Solubility Behavior and Thermodynamic Modeling of Inosine (Form β) in Four Cosolvency Systems at T = 278.15 to 323.15 K

Abstract

The N,N-dimethylformamide (DMF) as the main solvent with strong dissolving power was blended with four secondary solvents (ethanol, n-propanol, isopropanol, propylene glycol (PG)) with relatively weak dissolving power to form many new solvents. The dispersion index (Inosine (form β) mole fraction) in five organic solvents such as DMF and in the newly formed solvent was also obtained one by one with static method commonly used in solid-liquid equilibrium. The temperature environment is that the high temperature was set at 323.15 K, and the low temperature was set at 278.15 K and the interval between each temperature was 5 K. The pressure environment was the atmospheric pressure in the natural state and the usual value was 101.0 kPa. In a mixed system, temperature was a non-negligible influencing factor from beginning to end and its increase often leaded the solute to the trend of high solubility. In addition, the proportion of the main solvent also dominated the solubilization trend of the inosine (form β), the larger the proportion of DMF, the easier the dissolution process was. When both of the above factors were fixed at a certain point, the dispersing ability of the dispersing liquid composed of DMF and ethanol was undoubtedly the first. Three models (the Jouyban-Acree model, van't Hoff-Jouyban-Acree model and Modified Apelblat-Jouyban-Acree model) were used to correlate the solubility data. The largest RAD and RMSD were 4.66×10 -2 and 7.27×10 -4 . The dispersion data of inosine (form β) obtained through this experimental process and related thermodynamic parameters obtained through thermodynamic calculations have important application significance for its industrial production and further purification. ■ INTRODUCTIONFrom the history of the development of chemicals, there are many methods for the purification of drugs, such as membrane separation, supercritical fluid technology and so on, but the dissolution crystallization technology is undoubtedly the most efficient and cheapest one and the most widely used one. [1][2][3][4][5] Especially for poorly water-soluble chemicals, how to increase the solubility is a

Explanation for the selective crystallization from inosine solutions using mid-frequency Raman difference spectra analysis

“…Intramolecular rotations, especially in the part of ribofuranosyl, 10 could induce rich conformations of IR molecule, which are beneficial for the formation of various solid phases of IR. There are three common polymorphs of IR, α-anhydrous IR (α-IR, the commercial raw IR), 11 β-anhydrous IR (β-IR, the most stable polymorph), 11–13 and IR dihydrate (IRD). 14 The rich crystallization behavior makes IR a good model molecule to study the relationship between the selectivity of solution crystallization process and the degree of similarity of the short-range orders between organic molecular assemblies in solutions and the corresponding solution crystallization products.…”

Solubility Measurement and Correlation for Amrinone in Four Binary Solvent Systems at 278.15–323.15 K

“…The concrete instrument of solubility determination is shown in Figure S2 of the Supporting Information. The reliability of apparatus was verified before experiment by determining the benzoic acid solubility in toluene. , …”

“…Controlling the variable of temperature and measuring the solubility of substances under saturation have been widely recognized and used. − This is a commonly used method in thermodynamic experiments, and this method is still used in this study. Here is a brief description of the determination process of the content of amrinone.…”

“…The reliability of apparatus was verified before experiment by determining the benzoic acid solubility in toluene. 17,18 Preparation of Solvent Mixtures. Take a measuring cup or other suitable container, add organic solvent first, then add water, and the total quality is controlled at about 60 mL.…”