Co-reporter:Weiwei Tang, Huaping Mo, Mingtao Zhang, Junbo Gong, Jingkang Wang, and Tonglei Li
Crystal Growth & Design October 4, 2017 Volume 17(Issue 10) pp:5028-5028
Publication Date(Web):September 11, 2017
DOI:10.1021/acs.cgd.7b00969
As a simple amino acid, glycine (Gly)’s polymorphism is pH-dependent. The α form is typically obtained from aqueous solution between pH of 4 and 9, while the γ is produced at either lower or higher pH. Formation of cyclic, hydrogen-bonded dimer in water is debated as a possible cause for the formation of the α form. To further understand the pH-dependent polymorphism, our current study examined the self-association of Gly in aqueous solutions under a wide range of pH, utilizing NMR, FTIR, and electronic calculation. The results indicate that glycine molecules form open, not cyclic, hydrogen-bonded dimers in water. It is revealed that the dimerization becomes significant between pH of 4 and 8 but remains trivial at the two pH extremes. The apparent connection between the pH-dependent polymorphism and self-association in solution implies that formation of the α form is driven by the dimerization, and moreover, charged molecular species at the extreme pH facilitate stabilization of γ nuclei.
Co-reporter:Zhe Ding, Huihui Zhang, Dandan Han, Peipei Zhu, Peng Yang, Shasha Jin, Mingchen Li, and Junbo Gong
Journal of Chemical & Engineering Data November 9, 2017 Volume 62(Issue 11) pp:3929-3929
Publication Date(Web):October 30, 2017
DOI:10.1021/acs.jced.7b00638
The solubility data of fosfomycin sodium (FOM-Na) in six pure solvents (methanol, ethanol, propanol, cyclohexane, acetone, N,N-dimethylformamide) and two binary solvents (methanol + ethanol, methanol + acetone) at temperatures ranging from 283.15 to 323.15 K were measured by a laser monitoring dynamic method at atmospheric pressure. It turned out that the solubility data decreased with increasing temperature, and also varies with the composition of the solvents. Moreover, the experimental data in pure solvents have been correlated with two thermodynamic models (i.e., modified Apelblat and van’t Hoff), and the data in binary solvents have been correlated with CNIBS/R-K equation and two modified versions of Jouyban–Acree models (Van’t-JA equation and Apel-JA equation), respectively. All the results showed a good agreement with the experimental data. Intermolecular interaction force and dielectric constants are introduced to explain the relationship between solubility and temperature. In addition, the analysis of the solubilities implies that higher temperature may destroy the forces between the solvent and solute molecules, leading to lower solubility. And this can give a guide to the design and optimization of the crystallization process of FOM-Na in the industry.
Co-reporter:Haiyan Yang, Teng Zhang, Shijie Xu, Dandan Han, Shiyuan Liu, Yang Yang, Shichao Du, Mingchen Li, and Junbo Gong
Journal of Chemical & Engineering Data November 9, 2017 Volume 62(Issue 11) pp:3967-3967
Publication Date(Web):October 12, 2017
DOI:10.1021/acs.jced.7b00669
A gravimetric method was used to determine the solubility of azoxystrobin in seven monosolvents (methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and ethyl acetate) and two binary mixed solvents (n-propanol + ethyl acetate and methanol + ethyl acetate) at different temperatures from 288.15 to 328.15 K. The solubility of azoxystrobin is positively related with temperature in all selected solvents. Moreover, the solubility of azoxystrobin in methanol + ethyl acetate binary mixed solvent reaches a maximum when the mole fraction of ethyl acetate is 0.8, differing from that in n-propanol + ethyl acetate binary mixed solvent. The Apelblat, λh, combined nearly ideal binary solvent/Redlich–Kister, and nonrandom two-liquid model (NRTL) equations were applied to correlate the solubility of azoxystrobin, and all of the equations provided good fitting results to the data. In addition, the mixing thermodynamic properties of azoxystrobin in binary mixed solvents were calculated based on the NRTL equation. The results demonstrate that the mixing process in the experimental binary mixed solvents is endothermic and spontaneous.
Co-reporter:Weiwei Tang, Huaping Mo, Mingtao Zhang, Sean Parkin, Junbo Gong, Jingkang Wang, and Tonglei Li
The Journal of Physical Chemistry B November 2, 2017 Volume 121(Issue 43) pp:10118-10118
Publication Date(Web):October 10, 2017
DOI:10.1021/acs.jpcb.7b07763
The structural evolvement of a solute determines the crystallization outcome. The self-association mechanism leading to nucleation, however, remains poorly understood. Our current study explored the solution chemistry of a model compound, tolfenamic acid (TFA), in three different solvents mainly by solution NMR. It was found that hydrogen-bonded pairs of solute–solute or solute–solvent stack with each through forming a much weaker π–π interaction as the concentration increases. Depending on the solvent, configurations of the solution species may be retained in the resultant crystal structure or undergo rearrangement. Yet, the π–π stacking is always retained in the crystal regardless of the solvent used for the crystallization. The finding suggests that nucleation not only involves the primary intermolecular interaction (hydrogen bonding) but also engages the secondary forces in the self-assembly process.
Co-reporter:Hui Zhang;Zengkun Liu;Qiuxiang Yin
Industrial & Engineering Chemistry Research May 28, 2014 Volume 53(Issue 21) pp:8913-8919
Publication Date(Web):Publication Date (Web): May 12, 2014
DOI:10.1021/ie404073p
In this work, the solubility of IMP in a water + ethanol system was measured by a gravimetric method at the temperature range from 283.15 to 323.15 K. To explain the solubility behavior of IMP in this system, a model was applied to quantitatively describe the effect of dielectric constants on the solubility of IMP. Then, the induction time was determined to be related to the supersaturation level for analysis of the nucleation mechanism, indicating that homogeneous nucleation dominated the nucleation process at higher supersaturation, while heterogeneous nucleation was more important mechanism at lower supersaturation. Finally, the molecular modeling was carried out to understand the effect of supersaturation on the crystal habits of IMP: the rodlike products preferred to form at high supersaturation, while flakelike products formed at low supersaturation, as shown in the microscopy images. In summary, supersaturation should be considered in the process of optimizing IMP crystallization operation conditions.
Co-reporter:Shuang Jiang;Yujia Qin;Songgu Wu;Shijie Xu;Kangli Li;Kaifei Zhao;Peng Yang;Lanlan Lin
Journal of Chemical & Engineering Data January 12, 2017 Volume 62(Issue 1) pp:259-267
Publication Date(Web):November 2, 2016
DOI:10.1021/acs.jced.6b00630
The solubility of sorafenib free base (SFB) and sorafenib tosylate (ST) in five monosolvents and binary solvents of 2-propanol + 1,4-dioxane was measured over the temperature ranged from 283.15 to 333.15 K by using a UV spectroscopy method. The solubility of SFB and ST in different monosolvents increases with increasing temperature, while in the binary solvents, the solubility shows the maximum value at 0.50 and 0.75 2-propanol mole fraction for SFB and ST, respectively. The Apelblat model and the CNIBS/R-K model were applied to correlate the solubility data, which shows that the two selected thermodynamic models could give satisfactory results. Moreover, mixing thermodynamic properties of enthalpy, entropy, and Gibbs free energy of SFB and ST were obtained based on the nonrandom two-liquid model for further understanding of the mixing behavior.
Co-reporter:Songgu Wu, Mingyang Chen, Sohrab Rohani, Dejiang Zhang, Shichao Du, Shijie Xu, WeiBing Dong, and Junbo Gong
Crystal Growth & Design August 2, 2017 Volume 17(Issue 8) pp:4207-4207
Publication Date(Web):June 16, 2017
DOI:10.1021/acs.cgd.7b00529
A good powder performance is one of the essential targets for gabapentin (GBP). However, the low bulk density and flowability of GBP are still the industrial problems in practical production. The main purpose of this paper is to investigate the phase transformation of GBP from form I to form II in methanol, ethanol, propanol, acetone, acetonitrile, and ethyl acetate and improve the powder properties. The results suggested that there are two kinds of phase transformation mechanisms of GBP. One is the classic solvent-mediated transformation in alcohols, and the other is the solvent-mediated nonoriented self-aggregation transformation in other solvents, which is proposed for the first time. On account of the low water activity and solubility, there is a self-cleaving phenomenon caused by the dehydration in the form I particles, and then the unstable phase transforms into form II, but the growth of the stable form is confined by the size and shape of the initial metastable particle and the products are aggregates. These aggregates with a well-defined shape and size have good performance in the dissolution rate with improved bioavailability.
Co-reporter:Yaping Wang, Panpan Sun, Shijie Xu, Shichao Du, Teng Zhang, Bo Yu, Shixin Zhang, Yang Wang, Yuewei Wang, and Junbo Gong
Industrial & Engineering Chemistry Research April 19, 2017 Volume 56(Issue 15) pp:4539-4539
Publication Date(Web):March 28, 2017
DOI:10.1021/acs.iecr.6b04760
In this work, an ethanol solvate of argatroban was first discovered and fully characterized. The ternary phase diagrams for ethanol–water–argatroban at 35.0, 40.0, and 45.0 °C were established to determine the thermodynamic stability. In situ Raman and IR spectroscopy were applied for the analysis of the solution-mediated phase transformation of argatroban from monohydrate to ethanol solvate in ethanol–water solvent. It is evident that the rate-controlling step is the growth of ethanol solvate at the initial stage and the dissolution of monohydrate at the later stage. To further understand and control the transformation process, the effects of solvent composition, temperature, and solid loading on the transformation behavior were investigated in detail. Furthermore, a kinetic model was established to get a more detailed insight into the temperature’s role in this transformation process. This work can provide important instruction for optimum process control during the industrial production of argatroban.
Co-reporter:Bo Yu, Dejiang Zhang, Shichao Du, Yan Wang, Mingyang Chen, Jie Hou, Shijie Xu, Songgu Wu, and Junbo Gong
Crystal Growth & Design 2017 Volume 17(Issue 1) pp:
Publication Date(Web):November 22, 2016
DOI:10.1021/acs.cgd.6b01392
Cubic zeolitic imidazolate frameworks (ZIFs) nanocage was prepared by using a multitemplate and phase transfer directed method. Phase transfer of aqueous metal ions on the interface of cubic Cu2O template was achieved by coordinating etching and precipitating process, in which cubic morphology was preserved and hollow metal oxide nanocages were obtained due to the removal of templates. Therefore, cubic ZIFs nanocages could be formed by the transformation of metal oxide cages, which was a self-template transforming process. The former metal oxide nanocages will not only be the template, but also the metal source for the construction of ZIFs as well. This phase transfer directed method will offer a further development of porous metal–organic frameworks with functional hollow structure.
Co-reporter:Ying Wang, Ya Liu, Shijie Xu, Yumin Liu, Peng Yang, Shichao Du, Bo Yu, Junbo Gong
The Journal of Chemical Thermodynamics 2017 Volume 104() pp:138-149
Publication Date(Web):January 2017
DOI:10.1016/j.jct.2016.09.015
•The solubility of troxerutin in mono-solvents and binary solvents was determined.•Five thermodynamic models were used to correlate the solubility data of troxerutin.•Thermodynamic properties of dissolution of troxerutin were calculated and discussed.•Enthalpy-entropy compensation in 1,4-dioxane + isopropanol mixtures was analyzed.In this work, a UV spectroscopic method was used to determine the solubility of troxerutin in eleven mono-solvents and (1,4-dioxane + 2-propanol) mixtures at different temperatures from 288.15 K to 323.15 K. The solubility of troxerutin was positively correlated with temperature in all selected solvents, and it showed a maximum value when the mole fraction of 2-propanol was 0.4 in binary solvent mixtures. The modified Apelblat equation, λh equation, CNIB/R-K model, NRTL model and Jouyban-Acree model were used to correlate the solubility data of troxerutin. It turned out that all the selected thermodynamic models could fit the results well, especially for the modified Apelblat equation with all the ARD values are less than 2%. Furthermore, the thermodynamic properties of troxerutin in different pure and binary solvents were also calculated and are discussed. The results indicated that the dissolution process of troxerutin in the experimental solvents was endothermic. Through analysis of enthalpy-entropy compensation in (1,4-dioxane + 2-propanol) mixtures, a non-linear ΔdHoΔdHo versus ΔdHoΔdHo plot was obtained, indicating that the driving mechanism changes with the proportion of 2-propanol in the dissolution process of troxerutin.
