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, ...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.展开更多
Inclusion complexes of nitro-compounds using β-cyclodextrin and hydroxypropyl-β-cyclodextrin as host molecule have been studied by cyclic voltammetric method. The inclusion constants of the corresponding complexes h...Inclusion complexes of nitro-compounds using β-cyclodextrin and hydroxypropyl-β-cyclodextrin as host molecule have been studied by cyclic voltammetric method. The inclusion constants of the corresponding complexes have been determined. Strong inclusion complexation by hydroxypropyl-β-cyclodextrin has been verified展开更多
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
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.
The interaction of beta-cyclodextrin(beta-CD), hydroxypropyl-beta-CD and gamma-CD with the drug rutin has been investigated by using fluorimetry. The stoichiometry of the complexes and their formation constants have b...The interaction of beta-cyclodextrin(beta-CD), hydroxypropyl-beta-CD and gamma-CD with the drug rutin has been investigated by using fluorimetry. The stoichiometry of the complexes and their formation constants have been estimated. The thermodynamic parameters for the formation of complexes were obtained. The complexing ability of HP-beta-CD is remarkably stronger than beta-CD and gamma-CD.展开更多
The inclusion complexation behavior of 2,5-Bis(5-tert-butyl-benzoxazol-2yl)-thiophene (UVOB) with native β-cyclodextrin (βCD) and βCD-monochlorotriazinyl (βCD-MCT) was evaluated by fluorescence spectroscopy. The a...The inclusion complexation behavior of 2,5-Bis(5-tert-butyl-benzoxazol-2yl)-thiophene (UVOB) with native β-cyclodextrin (βCD) and βCD-monochlorotriazinyl (βCD-MCT) was evaluated by fluorescence spectroscopy. The association constant (K<sub>s</sub>), stoichiometry, , and were evaluated at 25℃ ± 0.1℃ in phosphate buffer solution (pH = 10.5, 0.1 mo•dm<sup>–3</sup>) in order to find out the complex formation ability and stability. Fluorescence enhancement for UVOB and UVBNB with both CDs has been observed as a result of the complex formation. A stoichiometry 1:1 for UVOB in both CDs was observed;a stoichiometry 3:1 for UVBNB in both CDs has been observed. The K<sub>s</sub>values for UVOB were 4916 ± 137 M<sup>–1</sup> and 655 ± 19 M<sup>–1</sup> (acetone: water 90/10, v/v) with βCD and βCD-MCT, respectively. The value obtained indicates a spontaneous and stable complex formation, but the complex βCD-UVOB showed high K<sub>s </sub>value as an indicative of a high concentration of complex formed. Additionally, K<sub>s </sub>and thermodynamic parameters and were evaluated in a commercial product UVBNB (UVOB, 13%, v/v). In aqueous solution, the values obtained were 2552 ± 115 and 1787 ± 75 M<sup>–1</sup> respectively. Complexation of UVOB with CDs is an interesting approach for utilization of UVOB in aqueous systems without the need of solvents and or surfactants used in commercial product (UVBNB).展开更多
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 ...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.展开更多
Inclusion of Acyclodextrin (ACD) with phenothiazine 1 and Nalkylpheno-thiazine derivatives (alkyl = ethyl 2, isobutyl 3 and isopentyl 4) in aqueous solution was studied by means of UV-vis spectroscopy. The association...Inclusion of Acyclodextrin (ACD) with phenothiazine 1 and Nalkylpheno-thiazine derivatives (alkyl = ethyl 2, isobutyl 3 and isopentyl 4) in aqueous solution was studied by means of UV-vis spectroscopy. The association constant Ka values for the inclusion of β-CD with 1, 2, 3 and 4 were determined to be 188, 214, 129 and 80 L/mol, respectively. It indicates that the stability of the inclusion complexes is dependent on the structure and the volume of the substituents in the guest compounds.展开更多
