The mole fraction solubility data of l-proline in five monosolvents (water, methanol, ethanol, acetone, and acetonitrile) and four binary solvent systems (methanol + acetone, ethanol + acetone, methanol + acetonitrile, and ethanol + acetonitrile) were experimentally measured by gravimetric method at temperatures ranging from 283.15 to 323.15 K. The results showed that l-proline solubility and experimental temperature were positively correlated when the solvent composition was constant. On the basis of the solubility scatter diagrams and our investigation of solvent properties, the solubility behavior of l-proline in the pure and binary solvent systems was influenced by a combination of many factors. The solubility data were correlated by the modified Apelblat model, CNIBS/R-K model, and Apelblat-Jouyban-Acree model. The fitting results were generally acceptable.

The solubility of moroxydine hydrochloride was determined by the gravimetrical method (temperature from 283.15 to 323.15 K, pressure at 101.325 kPa) in 12 pure solvents (water, methanol, ethanol, 1-propanol, 1-butanol, 2-methyl-1propanol, 2-propanol, 1-pentanol, 2-butanol, acetonitrile, ethyl acetate, and acetone) and a binary system (water + 2-propanol). The results of this experiment suggested that the solubility data of moroxydine hydrochloride increased with increasing mole fraction of water and experimental temperature in all investigated neat and mixed solvent systems. The moroxydine hydrochloride solubility order in the 12 neat solvents was shown as water > methanol > ethanol > 1-propanol > 1-butanol > 2-methyl-1propanol > 2-propanol > 1-pentanol > 2-butanol > acetonitrile ≈ ethyl acetate ≈ acetone. For polar protic solvents except for 1-pentanol, the main factor influencing the solubility behavior was the polarity. While it was affected by complicating factors in polar aprotic solvents. The fitting results of the moroxydine hydrochloride solubility data obtained by the modified Apelblat, Jouyban−Acree, and Apelblat−Jouyban−Acree models were all satisfactory.

Monosodium fumarate solubility in 12 monosolvents (water, methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 2-propanol, 2-methyl-1-propanol, ethyl acetate, 1,4-dioxane, acetonitrile, and acetone) and four binary solvents (water + methanol, water + ethanol, water + 2-propanol, and water + acetone) was determined by the gravimetric method from 283.15 to 323.15 K. The solubility order in pure solvents was water > methanol > ethyl acetate > 1,4-dioxane > ethanol > 1-propanol > 1-butanol > acetonitrile > 1-pentanol > 2-propanol > acetone > 2-methyl-1-propanol. Also, it was positively related to experimental temperature and solvent composition for all solvent systems. According to the solubility results, the dissolution behavior of monosodium fumarate in pure solvents was mainly affected by the solvent properties including polarity, hydrogen bond acidity (α), hydrogen bond basicity (β), bipolar/polarizability (π*) and Hildebrand solubility parameter (δH). The modified Apelblat, Jouyban–Acree, and Apelblat–Jouyban–Acree models were used to correlate the solubility data, and the values calculated by the three thermodynamic models were found to agree well with the experimental data.

Experimental solubility data of D-ribose in four binary (2-propanol + 1-hexane, ethanol + 1-hexane, methanol + dichloromethane, and ethanol + dichloromethane) and twelve pure (1-hexane, dichloromethane, ethyl acetate, acetonitrile, acetone, 2-methyl-1-propanol, 1-butanol, 2-propanol, 2-butanol, 1-propanol, ethanol, and methanol) solvent systems were measured at different temperatures under the atmospheric pressure by using the gravimetric method. The experimental results showed that the solubility of D-ribose increased with the increase of temperature and the content of positive solvent, and decreased with the increase of antisolvent composition. The dissolution behavior of D-ribose in pure solvents was mainly affected by the solvent types and solvent properties, and the solvent effect on D-ribose solubility was further examined by the KAT-LSER model. The solubility data were correlated by the modified Apelblat, Jouyban−Acree, and Apelblat−Jouyban−Acree models. The calculated values of the three thermodynamic models were in good agreement with the experimental data.

l-Cysteine solubility in 12 monosolvents (water, methanol, ethanol, n-propanol, n-butanol, sec-butanol, isopropanol, isobutanol, ethyl acetate, 1,4-dioxane, acetonitrile, and acetone) and three binary solvents (water + methanol, water + ethanol, and water + isopropanol) was determined by the gravimetric method from 283.15 to 323.15 K under the atmospheric pressure. The solubility order in pure solvents was acetonitrile < isobutanol < ethyl acetate ≈ sec-butanol < n-butanol < 1,4-dioxane < isopropanol < n-propanol < ethanol < methanol < acetone < water, and it was positively related to the experimental temperature and solvent composition for all solvent systems. For polar protic solvents, the key factors influencing the solubility were the length of the carbon chain and the solvent properties. The effect of solvent–solvent and solvent–solute intermolecular interactions on the solubility behavior was analyzed by the KAT-LSER model. The modified Apelblat, Jouyban–Acree, and Apelblat–Jouyban–Acree models were used to correlate the solubility data, and the values calculated by the three thermodynamic models were found to agree well with the experimental data.