 and 24 months. The data obtained associated with the infrared, TG, DSC and X-ray diffraction analysis was sufficient to study the behavior of complex darunavir: β-cyclodextrin. The results of this research indicate that the stability of the complex darunavir: β-cyclodextrin is high under conditions associated of
Publication Details (including relevant citation information): Nociari, M.M., Lehmann, G.L., Perez Bay, A.E., Radu, R.A., Jiang, Z., Goicochea,
The purpose of this study was to develop and evaluate a solid nonaqueous oral dosage form for a new hepatitis C drug, PG301029, which is insoluble and unstable in water. Hydroxypropyl-β-cyclodextrin...
Protein aggregation is the major challenge encountered during manufacturing, storage and transportation of biopharmaceuticals (1,2). The objective was to evaluate the effect of two ßcyclodextrins derivatives: (KLEPTOSE® HPB hydroxypropyl-ß-cyclodextrin, with MS=0.65) and (KLEPTOSE® HP hydroxypropyl-ß-cyclodextrin, with MS=0.9) on two biologic drugs (Infliximab and Etanercept) aggregation using high-throughput formulation screening (iFormulate™) and nanoDSF (Differential Scanning Fluorimetry) (3,4). Preliminary results demonstrate that KLEPTOSE® HPB BioPharma hydroxypropyl-ß-cyclodextrin and KLEPTOSE® HP BioPharma hydroxypropyl-ß-cyclodextrin at high molarity (200 mM) are efficient tools in modulating Infliximab…. ...
3BMV: Elimination of competing hydrolysis and coupling side reactions of a cyclodextrin glucanotransferase by directed evolution.
This is a report focusing on further development of a synthetic catalyst for hydrolysis of the phosphate ester bonds in RNA. The main goal was to construct a catalyst based on a cyclodextrin ligand suitable for carrying a lanthanide metal with the induced capability to hydrolyse the stable phosphate ester bonds in RNA. This was achieved through a six-step synthesis resulting in a lanthanide-salen-cyclodextrin complex. For simplicity in the product analysis of the reaction, adenosine diribonucleotide (ApA) was used as a model substrate for RNA. The hydrolysis was performed at 20°C and ph7 to mimic physiological conditions in the human body. The results showed indications that it was possible to hydrolysis RNA by this kind of complex.. ...
Fluticasone propionate is a highly potent corticosteroid used to treat asthma and allergic rhinitis. It is a very effective drug, but has the inconvenient factor of being insoluble in water. Cyclodextrins were used to improve this limitation because of their ability to form inclusion complexes with guest drug molecules as well as increase the stability and bioavailability of the drugs. A rapid and simple HPLC method was developed to detect and quantify fluticasone propionate in inhalation particles on several matrices. Liquid chromatography with a UV detector at a wavelength of 236 nm, using a C18 column, was employed in this study. Isocratic elution was employed using a mixture of acetonitrile and water (60:40, v/v). The analytical method validation was performed in accordance with ICH guidelines, which included selectivity, range, linearity, accuracy, detection limit, quantitation limit, precision, robustness, and stability of solutions. This method showed to be selective and specific. Acceptable
We have recently described a novel cyclic tetrasaccharide of D-glucose (Cote & Biely, Eur. J. Biochem. 226:641-648, 1994), and would like to know if anyone in the carbohydrate chemistry community has any ideas for using it. We would especially like to collaborate with someone who would like to study its ability to complex small molecules or ions. It has practically no internal cavity, so would probably not form inclusion complexes similar to those of cyclodextrins. We can only provide milligram amounts at this time, and only if your idea is interesting and has scientific merit. Please contact me via e-mail or snail mail. Gregory Cote USDA/ARS/NCAUR 1815 N. University St. Peoria, IL 61604 E-mail: cotegl at ncaur1.ncaur.gov ...
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