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Hydrates are common in pharmaceutical development, and the formation of hydrates affects the performance of the final product. However, the role that water plays in crystal packing remains unclear....

Effectively manipulating crystal nucleation and growth is an essential issue for controlling the crystal morphology. In this work, the effect of additives on promoting crystal nucleation and growth...

To investigate the effect of positional isomerism on cocrystallization and reveal the role of weak interactions in the formation of cocrystals, experimental characterization complemented with theoretical computations was thoroughly conducted by using p-hydroxybenzoic acid (PHBA), o-hydroxybenzoic acid (OHBA), m-hydroxybenzoic acid (MHBA) and malonic acid (MA) as model compounds. Selective formation of a new cocrystal was discovered between PHBA and MA molecules via several methods, while no cocrystal was formed between OHBA/MHBA and MA molecules. The PHBA–MA cocrystal was thoroughly characterized and analyzed through several solid characterization techniques such as powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) analysis, Fourier transform infrared (FTIR) spectroscopy, single crystal X-ray diffraction (SCXRD), etc. Taking advantage of a myriad of computational modelling techniques, the molecular recognition mechanism which drove the formation of cocrystals was comprehensively investigated and understood at a molecular level. The structural change accompanied by the cocrystal formation could be rationalized by FTIR spectroscopy and electron density variation analysis. Hirshfeld surface (HS) analysis indicated that O–H⋯O hydrogen bonds played a critical role in the formation of this cocrystal. Molecular electrostatic potential (MESP) surface analysis was employed to predict the interaction sites for cocrystallization, which were in good accordance with the experimental results. Moreover, possible reasons for the selective cocrystallization were analyzed and proposed.

In this work, to help the development and design of separation and purification processes for tris-(2,4-ditert-butylphenyl)-phosphite which is an antioxidant of plastic processing, its solution thermodynamics was investigated. Using a static gravimetric method, solubilities of tris-(2,4-ditert-butylphenyl)-phosphite in twelve pure solvents (including acetone, ethyl acetate, methyl acetate, ethyl formate, isopropyl acetate, butyl acetate, n-hexane, n-heptane, n-octane, isooctane, propyl acetate and ethyl butyrate) were measured at temperatures varying from 278.15 K to 323.15 K. It was found that, in all investigated solvents, the solubility data of tris-(2,4-ditert-butylphenyl)-phosphite increased with the increasing of temperature over the entire investigated temperature range. The modified Apelblat equation, the λh equation and the NRTL model were employed to correlate the solubility data. The computed data showed that the modified Apelblat equation correlated the solubility data better. Moreover, the mixing and dissolution thermodynamic properties of tris-(2,4-ditert-butylphenyl)-phosphite in various pure solvents were also calculated according to the NRTL model and the experimental solubility data.

Ultrasound-mediated method, which can effectively disperse agglomerates or even eliminate agglomeration, has received more and more attentions in industrial crystallization. However, the ultrasound-mediated de-agglomeration mechanism has not been well understood, and no general conclusions have been drawn. In this study, the crystallization and de-agglomeration process of ceftezole sodium agglomerates under ultrasound irradiation were systematically investigated. Kapur function was selected to investigate the de-agglomeration process under different ultrasonic powers. The results revealed that ultrasound could efficiently inhibit agglomeration. Besides, the de-agglomeration of large sized agglomerate particles was found to be easier to occur in comparison with small sized particles due to its higher specific breakage rate. Finally, the de-agglomeration mechanism under ultrasonic irradiation was proposed on the basis of the calculated cumulative breakage functions.

As persistent and detrimental contaminants, azo dyes are difficult to be removed from wastewater. It is a worldwide challenge to develop efficient technologies for their removal. Adsorption is widely recognized to be a practical, efficient, and low-cost technology for removal of contaminants. Compared with various conventional adsorbents, MoS2 nanocrystals possess larger specific surface area, higher surface energy, and better adsorptive properties. Since nitrogen-doping is a common approach for modification of materials, N-doped MoS2 nanocrystals (NDMN) were first used as adsorbents for removal of the azo dye methyl orange. Compared with bulk MoS2 and MoS2 nanocrystals, NDMN showed much higher efficiency and reusability. This study provides inspiration for exploring and expanding the applications of NDMN.

