Measurement solubility of Acetylsalicylic Acid in water and alcohols

Low aqueous solubility of drug is one of the problems in pharmaceutical industry and the enhancement of the solubility of these poorly soluble drugs has recently attracted the consideration of researchers. In this way, one of the essential methods to overcome this challenge is to use co-solvents. In this study, a set of experiments was conducted to measure the solubility and density of Acetylsalicylic Acid as a painkiller drug in water, 1-octanol, ethanol, methanol, and ethylene glycol as solvents in the temperature range of 298 to 330 K. Furthermore, the experiments are carried out at 298K in the binary mixture of solvents to investigate the interaction effect of another solvent or anti-solvent in different percentages of mixtures. The results of this investigation revealed that using binary solution of water and ethanol, as a solvent aid, was able to increase the solubility especially in high percentage of ethanol. Moreover, to indicate the applicability of simple empirical model, the experimental data was used to optimize two adjustable parameters of the selected model. In future research, a successful thermodynamic models will be offered based on gathered data for prediction of solubility in the different temperature with high accuracy.&nbsp

Extension of 2C Association Scheme to Polyols Phase Equilibria

The application of the 2C association scheme proposed by De Villiers et al. (<i>Ind. Eng. Chem. Res</i>. <b>2011</b> <i>50</i>, 8711–8725) in the association term of cubic plus association equation of state (CPA EoS) is extended to polyol containing systems to correlate the binary and predict the ternary mixtures. First, the CPA parameters of pure components were successfully adjusted by vapor pressure and saturated liquid density experimental data. Then, the performance of the aforementioned scheme is compared to the other classical schemes by modeling the vapor–liquid equilibria (VLE) and liquid–liquid equilibria (LLE) of binary {polyol/small alcohol}, {polyol/water}, {fatty acid ester/small alcohol}, and {polyol/alkane} and ternary {small alcohol/poyol/fatty acid ester} and {small alcohol/water/poyol} mixtures. Applying a simple and robust phase equilibria algorithm proposed by Privat et al. (<i>Comput.Chem. Eng.</i> <b>2013</b>, <i>50</i>, 139–151) to binary and ternary systems, the VLE and LLE correlative performance of CPA EoS coupled with various combined schemes are very satisfactory over extensive temperature ranges and shows that each model is within or close to experimental uncertainty. Then, using two temperature-independent binary interaction parameters (BIPs) fitted with binary VLE and LLE data, the predictive performance of different models is further evaluated in ternary systems phase equilibria (LLE and VLE), and acceptable results are achieved at different temperatures. Eventually, it has been demonstrated that 2C scheme exhibits remarkable precision in predicting the VLE and LLE of polyol containing systems