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...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.展开更多
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, F...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.展开更多
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 metho...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.展开更多
The objective of this paper is to prepare vinpocetine(VIN)inclusion complex and evaluate its brain targeting effect after intranasal administration.In the present study,VIN inclusion complex was prepared in order to i...The objective of this paper is to prepare vinpocetine(VIN)inclusion complex and evaluate its brain targeting effect after intranasal administration.In the present study,VIN inclusion complex was prepared in order to increase its solubility.Stability constant(Kc)was used for host selection.Factors influencing properties of the inclusion complex was investigated.Formation of the inclusion complex was identified by solubility study and DSC analysis.The brain targeting effect of the complex after intranasal administration was studied in rats.It was demonstrated that properties of the inclusion complex was mainly influenced by cyclodextrin type,organic acids type,system pH and host/guest molar ratio.Multiple component complexes can be formed by the addition of citric acid,with solubility improved for more than 23 times.Furthermore,In vivo study revealed that after intranasal administration,the absolute bioavailability of vinpocetine inclusion complex was 88%.Compared with intravenous injection,significant brain targeting effect was achieved after intranasal delivery,with brain targeting index 1.67.In conclusion,by intranasal administration of VIN inclusion complex,a fast onset of action and good brain targeting effect can be achieved.Intranasal route is a promising approach for the treatment of CNS diseases.展开更多
Sildenafil citrate is a potent and selective phosphodiesterase-5inhibitor. It is effectively used in the treatment of erectile dysfunction and pulmonary arterial hypertension. The drug is rapidly absorbed and pharmaco...Sildenafil citrate is a potent and selective phosphodiesterase-5inhibitor. It is effectively used in the treatment of erectile dysfunction and pulmonary arterial hypertension. The drug is rapidly absorbed and pharmacologically acts within30 min to 1 h after oral administration. However, it has a relatively low absolute bioavailability of 41%because its limited solubility in water is the major problem (1)To improve the oral bioavailability of poorly water-soluble drugs.展开更多
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 spect...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.展开更多
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...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.展开更多
PP can be included in the cavities of cyclodextrin (CD). The crystalline inclusion complex between β-CD and low molecular weight polypropylene (PP) was obtained and investigated. a-CD and γ-CD did not form crystalli...PP can be included in the cavities of cyclodextrin (CD). The crystalline inclusion complex between β-CD and low molecular weight polypropylene (PP) was obtained and investigated. a-CD and γ-CD did not form crystalline inclusion complexes with PP. The FTIR spectra, TGA, X-ray diffraction spectra were studied, 1H-NMR spectra and 13C CP/MAS NMR spectra were used to characterize the crystalline inclusion complexes.展开更多
The racemic spiro[4.4]nonane-1,6-dione was efficiently resolved through an enantioselective inclusion complexation using chiral host BINOL by simple recrystallization with 31 .9～38.4% yield and 1000%ee.
A novel bridged bis(β-cyclodextrin), 4, 4’-diaminodiphenyl ether–briged–bis (6-aimino- 6-deoxy-β-cyclodextrin) 3, has been synthesized and its inclusion complexation behavior with three linear guest dyes (AR, NR ...A novel bridged bis(β-cyclodextrin), 4, 4’-diaminodiphenyl ether–briged–bis (6-aimino- 6-deoxy-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-cyclodextrin) showed much higher affinities towards guest dyes than native β-cyclodextrin.展开更多
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 ...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...展开更多
The inclusion complex reaction condition and the mechanism of β cyclodextrin with hymecromone have been studied by fluorescent spectrum. The fluorescent intensity and the stability of the system can be qreatly increa...The inclusion complex reaction condition and the mechanism of β cyclodextrin with hymecromone have been studied by fluorescent spectrum. The fluorescent intensity and the stability of the system can be qreatly increased in qiven condition, and the formation constant of the inclusion complex reaction has been determined too. The system can be applied to the determination of trace amounts of hymecromone, the maximum fluorescent intensity is obtained with excitation and emission wavelength at 362 nm and 452 nm, respectively. The linear range for hymecromone is 8.0×10 -9 mol·L -1 to 1.0×10 -5 mol·L -1 . The detection limit is 1.8×10 -9 mol·L -1 . A simple, rapid and highly sensitive fluorimetric method is proposed for the determination of hymecromone. The results obtained are in agreement with those given by an official method.展开更多
An equation for determining the equilibrium association constant (KA) of cyclodextrin inclusion complex with fluorescence anisotropy is derived and used to determine KA of pyrene-B-cyclodextrin inclusion complex. The ...An equation for determining the equilibrium association constant (KA) of cyclodextrin inclusion complex with fluorescence anisotropy is derived and used to determine KA of pyrene-B-cyclodextrin inclusion complex. The existing forms of cyclodextrin inclusion complex in solution, the interaction type of host with guest, and the possibility of application of B-cyclodextrin in the analysis of metal ions using naphthalene derivative as a ligand are discussed based on the equation derived along with the curve of fluorescence anisotropy versus cyclodextrin concentration of guest/cyclodextrin system.展开更多
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.