A series of monomethoxy poly(ethylene glycol) (mPEG) grafted copolyglutamates (PmPEGs) were synthesized through ring-opening polymerization (ROP) followed by click chemistry. Supramolecular hydrogels based on ...A series of monomethoxy poly(ethylene glycol) (mPEG) grafted copolyglutamates (PmPEGs) were synthesized through ring-opening polymerization (ROP) followed by click chemistry. Supramolecular hydrogels based on polymer inclusion complexes (ICs) between PmPEG and α-cyclodextriri (α-CD) were prepared in aqueous solution. The rheological measurements indicated their gelation properties were affected by several factors including the mPEG length, graft density and the sample concentration. These hydrogels displayed thermo-sensitive gel-sol transition under appropriate conditions due to the reversible mPEG and α-CD inclusion complexation. These hydrogels also showed pH-sensitive behavior due to the deprotonate of carboxylic acid side groups. The ICs formation of a channel-type crystalline structure induced gelation mechanism was verified by various techniques. In vitro cytotoxicity assays demonstrated that the supramolecular hydrogels are nontoxic and cytocompatible.展开更多
The effect of temperature-responsive solution behavior of PNIPAM-b-PPEOMA-b-PNIPAM on its inclusion complexation with α-cyclodextrin was studied. The triblock polymer was prepared by reversible addition-fragmentation...The effect of temperature-responsive solution behavior of PNIPAM-b-PPEOMA-b-PNIPAM on its inclusion complexation with α-cyclodextrin was studied. The triblock polymer was prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization and formed inclusion complexes (ICs) after selective threading of the PEO segment of the triblock polymer through the cavities of α-CD units. For comparison, PPEOMA homopolymer was prepared and the inclusion complexation with α-CD was also studied. The ICs were prepared with a-CD when the polymer was in different conformations by changing the temperature, and the formed ICs were characterized by XRD, ^1H-NMR, TGA and DSC. The solutions of the ICs show temperature-responsive clear/turbid transition or fluidic emulsion/gel transition depending on the concentration of the α-CD added, and the stoichiometry determined by ^1H-NMR and TGA indicates that the stoichiometry of EO to α-CD of the resulted ICs increases with increasing of temperature.展开更多
Three novel β-cyclodextrin derivatives have been synthesized and their inclusion complexation behavior with Rhodamine B (RhB) was investigated by the fluorescence spectroscopy.
Aroma compounds are low-molecular-weight organic volatile molecules and are broadly utilized in the food industry.However,due to their high volatility and evaporative losses during processing and storage,the stabiliza...Aroma compounds are low-molecular-weight organic volatile molecules and are broadly utilized in the food industry.However,due to their high volatility and evaporative losses during processing and storage,the stabilization of these volatile ingredients using encapsulation is a commonly investigated practice.Complexation of aroma compounds using starch inclusion complex could be a potential approach due to the hydrophobicity of the left-handed single helical structure.In the present study,we used starch of three different V-type structures,namely V,V,and V,to encapsulate six different aroma compounds,including1-decanol(DN),cis-3-hexen-1-ol(HN),4-allylanisole(AN),γ-decalactone(DA),trans-cinnamaldehyde(CA),and citral(CT).The formed inclusion complexes samples were characterized using complementary techniques,including X-ray diffraction(XRD)and differential scanning calorimetry(DSC).The results showed that upon complexation with aroma compounds,all V-subtypes retained their original crystalline structures.However,different trends of crystallinity were observed for each type of the prepared inclusion complexes.Additionally,among three V-type starches,V-type starch formed inclusion complexes with aroma compounds most efficiently and promoted the formation of FormⅡcomplex.This study suggested that the structure of aroma compounds and the type of V starch could both affect the complexation properties.展开更多
