Solubility Determination and Modeling for Milrinone in Binary Solvent Mixtures of Ethanol, Isopropanol, Ethylene Glycol, and N,N-Dimethylformamide plus Water

The equilibrium solubility of milrinone in the solvent mixtures of ethanol + water, isopropanol + water, N,N-dimethylformamide (DMF) + water, and ethylene glycol (EG) + water was determined experimentally using the isothermal dissolution equilibrium method within the temperature range from 278.15 to 323.15 K under atmospheric pressure (101.1 kPa). Results show that when the temperature approaches a high level, more drugs can be dissolved in the same amount of solvent. Conversely, when the temperature is close to a low level, the drug is more difficult to dissolve. When the temperature is constant, the proportion of organic solvent is large and the dissolving capacity of the dispersion system develops in a positive direction. Conversely, if the proportion of water is large, the dissolving power of the system will decrease. Milrinone crystals accepted the determination of various dissolution data including undissolved raw materials have undergone X-ray power diffraction (XP RD) detection. The results obtained are encouraging, showing no change in the crystal structure of the substance. Three models, Jouyban-Acree model, van't Hoff-Jouyban-Acree model, and modified Apelblat-Jouyban-Acree model, were employed to calculate the experimental milrinone solubility, and the relative average deviation (RAD) and the root-mean-square deviation (RMSD) were no higher than 1.44% and 8.0 X 10(-7), respectively. The research on milrinone gives not only is a simple measurement of the dissolution data but, more importantly, with the support of this data more thermodynamic data can be calculated to obtain milrinone, which is an indispensable link between improving the production process of milrinone and the synthesis of pharmaceutical preparations.