Silver Nanoparticles Produced by Magnetron Sputtering and Selective Nanodecoration onto <i>α</i>-Cyclodextrin/Carboxylic Acid Inclusion Compounds Crystals

In this work, we report the preparation of silver nanoparticles (AgNPs) and the nanodecoration of α-cyclodextrin inclusion compounds (α-CD IC) microcrystals that contain palmitic (PAc) and stearic acids (SAc) like guest molecules. These IC provide a suitable environment for nucleation, epitaxial growth and immobilization of AgNPs that were obtained by the magnetron sputtering technique. The use of α-CD IC substrates with a specific surface morphology in which the functional group of the guest molecule faces outward preferentially from a crystal plane, is an efficient method for the preparation of AgNPs with a low size dispersion, which is probably due to the high affinity between the functional group of the surfactant carboxylic acid guest with the metal nanoparticles.

Inclusion complexes of cefuroxime axetil with β-cyclodextrin:Physicochemical characterization, molecular modeling and effect of Larginine on complexation

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.

Study on the Structure of Supramolecular Inclusion Complex of β-Cyclodextrin with Retinoic Acid

Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, FT-IR spectroscopy and X-ray diffractometry, and the formed supramolecule self-assembles in aqueous solution according to molar ratio 2:1 of host-guest.

Formation of the Inclusion Complex of Orange Ⅱ with β-Cyclodextrin and Its Photostability

Inclusion complex of Orange II with β-Cyclodextrin (β-CD) and the anti-photolysis effect under UV-light were investigated. The molar ratio of inclusion complex of β-Cyclodextrin and Orange Ⅱ is 1∶1. The formation constant K=1.236×10 3 L/mol was determined by the UV and Fluorescence spectra respectively, which was quite in accordance with the calculation with a modified Benesi-Hildbrand equation. The inclusion complex was characterized by the IR spectra and the molar ratio of inclusion complex is 1∶1 too. The formation constant K=1.266×10 3 L/mol was determined by 1 H NMR analysis and was nearly the same by UV and fluorescence spectra. The photocatalytic decolorization rate of Orange Ⅱ solutions containing β-CD and TiO_ 2 was smaller by 51.9% than that of the Orange Ⅱ solutions only containing TiO_ 2 , while in the case of direct photolysis of Orange Ⅱ solutions, β-CD can lower the photolysis rate by 48.1% under UV-light. This result indicates β-CD can inhibit the photolysis and photocatalytic decolorization of Orange Ⅱ under UV-light. The β-CD inclusion complex was found to be persistent to UV-light photolysis.

Inclusion Modes of Berberine with β-Cyclodextrin in Aqueous Solution

The possible inclusion modes of berberine（Berb） with β-cyclodextrin（BCD） in aqueous solution were predicted by molecular docking,molecular dynamics（MD） simulation and binding free energy calculations.Firstly,the molecular docking result reveals that the docking conformations of Berb appeared in two clusters ranked in two opposite orientations.Then,10 ns MD simulation was performed separately on the lowest energy conformation of each orientation（Mode I and Mode II） obtained by molecular docking.Moreover,based on the trajectories from MD simulation,the binding free energies of the two different modes were calculated by the Molecular Mechanics/Poisson Boltzmann surface area（MM/PBSA） method.Through analyzing the binding free energies of Berb with BCD,we found that Mode II was the preferential inclusion mode,which was in good agreement with the experimental result.In addition,the computed results show that the main impetus for the complex was the van der Waals interaction,but the solvation energy and the entropy change produced an adverse effect on the complex.

Synthesis of a Novel Aromatic Diamino-bridged Bis(β-cyclodextrin) and its Inclusion Complexation with Dyes Molecules

A novel brideed bis（β-cvclodextrin）, 4, 4＇-diaminodiphenyl ether-bfiged-bis （6-aimino-6-deoxv-β-cyclodextrin） 3, has been synthesized and its inclusion complexation behavior with three linear＇guest dyes （AR, NR and MB ） has been investigated by. means of fluorescence spectrometry. The-result obtained demonstrated that the novel bridged bis（β-cyclodextnn） showed much higher affinities towards guest dyes than native β-cyclodextrin.