Aim To prepare and characterize the QURC-HP-β-CD inclusion complexes and investigate the thermodynamic parameters of the process. Methods QURC-HP-β-CD inclusion complexes were prepared by the grinding method. The eq...Aim To prepare and characterize the QURC-HP-β-CD inclusion complexes and investigate the thermodynamic parameters of the process. Methods QURC-HP-β-CD inclusion complexes were prepared by the grinding method. The equilibrium inclusion constants and thermodynamic parameters were determinated by phase solubility analysis. Dissolution tests were performed to study the dissolution rate of inclusion complexes. The formation of inclusion complexes was confirmed by differential scanning calorimetry ( DSC), infrared spectroscopy (IR) , powder X-ray diffractometry (PXRD) and scanning electron microscopy (SEM). Results The aqueous solubility of quercetin was greatly increased ( about 37 folds) by inclusion technique, and the initial dissolution rate was markedly improved (10 folds) in the first 5 min. The results of DSC and SEM photographs showed that quercetin crystal disappeared in inclusion complexes, which indicated the formation of new phase. FT-IR spectra showed that the carbonyl quercetin crystal grinding method. absorption band of quercetin was shifted. PXRD showed that the diffraction peak of disappeared. Conclusion QURC-HP-β-CD inclusion complexes are produced by the The solubility of quercetin is improved by the inclusion technique.展开更多
The formation of oxide inclusions in one of the carbon steel productions of Mobarakeh Steel Complex of Isfahan has been evaluated. Several samples from different steps of steel production were taken, from arc furnace,...The formation of oxide inclusions in one of the carbon steel productions of Mobarakeh Steel Complex of Isfahan has been evaluated. Several samples from different steps of steel production were taken, from arc furnace, ladle furnace, tundish, and continuous casting mold. Moreover, samples of slab and hot rolling products were prepared. The samples were investigated by optical and scanning electron microscopes equipped with the EDS system. According to the results, the number, composition, and kind of inclusions were directly influenced by the production variables. It was found that when the amount of dissolved oxygen was high (say more than 0. 002 5%), the dissolved aluminum was able to reduce silicon oxide and react with the dissolved oxygen simultaneously, whilst, the dissolved aluminum could reduce the magnesium oxide only when the oxygen content was below 0. 000 5%. Based on this research, a mechanism for forming the complex inclusions was suggested. It was also found that if the aluminum is added to the melt as late as possible, a cleaner melt with fewer inclusions is prepared; this method will be more effective, especially in the case of complex inclusions.展开更多
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 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,展开更多
Inclusion complexation between ibuprofen (IBF) and βcyclodextrin (βCD) was investigated. Phase solubility studies of the complexation suggested the formation of a 1:3 complex and a 2:3 complex between IBF and βCD a...Inclusion complexation between ibuprofen (IBF) and βcyclodextrin (βCD) was investigated. Phase solubility studies of the complexation suggested the formation of a 1:3 complex and a 2:3 complex between IBF and βCD at room temperature (23℃) and at 37℃ respectively. Solid inclusion complexes were prepared by the homogeneous coprecipitation method. Scanning electron microscopy, differential scanning calorimetry, IR spectroscopy, and Xray diffractometry were used for the characterization and evaluation of the complexes. The solubility and dissolution rate of the complexes formed were found to have improved considerably over that of the physical mixture and the drug alone, indicating that βcyclodextrin played an important role in the solubilization of ibuprofen.展开更多
基金supported by the Yunnan Province Natural Science Foundation (Nos. 2003C009M and 2003B0014Q)
文摘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.
文摘Inclusion complexes of nitro-compounds using β-cyclodextrin and hydroxypropyl-β-cyclodextrin as host molecule have been studied by cyclic voltammetric method. The inclusion constants of the corresponding complexes have been determined. Strong inclusion complexation by hydroxypropyl-β-cyclodextrin has been verified
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.
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.
文摘The interaction of beta-cyclodextrin(beta-CD), hydroxypropyl-beta-CD and gamma-CD with the drug rutin has been investigated by using fluorimetry. The stoichiometry of the complexes and their formation constants have been estimated. The thermodynamic parameters for the formation of complexes were obtained. The complexing ability of HP-beta-CD is remarkably stronger than beta-CD and gamma-CD.
