Solubility of pharmaceutical compounds in ionic liquids

• Author(s): Santos, Ana Duarte dos ; Morais, Ana Rita ; Melo, Catarina I. ; Bogel-Lukasik, R. ; Bogel-Lukasik, Ewa
• Date: 2013
• Persistent ID: http://hdl.handle.net/10400.9/2327
• Origin: Repositório do LNEG
• Subject(s): Solubility; Solid–liquid equilibria; Ionic Liquids; Thermochemical properties; Partition coefficient
• Document Type: Article
• Language: English

Description

The solubility of N-acetyl-l-cysteine, coumarin and 4-hydroxycoumarin in alternative solvents was studied in this work. The solid–liquid equilibrium (SLE) measurements have been performed using a dynamic(synthetic) method. Melting points and enthalpies of fusion of the pharmaceutical compounds were acquired using a differential scanning calorimetry (DSC). The solubility of N-acetyl-l-cysteine and 4-hydroxycoumarin in trifluoromethanesulfonate ionic liquids was found to be significantly higher thanin the studied bis(trifluoromethylsulfonyl)amide ionic liquids while coumarin exhibited the oppositebehaviour.The solid–liquid phase equilibria were described using the six different correlation equations whichrevealed a good description with an acceptable standard deviation temperature range.Moreover, the solubility data were used to calculate the 1-octanol/water partition coefficients of thestudied drugs. Coumarin has a high partition coefficient, which is considered to be favourable for a rapidabsorption of compounds once they are in an aqueous solution. N-acetyl-l-cysteine showed oppositeresults for the system with 1-octanol/water.