Solubility and solid phase studies of isomeric phenolic acids in pure solvents

authors	Vilas-Boas, SM; Brandao, P; Martins, MAR; Silva, LP; Schreiner, TB; Fernandes, L; Ferreira, O; Pinho, SP
nationality	International
journal	JOURNAL OF MOLECULAR LIQUIDS
author keywords	Solubility; Phenolic acids; NRTL-SAC; Melting; X-ray diffraction
keywords	ACTIVITY-COEFFICIENT MODEL; DRUG MOLECULE SOLUBILITY; MEDIUM-SIZED CHEMICALS; GALLIC ACID; PLUS WATER; PROTOCATECHUIC ACID; AQUEOUS SOLUBILITY; SYSTEM SELECTION; SALICYLIC-ACID; VANILLIC ACID
abstract	The solubilities of gallic, protocatechuic, gentisic or alpha-resorcylic acids were measured in nine pure solvents (water, methanol, ethanol, 1-propanol, 2-propanol, 2-butanone, ethyl acetate, acetonitrile and dimethylformamide) at 298.15 K and 313.15 K, using the analytical isothermal shake-flask method. Additionally, solid phase studies of the selected phenolic acids were carried out using differential scanning calorimetry (DSC) and X-ray diffraction (XRD), giving access to important data on melting properties as well as on the structure of the solid phase before and after the dissolution. The NRTL-SAC model coupled to the reference solvent approach (RSA) were applied to correlate the solubility data in a set of seven solvents and, after used to predict the solubility in 1-propanol and dimethylformamide. Average relative deviations (ARD) between 28 and 40% for the correlation and between 16 and 59% for the predictions were obtained. These values are within the order of magnitude usually found for such type of semipredictive models, using a limited set of data. (C) 2018 Elsevier B.V. All rights reserved.
publisher	ELSEVIER SCIENCE BV
issn	0167-7322
year published	2018
volume	272
beginning page	1048
ending page	1057
digital object identifier (doi)	10.1016/j.molliq.2018.10.108
web of science category	Chemistry, Physical; Physics, Atomic, Molecular & Chemical
subject category	Chemistry; Physics
unique article identifier	WOS:000451494700116