Solubility data of many pharmaceutical compounds are important for
research topics and commercial applications, and efforts are extented to
obtain a number of mathematical fitting models for solubility prediction.
Gallic acid is used as inhibitor of human cell fiberization and propyl
gallate is used as antioxidant in food processes. In this investigation, the
solubilities of gallic acid and propyl gallate in ethanol (EtOH), propylene
glycol (PG), and N-methyl-2-pyrrolidone (NMP) and their binary
mixtures of EtOH+PG, NMP+EtOH, and NMP+PG were measured by a
spectrophotometer at the temperatures of 303.15, 308.15, 313.15, 318.15,
323.15 K and atmopheric pressure condition. The results show that the
solubility of both solids increases with increasing temperature in all pure
and binary solvents. The generated data in mono-solvents at different
temperatures were fitted to van't Hoff plot, the overall mean deviations
gallic acid and propyl gallate in pure solvents were 1.77% and 1.94%,
respectively. And the data in solvent mixtures were fitted to the
Jouyban–Acree model, the overall mean deviations for gallic acid and
propyl gallate in mixed solvents were 3.28% and 2.16%, respectively.