文摘The inclusion complexation behavior of 2,5-Bis(5-tert-butyl-benzoxazol-2yl)-thiophene (UVOB) with native β-cyclodextrin (βCD) and βCD-monochlorotriazinyl (βCD-MCT) was evaluated by fluorescence spectroscopy. The association constant (K<sub>s</sub>), stoichiometry, , and were evaluated at 25℃ ± 0.1℃ in phosphate buffer solution (pH = 10.5, 0.1 mo•dm<sup>–3</sup>) in order to find out the complex formation ability and stability. Fluorescence enhancement for UVOB and UVBNB with both CDs has been observed as a result of the complex formation. A stoichiometry 1:1 for UVOB in both CDs was observed;a stoichiometry 3:1 for UVBNB in both CDs has been observed. The K<sub>s</sub>values for UVOB were 4916 ± 137 M<sup>–1</sup> and 655 ± 19 M<sup>–1</sup> (acetone: water 90/10, v/v) with βCD and βCD-MCT, respectively. The value obtained indicates a spontaneous and stable complex formation, but the complex βCD-UVOB showed high K<sub>s </sub>value as an indicative of a high concentration of complex formed. Additionally, K<sub>s </sub>and thermodynamic parameters and were evaluated in a commercial product UVBNB (UVOB, 13%, v/v). In aqueous solution, the values obtained were 2552 ± 115 and 1787 ± 75 M<sup>–1</sup> respectively. Complexation of UVOB with CDs is an interesting approach for utilization of UVOB in aqueous systems without the need of solvents and or surfactants used in commercial product (UVBNB).
基金Supported by the National Natural Science Foundation of China (20177017 and 20477031).
文摘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.
文摘Inclusion of Acyclodextrin (ACD) with phenothiazine 1 and Nalkylpheno-thiazine derivatives (alkyl = ethyl 2, isobutyl 3 and isopentyl 4) in aqueous solution was studied by means of UV-vis spectroscopy. The association constant Ka values for the inclusion of β-CD with 1, 2, 3 and 4 were determined to be 188, 214, 129 and 80 L/mol, respectively. It indicates that the stability of the inclusion complexes is dependent on the structure and the volume of the substituents in the guest compounds.
基金financially supported by the National Natural Science Fund for Distinguished Young Scholars(No.51225306)the National Natural Science Foundation of China(No.21434008)
文摘A series of monomethoxy poly(ethylene glycol) (mPEG) grafted copolyglutamates (PmPEGs) were synthesized through ring-opening polymerization (ROP) followed by click chemistry. Supramolecular hydrogels based on polymer inclusion complexes (ICs) between PmPEG and α-cyclodextriri (α-CD) were prepared in aqueous solution. The rheological measurements indicated their gelation properties were affected by several factors including the mPEG length, graft density and the sample concentration. These hydrogels displayed thermo-sensitive gel-sol transition under appropriate conditions due to the reversible mPEG and α-CD inclusion complexation. These hydrogels also showed pH-sensitive behavior due to the deprotonate of carboxylic acid side groups. The ICs formation of a channel-type crystalline structure induced gelation mechanism was verified by various techniques. In vitro cytotoxicity assays demonstrated that the supramolecular hydrogels are nontoxic and cytocompatible.
基金financially supported by the Hunan Normal University for providing start-up
文摘The effect of temperature-responsive solution behavior of PNIPAM-b-PPEOMA-b-PNIPAM on its inclusion complexation with α-cyclodextrin was studied. The triblock polymer was prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization and formed inclusion complexes (ICs) after selective threading of the PEO segment of the triblock polymer through the cavities of α-CD units. For comparison, PPEOMA homopolymer was prepared and the inclusion complexation with α-CD was also studied. The ICs were prepared with a-CD when the polymer was in different conformations by changing the temperature, and the formed ICs were characterized by XRD, ^1H-NMR, TGA and DSC. The solutions of the ICs show temperature-responsive clear/turbid transition or fluidic emulsion/gel transition depending on the concentration of the α-CD added, and the stoichiometry determined by ^1H-NMR and TGA indicates that the stoichiometry of EO to α-CD of the resulted ICs increases with increasing of temperature.
基金Project supported by the National Outstanding Youth Fund (Grant No.29625203), the National Natural Science Foundation of China (No. 29672021) and Postdoctoral Science Foundation of China.
文摘Three novel β-cyclodextrin derivatives have been synthesized and their inclusion complexation behavior with Rhodamine B (RhB) was investigated by the fluorescence spectroscopy.