Synthesis and Crystal Structure of an Inclusion Compound Constructed through Self-assembly of Nicotinamide and Dicyanamide Coordination Bridges

A novel inclusion compound of [Mn（dca）2（3-nic）2]n·（3-nic）2n（1,dca = dicyanamide,3-nic = nicotinamide） has been prepared and characterized by single-crystal X-ray diffraction,elemental analysis and IR.This complex crystallizes in the triclinic system,space group P1 with a = 7.5979（8）,b = 7.7128（9）,c = 14.5346（17）,α = 100.094（2）,β = 92.444（2）,γ = 116.736（2）o,V = 741.72（15） 3,Z = 1,Dc = 1.512 g/cm3,Mr = 675.55,μ = 0.507 mm-1,F（000） = 347,S = 1.023,the final R = 0.0400 and wR = 0.1010.The inclusion compound is constructed by a three-dimensional host network that consists of dca,3-nic and Mn2＋ with coordination and hydrogen-bonding interactions.In the network,one-dimensional rectangular channels are formed,and the guest molecules（3-nic） are included in the channels.The guest molecules interlink with the host through strong hydrogen bonds.

Inclusion Behavior of Dimer β-CyclodextrinBridged with Aspartic Acid Derivative

The (β-cyclodextrin (CD) dimer bridged with aspartic acid (ASP) derivative, FITC-ASP(NH-(-CD)2 (Host, FITC=fluorescein-4-isothiocyanate), was synthesized. Fluorescence polarization study showed that the novel host formed an inclusion compound, [FITC-ASP(NH-(-CD)2]ATA, for which Kd was determined to be 5.0×10-6 mol/L by Beacon 2000 Analyzer, when ATA (Guest) = Adm-Trp-Arg-Arg-NH2 (Adm = 1-adamantanecarboxylic acid, Trp = tryptophan, Arg = arginine), where Kd is the dissociation constant in aqueous solution at 298 K.

Multiform Host Lattices in the Layer Type Inclusion Compound of Thiourea with Tetrabutylammonium Salicylate and Water

A new inclusion complex thiourea with tetrabutylammonium salicylate and water, 4(C4H9)4N+C7H5O3 ?4(NH2)2CS?2H2O, has been prepared and characterized by X-ray crystallo- graphy. Crystal data: MoKα radiation, triclinic, space group P1 with a = 13.505(5), b = 13.645(5), c = 30.720(10) ?, α = 92.872(7), β = 92.329(7), γ = 92.538(7)°, V = 5643.0(3) ?3, C96H184N12O14S4, Mr = 1858.79, Z = 2, Dc = 1.094 g/cm3, μ = 0.143 mm-1, F(000) = 2040, R = 0.0694 and wR = 0.1282 for 4303 observed reflections with I > 2σ(I). There are three different layer type host-lattices in the crystal structure of the title compound. All of them are formed by [(NH2)2CS·(C7H5O3 )]4 tetramers, but water molecules are located between tetramers and link them by hydrogen bonds to generate ribbons at c = 0 and 1/2, and isolated tetramers are arranged side by side at c = 1/4. The tetrabutylammonium cations are sandwiched between puckered layers.

Crystal Structure of a Novel Sandwich Inclusion Complex of β-Cyclodextrin with α-Naphthylacetic Acid

A supramolecular inclusion complex between β-cyclodextrin（β-CD） and α-naphthylacetic acid was prepared, and its crystal structure was investigated by single-crystal X-ray crystallography. The complex contains two β-CD molecules, one α-naphthylacetic acid, two ethanols and twenty-eight water molecules in the asymmetric unit, which could be formulated as [（C42H70O35）2·（C12H10O2）·（C2H5OH）2·28H2O]. Two β-CD molecules constitute a dimer by face-to-face contact of their secondary hydroxyl sides. At the interface of the dimer, one α-naphthylacetic acid molecule is sandwiched between two β-CD molecules. Each β-CD unit of the dimer includes one ethanol molecule in its cavity. The β-CD dimers are linked together via hydrogen bonding to form layers that are stacked in a brickwork-like pattern. The comparative study of some sandwich complexes elucidates that the interface of the β-CD dimer has a stronger inclusion capacity than the cavity of β-CD for some suitable planar guest molecules. The novel inclusion structure results from the competitive inclusion of α-naphthylacetic acid and ethanol.