Co-reporter:Ya Liu, Ying Wang, Yumin Liu, Shijie Xu, Mingyang Chen, Shichao Du, Junbo Gong
The Journal of Chemical Thermodynamics 2017 Volume 105() pp:1-14
Publication Date(Web):February 2017
DOI:10.1016/j.jct.2016.09.039
•The solubility of L-histidine in three binary solvents was determined.•Apelblat, CNIBS/R-K, Jouyban-Acree and NRTL models were used to correlate the data.•The mixing thermodynamics were calculated and discussed based on NRTL model.In this study, the solubility of L-histidine in three different binary solvents, including (water + acetone), (water + ethanol) and (water + 2-propanol), was measured over temperatures from 283.15 K to 318.15 K by employing a gravimetric method at atmospheric pressure. It was found that the solubility of L-histidine in the binary mixed solvents increases with the increasing temperature at a given solvent composition, whereas it decreases with the rise of mole fraction of organic solvents. The experimental results were well correlated by the modified Apelblat equation, CNIBS/R-K model, combined version of the Jouyban-Acree model and NRTL model, respectively. This shows that these models can correlate the solubility in three binary mixed solvents accurately. Furthermore, the mixing thermodynamic properties of L-histidine in different binary solvent mixtures were also calculated based on the NRTL model. The result indicates that the mixing process of L-histidine is endothermic and spontaneous.
Co-reporter:Huan Shen, Songgu Wu, Yumin Liu, Kangli Li, Shijie Xu, Junbo Gong
The Journal of Chemical Thermodynamics 2017 Volume 105() pp:253-266
Publication Date(Web):February 2017
DOI:10.1016/j.jct.2016.10.022
•The solubility of Avermectin B1a in three binary mixtures was determined.•The experimental solubility were correlated by three thermodynamic models.•Thermodynamic properties of mixing of Avermectin B1a were calculated.The solubility of Avermectin B1a (AVM B1a) in the three binary solvent mixtures, (acetone + water), (acetone + n-hexane) and (isopropanol + n-hexane) was determined gravimetrically with the temperature ranging from 283.15 K to 313.15 K under atmospheric conditions. The experimental results indicate that the solubility of AVM B1a increased with increasing temperature at certain solvent composition, and decreased with increasing mole fraction of water and n-hexane. Besides, the modified Apelblat equation, CNIBS/R-K model and Jouyban-Acree model were employed to correlate the solubility results obtained. All the selected models provide satisfactory results. Furthermore, the mixing thermodynamic properties were calculated based on the NRTL equation, a binary activity coefficient model. We also calculated the thermodynamic properties of the dissolution process of AVM B1a. The calculated results indicate that the dissolution process of AVM B1a in the tested solvents is endothermic and spontaneous.
Co-reporter:Bo Yu;Jie Hou
Catalysis Science & Technology (2011-Present) 2017 vol. 7(Issue 21) pp:5004-5010
Publication Date(Web):2017/10/30
DOI:10.1039/C7CY01783A
Porous metal–organic frameworks associated with functional materials have attracted considerable attention due to their excellent catalytic performance. In this work, AuCo–MeIm was synthesized by coating amorphous cobalt–methylimidazole [Co(MeIm)2] frameworks on AuCo particles, which was also used as a Co(II) source for the construction of Co(MeIm)2. TEM, XRD and TG results indicated the identification of amorphous Co(MeIm)2 in the heterostructured composite. AuCo–MeIm showed size-selective catalytic performance in the photocatalytic removal of Cr(VI) and methylene blue attributed to the network of amorphous Co(MeIm)2 coatings. Although Co(MeIm)2 coatings contributed to the adsorption and photocatalytic degradation of MB by the affinity of aromatic rings and ligands for the metal charge transfer mechanism, the coatings still showed a significant inhibitory effect on the removal of methylene blue. This size-selective property was also well described by the proposed interface transfer kinetics.
Co-reporter:Lina Jia;Shijie Xu;Shiyuan Liu;Shichao Du;Songgu Wu
CrystEngComm (1999-Present) 2017 vol. 19(Issue 47) pp:7146-7153
Publication Date(Web):2017/12/04
DOI:10.1039/C7CE01716B
Daidzein (DAID), known as a phytoestrogen, is an important bioactive flavonoid isolated from soybean and pueraria. However, its poor solubility and low dissolution rate limit its clinical application. With the aim of finding a form with fit-for-purpose physicochemical properties, a comprehensive solid-state screening experiment was performed. As a result, three polymorphs were discovered and the single crystal structure of stable form II was revealed for the first time. Form II was obtained in solvents with high β and π* values, while form III was produced under opposite conditions. To clarify this phenomenon, intermolecular interactions were investigated through single crystal structure analysis, solvent property analysis and computational methods. The results demonstrated that the compact arrangement of DAID and the solvents used played a critical role in solution crystallization. Moreover, the physicochemical properties of these three polymorphs were fully characterized, and the powder dissolution behavior was determined in pure water and pH 1.2 and pH 6.8 buffer solutions. The newly discovered form II exhibited better thermal stability, lower moisture sorption and faster dissolution rate compared with the other forms.
Co-reporter:Yang Yang, Weiwei Tang, Shiyuan Liu, Dandan Han, Yumin Liu, Junbo Gong
Journal of Molecular Liquids 2017 Volume 243(Volume 243) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.molliq.2017.07.125
•The solubility of benzoin was measured by static method in three mixtures.•Solute-solvent and solvent-solvent interactions were investigated by solvation free energy, DFT and RDF, respectively.•Acetone have agglomeration tendency when adding organic solvents because of formation of hydrogen bonds.•Solute-solvent and solvent-solvent interactions have great impact on solubility behavior of benzoin.Solubility of benzoin in three binary solvent systems of acetone + ethanol, acetone + 1-butanol, acetone + 1-propanol was measured by static analytical method ranging from 283.15 K to 318.15 K at atmospheric pressure. Density functional theory (DFT) and molecular dynamic (MD) simulation were employed to investigate relationship between solute and solvent molecules. According to results of Solvation free energy and hydrogen bond strength, the solubility of benzoin increases with increasing value of hydrogen bond strength. Radial distribution function (RDF) resulted shows that ethanol, 1-butanol, 1-propanol have an effect on the acetone aggregation in binary mixed solvents, which means it will weaken the interactions between benzoin and acetone molecules. Therefore, solubility behavior was influenced by both solute-solvent and solvent-solvent interactions. The solubility data was correlated with Apelblat equation, CNIBS/R-K equation, and λh model, respectively, and the CNIBS/R-K equation shows the best correlations in three thermodynamic equations. Thermodynamic properties of mixing enthalpy, entropy, and Gibbs energy were further estimated and their implication on dissolution process of benzoin was discussed.Download high-res image (130KB)Download full-size image
Co-reporter:Junbo Gong;Dejiang Zhang;Yuanyuan Ran
Frontiers of Chemical Science and Engineering 2017 Volume 11( Issue 2) pp:220-230
Publication Date(Web):14 March 2017
DOI:10.1007/s11705-017-1624-4
Clindamycin phosphate (CP), an antibacterial agent, has been reported to form several solid-state forms. The crystal structures of two CP solvates, a dimethyl sulfoxide (DMSO) solvate and a methanol/water solvate (solvate V), have been determined by single crystal X-ray diffraction. The properties and transformations of these forms were characterized by powder X-ray diffraction, Single-crystal X-ray diffraction, differential scanning calorimetry, thermo gravimetric analysis, hot-stage microscopy, and dynamic vapor sorption. Very different hydrogen bonding networks exist among the host-host and host-solvent molecules in the two crystal structures, resulting in different moisture stabilities. The thermal stabilities of the two solvates upon heating and desolvation were also studied. When the temperature was above the boiling point of methanol, solvate V converted to a polymorphic phase after a one step desolvation process, whereas the desolvation temperature of the DMSO solvate was below the boiling point of DMSO. At the relative humidity above 43%, the DMSO solvate transformed to a hydrate at 25 °C. In contrast, solvate V did not transform at any of the humidities studied.
Co-reporter:Yingdan Cui, Shijie Xu, Songgu Wu, Shichao Du, Yun Cao, Yifu Chen, Ling Liu, Weibing Dong, Junbo Gong
Journal of Molecular Liquids 2017 Volume 241(Volume 241) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.molliq.2017.05.118
•The solubility of tetrabromobisphenol A in nine pure solvents and two binary solvents was experimentally determined.•The experimental solubility data of TBBPA was correlated by four models.•Thermodynamic properties of the mixing process were calculated and discussed.The mole fraction solubility of tetrabromobisphenol A in nine pure solvents and two binary solvents was determined using the gravimetric method. Different thermodynamic models were employed to analyze the dissolution behavior of tetrabromobisphenol A in pure and binary solvents. In addition, the analysis of the thermodynamic properties implies that the lower mixing Gibbs free energy is, the stronger interaction between solute and solvent is, leading to higher solubility.
Co-reporter:Yaping Wang, Ya Liu, Peng Shi, Shichao Du, Yumin Liu, Danan Han, Panpan Sun, Mengmeng Sun, Shijie Xu, Junbo Gong
Journal of Molecular Liquids 2017 Volume 243(Volume 243) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.molliq.2017.07.103
•The addition of organic solvents will decrease the solubility of l-norvaline.•The experimental solubility data was correlated using three thermodynamic models.•The variation of dielectric constants in binary solvent mixtures was in line with solubility data.The solid-liquid equilibrium (SLE) of l-norvaline in three different binary solvents, including water + methanol, water + ethanol and water + 2-propanol, was determined by employing a gravimetric method over temperatures from 283.15 K to 318.15 K. It is found that the equilibrium solubility of l-norvaline in the mixed solvents increases with rising temperature at constant solvent composition and decreases with the increasing molar fraction of organic solvents. Moreover, the dissolving capacity of l-norvaline in the three binary solvent mixtures at constant temperature can be ranked as (methanol + water > ethanol + water > 2-propanol + water) in general. Furthermore, a model which can be called polar equation was applied to quantitatively describe the relationship between solubility and polarity of solvent mixtures. The results demonstrate that the increasing polarity of the binary solvents can enhance the solubility of l-norvaline. Besides, the experimental solubility was well correlated by the modified Apelblat equation, λh equation, and NRTL model, with the maximum ARD % values: 1.89%, 3.48%, and 6.42%, respectively. Additionally, the mixing thermodynamic properties of l-norvaline in three binary solvent mixtures were also discussed based on the NRTL model. Results show that the mixing processes of l-norvaline are endothermic and spontaneous.
Co-reporter:Huihui Zhang, Yaoyao Yang, Minghe Zhu, Shuang Jiang, Shijie Xu, Shichao Du, Bo Yu, Junbo Gong
Journal of Molecular Liquids 2017 Volume 240(Volume 240) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.molliq.2017.05.018
•The solubility of prothioconazole in seven mono-solvents and two binary solvent mixtures was determined.•Three thermodynamic models were employed to correlate experimental solubility data.•Apparent dissolution thermodynamic parameters of prothioconazole were calculated and discussed.Solid-liquid phase equilibrium solubility of prothioconazole in seven mono-solvents and (2-propanol ± cyclohexane, 1-butanol ± cyclohexane) binary solvent mixtures was determined by gravimetric method from 283.15 K to 313.15 K at atmospheric pressure. The solubility of prothioconazole increased with increasing temperature in all tested solvents. In mono-solvents, the solubility values at a fixed temperature ranked as: 1-butanol > 1-propanol > 2-propanol > methanol > 2-butanol > acetonitrile > toluene. In binary solvent systems, the maximum solubility values were achieved at a certain solvent composition. The Apelblat equation, λh equation and NRTL model were employed to correlate the solubility data in mono-solvents, and the Apelblat equation in two binary solvent mixtures. The selected thermodynamic models can all give acceptable results. Furthermore, the apparent standard Gibbs free energy, enthalpy and entropy for the dissolution of prothioconazole were calculated, which indicates that the dissolution process of prothioconazole is an endothermic and entropy favorable process.
Co-reporter:Mingchen Li, Peipei Zhu, Dandan Han, Yingdan Cui, Zhe Ding, Haiyan Yang, Lingyu Wang, Junbo Gong
Journal of Molecular Liquids 2017 Volume 248(Volume 248) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.molliq.2017.09.118
•The solubility of 2-Mercaptomethyl Benzimidazole in eight pure solvents and two binary solvents was experimentally determined.•The experimental solubility data of MMB was correlated by three models in pure solvents and four models in binary solvents.•Dielectric constants relative to temperature were used to explain the properties of dissolving.In this work, the solubility of 2-Mercaptomethyl Benzimidazole (MMB)in eight pure solvents (i.e., ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, ethyl acetate, acetonitrile and acetone) and two binary solvents (ethanol + ethyl acetate and 1-butanol + acetonitrile) were measured by a dynamic method at a temperature ranging from (283.15 to 328.15) K at atmospheric pressure. For the temperature range investigated, the solubility of MMB in all solvents increased with increasing temperature. The solubility in the pure solvents was well-correlated with the Apelblat equation, λh equation and NRTL equation. Further, RK model, together with Apelblat equation λh equation and NRTL equation were employed to correlate the solubility in binary solvents. Besides, the thermodynamic data in both pure and binary solvents (i.e., Gibbs energy, enthalpy, and entropy of mixing) were calculated by using the NRTL model to rank the solubility values in different pure solvents.