基金funded by the USDA National Institute of Food and Agriculture,Agriculture and Food Research Initiative Program,Competitive Grants Program award from the Improving Food Quality(A1361)program FY 2018 as grant#2018-67017-27558。
文摘Aroma compounds are low-molecular-weight organic volatile molecules and are broadly utilized in the food industry.However,due to their high volatility and evaporative losses during processing and storage,the stabilization of these volatile ingredients using encapsulation is a commonly investigated practice.Complexation of aroma compounds using starch inclusion complex could be a potential approach due to the hydrophobicity of the left-handed single helical structure.In the present study,we used starch of three different V-type structures,namely V,V,and V,to encapsulate six different aroma compounds,including1-decanol(DN),cis-3-hexen-1-ol(HN),4-allylanisole(AN),γ-decalactone(DA),trans-cinnamaldehyde(CA),and citral(CT).The formed inclusion complexes samples were characterized using complementary techniques,including X-ray diffraction(XRD)and differential scanning calorimetry(DSC).The results showed that upon complexation with aroma compounds,all V-subtypes retained their original crystalline structures.However,different trends of crystallinity were observed for each type of the prepared inclusion complexes.Additionally,among three V-type starches,V-type starch formed inclusion complexes with aroma compounds most efficiently and promoted the formation of FormⅡcomplex.This study suggested that the structure of aroma compounds and the type of V starch could both affect the complexation properties.
文摘Aim To prepare and characterize the QURC-HP-β-CD inclusion complexes and investigate the thermodynamic parameters of the process. Methods QURC-HP-β-CD inclusion complexes were prepared by the grinding method. The equilibrium inclusion constants and thermodynamic parameters were determinated by phase solubility analysis. Dissolution tests were performed to study the dissolution rate of inclusion complexes. The formation of inclusion complexes was confirmed by differential scanning calorimetry ( DSC), infrared spectroscopy (IR) , powder X-ray diffractometry (PXRD) and scanning electron microscopy (SEM). Results The aqueous solubility of quercetin was greatly increased ( about 37 folds) by inclusion technique, and the initial dissolution rate was markedly improved (10 folds) in the first 5 min. The results of DSC and SEM photographs showed that quercetin crystal disappeared in inclusion complexes, which indicated the formation of new phase. FT-IR spectra showed that the carbonyl quercetin crystal grinding method. absorption band of quercetin was shifted. PXRD showed that the diffraction peak of disappeared. Conclusion QURC-HP-β-CD inclusion complexes are produced by the The solubility of quercetin is improved by the inclusion technique.
文摘The formation of oxide inclusions in one of the carbon steel productions of Mobarakeh Steel Complex of Isfahan has been evaluated. Several samples from different steps of steel production were taken, from arc furnace, ladle furnace, tundish, and continuous casting mold. Moreover, samples of slab and hot rolling products were prepared. The samples were investigated by optical and scanning electron microscopes equipped with the EDS system. According to the results, the number, composition, and kind of inclusions were directly influenced by the production variables. It was found that when the amount of dissolved oxygen was high (say more than 0. 002 5%), the dissolved aluminum was able to reduce silicon oxide and react with the dissolved oxygen simultaneously, whilst, the dissolved aluminum could reduce the magnesium oxide only when the oxygen content was below 0. 000 5%. Based on this research, a mechanism for forming the complex inclusions was suggested. It was also found that if the aluminum is added to the melt as late as possible, a cleaner melt with fewer inclusions is prepared; this method will be more effective, especially in the case of complex inclusions.
文摘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,
文摘Inclusion complexation between ibuprofen (IBF) and βcyclodextrin (βCD) was investigated. Phase solubility studies of the complexation suggested the formation of a 1:3 complex and a 2:3 complex between IBF and βCD at room temperature (23℃) and at 37℃ respectively. Solid inclusion complexes were prepared by the homogeneous coprecipitation method. Scanning electron microscopy, differential scanning calorimetry, IR spectroscopy, and Xray diffractometry were used for the characterization and evaluation of the complexes. The solubility and dissolution rate of the complexes formed were found to have improved considerably over that of the physical mixture and the drug alone, indicating that βcyclodextrin played an important role in the solubilization of ibuprofen.