Two Polymorphs of the Inclusion Compound [(n-C_4H_9)_4N]^+·(C_(13)H_9O_3)^-·H_2O

Two polymorphs of the inclusion compound [（n-C4H9）4N]＋＇（C13H903）H2O have been prepared and characterized by X-ray crystallography. Polymorph 1： triclinic P1, a = 13.4982（2）, b = 13.5743（2）, c = 17.1996（2） A, at = 67.045（1）,β = 77.845（1）, γ= 88.762（1）°, V = 2830.43（7） A3, Z = 4, R = 0.0491, wR= 0.1276; Polymorph 2： tetragonal P43, a = b = 13.53690（1） A, c = 30.8491（8） A, V = 5653.02（16） A3, Z = 8, R = 0.0448, wR = 0.0984. In these two crystal structures, the hydrogen-bonded ribbons built of 4,4＇-dihydroxybenzophenone （DHBP, C13H1003） anions and water molecules are orderly arranged to generate two-dimensional host layers, with tetrabutylammonium cations contained between the layers to form the sandwich-like inclusion compounds. The structures of 1 and 2, which exist as two polymorphs, both display the similar packing pattern and hydrogen-bond linking model.

INCLUSION COMPLEX FORMATION BETWEENα-CYCLODEXTRIN AND BIODEGRADABLE COMBLIKE COPOLYMERS WITH POLY(α,β-MALIC ACID) BACKBONES AND mPEG SIDE CHAINS

Inclusion complexes(ICs) composed ofα-cyclodextrins(α-CD) and biodegradable comblike copolymers with poly(α,β-malic acid)(PMA) backbones and methylated poly(ethylene glycol)(mPEG) side chains were prepared by the host-guest reaction.Two series of ICs with mPEG750 and mPEG2000 were prepared.The stoichiometry(EG/CD) of all the ICs in mPEG2000 series was 3.1,no matter what the graft degree was.While in mPEG750 series,the stoichiometry(EG/CD) was very different:it increased with the amount of mPEG decreasing.Th...

X-Ray Diffraction and NMR Study of Inclusion Complex of Podophyllotoxin with β-Cyclodextrin

The inclusion complex of podophyllotoxin (P) with β-cyclodextrin (β-CD) has been studied by X-ray diffractometry and 1HNMR、13CNMR spectroscopy. The complex structure is deduced.

Research of Inclusion Complexation of 4,4'-Thiodiphenol Effected by β-Cyclodextrin in Aqueous Solutions and the Effect on Photodegradation

The inclusion behavior of 4, 4＇ -Thiodiphenol （TDP）, a typical bisphenol and endocrine disruptor, reacts with β-cyclodextrin （β-CD） in aqueous solutions has been investigated by means of UV absorption spectrum and quantum-chemical calculation with Gaussian 98 software. The results show that the inclusion behavior of TDP is quite different in acidic solutions （pH 5.9） from that in alkaline solutions （pH 10.0）. This behavior difference is attributed to the different formula structures in aqueous solutions at acidic and alkaline pH values that are demonstrated by quantum- chemical modeling and calculation. TDP forms a 1 ： 1 fl-CD inclusion complex in aqueous solutions. The equiiibrium constant K was calculated to be 553.49 L/mol at pH 5.9 and 1 318.20 L/mol at pH 10.0 respectively for the inclusion complex reaction by using the modified Benesi-Heldbrand equation. After inclusion TDP＇s structure is changed especially at the inclusion part with the bond order becoming larger, which results in inhibitive photodegradation during direct photooxidation and H2O2 assisted photooxidation.

