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.

Intramolecular Charge Transfer Dual Fluorescence pH Sensing using p-Dibutylaminobenzoic Acid-β-cyclodextrin Inclusion Complex

The intramolecular charge transfer dual fluorescence of p-dibutylaminobenzoic acid-b-cyclodextrin inclusion complex showed a substantially higher sensitivity toward aqueous solution pH variation when compared with that of p-dibutylaminobenzoic acid alone, which established a new principle for direct CT fluorescence sensing in aqueous solution by using the CT fluorophore-cyclodextrin inclusion complex.

Pharmacokinetics of Eb and its hydroxypropyl-β-cyclodextrin inclusion complex in rats

In our previous study,a novel organic selenium compound Eb was synthesized and found to have significant antitumor activity with much less toxicity compared with the leading compound Ebselen.Unfortunately,Eb was practically insoluble in water （2.57 μg/mL） and had very low oral bioavailability,thus its clinical application was greatly limited.In the present study,the inclusion complex of Eb with 2-hydroxypropyl-β-cyclodextrin （HP-βCD） was prepared and pharmacokinetics of Eb and the inclusion complex were investigated.The water solubility of Eb was dramatically enhanced by inclusion with HP-βCD,which reached 8.4 mg/mL.The pharmacokinetic study showed that the elimination half-life （t 1/2β） of Eb was between 22 h and 30 h and the distribution half-life （t 1/2α） of Eb was 1 h.The results indicated that Eb was rapidly distributed to tissues but slowly eliminated in rats.The absolute bioavailability of Eb/HP-βCD inclusion complex solution through the oral route was 28.3%,and it was 1552% that of Eb in its pure form.In summary,the absorption of Eb in the Eb/HP-βCD inclusion complex was better and faster than that of Eb in its pure form.

Inclusion Complex of β-cyclodextrin with CTAB in Aqueous Solution

Cetyltrimethylammonium bromide （CTAB）/potassium bromide （KBr） micellar system has been used as a viscosity probe to study the inclusion complexation between β-cyclodextrin （β-CD） and CTAB. Viscosity measurements show that the inclusion complexation between β-CD and CTAB may cause the breakdown of CTAB/KBr wormlike micelles, resulting in the decrease of the solution viscosity. The viscosity minimum at Cβ-CD/CCTAB=2 indicate the molecular ratio of host molecule to guest molecule is 2：1 in the β-CD/CTAB inclusion complex.

Physical characterization of meloxicam-β-cyclodextrin inclusion complex pellets prepared by a fluid-bed coating method

Meloxicam-β-cyclodextrin （ME-β-CD） inclusion complex was prepared by a fluid-bed coating technique upon solvent removal and simultaneous depositing onto the surface of nonpareil pellets and using PVP K30 as a binding agent to facilitate good coating. The resultant pellets were spherical and intact in shape with good flowability and friability. SEM analysis showed that the pellets were smooth and had a tightly coated inclusion complex layer. In vitro dissolution of the inclusion complex pellets in pH 7.4 phosphate buffer was dramatically enhanced at an ME/CD ratio of 1/1. DSC and powder X-ray diffractometry proved the absence of crystallinity in the ME/CD inclusion complexes. Moreover, Fourier transform-infrared spectrometry together with Raman spectrometry indicated that the thiazole ring of ME was possibly included in the cavity of β-CD.

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.

Mechanism and Kinetics of Thermal Dissociation of Inclusion Complex of β-Cyclodextrin and 1-Methylcyclopropene

The inclusion-complex of CD-MCP （β-cyclodextrin （β-CD） including 1-methylcyclopropene （1-MCP）） was prepared and characterized. Basing on programmed-heating procedure and weight-temperature analysis, as well as the application of Satava-Sestak＇s, Ozawa＇s and Kissinger＇s methods, the mechanism and kinetics of thermal dissociation of this inclusion complex were studied. An additional mass loss is found at 170-180℃. The mechanism of thermal dissociation of CD-MCP is dominated by a one-dimensional random nucleation and subsequent growth process （A2/3）. The activation energy Es and the pre-exponential factor AS for the process are 102.14 kJ/mol and 3.63×10^10s^-1, respectively. This ES value shows that there is no strong chemical intere, ctions between β-CD and 1-MC;P,

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.