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 reactio...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.展开更多
文摘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.
文摘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.
文摘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.
文摘The objective of this paper is to prepare vinpocetine(VIN)inclusion complex and evaluate its brain targeting effect after intranasal administration.In the present study,VIN inclusion complex was prepared in order to increase its solubility.Stability constant(Kc)was used for host selection.Factors influencing properties of the inclusion complex was investigated.Formation of the inclusion complex was identified by solubility study and DSC analysis.The brain targeting effect of the complex after intranasal administration was studied in rats.It was demonstrated that properties of the inclusion complex was mainly influenced by cyclodextrin type,organic acids type,system pH and host/guest molar ratio.Multiple component complexes can be formed by the addition of citric acid,with solubility improved for more than 23 times.Furthermore,In vivo study revealed that after intranasal administration,the absolute bioavailability of vinpocetine inclusion complex was 88%.Compared with intravenous injection,significant brain targeting effect was achieved after intranasal delivery,with brain targeting index 1.67.In conclusion,by intranasal administration of VIN inclusion complex,a fast onset of action and good brain targeting effect can be achieved.Intranasal route is a promising approach for the treatment of CNS diseases.
文摘Sildenafil citrate is a potent and selective phosphodiesterase-5inhibitor. It is effectively used in the treatment of erectile dysfunction and pulmonary arterial hypertension. The drug is rapidly absorbed and pharmacologically acts within30 min to 1 h after oral administration. However, it has a relatively low absolute bioavailability of 41%because its limited solubility in water is the major problem (1)To improve the oral bioavailability of poorly water-soluble drugs.
文摘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.
文摘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.
基金This work was financially supported by the National Natural Science Foundation of China (Grant No. 29974017) and the fund of the Analytical Center and the Key Laboratory of Education Ministry for Optical and Magnetic Resonance Spectroscopy also sponsored
文摘PP can be included in the cavities of cyclodextrin (CD). The crystalline inclusion complex between β-CD and low molecular weight polypropylene (PP) was obtained and investigated. a-CD and γ-CD did not form crystalline inclusion complexes with PP. The FTIR spectra, TGA, X-ray diffraction spectra were studied, 1H-NMR spectra and 13C CP/MAS NMR spectra were used to characterize the crystalline inclusion complexes.
文摘The racemic spiro[4.4]nonane-1,6-dione was efficiently resolved through an enantioselective inclusion complexation using chiral host BINOL by simple recrystallization with 31 .9～38.4% yield and 1000%ee.
基金supported by the Yunnan Province Natural Science Foundation （Nos. 2003C009M and 2003B0014Q）
文摘A novel bridged bis(β-cyclodextrin), 4, 4’-diaminodiphenyl ether–briged–bis (6-aimino- 6-deoxy-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-cyclodextrin) showed much higher affinities towards guest dyes than native β-cyclodextrin.
基金supported by the National Basic Research Program of China(National 973 program,No2005CB623903)National Natural Science Foundation of China(No20604016)Sichuan Youth Science & Technology Foundation(No07ZQ026-013)
文摘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...
文摘The inclusion complex reaction condition and the mechanism of β cyclodextrin with hymecromone have been studied by fluorescent spectrum. The fluorescent intensity and the stability of the system can be qreatly increased in qiven condition, and the formation constant of the inclusion complex reaction has been determined too. The system can be applied to the determination of trace amounts of hymecromone, the maximum fluorescent intensity is obtained with excitation and emission wavelength at 362 nm and 452 nm, respectively. The linear range for hymecromone is 8.0×10 -9 mol·L -1 to 1.0×10 -5 mol·L -1 . The detection limit is 1.8×10 -9 mol·L -1 . A simple, rapid and highly sensitive fluorimetric method is proposed for the determination of hymecromone. The results obtained are in agreement with those given by an official method.
文摘An equation for determining the equilibrium association constant (KA) of cyclodextrin inclusion complex with fluorescence anisotropy is derived and used to determine KA of pyrene-B-cyclodextrin inclusion complex. The existing forms of cyclodextrin inclusion complex in solution, the interaction type of host with guest, and the possibility of application of B-cyclodextrin in the analysis of metal ions using naphthalene derivative as a ligand are discussed based on the equation derived along with the curve of fluorescence anisotropy versus cyclodextrin concentration of guest/cyclodextrin system.
文摘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.
文摘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.