SPECTROSCOPIC STUDY AND APPLICATION ON THE INCLUSION COMPLEXATION β-CYCLODEXTRIN WITH ESTRADIOL BENZOATE IN AQUEOUS SOLUTION

The inclusion complexation reaction of β-cyclodextrin with estradiol benzoate (EB) in the presence ofcetyltrimethylammonium bromide has been studied by means of UV absorption and fluorescent spectrometry. The reaction conditions, the formation constant, the mechanism of the host-guest inclusion complexhave been studied and a simple, highly sensitive fluorescent synergistic method for the determination of EBhas been established with satisfactory results.

Preparation of Forsythiaside-hydroxypropyl-β-cyclodextrin Inclusion Complex and Its Characters

To overcome the chemical instability of forsythiaside,the forsythiaside-hydroxypropyl-β-cyclodextrin inclusion complex was prepared by triturating. The inclusion complex was found having a varied UV spectrum and melt temperature point. Inclusion complex has a higher stability to UV light and temperature over forythiaside itself. Pharmacological evidence showed that inclusion complex has little effect on pharmacokinetics by chicken intravenous injection. This study is favorable for developing preparations for forsythiaside and its clinical application.

Theoretical Study on the Inclusion Complex of β-Cyclodextrin and Nitrobenzene

Quantum chemical calculations were carried out to investigate the structures and properties for the inclusion complexes of nitrobenzene （NB） into β-cyclodextrin. Two low-energy conformations of β-cyclodextrin （A and B） in the gas phase were initially investigated by the PM3 and B3LYP/6-31＋G（d,p） calculations, respectively. Three different orientations were considered in the inclusion process of A and B with NB to form 1：1 complexes. Potential energy scan by PM3 calculations indicated that the phenyl orientation Ab for conformation A and the equator orientation Bc for conformation B are more favorable in energy, respectively. We also considered the 2：1 inclusion complexes of host A or B with guest NB in the gas phase. PM3 calculation indicated that the host-guest interaction energies to form 1：1 complexes are more negative than those to form 2：1 NB/B complexes. Finally, we studied the solvent effect of NB/CD complex, and PM3 results show that the influence of water molecules on the inclusion process is very important. The driving forces for the inclusion process and the geometries of complexes were discussed in detail.

Solubility Enhancement of Domperidone Fast Disintegrating Tablet Using Hydroxypropyl-<i>β</i>-Cyclodextrin by Inclusion Complexation Technique

Domperidone Maleate (DOM), an antiemetic drug, has been used in treatment of adults and children. It has low aqueous solubility and hence low bioavailability. In present study, an attempt has been made to enhance the solubility of DOM by inclusion complexation with Hydroxypropyl-β-Cyclodextrin (HP-β-CD) using kneading technique and formulation of fast disintegrating tablets by using Sodium Starch Glycolate as superdisintegrant. Solubility analysis of DOM in different concentrations of HP-β-CD was carried out. Design of experiment (DOE) is done by using MINITAB 15.1 software to find out the variable for dissolution and disintegration time. HP-β-CD and SSG were identified as the variable for disintegration time and dissolution. For optimization of the concentration of HP-β-CD and SSG, two factors at two levels design through central composite design (CCD) were used which gave 13 formulations. All formulations are evaluated for characteristics such as weight variation, hardness, friability, disintegration time and dissolution of drug. Solubility of DOM increases linearly with increase in concentration of HP-β-CD. The optimum concentration of HP-β-CD is found to be in 1:2 molar ratios and SSG of 7%. The In-Vitro dissolution studies of optimized formulation and market sample were carried out in USP type II apparatus at different time intervals of 5, 10, 15 and 30 minutes at 50 rpm in 0.1 N HCl. The dissolution and disintegration time of optimized formulation is found better than market sample.