Co-reporter:Minghe Zhu, Huihui Zhang, Keke Zhang, Yaoyao Yang, Shuang Jiang, Shijie Xu, Yumin Liu, Junbo Gong
The Journal of Chemical Thermodynamics 2017 Volume 112(Volume 112) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.jct.2017.04.017
•The solubility of boscalid in pure solvents and binary solvents was determined.•Four thermodynamic models were used to correlate the solubility data of boscalid.•The mixing thermodynamics were calculated and discussed based on NRTL model.The solubility of boscalid in five pure solvents, including methanol, ethanol, isopropanol, ethyl acetate and n-propyl acetate, and two binary solvent mixtures, including (ethanol + ethyl acetate) and (isopropanol + ethyl acetate), was determined by a gravimetric method with temperatures ranging from (288.15 to 313.15) K. It turns out that the solubility of boscalid increases with the increasing of temperature in all selected solvents. Moreover, it is interesting that the solubility of boscalid in the two binary solvent mixtures performed a maximum effect with the decreasing mole fraction of ethyl acetate at a given temperature. The solubility of boscalid in pure solvents was correlated by the modified Apelblat model and λh model while that in binary solvent mixtures was correlated by the modified Apelblat model, CNIBS/R-K model and Jouyban-Acree model. It is found that all the models could give satisfactory correlation results with less than 3% of all the ARD values. Furthermore, the thermodynamic properties of the mixing processes in all solvents selected were calculated and discussed based on the NRTL model.
Co-reporter:Dandan Han, Yumin Liu, Xiaona Li, Teng Zhang, Zhenfang Li, Shichao Du, Mingxia Guo, Shijie Xu, Bo Yu, Baohong Hou, Junbo Gong
The Journal of Chemical Thermodynamics 2017 Volume 113(Volume 113) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.jct.2017.05.030
•Solubility correlated by new Cohen equation suggested by Acree Jr and the original Cohen equation was compared and analyzed.•The applicability of Cohen equation was discussed.•The parameters of Solubility-Polarity equation were verified.Those comments from Acree on “Effect of β-alanine and the solvent composition on the solubility of solvate of calcium d-pantothenate containing four molecules of methanol and one molecule of water (d-PC·4MeOH·1H2O)” are very valuable and helpful for improving the quality of our paper. Here according to the comments, we make a deep analysis and discussion of our article again. Firstly, we need to make a restatement that S0 and S actually represent the solubility with no impurity in the solution and the solubility in the solution containing impurity in our article, respectively. Secondly, the experimental solubility was reanalysed by the new Cohen equation suggested by Acree Jr, and the results show that the original Cohen equation could give the better agreement. Finally, the modified Solubility-Polarity equation was adopted to correlate the solubility in terms of the relative dielectric constant.
Co-reporter:Keke Zhang, Huan Shen, Shijie Xu, Huihui Zhang, Minghe Zhu, Peng Shi, Xiaoyan Fu, Yaoyao Yang, Junbo Gong
The Journal of Chemical Thermodynamics 2017 Volume 112(Volume 112) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.jct.2017.04.014
•The solubility of pyrazinamide was determined by using gravimetric method.•Four models were employed to correlate the solubility in the selected solvents.•The mixing thermodynamic properties of pyrazinamide were calculated and discussed.The solubility of pyrazinamide in ten solvents (water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, acetone, acetonitrile and ethyl acetate) at temperatures ranging from (278.15 to 323.15) K was determined by using the gravimetric method. The experimental results indicated that in different solvents, the solubility of pyrazinamide was temperature dependent and increased with the increasing temperature. Besides, the modified Apelblat equation, λh equation, Wilson model and NRTL model were employed to correlate the solubility data in the solvents. The results show that the correlated data are in good agreement with the experimental solubility. Furthermore, the mixing thermodynamic properties of pyrazinamide in different solvents were calculated based on the Wilson model. The outcome indicates that the mixing process of pyrazinamide is endothermic.
Co-reporter:Yan Wang, Shichao Du, Songgu Wu, Long Li, Dejiang Zhang, Bo Yu, Lina Zhou, Hibest kiflegiorgis Bekele, Junbo Gong
The Journal of Chemical Thermodynamics 2017 Volume 113(Volume 113) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.jct.2017.05.041
•Solubility of gabapentin anhydrate/monohydrate in alcohol-water mixtures was experimentally determined.•Molecular dynamics simulations were carried out to explore the effect of solvent composition on the solubility.•Critical water activity and the transition temperature of gabapentin anhydrate/hydrate were determined.•Ternary phase diagram of (gabapentin-ethanol-water) at 293.15 K was built.Solubility of gabapentin anhydrate/monohydrate in alcohol-water mixtures was experimentally determined. An interesting trend of the solubility was found, which showed both maximum and minimum solubility with different solvent compositions at one temperature. Molecular dynamics simulations were carried out to explore the effect of solvent composition on the solubility, indicating that the water association played an important role. Critical water activity and the transition temperature of gabapentin anhydrate/hydrate were also determined, and a relationship between them was established to investigate the factors influencing the hydration. Furthermore, the ternary phase diagram of (gabapentin-ethanol-water) at 293.15 K was built by slurry experiments for further understanding of the crystal form transformation, which confirmed the stability regions of anhydrate/monohydrate and verified the above established relations. Then the dehydration/hydration process in the solution can be predicted and controlled, thus obtaining the desired product.In alcohol-water system, gabapentin anhydrate can transform to monohydrate with the increasing of water, which is influenced both by temperature and water activity. The solubility of anhydrate/hydrate have strange trend, especially existing a minimum in water rich region. Molecular dynamics simulations show the water association and solvent-solute interactions are the key factors.Download high-res image (83KB)Download full-size image
Co-reporter:Jie Hou, Chunlei Guo, Yuzhi Shi, Ergang Liu, Weibing Dong, Bo Yu, Shiyuan Liu, Junbo Gong
International Journal of Pharmaceutics 2017 Volume 533, Issue 1(Issue 1) pp:
Publication Date(Web):25 November 2017
DOI:10.1016/j.ijpharm.2017.09.058
A novel high drug loading pH-cleavable polymer hybrid nanoparticle was prepared via doxorubicin (DOX) grafted onto PEGylated, mussel-inspired polydopamine (PDA) and then coated onto hollow silica nanoparticles for drug delivery. A series of characterization shed light on the formation mechanisms of PDA coatings on hollow silica. We hypothesized that dopamine was first absorbed onto the surface of hollow silica and then began self-polymerization. A Dox-containing thiol moiety was fabricated with conjugation between doxorubicin hydrochloride and Mercaptopropionyalkali with a pH-cleavable hydrozone bond. Using a Michael addition reaction, several Dox-containing thiol moieties were grafted onto the surface of the PDA. The drug loading capacity can reach 35.43%. It can minimize the metabolic problem of silica. The released behavior of Dox can be significantly enhanced at endosomal pH compared to physiological pH. After folate modification, nanoparticles can lead to more cellular endocytosis. Meanwhile animal assays showed that more Dox accumulated in tumor tissue, which can enhanced the cytotoxicity to 4T1 cancer cells with a targeting group compared to free DOX and untargeted groups. Meanwhile, the tumor growth was significantly inhibited. This promising material shows a promising future as a drug delivery system.Download high-res image (183KB)Download full-size image
Co-reporter:Dejiang Zhang, Shijie Xu, Shichao Du, Jingkang Wang, Junbo Gong
Engineering 2017 Volume 3, Issue 3(Volume 3, Issue 3) pp:
Publication Date(Web):1 June 2017
DOI:10.1016/J.ENG.2017.03.023
Crystallization is an important unit operation in the pharmaceutical industry. At present, most pharmaceutical crystallization processes are performed in batches. However, due to product variability from batch to batch and to the low productivity of batch crystallization, continuous crystallization is gaining increasing attention. In the past few years, progress has been made to allow the products of continuous crystallization to meet different requirements. This review summarizes the progress in pharmaceutical continuous crystallization from a product engineering perspective. The advantages and disadvantages of different types of continuous crystallization are compared, with the main difference between the two main types of crystallizers being their difference in residence time distribution. Approaches that use continuous crystallization to meet different quality requirements are summarized. Continuous crystallization has advantages in terms of size and morphology control. However, it also has the problem of a process yield that may be lower than that of a batch process, especially in the production of chirality crystals. Finally, different control strategies are compared.
Co-reporter:Shichao Du, Yan Wang, Songgu Wu, Bo Yu, Peng Shi, Lin Bian, Dejiang Zhang, Jie Hou, Jingkang Wang, Junbo Gong
European Journal of Pharmaceutical Sciences 2017 Volume 110(Volume 110) pp:
Publication Date(Web):15 December 2017
DOI:10.1016/j.ejps.2017.06.001
Crystal engineering strategy was applied to develop new solid forms of lamotrigine. Two novel cocrystals of lamotrigine forming with 4,4′-bipyridine (2:1) and 2,2′-bipyridine cocrystal (1:1.5) were successfully obtained by neat grinding and liquid assisted grinding. The novel cocrystals were fully characterized and confirmed by X-ray diffraction, thermal and spectroscopic analysis. DXRxi Raman microscope was also used to identify the cocrystals. The factors such as solvent and the structure of coformers which influenced the cocrystal formation were discussed. Furthermore, the novel cocrystals were both obtained by slurry crystallization. Process analytical technologies including focused beam reflectance measurement and attenuated total reflectance Fourier Transform Infrared were applied to investigate the cocrystallization process and the mechanism. HPLC analysis showed that the dissolution rate and the solubility of the two novel cocrystals were both improved.Download high-res image (52KB)Download full-size image
Co-reporter:Shiyuan Liu, Estevao G.J. Macaringue, Xiaona Li, Lina Jia, Yumin Liu, Junbo Gong
Journal of Molecular Liquids 2017 Volume 238(Volume 238) pp:
Publication Date(Web):1 July 2017
DOI:10.1016/j.molliq.2017.04.127
•The addition of organic solvents will facilitate the water cluster formation.•Water would be more likely to associate together in acetone than alcohols.•The strength sequence of d-man-cosolvent interaction in line with solubility data•Solubility behavior relies on solute-solvent and solvent-solvent interactions.Solubility behavior of d-mannitol (d-man) in pure water and four water-organic solvents from 288.15 K to 318.15 K at atmospheric pressure was studied by both phase equilibria and molecular modelling methods. A dynamic method was employed to determine the data on equilibrium, both molecular dynamic (MD) simulations and density functional theory (DFT) calculations were carried out to uncover the relationship between intermolecular interactions and solubility behavior. The MD results illustrate that the strength in hydrogen bond of solute-organic solvent captures the solubility ranking of d-man in corresponding mixed solvents, and the radial distribution function (RDF) plots indicate that organic solvents have enhancement effect on the water aggregation in solution which weakened the strong interaction between d-man and water molecules. Both of them suggest that solubility behavior not only depends on solute-solvent interaction, the solvent-solvent interaction also plays a key role in determining it. The solubility was further fitted by the modified Apelblat model, λh model, NRTL model and finally, mixing properties (enthalpy, Gibbs energy and entropy) were discussed, indicating the dissolution process is governed by both enthalpy and entropy of solution.
Co-reporter:Zhilong Luo, Yingdan Cui, Weibing Dong, Qipeng Xu, Gaoxing Zou, Chao Kang, Baohong Hou, Song Chen, Junbo Gong
Journal of Crystal Growth 2017 Volume 480(Volume 480) pp:
Publication Date(Web):15 December 2017
DOI:10.1016/j.jcrysgro.2017.10.012
•NQ crystals with multiple morphologies and single crystal form were obtained.•Modification of morphologies of NQ crystals made mechanical performance improved.•The additives delayed nucleation of NQ crystals and inhibited crystal growth.•The morphology controlled NQ crystals suggested higher thermodynamic stability.Nitroguanidine (NQ) is a commonly used explosive, which has been widely used for both civilian and military explosive applications. However, the weak flowability and mechanical performance limit its application. In this work, mechanical performance and thermodynamic stability of NQ crystals were improved by controlling crystal morphologies in the crystallization process. Typical NQ crystals with multiple morphologies and single crystal form were obtained in the presence of additives during the cooling crystallization. The morphology controlled NQ crystals showed higher density, unimodal crystal size distribution and enhanced flowability. The additives showed the inhibitory effect on the nucleation of NQ crystals by in-situ FBRM and PVM determination, and the mechanism was analyzed by means of morphological prediction and molecular simulation. Furthermore, the morphology controlled NQ crystals suggested higher thermodynamic stability according to the calculation of entropy, enthalpy, Gibbs free energy and apparent activation energy on the basis of DSC results.