Structural Study of Inclusion Complex of Andrographolide with β-Cyclodextrin Prepared under Microwave Irradiation

An inclusion complex of b-cyclodextrin with andrographolide (Andro) was prepared by using a convenient method of microwave irradiation. The structure of the inclusion complex was determined by the 1H NMR, 2D NMR spectroscopy as well as the elemental analysis.

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.

Gallic Acid/2-Hydroxypropyl-β-cyclodextrin Inclusion Complexes Electrospun Nanofibrous Webs:Fast Dissolution,Improved Aqueous Solubility and Antioxidant Property of Gallic Acid

Gallic acid(GA)is a kind of natural polyphenolic compound,but its low aqueous solubility restricts its application in the fields of food and medicine.Cyclodextrin can form inclusion complexes with guest molecules(e.g.,essential oils,food supplements)through cavities with special properties to improve aqueous solubility,thermal stability,and bioavailability of guest molecules.In this research,gallic acid/2-hydroxypropyl-β-cyclodextrin inclusion complexes(GA/2-HP-β-CD/ICs)were formed in a highly concentrated solution of 2-HP-β-CD.Bead-free and uniform nanofibrous webs(GA/2-HP-β-CD/IC-NWs)were produced successfully by electrospun GA/HP-β-CD/IC aqueous solution.The initial molar ratio(GA:2-HP-β-CD=1:1)of GA/2-HP-β-CD/IC in the solutions was largely maintained in GA/2-HP-β-CD/IC-NW.The aqueous solubility of GA was enhanced and GA/2-HP-β-CD/IC-NW has displayed fast dissolution property.Furthermore,in comparison with GA powder,GA/2-HP-β-CD/IC-NW demonstrated improved antioxidant capacity.The results suggested that GA/2-HP-β-CD/IC-NW have broad application prospects as orally fast dissolution systems for food supplements.

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

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 tmaxindicated 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.

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.

Preparation and Spectroscopic Study of Different Stoichiometric Solid Supramolecular Inclusion Complexes of β-Cyclodextrin with Short Chain Aliphatic Amines

The solid Supramolecular complexes of β-cyclodextrin （β-CD） with ethylenediamine 1, diethylenetriamine 2 and triethylamine 3 were obtained and characterized using elemental analysis, powder X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, and ^1H nuclear magnetic resonance spectroscopy. Based on the results of elemental analysis and ^1H NMR, the guest-host stoichiometries of the three solid complexes were determined to be 5：2 for 1-β-CD, hl for 2-β-CD, and 1：3 for 3-β-CD. The yields were relative to the molar volume ratio of guest to β-CD cavity, and increased in the order： 1-β-CD〈2-3-CD〈3-β-CD. X-ray diffraction patterns of the inclusion complexes gave very good exhibitions not only in location of diffraction peaks but also in shape and diffraction intensity of the peaks due to the intermolecular complexations between β-CD and the guests. The formation of host-guest inclusion complexes exhibited obviously enhanced phase change temperatures of the complexed guests such as 1 and 3. The H-5 protons located at the narrower rim inside the CD cavity experienced a higher shift upon inclusion while all other protons experienced lower shifts.

Physicochemical Properties and Gastric Mucosa Irritation of Cantharidin-hydroxypropyl-β-cyclodextrin Inclusion Complex

Objective To increase the solubility and relieve the mucous irritation of cantharidin (CA) by preparing cantharidin-hydroxypropyl-β-cyclodextrin (CA/HP-β-CD) inclusion complex. Methods The inclusion complex was prepared by co-evaporation method and characterized by differential scanning calorimetry (DSC), X-ray diffractometry (XRD), and nuclear magnetic resonance (NMR). Results The disappearance of CA as well as the shift of exothermic peaks shown in DSC results indicated the complexation phenomenon. XRD results showed that the crystalline CA pattern had disappeared, and in NMR results, H-5 shifted from δ 3.731 to 3.695 after complexation and H-2 shifted from δ 3.626 to 3.598, which suggested that part of the drug had entered the HP-β-CD cavity to form an inclusion complex. The solubility increased 10.3 times after complexation and the mucous irritation of CA was relieved remarkably. Conclusion Through complexation with HP-β-CD, the solubility and dissolution rate of CA are improved significantly, and the irritation of musous is relieved.