Background: In the pharmaceutical field, it is vital to ensure a consistent product containing a single solid-state form of the active pharmaceutical ingredient (API) in the drug product. However, some APIs are suffering from the risk of transformation of their target forms during processing, formulation and storage. Methods: The purpose of this review is to summarize the relevant category of excipients and demonstrate the availability and importance of using excipients as a key strategy to manipulate pharmaceutical polymorphic transformation. Results: The excipient effects on solvent-mediated phase transformations, solid-state transitions and amorphous crystallization are significant. Common pharmaceutical excipients including amino acids and derivatives, surfactants, and various polymers and their different manipulation effects were summarized and discussed. Conclusion: Appropriate use of excipients plays a role in manipulating polymorphic transformation process of corresponding APIs, with a promising application of guaranteeing the stability and effectiveness of drug dosage forms.

In this work, solubility data of ceftezole in seven pure solvents and two binary solvent systems were experimentally measured via a static gravimetric method in the temperature range from 278.15 K to 313.15 K under atmospheric pressure. The results indicated that the solubility of ceftezole in all the selected pure and binary solvent systems increased with the rising of temperature. It was also found that the solubility order of ceftezole in the seven mono-solvents was generally ranked as: water

The solubility data of cefradine in different solvent systems as a function of pH were determined by dynamic method. The effect of pH and solvent compositions on the solubility data and the isoelectric points were evaluated and discussed. It was found that the solubility data of cefradine are consistent with the dissolution property of ampholyte, whether in mono-solvent or binary mixed solvent, which has a large solubility at large pH and small pH values and the solubility curves exhibit U shapes. The isoelectric points of cefradine in different solvent systems were also determined and discussed. Two theoretical models were used to correlate the experimental solubility data. It was found that model I can give better correlation results.

Recyclable nanomaterials are in great need to develop clean technology for applications in the removal of water contaminants. In this work, easily separable montmorillonite/Fe3O4/humic acid (MFH) nanocomposites were fabricated through a facile hydrothermal route. It was found the adsorption ability and stability of MFH was significantly enhanced due to the synergistic effects between montmorillonite, Fe3O4 nanoparticles and humic acid. The MFH nanocomposites are highly efficient and recyclable as they can remove at least 82.3% of Cr(VI) and 95.1% of aniline in six consecutive runs. The adsorption mechanism was investigated by analyzing the kinetic parameters of pseudo first-order, pseudo second-order, and intraparticle diffusion models and describing the equilibrium isotherms of Langmuir and Freundlich models. Results indicated different adsorption mechanisms of Cr(VI) and aniline by MFH. The readily synthesized MFH nanocomposites can act as effective and practical materials for environmental applications.

In this work, solution thermodynamic properties including solubility, mixing thermodynamic properties and dissolution thermodynamic properties are investigated in detail. Gravimetric method was utilized for measuring the solubility data of flurbiprofen in twelve pure solvents including n-propanol, isopropanol, n-butanol, isobutanol, isopentanol, isopropyl acetate, methyl tert-butyl ether, isopropyl ether, acetonitrile, n-octane, n-heptane and n-hexane over the temperatures range from 283.15 to 323.15 K under atmospheric pressure. The results indicated that the solubility of flurbiprofen increased with the increasing temperature. Furthermore, the experimental solubility data were correlated by the modified Apelblat equation, λh equation, Wilson model and NRTL model. And the modified Apelblat equation can give better correlation results with lower values of ARD%. Moreover, mixing and dissolution thermodynamic properties of flurbiprofen in different solvents were calculated according to the experimental data and the NRTL model.