Co-reporter:Songgu Wu, Huan Shen, Kangli Li, Bo Yu, Shijie Xu, Mingyang Chen, Junbo Gong, and Bao hong Hou
Industrial & Engineering Chemistry Research 2016 Volume 55(Issue 17) pp:4905-4910
Publication Date(Web):April 13, 2016
DOI:10.1021/acs.iecr.5b04437
The main purpose of this investigation was to investigate the agglomeration mechanism of azithromycin dihydrate in mixed water and acetone systems and improve the powder properties of azithromycin dihydrate. The solubilities and crystallization processes of azithromycin monohydrate and dihydrate in mixed water + acetone systems were measured and investigated. The solubilities of the two hydrates were very close, and the products obtained from water + acetone mixtures were strongly agglomerated. It was found that surface nucleation and growth of dihydrate on monohydrate crystals during the hydrate transformation process were the reasons which caused agglomeration. There was no hydrate transformation during the crystallization process of azithromycin in ethyl acetate, and the products were single crystals. By comparison of the powder properties of agglomerated and nonagglomerated solids, the agglomeration has a serious impact on the crystal size distribution, bulk density, and flowability.
Co-reporter:Kangli Li, Songgu Wu, Shijie Xu, Shichao Du, Kaifei Zhao, Lanlan Lin, Peng Yang, Bo Yu, Baohong Hou, and Junbo Gong
Industrial & Engineering Chemistry Research 2016 Volume 55(Issue 44) pp:11631-11637
Publication Date(Web):October 18, 2016
DOI:10.1021/acs.iecr.6b03097
In this study, phase diagrams of form II (metastable form) of pyraclostrobin under different cooling rates were measured with the aid of in situ tools such as ATR-FTIR, FBRM, and PVM. It was found that the initial concentration of pyraclostrobin corresponding to the metastable state critical oiling out point upon cooling decreases with the increase of cooling rate. Meanwhile, the seeding strategy experiments illuminated that seed loading and seed size are important factors to avoid the oiling out and to obtain form IV (stable form) of pyraclostrobin. By optimizing the cooling rate and employing the seeding strategy, oiling out could be eliminated and products of pure form IV of pyraclostrobin could be obtained.
Co-reporter:Junbo Gong;Yan Wang;Shichao Du;Weibing Dong;Bo Yu;Songgu Wu;Jie Hou;Jingkang Wang
Chemical Engineering & Technology 2016 Volume 39( Issue 5) pp:807-814
Publication Date(Web):
DOI:10.1002/ceat.201500718
Abstract
The latest developments of industrial crystallization in China are reviewed. This includes the introduction of representative scientists and institutions promoting the progress of Chinese industrial crystallization. Additionally, primary application fields related to industrial crystallization are outlined to give an overview of the current research trends in China. National and international industrial crystallization meetings held in China are also presented. Finally, the expectations for the future research activities in the field of industrial crystallization in China are briefly described.
Co-reporter:Yanni Du, Haiyang Wang, Shichao Du, Yan Wang, Cui Huang, Yujia Qin, Junbo Gong
Fluid Phase Equilibria 2016 Volume 409() pp:84-91
Publication Date(Web):15 February 2016
DOI:10.1016/j.fluid.2015.09.011
In this study, the liquid–liquid phase separation and crystallization of vanillin from 1-propanol/water solution were investigated. It was found that water could contribute to the improvement of vanillin solubility in 1-propanol/water solution, but the solubility of vanillin decreased with the increasing water/1-propanol ratios, when the water content was over 30 wt.%. High water fraction in 1-propanol/water solvents will result in the liquid–liquid phase separation in the crystallization process, and the liquid–liquid phase separation dominated the process before the nucleation of crystals during the crystallization of vanillin. A ternary phase diagram (vanillin/1-propanol/water) including the solubility curves and the liquid–liquid phase separation curves was measured and could, in certain cases, clearly illustrate the liquid–liquid phase separation and crystallization process of vanillin in 1-propanol/water solutions. As shown in the ternary phase diagram, liquid–liquid phase separation under high initial vanillin concentration results in low purity of vanillin crystals due to the inhibited crystallization process by liquid–liquid phase separation. Partial phase immiscibility was a function of temperature and the range of immiscibility decreased with increasing temperature. Moreover, nucleation and crystal growth of vanillin in the presence of liquid–liquid phase separation were investigated; process parameters such as the composition of solvent, cooling profiles and seeding were optimized to avoid liquid–liquid phase separation and thus increase the purity of crystallization products.
Co-reporter:Mingyang Chen, Lanlan Lin, Yuqi Zhang, Songgu Wu, Ergang Liu, Kun Wang, Jingkang Wang, Junbo Gong
Particuology 2016 Volume 27() pp:115-121
Publication Date(Web):August 2016
DOI:10.1016/j.partic.2015.04.005
•Particles shape and solubility were studied for caking mechanism.•The research based on theories of adhesion free energy and crystal bridge.•Relationship between caking ratio and adhesion free energy was studied.•Caking could be inhibited by screening rinsing liquids, and optimizing particle shape and size.We investigated the influence of particle shape and solubility on the caking behavior of trisodium phosphate by considering the adhesion free energy and crystal bridge theory. Caking of trisodium phosphate during the drying process under static conditions is a two-step process: adhesion followed by crystal bridge formation between particles. The adhesion free energy plays an important role in adhesion. Trisodium phosphate particles cannot adhere to each other and cake when the adhesion free energy is greater than a critical value, which varies with particle shape. Compared with granular particles, cylindrical particles have larger contact area between particles, which results in more crystal bridges forming and a higher caking ratio. Thus, the critical value is about 100 mJ/m2 for cylindrical particles, but 60 mJ/m2 for granular particles at 25 °C. Concerning the solubility, when particles are similar shapes and soluble in the rinsing liquid, the caking ratio has a linear relationship with adhesion free energy. However, if the particles are insoluble in the rinsing liquid, caking can be completely prevented regardless of adhesion free energy because no crystal bridges form during the growth process. Hence, caking of trisodium phosphate particles could be inhibited by screening rinsing liquids, and optimizing the particle shape and size distribution.
Co-reporter:Teng Zhang, Zhenfang Li, Yan Wang, Cong Li, Bo Yu, Xiaochen Zheng, Lei Jiang, Junbo Gong
The Journal of Chemical Thermodynamics 2016 Volume 96() pp:82-92
Publication Date(Web):May 2016
DOI:10.1016/j.jct.2015.12.022
•The solubility data of l-methionine in three different binary mixed solvents were experimentally determined.•The experimental solubility data of l-methionine were correlated by three models.•Almost all studied solutions show good agreement with the “like dissolves like” empirical rule.•Thermodynamic properties of l-methionine dissolution process were calculated and studied.The solubility of l-methionine in three different binary mixed solvents of water + (methanol, ethanol, acetone) were experimentally measured by gravimetric method from T = (283.15 to 313.15) K (P = 0.1 MPa). The experimental data indicate that the solubility of l-methionine in the binary mixed solvents increases with the increasing temperature and decreases with the rise of molar concentration of organic solvents. The modified Apelblat model, the λh model and the CNIBS/R–K model were used to correlate the experimental data, and all of the models provided good fitting to the data. Furthermore, the mixing thermodynamic properties of l-methionine in different binary solvent mixtures were also calculated and discussed. The results indicate that the mixing process of l-methionine in the investigated solvents is endothermic and spontaneous. The experimental solubility and correlation equations can be used as essential data and simulation models in the purification and separation of l-methionine.
Co-reporter:Kaifei Zhao, Peng Yang, Shichao Du, Kangli Li, Xiaona Li, Zhenfang Li, Yumin Liu, Lanlan Lin, Baohong Hou, Junbo Gong
The Journal of Chemical Thermodynamics 2016 Volume 102() pp:276-286
Publication Date(Web):November 2016
DOI:10.1016/j.jct.2016.07.014
•The solubility of 4-aminobutyric acid in mono-solvents and binary solvent mixtures were experimentally determined.•The solubility data in five mono-solvents were correlated by three models.•Four models were employed to correlate solubility data in methanol + water binary solvent mixtures.•Solution mixing thermodynamics were calculated and the dissolution process were discussed.A laser monitoring dynamic method was used to determine the solubility of 4-aminobutyric acid in five mono-solvents of methanol, formamide, 1,2-propanediol, 1,3-propanediol and water, and (methanol + water) binary solvent mixtures over the temperature ranging from 283.15 K to 323.15 K at atmospheric pressure. It turns out to be that in different mono-solvents, the solubility of 4-aminobutyric acid is temperature dependent and increases with the increasing temperature. While in (methanol + water) binary solvent mixtures, the solubility is positively correlated with temperature and negatively correlated with the mole fraction of methanol. The modified Apelblat equation, λh equation and NRTL_Binary model were employed to correlate the solubility data in five mono-solvents. While in (methanol + water) binary solvent mixtures, the NRTL_Ternary model, CNIBS/R-K model and Jouyban-Acree models were applied. It is found that the correlated results are in good agreement with the experimental results. Furthermore, with the activity coefficients considered, solution mixing thermodynamics were calculated and the dissolution process of 4-aminobutyric acid is also discussed.
Co-reporter:Mengmeng Sun, Kangli Li, Shichao Du, Yumin Liu, Dandan Han, Xiaona Li, Peng Yang, Shiyuan Liu, Junbo Gong
The Journal of Chemical Thermodynamics 2016 Volume 103() pp:355-365
Publication Date(Web):December 2016
DOI:10.1016/j.jct.2016.08.024
•The solubility data of cefmetazole acid in three (alcohol + water) binary solvents were experimentally determined.•The experimental solubility data of cefmetazole acid were correlated by three models.•Almost all studied solutions show good agreement with the “like dissolves like” empirical rule.•Thermodynamic properties of cefmetazole acid of mixing process were calculated and discussed.The solubility of cefmetazole acid in binary solvent mixtures, (methanol + water), (ethanol + water) and (isopropanol + water), was determined by UV spectroscopic method at temperatures from 278.15 to 303.15 K. The solubility of cefmetazole acid increased with the increase of temperature in all solvents. In (methanol + water) co-solvent mixture, the solubility of cefmetazole acid is maximal in neat methanol. In (ethanol + water) and (isopropanol + water) solvent mixtures, the solubility of cefmetazole acid reaches its maximum when the mole fraction of alcohol is 0.5 and 0.4, respectively. The modified Apelblat equation, the CNIBS/R-K model and the Jouyban–Acree model were applied to correlate the experimental solubility of cefmetazole acid. Moreover, the activity coefficients as well as the thermodynamic properties of mixing were calculated and discussed based on the NRTL model and experimental solubility values.
Co-reporter:Peng Yang, Shichao Du, Yujia Qin, Kaifei Zhao, Kangli Li, Baohong Hou, Junbo Gong
The Journal of Chemical Thermodynamics 2016 Volume 101() pp:84-91
Publication Date(Web):October 2016
DOI:10.1016/j.jct.2016.05.005
•The solubility data of pyraclostrobin in pure and binary solvents were determined and correlated.•The theory of solubility parameter was used to explain the cosolvency in binary solvents.•A modified mixing rule was proposed to calculate the solubility parameter of binary solvents.•The dissolution thermodynamic properties were calculated and discussed.The solubility of pyraclostrobin in five pure solvents and two binary solvent mixtures was measured from 283.15 K to 308.15 K using a static analytical method. Solubility in five pure solvents was well correlated by the modified Apelblat equation and Wilson model. While the CNIBS/R–K model was applied to correlate the solubility in two binary solvent mixtures, the correlation showed good agreement with experimental results. The solubility of pyraclostrobin reaches its maximum value at a certain cyclohexane mole fraction in the two binary solvent mixtures. The solubility parameter of pyraclostrobin was calculated by the Fedors method and a new modified mixing rule with preferable applicability was proposed to determine the solubility parameter of solvents. Then the co-solvency in the binary solvent mixtures can be explained based on the obtained solubility parameters. In a addition, the dissolution thermodynamic properties were calculated from the experimental values using the Wilson model.
Co-reporter:Lanlan Lin; Kaifei Zhao; Bo Yu; Haisheng Wang; Mingyang Chen
Journal of Chemical & Engineering Data 2016 Volume 61(Issue 1) pp:412-419
Publication Date(Web):November 12, 2015
DOI:10.1021/acs.jced.5b00617
In this study, the solubility of cefathiamidine was measured in water + (acetone, ethanol, or 2-propanol) at temperature from (278.15 to 313.15) K by using a gravimeteic method. The solubility of cefathiamidine increased with increasing temperature. Besides, at a given temperature, solubility in different mixtures follows different rules. In water + (acetone or 2-propanol), it decreases with the increase of the initial molar fraction of acetone or 2-propanol; whereas synergistic effect of mixed solvents was observed in water + ethanol mixtures, and solubility reached maximum at the ethanol molar fraction of 0.4. The experimental data were well correlated by the modified Apelblat equation, the CNIBS/R-K model, the combined version of the Jouyban–Acree and van’t Hoff model, and the combined version of the Jouyban–Acree and the modified Apelblat model. Furthermore, the thermodynamic functions of dissolution of cefathiamidine in different mixtures were obtained based on the van’t Hoff equation and the modified Apelblat equation. The results indicate that the dissolution process of cefathiamidine is endothermic.