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

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.

FORMATION OF THE CRYSTALLINE INCLUSION COMPLEX BETWEEN β-CYCLODEXTRIN AND POLYPROPYLENE

PP can be included in the cavities of cyclodextrin (CD). The crystalline inclusion complex between β-CD and lowmolecular weight polypropylene (PP) was obtained and investigated. α-CD and γ-CD did not form crystalline inclusioncomplexes with PP. The FTIR spectra, TGA, X-ray diffraction spectra were studied, ~1H-NMR spectra and ^(13)C CP/MAS NMR spectra were used to characterize the crystalline inclusion complexes.

Flame Retardancy of Epoxy Resin/β-cyclodextrin@Resorcinol Bisdiphenylphosphate Inclusion Composites

In order to improve the efficiency of β-CD,the inclusion complex of β-CD and resorcinol bisdiphenylphosphate (RDP) (β-CD@RDP) was prepared,which β-CD was as the host component and RDP was as the guest.The structure and thermal stability property of β-CD@RDP was also characterized.EP/β-CD@RDP composites were prepared by adding β-CD@RDP into EP matrix.The results of thermogravimetric test showed that the flame retardant systems could effectively increase the corresponding temperature of EP matrix to reach the maximum thermal decomposition rate,and exhibited good char-forming property.When the amount of β-CD@RDP in EP was 20wt%,the limiting oxygen index (LOI) value of EP was increased to 26.5% from 19.8%,and the vertical burning test (UL-94) reached V-1 level.The cone calorimeter test indicated that 20wt% loading in EP could reduce the peak of heat release rate (PHRR) and the total heat release (THR) of EP by 94.7% and 93.4% respectively,and the peak of smoke production rate (PSPR) and the total smoke production (TSP) was reduced by 16.7% and 22.2%,respectively.Therefore,the addition of β-CD@RDP could reduce the fire risk of EP effectively.

Evolution of nonmetallic inclusions in 80-t 9CrMoCoB large-scale ingots during electroslag remelting process

In combination with theoretical calculations,experiments were conducted to investigate the evolution behavior of nonmetallic inclusions(NMIs)during the manufacture of large-scale heat-resistant steel ingots using 9CrMoCoB heat-resistant steel and CaF_(2)–CaO–Al_(2)O_(3)–SiO_(2)–B_(2)O_(3)electroslag remelting(ESR)-type slag in an 80-t industrial ESR furnace.The main types of NMI in the consumable electrode comprised pure alumina,a multiphase oxide consisting of an Al_(2)O_(3)core and liquid CaO–Al_(2)O_(3)–SiO_(2)–MnO shell,and M_(23)C_(6)carbides with an MnS core.The Al_(2)O_(3)and MnS inclusions had higher precipitation temperatures than the M_(23)C_(6)-type carbide under equilibrium and nonequilibrium solidification processes.Therefore,inclusions can act as nucleation sites for carbide layer precipitation.The ESR process completely removed the liquid CaO–Al_(2)O_(3)–SiO_(2)–MnO oxide and MnS inclusion with a carbide shell,and only the Al_(2)O_(3)inclusions and Al_(2)O_(3)core with a carbide shell occupied the remelted ingot.The M_(23)C_(6)-type carbides in steel were determined as Cr_(23)C_(6)based on the analysis of transmission electron microscopy results.The substitution of Cr with W,Fe,or/and Mo in the Cr_(23)C_(6)lattice caused slight changes in the lattice parameter of the Cr_(23)C_(6)carbide.Therefore,Cr_(21.34)Fe_(1.66)C_(6),(Cr_(19)W_(4)C_(6),Cr_(18.4)Mo_(4.6)C_(6),and Cr_(16)Fe_(5)Mo_(2)C_(6)can match the fraction pattern of Cr_(23)C_(6)carbide.The Al_(2)O_(3)inclusions in the remelted ingot formed due to the reduction of CaO,SiO_(2),and MnO components in the liquid inclusion.The increased Al content in liquid steel or the higher supersaturation degree of Al_(2)O_(3)precipitation in the remelted ingot than that in the electrode can be attributed to the evaporation of CaF_(2)and the increase in CaO content in the ESR-type slag.