Journal of Chemical and Engineering Data, Vol.65, No.11, 5524-5531, 2020
Study on the Determination and Correlation of Rimsulfuron Solubility in Four Aqueous Cosolvent Mixtures of Methanol, Ethanol, Ethylene Glycol, and N,N-Dimethylformamide
Water as an auxiliary solvent is added to various alcohol solvents (methanol, ethanol, ethylene glycol (EG)) and N,N-dimethylformamide (DMF) to form a variety of liquid mixtures, which are divided into different types according to different proportions. Starting from pure water, 0.1 mass fraction of organic solvents is added at a time, until the ratio of organic solvent is 1. The above- mentioned liquid mixtures are used as solvents to dissolve rimsulfuron at 278.15- 323.15 K under 101.1 kPa by means of the isothermal static technique. Considering that there are many factors that change the experimental results, this experiment mainly selected temperature and water content, two factors, as the main independent variables. From the point of view of temperature, it changes from a low value to a high value, so it is obvious that the solute mole fraction also follows its footsteps. Unlike the temperature, as the organic solvent is continuously diluted by water, the solute solubility changes in the opposite direction to the water content. By controlling the variable method to ensure that the above two variables remain unchanged, DMF has the best dispersion ability for all of the selected solvents to dissolve rimsulfuron. The dissolution strength of the selected solvents at 323.15 K obeyed the following ascending sequence: EG (3.192 x 10(-5) ) < ethanol (8.497 X 10(-5)) < methanol (9.849 x 10(-5)) < DMF (2.622 X 10(-4)). We employed Jouyban-Acree, van't Hoff-Jouyban-Acree, and a combination of the Apelblat-Jouyban-Acree model to calculate solubility values of rimsulfuron. Results of relative average deviation (RAD) and root-mean-square deviation (RMSD) from the van't Hoff-Jouyban-Acree model were 2.11% and 1.50 x 10(-6), respectively. For drugs with poor water solubility and dissolution rate, measuring their solubility and understanding their dissolution properties can effectively help solve the problem of nonwetting and nondiffusion.