Co-reporter:Kaifei Zhao; Lanlan Lin; Cong Li; Shichao Du; Cui Huang; Yujia Qin; Peng Yang; Kangli Li
Journal of Chemical & Engineering Data 2016 Volume 61(Issue 3) pp:1210-1220
Publication Date(Web):February 26, 2016
DOI:10.1021/acs.jced.5b00829
The solubility of γ-aminobutyric acid (GABA) in binary solvent mixtures of ethanol + methanol, 1-propanol + methanol and 2-propanol + methanol was measured over the temperature ranging from(283.15 to 323.15 K with the gravimetric method. It is found that the solubility of GABA increases with increasing temperature, whereas it decreases with the increase of the GABA free-base mole fraction of ethanol, 1-propanol, or 2-propanol. The solubility data have been correlated with the modified Apelblat equation, the CNIBS/R-K equation, two modified versions of Jouyban-Acree models (the Van’t-JA equation and the Apel-JA equation) and NRTL model, respectively. The results show that the CNIBS/R-K equation gives the best correlation results in these three binary mixed solvents. Also, the mixing thermodynamic properties of enthalpy, entropy, and Gibbs energy change of GABA in these solvent mixtures have also been calculated and discussed.
Co-reporter:Zhenfang Li; Teng Zhang; Cui Huang; Haisheng Wang; Bo Yu
Journal of Chemical & Engineering Data 2016 Volume 61(Issue 3) pp:1065-1070
Publication Date(Web):February 15, 2016
DOI:10.1021/acs.jced.5b00565
A gravimetric method was used to determine the solubility of maltitol in five pure solvents, methanol–water mixtures, and ethanol–water mixtures at different temperatures from 298.15 to 323.15 K. At a given temperature, the solubility of maltitol in the five pure solvents follows this order: 2-propanol < ethanol < methanol < DMF < water. Compared with the modified Van’t Hoff equation, the modified Apelblat equation presents a better consistence with the solubility of maltitol in different pure solvents. The solubility of maltitol increases with rising temperature, but decreases with the increase of the initial mole fraction of methanol or ethanol. It is found that the modified Apelblat equation can give better correlation results in methanol–water mixtures and ethanol–water mixtures than the combined nearly ideal binary solvent/Redlich–Kister equation or the two kinds of Jouyban–Acree models.
Co-reporter:Xiaona Li, Dandan Han, Yan Wang, Shichao Du, Yumin Liu, Jiaqi Zhang, Bo Yu, Baohong Hou, and Junbo Gong
Journal of Chemical & Engineering Data 2016 Volume 61(Issue 10) pp:3665-3678
Publication Date(Web):September 19, 2016
DOI:10.1021/acs.jced.6b00613
Data on (solid + liquid) equilibrium of thiamine hydrochloride hemihydrate (HH) in {water + (ethanol, acetone, or 2-propanol)} solvents will provide essential support for industrial design and further theoretical studies. In this study the solid–liquid equilibrium (SLE) was experimentally measured over temperatures ranging from 278.15 to 313.15 K under atmospheric pressure by a dynamic method. For the temperature range investigated, the equilibrium solubility of thiamine hydrochloride hemihydrate (HH) varies with temperature and the composition of the solvents. The experimental solubility was regressed with different models including the modified Apelblat equation, λh equation, as well as NRTL equation. All the models gave good agreements with the experimental results. On the basis of the solubility data of HH, the thermodynamic properties of mixing process of HH with mixed solvents were also discussed. The results indicate that the mixing process of HH is exothermic. Besides, the model outwardly like the Arrhenius equation was employed to quantitatively exhibit the relationship between solubility and solvents mixtures polarity of solvents mixtures.
Co-reporter:Shichao Du, Yan Wang, Jianyu Li, Songgu Wu, Weiqiang Dun, Xiaopeng Song, Jingkang Wang, Junbo Gong
The Journal of Chemical Thermodynamics 2016 Volume 93() pp:132-142
Publication Date(Web):February 2016
DOI:10.1016/j.jct.2015.09.032
•The solubility of diphenhydramine hydrochloride in four pure and two binary solvents were experimentally determined.•The experimental solubility of diphenhydramine hydrochloride were correlated by three models.•The activity coefficients as well as thermodynamic properties of mixing were obtained and discussed.The solubility of diphenhydramine hydrochloride (DH) in four pure solvents (methanol, ethanol, acetone and ethyl acetate) and two binary solvents (ethanol + ethyl acetate) and (ethanol + acetone) was determined at temperatures from (278.15 to 323.15) K. The experimental solubility of DH is well correlated by the modified Apelblat equation, the CNIBS/R-K equation and the hybrid model, respectively. All the measured solubility of DH shows temperature dependence. In binary mixtures, the solubility curve displays a maximum with the solvent composition changing, particularly, the maximum point increases with temperature. Moreover, the activity coefficients as well as thermodynamic properties of mixing were obtained and discussed.
Co-reporter:Dandan Han, Xiaona Li, Haisheng Wang, Yan Wang, Shichao Du, Bo Yu, Yumin Liu, Shijie Xu, Junbo Gong
The Journal of Chemical Thermodynamics 2016 Volume 94() pp:138-151
Publication Date(Web):March 2016
DOI:10.1016/j.jct.2015.09.026
•Solubility of pyridoxine hydrochloride in three binary mixtures was determined.•Experimental solubility of pyridoxine hydrochloride was correlated by four models.•Mixing thermodynamics of pyridoxine hydrochloride were calculated and discussed.The solubility of pyridoxine hydrochloride in binary solvent mixtures, including (acetone + water), (methanol + water) and (ethanol + water), was measured over temperature range from (278.15 to 313.15) K by a gravimetric method at atmospheric pressure (P = 0.1 MPa). The solubility increased with increasing temperature in binary solvent mixtures at constant solvent composition. Besides, the dissolving capacity of pyridoxine hydrochloride in the three binary solvent mixtures at constant temperature ranked as (methanol + water > ethanol + water > acetone + water) in general, partly depending on the polarity of the solvents. Additionally, the modified Apelblat equation, van’t Hoff equation, CNIBS/R–K model and Jouyban–Acree model were used to correlate the solubility data in binary mixtures, it turned out that all the selected thermodynamic models could give satisfactory results. Furthermore, the mixing thermodynamic properties of pyridoxine hydrochloride in different binary solvent mixtures were also calculated and discussed. The results indicate that the mixing process of pyridoxine hydrochloride in the selected solvents is exothermic.
Co-reporter:Kangli Li, Shichao Du, Songgu Wu, Dongchen Cai, Jinxu Wang, Dejiang Zhang, Kaifei Zhao, Peng Yang, Bo Yu, Baisong Guo, Daixi Li, Junbo Gong
The Journal of Chemical Thermodynamics 2016 Volume 96() pp:12-23
Publication Date(Web):May 2016
DOI:10.1016/j.jct.2015.11.007
•The solubility of racemic oxiracetam in three binary solvents were determined.•The experimental solubility of racemic oxiracetam were correlated by four models.•The dissolution thermodynamic properties of racemic oxiracetam were calculated.In this paper, we proposed a static analysis method to experimentally determine the (solid + liquid) equilibrium of racemic oxiracetam in (methanol + water), (ethanol + water) and (isopropanol + water) binary solvents with alcohol mole fraction ranging from 0.30 to 0.90 at atmosphere pressure (p = 0.1 MPa). For the experiments, the temperatures range from (283.15 to 308.15) K. The results showed that the solubility of oxiracetam increased with the increasing temperature, while decreased with the increasing organic solvent fraction in all three tested binary solvent systems. The modified Apelblat model, the CNIBS/Redlich–Kister model, the combined version of Jouyban–Acree model and the NRTL model were employed to correlate the measured solubility values, respectively. Additionally, some of the thermodynamic properties which can help to evaluate its dissolution behavior were obtained based on the NRTL model.
Co-reporter:Yaoyao Yang, Peng Yang, Shichao Du, Kangli Li, Kaifei Zhao, Shijie Xu, Baohong Hou, Junbo Gong
The Journal of Chemical Thermodynamics 2016 Volume 103() pp:432-445
Publication Date(Web):December 2016
DOI:10.1016/j.jct.2016.08.035
•The solubility of allisartan isoproxil in binary solvent mixtures were determined.•Apelblat, CNIBS/R-K and Jouyban-Acree models were used to correlate the solubility.•Solubility parameter theory was used to explain the co-solvency phenomenon.•Regular mixing rules were used to calculate solubility parameter of binary solvents.•The mixing thermodynamics were calculated and discussed based on NRTL model.In this work, the solubility of allisartan isoproxil in binary solvent mixtures, including (acetone + water), (acetonitrile + water) and (methanol + water), was determined by a gravimetric method with the temperature ranging from (278.15 to 313.15) K at atmospheric pressure (p = 0.1 MPa). The solubility of allisartan isoproxil in three binary solvent mixtures all increased with the rising of temperature at a constant solvent composition. For the binary solvent mixtures of (methanol + water), the solubility increased with the increasing of methanol fraction, while it appeared maximum value at a certain solvent composition in the other two binary solvent mixtures (acetone + water and acetonitrile + water). Based on the theory of solubility parameter, Fedors method and two mixing rules were employed to calculate the solubility parameters, by which the proximity of solubility parameters between allisartan isoproxil and binary solvent mixtures explained the co-solvent phenomenon. Additionally, the modified Apelblat equation, CNIBS/R-K model and Jouyban-Acree model were used to correlate the solubility data in binary solvent mixtures, and it turned out that all the three correlation models could give a satisfactory result. Furthermore, the mixing thermodynamic properties were calculated based on NRTL model, which indicated that the mixing process was spontaneous and exothermic.
Co-reporter:Mingyang Chen, Songgu Wu, Weiwei Tang, Junbo Gong
Powder Technology 2015 Volume 272() pp:235-240
Publication Date(Web):March 2015
DOI:10.1016/j.powtec.2014.12.012
•Caking mechanism of sugar and sugar polyol in adhesion process was explained with adhesion free energy theory.•Main factors were found to improve adhesion free energy to avoid caking.•Crystal size distribution controlling and rinsing liquid screening are guided for industrial production.Caking is a common phenomenon of maltitol that causes problems of separation, processing and transportation. To study the mechanism of caking, method of capillary rise was used to measure the contact angles between maltitol particles and relevant liquids. Based on the calculation of adhesion free energy of maltitol particles in different liquids by Lifshitz–van der Waals acid-base theory, the relationship between adhesion free energy and the maltitol particles size has been established. It is concluded that the adhesion free energy of maltitol with rinsing liquid plays a key role in caking. When the adhesion free energy is higher than a critical value (about 60 mJ/m2), the repulsion between the particles can avoid caking. In general, the adhesion free energy depends on the rinsing liquid used and maltitol particles size. The adhesion free energy increases with increasing the particles size of maltitol and type of liquids (water, ethyl acetate, formamide, ethylene glycol, ethanol, methanol in sequence). Hence, controlling particles size distribution and screening of rinsing liquid are crucial factors to avoid caking.25 °C maltitol caking ratio vs. adhesion free energy (caking ratio is the proportion of caked maltitol particles mass in the whole maltitol particles mass).
Co-reporter:Yujia Qin, Haisheng Wang, Peng Yang, Shichao Du, Cui Huang, Yanni Du, Songgu Wu, Junbo Gong, Qiuxiang Yin
Fluid Phase Equilibria 2015 Volume 403() pp:145-152
Publication Date(Web):15 October 2015
DOI:10.1016/j.fluid.2015.06.026
•The solubility data of flunixin meglumine in pure and mixed solvents were experimentally determined.•Thermodynamic properties of flunixin meglumine dissolution process were calculated.•The experimental solubility data of flunixin meglumine were correlated by three models and a new model was proposed.The solubility of flunixin meglumine (FM) in six pure solvents and binary solvents of ethanol + isopropanol was measured over the temperature ranged from 283.15 K to 328.15 K by using a static gravimetric method. It is positively correlated with temperature and negatively correlated with the molar fraction of isopropanol. The modified Apelblat equation was used to correlate the experimental solubility in pure solvents. Dissolution properties based on the modified Apelblat equation were calculated and discussed. The solubility in binary solvents at various temperatures was well correlated by the nearly ideal binary solvent (NIBS)/Redlich–Kister model. In addition, in order to correlate the solubility to both the composition and temperature in mixed solvents, a new model related to dielectric constant was proposed.
Co-reporter:Bo Yu, Feifei Wang, Weibing Dong, Jie Hou, Pingchao Lu, Junbo Gong
Materials Letters 2015 Volume 156() pp:50-53
Publication Date(Web):1 October 2015
DOI:10.1016/j.matlet.2015.04.142
•Core–shell ZnO@ZIF-8 nanospheres were synthesized via self-template method.•Core–coronal–shell ZnO@ZIF-8 was obtained by morphological controlled synthesis.•ZnO@ZIF-8 showed good activity in methylene blue degradation under UV irradiation.•Ligand metal charge transfer is dominating photocatalytic mechanism.Core–shell ZnO@zeolitic imidazolate frameworks-8 (ZnO@ZIF-8) nanospheres was synthesized via a self-template method. Spherical ZnO is employed not only as the template but also as Zn(II) for the composition of zeolitic imidazolate frameworks-8 (ZIF-8). Core–shell ZnO@ZIF-8 showed molecule size selectivity and good photocatalytic activity under UV irradiation, and the outer ZIF-8 shell dominated the photocatalysis via ligand metal charge transfer mechanism during the degradation of methylene blue (MB). Photocatalysis of core–shell metal–organic frameworks (MOFs) will facilitate new efforts in the treatment of pollutants.
Co-reporter:Songgu Wu;Kangli Li;Tianwei Zhang
Chemical Engineering & Technology 2015 Volume 38( Issue 6) pp:1081-1087
Publication Date(Web):
DOI:10.1002/ceat.201400721
Abstract
Atorvastatin calcium (AC) spherical crystals were prepared by spherical agglomeration. CH2Cl2 acting as bridging liquid was added together with the drug solution or after the antisolvent precipitation process. Polymorph transformation in antisolvent crystallization and agglomeration processes was observed by focused-beam reflectance measurement (FBRM). The results suggested the occurrence of an immediate agglomeration when CH2Cl2 was added together with the drug solution. Size-controllable AC spherical crystals with improved flowability and compressibility can be obtained by adjusting the amount of CH2Cl2 and the stirring speed. The improved compaction behavior of the AC particles can be applied for direct tableting. A higher stirring speed can reduce the amount of bridging liquid which is required for effective agglomeration. It was a prerequisite for fine particles to be wetted by the bridging liquid in the spherical agglomeration process.
Co-reporter:Tingting Wei; Chen Wang; Shichao Du; Songgu Wu; Jianyu Li
Journal of Chemical & Engineering Data 2015 Volume 60(Issue 1) pp:112-117
Publication Date(Web):December 15, 2014
DOI:10.1021/je5008422
The solubility of penicillin V potassium (PVK) in binary ethanol + water and 1-butyl alcohol + water solvent mixtures was measured at temperatures ranging from (278.15 to 313.15) K. The solubility in ethanol + water was measured by a static analytical method while in 1-butyl alcohol + water a dynamic method was adopted. It was found that the solubility of PVK increased with increasing temperature as well as the increase of the initial mole fraction of water. The modified Apelblat equation, the CNIBS/R-K equation, the combined version of the Jouyban-Acree and van’t Hoff model, and the hybrid model were used to correlate the solubility data in ethanol + water solvent mixtures, among which the CNIBS/R-K equation gave the best correlation results. The experimental solubility data in 1-butyl alcohol + water were correlated well by the van’t Hoff equation and the modified Apelblat equation. The dissolution enthalpy, entropy, and Gibbs energy of PVK in these solvent mixtures were obtained based on the van’t Hoff equation.
Co-reporter:Cui Huang; Zhiping Xie; Jinchao Xu; Yujia Qin; Yanni Du; Shichao Du
Journal of Chemical & Engineering Data 2015 Volume 60(Issue 3) pp:870-875
Publication Date(Web):January 30, 2015
DOI:10.1021/je500996n
The solubility of d-pantolactone in water, ethanol, methanol, ethyl acetate, and ethanol–water mixtures was determined at temperatures between (278.15 and 318.15) K using a digital densitometer by a static method. The measured solubility data were correlated with Apelblat equation, van’t Hoff equation, nonrandom two liquid model, and Wilson model. The results indicate that the Wilson model is the most suitable model in pure solvents and the Apelblat model is the best model in ethanol–water mixtures.
Co-reporter:Riju Ren, Dengqiong Sun, Tingting Wei, Shixin Zhang, and Junbo Gong
Organic Process Research & Development 2014 Volume 18(Issue 6) pp:709-716
Publication Date(Web):May 13, 2014
DOI:10.1021/op500026z
Isolating enantiomers by crystallization via diastereomer salt formation is widely used in the pharmaceutical industry. Unfortunately, we found that, when some diastereomer impurity exists, oiling-out will take place and significantly decrease the resolution efficiency. To identify the role of impurities in oiling-out, three series of chiral resolution of trans-4-methyl-2-piperidine carboxylic ethyl ester (trans-4MPE) with different levels of diastereomer impurity were performed. Using process analytical technologies (PAT) technologies, the demixing region was identified by measuring TL–L curves and supersolubility curves for different series. It was found that a series with a higher level of impurity has a higher TL–L point and a wider demixing region. Besides, it seems that the resolution efficiency through oiling-out, as well as the crystallization kinetics, was significantly decreased. Here we initially put forward this particular diastereomer purification problem, where the impurity has a positive effect on oiling-out. To reduce or eliminate oiling-out, an efficient prepurification strategy must be ensured.
Co-reporter:Wei Du, Qiuxiang Yin, Hongxun Hao, Ying Bao, Xia Zhang, Jiting Huang, Xiang Li, Chuang Xie, and Junbo Gong
Industrial & Engineering Chemistry Research 2014 Volume 53(Issue 14) pp:5652-5659
Publication Date(Web):March 11, 2014
DOI:10.1021/ie404245s
In situ Raman spectroscopy was applied for the analysis of the solution-mediated polymorphic transformation of prasugrel hydrochloride from the metastable form II to the stable form I. The solution concentration during the transition process was monitored by a gravimetric method. The main factors studied were solvent, temperature, solid loading, and agitation speed. Because of the balance between the solubility and the strength of solute–solvent interactions, the transformation rate was highest in ethyl acetate and lowest in butanone at all three temperatures studied (20, 30, and 40 °C). The thermodynamic driving force of the polymorphic transformation from form II to form I was evaluated through solubility measurements of the two forms in ethyl acetate, acetone, and butanone. At increasing temperature, the nucleation induction time and the overall transformation time decreased despite the decreasing driving force. The solid loading seemed to have no effect on the transformation time because of surface nucleation of form I on form II, as determined from the morphology–time profile through polarizing microscope analysis, whereas increasing the agitation rate resulted in a faster polymorphic transformation process. It was confirmed by transformation experiments that the polymorphic transformation from form II to form I is controlled by the nucleation and growth of the stable form I crystal.
Co-reporter:Weiwei Tang, Zhao Wang, Ying Feng, Chuang Xie, Jingkang Wang, Chengsheng Yang, and Junbo Gong
Industrial & Engineering Chemistry Research 2014 Volume 53(Issue 28) pp:11538-11549
Publication Date(Web):2017-2-22
DOI:10.1021/ie501221x
This article evaluates the accuracy and applicability of three of the most common solubility models (i.e., Jouyban–Acree, NRTL-SAC, and COSMO-RS) in prediction of androstenedione (AD) solubility in binary mixtures of methanol + water and ethanol + water. The solubilities were measured from (275 to 325) K using medium-throughput experiments and then well represented mathematically by modified Apelblat and CNIBS/Redlich–Kister equations. The computational results show that AD solubility decreases monotonically with increasing water concentration in methanol + water mixtures, but it has a maximum at 0.15–0.30 mole fraction of water in the ethanol aqueous solution. Moreover, the performance of three solubility prediction models in this particular case was compared to identify the advantages and disadvantages of each model. The overall average relative deviation (ARD) for solubility prediction is 4.4% using Jouyban–Acree model, while it is 18.3% with NRTL-SAC model. Surprisingly, COSMO-RS model in combination with reference solubility achieves a good performance for solubility prediction in mixed solvents, including the prediction of synergistic effect of solvents, with overall ARD of only 4.9%.
Co-reporter:Weiwei Tang, Chuang Xie, Zhao Wang, Songgu Wu, Ying Feng, Xuemei Wang, Jingkang Wang, Junbo Gong
Fluid Phase Equilibria 2014 Volume 363() pp:86-96
Publication Date(Web):15 February 2014
DOI:10.1016/j.fluid.2013.11.008
•Solubility of androstenedione in lower alcohols was investigated.•Solubility predictions by COSMO-RS agreed with experimental data well.•The thermodynamic functions of solution and mixture were calculated.•Solute–solvent interactions were evaluated based on COSMO-RS computation.Androstenedione (AD) solubilities in methanol, ethanol, 2-propanol, and 1-butanol were measured from 277.65 K to 319.45 K with medium-throughput experiments. The results show that AD solubilities increase with increasing temperature and solvent polarity. The experimental data are well correlated by modified Apelblat, λhλh, Margules, Wilson, NRTL, and UNIQUAC models, and the NRTL model obtains the best fitting results. The thermodynamic functions (i.e., Gibbs free energy, enthalpy, and entropy of solution and mixture) are calculated using the van’t Hoff and NRTL equations. Molecular interaction energies between AD and alcohols are calculated by COSMO-RS to investigate the effects of temperature and solvent polarity on AD solubility, and predicted AD solubilities in different alcohols agree well with the experimental data. The results suggest that temperature influence on AD solubility is driven by cavity formation enthalpy, whereas hydrogen bonding and electrostatic interactions between AD and alcohol molecules play a key role in solvent polarity effect on AD solubility.σ-Profiles and COSMO-cavities of studied compounds. The blue color indicates a negative surface screening charge resulting from positive partial charges within the molecule. The red color indicates a positive surface charge and green symbolizes almost neutral charges.
Co-reporter:Tiantian Liu;Yuanyuan Ran;Bochao Wang
Frontiers of Chemical Science and Engineering 2014 Volume 8( Issue 1) pp:55-63
Publication Date(Web):2014 March
DOI:10.1007/s11705-013-1352-3
Powders of donepezil hydrochloride monohydrate (Form I) underwent isomorphic dehydration, losing 3% w/w water between 90% and 10% relative humidity (RH) without changing its powder X-ray pattern. Below 10% RH, additional dehydration occurred in conjunction with a reversible phase transition between the monohydrate state and a dehydrated state, with a 4.0% w/w loss to 0% RH. A combination of methods was used to understand the structural changes occurring during the desolvation process, including dynamic vapor sorption measurements, thermal analysis and powder X-ray diffraction. Form I showed the characteristics of the channel hydrate, whose non-isothermal dehydration behavior proceeds in two steps: (1) the loss of non-crystalline water adsorbed on the surface, and (2) the loss of one crystalline water in the channel. Dehydrated Form I is structurally similar to the monohydrate Form I. According to the heat of fusion and the crystal density criteria, the two crystal forms belonged to the univariant system, and the anhydrate (Form III) is stable. The dehydration kinetics was achieved from the TG-DTG curves by both the Achar method and the Coats-Redfern method with 15 frequently cited basic kinetic models. The dynamic dehydration processes for steps 1 and 2 were best expressed by the Zhuralev-Lesokin-Tempelman equation, suggesting a three-dimensional diffusion-controlled mechanism.
Co-reporter:Yanan Qin, Xuemei Wang, Songgu Wu, and Junbo Gong
Journal of Chemical & Engineering Data 2014 Volume 59(Issue 2) pp:376-381
Publication Date(Web):January 15, 2014
DOI:10.1021/je400838e
The solubility of 2-hydroxypropane-1,2,3-tricarboxylic acid monohydrate in (water + methanol), (water + ethanol) and (water + propan-2-ol) at temperatures ranging from (278.15 to 303.15) K were determined by a static method. It was found that the solubility of 2-hydroxypropane-1,2,3-tricarboxylic acid monohydrate increases with increasing temperature and decreases with increasing water fraction in (water + methanol), (water + ethanol) and (water + propan-2-ol). The Wilson model and NRTL model were used to correlate the experimental data and the NRTL model gave the best correlation results. The mixing Gibbs free energy was calculated based on the NRTL model. The negative values of mixing Gibbs free energy were obtained and indicated the variation trend of the solubility.
Co-reporter:Weiqiang Dun, Songgu Wu, Weiwei Tang, Xuemei Wang, Dengqiong Sun, Shichao Du, and Junbo Gong
Journal of Chemical & Engineering Data 2014 Volume 59(Issue 11) pp:3415-3421
Publication Date(Web):October 9, 2014
DOI:10.1021/je5004093
The solubility of ibuprofen sodium dihydrate (ISD) in acetone + water mixtures was measured by the gravimetric method at temperatures ranging from (279.55 to 312.05) K. The measured solubilities were correlated by the modified Apelblat equation, the λh (Buchowski) equation, the van’t Hoff model, the combined nearly ideal binary solvent/Redlich–Kister (CNIBS/R-K) equation, and the general single model. The modified Apelblat equation was the best model for correlating the solubility of ISD, while the general single model fits the best for mixed solvents. The standard enthalpy, entropy, and Gibbs energy of the dissociation process of ISD were calculated by the van’t Hoff equation and the modified Apelblat model. In addition, there was a maximum value of solubility at a certain acetone mole fraction in the acetone + water mixture.
Co-reporter:Dengqiong Sun, Riju Ren, Weiqiang Dun, Haihong Zhang, Lijun Zhao, Li Zhang, Wenqing Zhang, and Junbo Gong
Journal of Chemical & Engineering Data 2014 Volume 59(Issue 6) pp:1984-1990
Publication Date(Web):May 14, 2014
DOI:10.1021/je500078n
A gravimetric method was used to determine the solubility of l-carnitine in different pure solvents and ethanol–acetone solvent mixture. The solubility in different pure solvents were then correlated by the modified Apelblat equation, λh equation and the modified van’t Hoff equation, with the modified van’t Hoff equation presenting the best consistence. Meanwhile, to illustrate the effect of ethanol or acetone on the change of the solubility, a new parameter defined as influence coefficient was introduced and the coefficient of acetone depending on temperature and molar faction of acetone was depicted. In addition, the changes for enthalpy, entropy and Gibbs free energy were calculated by the modified van’t Hoff equation. It can be drawn that the changes for enthalpy and entropy in a solvent mixture decrease to a minimum before consequent increasing with increasing molar faction of acetone. Furthermore, the change for Gibbs free energy shows a linear relationship with natural logarithm of the solubility.
Co-reporter:Tianwei Zhang, Quan Liu, Zhiping Xie, Xiaopeng Song, and Junbo Gong
Journal of Chemical & Engineering Data 2014 Volume 59(Issue 6) pp:1915-1921
Publication Date(Web):May 22, 2014
DOI:10.1021/je5000605
Solvent screening plays a key role in the optimization of the drug crystallization process based on the solubility data and dissolution thermodynamic data. In this article, the solubility of cefixime trihydrate in ethanol, propan-2-ol, butan-1-ol, butan-2-ol, pentan-1-ol, ethyl acetate, and acetone from 278.15 to 323.15 K at atmospheric pressure is reported. It is found that the solubility of cefixime trihydrate in all seven solvents increases with temperature. The modified Apelblat equation fits well with the experimental solubility data in all selected solvents with the average percent deviation less than 3.5 %. The mixing properties including the mixing free Gibbs energy, enthalpy, and entropy of cefixime trihydrate were calculated based on the van’t Hoff equation. The results indicate that the dissolution process of cefixime trihydrate in all tested solvents is endothermic, entropically driven and not spontaneous.
Co-reporter:Xuemei Wang, Yanan Qin, Tianwei Zhang, Weiwei Tang, Boai Ma, and Junbo Gong
Journal of Chemical & Engineering Data 2014 Volume 59(Issue 3) pp:784-791
Publication Date(Web):February 11, 2014
DOI:10.1021/je400899e
The solubility of azithromycin monohydrate in ethanol, propan-2-ol, butan-1-ol, ethyl ethanoate, and 2-propanone from 278.15 K to 323.15 K was measured by a synthetic method. The measured solubility data were correlated by van’t Hoff equation, modified Apelblat equation, λh equation, Wilson, and NRTL models. It was found that the Wilson equations give the best correlation results. The mixing properties including the mixing free Gibbs energy, enthalpy, and entropy of azithromycin monohydrate were also calculated based on the Wilson model parameters. The results indicate that the dissolution process of azithromycin monohydrate in all tested solvents is spontaneous and endothermic.
Co-reporter:Yajuan Sun, Weibing Dong, Huiyuan Wang, Yongzhuo Huang, Huike Gu, Victor C. Yang and Junbo Gong
Polymer Chemistry 2013 vol. 4(Issue 8) pp:2489-2495
Publication Date(Web):05 Feb 2013
DOI:10.1039/C3PY21157F
Nanorods are capable of enhanced intracellular delivery and prolonged blood circulation over their spherical counterparts, and thus can be used as unmatched drug carriers for cancer chemotherapy. An innovative method was developed to synthesize size-tunable, PMAA@chitosan-based, hollow polymeric nanorods for intracellular delivery, by using mesoporous silica nanorod templates. The morphology of the polymeric hollow nanorods was examined by TEM and FT-IR spectra, which indicated a homogeneous three-dimensional structure. An uptake study using human lung carcinoma A-549 cell lines revealed highly efficient cell internalization of the FITC-labeled nanorods, suggesting the potential of utilizing these nanorods as carriers in achieving effective intracellular drug delivery. Cell viability studies of the docetaxel-loaded nanorods yielded consistent results, as the drug-loaded nanorods produced a significantly higher inhibition of the growth of A-549 tumor cells when compared with treatment by free docetaxel. Overall, this preliminary in vitro investigation sheds light on the use of prepared hollow polymeric nanorods for drug delivery applications.
Co-reporter:Yuanyuan Ran, Weibing Dong, Songgu Wu, Jingkang Wang, and Junbo Gong
Organic Process Research & Development 2013 Volume 17(Issue 11) pp:1445-1450
Publication Date(Web):October 22, 2013
DOI:10.1021/op400232v
An experimental study is undertaken to establish a transformation screen for the solid-state forms of clindamycin phosphate. The experimental study results in six novel crystalline forms: two solvates (with ethanol/water, methanol/water), one hydrate (Form III), and three polymorph forms. Further, all solid-state forms are characterized by various analytical techniques such as X-ray diffraction, differential scanning calorimetry, etc. Two polymorph forms (IV and VI) are selectively prepared by desolvation of the solvates (I and V). The solid-state desolvation results in the appearance of delamination of the 2D layers. Moreover, polymorph IV shows a clear polymorphic transition to a new polymorph form (polymorph II) above 165 °C. Phase transformations of the solid-state forms were also established by slurry conversions at 25 °C. These experiments suggest the reversible relationship between solvate I/V and hydrate Form III at different solvent mixtures. Through the aqueous dissolution test, it is also judged that polymorph II, IV, VI can transform to Form III in water at 25 °C. The conversion relationships among the six solid forms are illustrated.
Co-reporter:Wei Du, Qiuxiang Yin, Ying Bao, Chuang Xie, Baohong Hou, Hongxun Hao, Wei Chen, Jingkang Wang, and Junbo Gong
Industrial & Engineering Chemistry Research 2013 Volume 52(Issue 46) pp:16182-16189
Publication Date(Web):October 22, 2013
DOI:10.1021/ie4020815
Concomitant polymorphism of prasugrel hydrochloride was investigated in reactive batch crystallization experiments at 20 and 40 °C. The solubility of prasugrel hydrochloride form I and form II was experimentally determined. To understand the effects of reaction kinetics, supersaturation ratio, and nucleation kinetics on the behavior of concomitant polymorphism of prasugrel hydrochloride and the solvent-mediated transformation process, online techniques such as attenuated transform reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, Raman spectroscopy, and focused beam reflectance measurement (FBRM) were used to in situ monitor the reactive crystallization of prasugrel hydrochloride. It was found that prasugrel and hydrochloric acid react promptly and the designed supersaturation can be established almost instantly. The interfacial energies and thus relative nucleation rates of prasugrel hydrochloride form I and form II were calculated, and it was concluded that, at all investigated supersaturations, the nucleation rate of form II is always higher than the nucleation rate of form I. At lower supersaturation, thermodynamics dominated the crystallization process and form I was obtained, while at higher supersaturation, kinetics was critical in the crystallization process and form II was produced. At moderate supersaturation, both thermodynamics and kinetics played important roles and concomitant polymorphism of form I and form II was observed. Solvent-mediated transformation experiments were performed with and without seeding. It turns out that the transformation cannot happen without seeding of form I. Therefore, not reaction kinetics and polymorphic transformation but the concomitant nucleation should be the inherent reason for the observed concomitant polymorphism.
Co-reporter:Xuemei Wang, Songgu Wu, Weibing Dong, and Junbo Gong
Organic Process Research & Development 2013 Volume 17(Issue 9) pp:1110-1116
Publication Date(Web):August 27, 2013
DOI:10.1021/op400165c
In situ monitoring phase transformation process is of great importance to control the quality of crystalline products. In this paper, the transformation of N,N-dimethylformamide (DMF) solvate into monohydrate of cefadroxil was studied in DMF-water mixtures. The solvates were characterized by several offline methods such as Powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). Thermodynamic stability of DMF solvate and monohydrate of cefadroxil in DMF-water mixtures were investigated to analyze the relationship between solubility ratio and transformation kinetics at different temperatures, water content and stirring speeds. Results indicate that solubility ratio increases with temperature and water content, which leads to less transformation time. Transformation rate is governed by the growth of cefadroxil monohydrate and process parameters must be controlled based on in situ techniques to prepare high quality products. According to process analysis results by SEM, the mechanism of transformation was interpreted as the surface nucleation of monohydrate.
Co-reporter:Penglei Cui, Qiuxiang Yin, Junbo Gong, Yongli Wang, Hongxun Hao, Chuang Xie, Ying Bao, Meijing Zhang, Baohong Hou, Jingkang Wang
Fluid Phase Equilibria 2013 Volume 337() pp:354-362
Publication Date(Web):15 January 2013
DOI:10.1016/j.fluid.2012.09.027
The solubility of candesartan cilexetil (Form I) was measured by a gravimetric method in aqueous solvent mixtures (ethanol–water, acetonitrile–water and acetone–water), and the calculated values by (NIBS)/Redlich–Kister equation agreed well with the experimental data. The relationship between solubility of candesartan cilexetil (Form I) and molar fraction of organic solvents (ethanol, acetonitrile and acetone) shown unimodal curves, and this phenomenon can be explained by ΔHsol–ΔGsol compensation theory. For ethanol–water and acetonitrile–water mixture, the plot of ΔHsol–ΔGsol compensation was nonlinear with positive and negative slopes, indicating that the increases of solubility were controlled by two different mechanisms (entropy and enthalpy). However, for acetone–water mixture, the plot of ΔHsol–ΔGsol compensation was a linear curve, indicating that enthalpy is the dominant mechanism to control the solubility enhancement. These results can also be used to explain that acetone molecule played an important role in increasing the solute–solvent interactions of the candesartan cilexetil (Form I).Highlights► The solubility of candesartan cilexetil (Form I) was measured in three aqueous solvent mixtures. ► The experimental data were correlated with (NIBS)/Redlich–Kister equation. ► The thermodynamic functions of solution and mixing were obtained from these solubility data. ► The dominant mechanism for the solubility enhancement was determined by thermodynamic analysis.
Co-reporter:T. Liu;B. Wang;W. Dong;J. Gong
Chemical Engineering & Technology 2013 Volume 36( Issue 8) pp:1327-1334
Publication Date(Web):
DOI:10.1002/ceat.201300131
Abstract
The solubility of form I (hydrate) and form III (anhydrous form) of donepezil hydrochloride (DHCl) in methanol/isopropyl ether mixtures was determined at different temperatures by a synthetic method with laser monitoring observation. The experimental data were correlated with the modified Apelblat equation. Dissolution enthalpy and entropy were predicted by this equation. The mechanisms involved in solution-mediated transformation of a hydrate (form I) to its anhydrous form (form III) was investigated and characterized by in situ and offline measurement technologies, such as focused-beam reflectance measurement (FBRM), powder X-ray diffraction (PXRD), differential scanning calorimetry analysis (DSC), and moisture analyzer. The transformation involves nucleation of the metastable solid (form I), dissolution of the metastable solid, self-recognition of the molecular units to nucleate a more stable solid phase (form III), and growth of the stable phase. The results indicate that the rate of transformation increases with increasing temperature and driving force.
Co-reporter:L. Bian;H. Zhao;H. Hao;Q. Yin;S. Wu;J. Gong;W. Dong
Chemical Engineering & Technology 2013 Volume 36( Issue 8) pp:1292-1299
Publication Date(Web):
DOI:10.1002/ceat.201200720
Abstract
An efficient and reliable approach to discover new pharmaceutical cocrystals in the early development stage is proposed and used to develop cocrystals of piracetam with some aliphatic diacids. A 1:1 cocrystal of piracetam and glutaric acid was screened by a mechanochemical method and identified by powder X-ray diffraction and differential scanning calorimetry. Followed by solution crystallization, this cocrystal was reproduced. To better understand the mechanism of cocrystal formation in solution crystallization, process analytical technologies including focused beam reflectance measurement, attenuated total reflectance-Fourier transform infrared, and particle vision measurement were applied to investigate the cocrystallization process of piracetam with glutaric acid. The mechanism of cocrystal formation during solution-mediated phase transformation is discussed in detail.
Co-reporter:Songgu Wu;Fei Feng
Journal of Solution Chemistry 2013 Volume 42( Issue 4) pp:841-848
Publication Date(Web):2013 May
DOI:10.1007/s10953-013-9986-9
The solubilities of donepezil hydrochloride polymorphic form III in methanol, ethanol, 1-propanol and dimethyl formamide were measured at temperatures ranging from 278.15 to 333.15 K at atmosphere pressure using a gravimetrical method. The modified Apelblat model fitted the experimental data well with the root-mean-square deviations less than 6.287 × 10−4. The dissolution enthalpy and entropy of solute were predicted from the solubility data in different solvents using the van’t Hoff equation. The relationships among solubility, temperature, the intermolecular force and hydrogen bonding between solute and solvent, and the viscosity of solvents were investigated. The viscosity and surface tension of solvents affect the dissolution enthalpy and entropy of donepezil hydrochloride polymorphic form III.
Co-reporter:Runyan Li, Hao Yan, Zhao Wang, and Junbo Gong
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 23) pp:8141-8148
Publication Date(Web):May 22, 2012
DOI:10.1021/ie300945p
The solubilities of ginsenoside compound K in pure solvents and binary mixture solvents were determined at several temperatures from 278.15 K to 318.15 K by a static analytical method. The experimental solubility data in pure solvents were correlated by the van’t Hoff plot, the modified Apelblat equation, the λh (Buchowski) equation, the Wilson model, and the NRTL model, with the Wilson model giving the best correlation results. Based on the Wilson model and experimental data, the mixing Gibbs free energies, enthalpies, and entropies of solutions and activity coefficients in pure solvents were predicted, and other thermodynamic properties (infinite-dilution activity coefficients and excess enthalpies) were calculated as well. In addition, the solubility was maximal at a certain water mole fraction in acetone + water mixture and acetonitrile + water mixture, whereas in a methanol + water system, the solubility decreases as the water concentration increases monotonically. The solubilities in mixture solvents were correlated by the solvent components using the Wilson model. The partial molar Gibbs free energies with negative values were obtained, which indicates the changing of the solubility.
Co-reporter:Xinwei Zhang, Qiuxiang Yin, Penglei Cui, Zengkun Liu, and Junbo Gong
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 19) pp:6933-6938
Publication Date(Web):April 18, 2012
DOI:10.1021/ie202624d
In this paper, the polarity of binary solvents was studied by the sum law of cube roots of the dielectric constant. During the antisolvent crystallization process, the composition of the binary solvents and their dielectric constants changed simultaneously. These results demonstrated that variation of the solubility is dependent on the polarity of the binary solvents. On the basis of experiments, a new model was put forward to quantitatively describe the relationship between the solubility of hydrophilic pharmaceuticals and the dielectric constants of the binary solvents. Furthermore, this model was tested and verified by solubility data of other pharmaceuticals published in the literature with high accuracy.
Co-reporter:Penglei Cui, Qiuxiang Yin, Yuhong Guo, and Junbo Gong
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 39) pp:12910
Publication Date(Web):September 10, 2012
DOI:10.1021/ie2024855
In this paper, the acetone solvate of candesartan cilexetil was preferentially crystallized from the acetone solution by cooling crystallization and was characterized by combination methods of X-ray powder diffraction (XRPD), 13C nuclear magnetic resonance (NMR), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), Forier transform infrared (FTIR), Raman spectroscopy, and dynamic vapor sorption (DVS). The polymorphic transformation among two polymorphs (form I and form II) and acetone solvates of candesartan cilexetil was investigated, respectively. By regulating the initial solution concentration and composition of solvent mixture (water/acetone), form I or acetone solvate could be obtained. With the aid of in situ Raman spectroscopy, the kinetics of solvent-mediated transformation (form II → acetone solvate) and solid-state transition (acetone solvate → form II) were systematically studied at different temperatures. The results show that the mechanism of solid-state transformation of acetone solvate to form II depends on one-dimensional diffusion.
Co-reporter:J. Hou;S. Wu;R. Li;W. Dong;J. Gong
Crystal Research and Technology 2012 Volume 47( Issue 8) pp:888-895
Publication Date(Web):
DOI:10.1002/crat.201200152
Abstract
Maltitol is crystallized with seeds by cooling mode in industry, often with large amount of fine crystals and wide crystal size distribution. To eliminate the fine nucleation, it's necessary to understand the nucleation kinetics. In this work, the solubility of maltitol in water was measured by the gravimetric method, the nucleation kinetics of maltitol in batch cooling crystallization was investigated using focus beam reflectance measurement (FBRM), and a novel method was proposed to determine the induction time from the trend of the crystal median chord given by FBRM. Based on the relationship between the induction time and the supersaturation, the nucleation mechanism was obtained, including homogenous nucleation at high supersaturation and heterogenous nucleation at low supersaturation. Additionally, combining the classical nucleation theory (CNT) and Arrhenius’ principle, the crystal-solution interfacial energy and the energy barrier of homogenous nucleation were calculated. From the scanning electron microscope (SEM) images, the growth mechanism of maltitol was identified as surface nucleation growth and the surface entropy factor calculated from the kinetic analyses of tind data corroborated this growth mechanism.
Co-reporter:Runyan Li;Weibing Dong;Huining He;Hao Yan;Xiaobin Jiang
Crystal Research and Technology 2012 Volume 47( Issue 4) pp:377-384
Publication Date(Web):
DOI:10.1002/crat.201200016
Abstract
Two new solvates of ginsenoside compound K (nonstoichiometric hydrate/CKH and methanol solvate/CKM) have been discovered and characterized in this paper. They were obtained through cooling crystallization in different solvents, and CKM could be prepared by transformation from CKH as well. The solvates were analysed by Power X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and fourier transform infrared (FTIR) spectroscopy. From the thermal studies, it is shown that the two new products are both solvates with different onset melting points. The PXRD and FTIR data support different crystal structures of them. It also describes the solution-mediated phase transformation from CKH to CKM with a combination usage of process analytical technology tools. It is shown that the transformation process can be divided into three stages. The results reveal that seeding and low temperature help to accelerate the transformation, but initial solution concentration do little to the transformation kinetics. The kinetics and the rate-controlling step for the transformation depend on the nucleation of the CKM. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Co-reporter:Songgu Wu, Xiaobin Jiang, Weibing Dong, and Junbo Gong
Journal of Chemical & Engineering Data 2012 Volume 57(Issue 1) pp:204-207
Publication Date(Web):November 17, 2011
DOI:10.1021/je200950f
The phase diagram of flunixin meglumine + meglumine system has been investigated with the method of differential scanning calorimetry (DSC). The results show that the flunixin meglumine and meglumine hold the formation of a simple eutectic mixture. The linear velocity of solidification of both pure components and the eutectic mixture was determined at different undercooling rates. The fusion enthalpy and the linear velocity of crystallization indicate the nonideal properties of the eutectic mixture in the melt. The roughness parameter of the eutectic system was calculated from the enthalpy of fusion value. The anisotropic and isotropic crystallizations of flunixin meglumine, meglumine, and the eutectic mixture were studied.
Co-reporter:Hao Yan, Runyan Li, Qiang Li, Jingkang Wang, and Junbo Gong
Journal of Chemical & Engineering Data 2011 Volume 56(Issue 5) pp:2720-2722
Publication Date(Web):April 4, 2011
DOI:10.1021/je1012839
The solubility of minoxidil in pure methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and water was measured at temperatures ranging from (278.15 to 333.15) K by a gravimetrical method. The experimental data were well-correlated as a function of temperature using the Apelblat equation. At the same temperature, the mole fraction solubility decreases in the order: methanol > 1-propanol > 1-butanol > ethanol > 2-propanol > water.
Co-reporter:Liangcheng Song, Yuan Gao, and Junbo Gong
Journal of Chemical & Engineering Data 2011 Volume 56(Issue 5) pp:2553-2556
Publication Date(Web):March 4, 2011
DOI:10.1021/je200067e
The solubility equilibrium of clopidogrel hydrogen sulfate (Form I) was set up without the nucleation of Form II, as the nucleation rate of Form II is very slow under the low supersaturation. Using the laser monitoring technique, solubilities of clopidogrel hydrogen sulfate (Form I) in ethanol, 1-propanol, 1-butanol, 1-pentanol, and 2-propanol were measured at temperatures ranging from (273.15 to 318.15) K. The experimental data were correlated by the modified Apelblat equation, and the dissolution enthalpy and entropy of Form I were determined with van't Hoff plots. Compared with those of Form II, Form I exhibits a higher solubility and a lower enthalpy of dissolution. Therefore, we can draw the conclusion that Form I was the metastable form under the conditions in this work.
Co-reporter:Penglei Cui, Qiuxiang Yin, and Junbo Gong
Journal of Chemical & Engineering Data 2011 Volume 56(Issue 3) pp:658-660
Publication Date(Web):February 10, 2011
DOI:10.1021/je101020m
The solubility data of candesartan cilexetil of form I in ethanol, 1-propanol, 2-propanol, acetone 2-butanone, and acetonitrile at various temperatures were measured by gravimetrical method under atmospheric pressure, and the solubility data was fitted well with the Apelblat equation. The results show that the solubility of form I in the above solvents increased with an increase of temperature, and at the same temperature, the order of solubility is 2-butanone > acetone > 1-propanol > ethanol > 2-propanol > acetonitrile.
Co-reporter:Weibing Dong;Huining He
Frontiers of Chemical Science and Engineering 2010 Volume 4( Issue 1) pp:87-90
Publication Date(Web):2010 March
DOI:10.1007/s11705-009-0298-y
Amino-modified silica hydrogel (N-MSHG) was prepared by a simple sol-gel processing via the co-condensation of commercial silica sol with 3-aminopropyltrieoxysilane. Penicillin G acylase (PGA), a model enzyme, was covalently immobilized onto the N-MSHG and then was used for the enzymatic synthesis of amoxicillin. The samples were characterized by Nitrogen sorption analysis, FT-IR and thermal gravimetric analysis (TGA). The results showed that the amino-modified gel was a mesoporous material with an average pore size of 12.64±0.17 nm. The immobilization process was efficient and the immobilized enzyme showed high catalytic efficiency. The yield of the synthesis of amoxicillin in aqueous media was 38% for 2.5 h. This sol-gel preparation is simple and shows prominent potential value in industrial processing.
Co-reporter:Liangcheng Song, Minxu Li, and Junbo Gong
Journal of Chemical & Engineering Data 2010 Volume 55(Issue 9) pp:4016-4018
Publication Date(Web):April 28, 2010
DOI:10.1021/je100022w
As an urgent need in the design and upscale of the industrial crystallization process, solubilities of clopidogrel hydrogen sulfate (Form II) in ethanol, propanol, isopropanol, butanol, and acetone were measured using a laser-monitoring technique at temperatures ranging from (278.15 to 318.15) K. The experimental data were fitted well by the modified Apelblat equation.
Co-reporter:Wenli Liu, Xiaona Wang, Ruilian Chen, Kaixuan Zhang, Yao Li, Yi Li, Duanyun Si, Junbo Gong, Dianshu Yin, Yongli Wang, Zhenping Wei, Mingshi Yang
Acta Pharmaceutica Sinica B (September 2016) Volume 6(Issue 5) pp:468-474
Publication Date(Web):September 2016
DOI:10.1016/j.apsb.2016.07.010
Co-reporter:Dandan Han, Yumin Liu, Xiaona Li, Teng Zhang, Zhenfang Li, Shichao Du, Mingxia Guo, Shijie Xu, Bo Yu, Baohong Hou, Junbo Gong
The Journal of Chemical Thermodynamics (March 2017) Volume 106() pp:
Publication Date(Web):March 2017
DOI:10.1016/j.jct.2016.11.011
•The solubility of calcium d-pantothenate in water + methanol mixtures was measured by HPLC analysis method.•The effect of β-alanine on the solubility of calcium d-pantothenate in a constant mole ratio of methanol and water was also determined by HPLC analysis method.•The quaternary NRTL equation was first applied to correlating the quaternary solid-liquid equilibrium.The solubility of calcium d-pantothenate in (water + methanol) mixtures and the effect of β-alanine on the solubility of calcium d-pantothenate in a constant mole ratio of methanol and water was measured from 263.15 K to 303.15 K by the HPLC analysis method (P = 0.1 MPa). The solubility of calcium d-pantothenate increased with increasing temperature in all the mixtures at constant composition. Besides, it also increased with mole fraction of water in (water + methanol) mixtures at a constant temperature. Additionally, the solubility of calcium d-pantothenate was enhanced by β-alanine at a given temperature. The experimental solubility in (water + methanol) mixtures was correlated by the modified Apelblat equation, the ternary NRTL equation and Solubility-Polarity Model. The Apelblat equation, the quaternary NRTL equation and the Cohn equation were adopted to correlate the experimental solubility in the (water + methanol + β-alanine) mixtures. Worthwhile, the quaternary NRTL equation was first applied to correlating the quaternary solid-liquid equilibrium. It turned out that all the selected models give good performance on solubility prediction.
Co-reporter:Panpan Sun, Yumin Liu, Shichao Du, Bo Yu, Yaping Wang, Mengmeng Sun, Peng Shi, Ya Liu, Junbo Gong
Journal of Molecular Liquids (April 2017) Volume 232() pp:522-531
Publication Date(Web):April 2017
DOI:10.1016/j.molliq.2017.02.075
![2-BROMO-4-[(ETHOXYCARBONOTHIOYL)SULFANYL]BENZOIC ACID](http://img.cochemist.com/ccimg/78400/78306-52-2.png)
![2-BROMO-4-[(ETHOXYCARBONOTHIOYL)SULFANYL]BENZOIC ACID](http://img.cochemist.com/ccimg/78400/78306-52-2_b.png)
