Submit to FacebookSubmit to TwitterSubmit to LinkedIn

jascm-logo-pdf copy 1350290716

Preferential Solvation of Acetaminophen in Propylene Glycol + Water Co-Solvent Mixtures
Pages 65-73
María Ángeles Peña, Daniel Ricardo Delgado and Fleming Martínez


Published: 30 May 2014


Abstract: The preferential solvation parameters defined as the differences between the local mole fraction of solvents around analgesic drug acetaminophen and those for the bulk co-solvent composition in propylene glycol + water mixtures were derived from their thermodynamic properties by means of the inverse Kirkwood-Buff integrals (IKBI) and the quasi-lattice-quasi-chemical (QLQC) methods. It is found that acetaminophen is sensitive to solvation effects, so according to IKBI method the preferential solvation parameter δxPG,A, is negative in water-rich mixtures but positive in medium compositions and in co-solvent-rich mixtures. It is conjecturable that in water-rich mixtures the hydrophobic hydration around the aromatic ring and methyl group present in the drug plays a relevant role in the solvation. The bigger drug solvation by co-solvent in mixtures of similar solvent proportions and in propylene glycol-rich mixtures could be due mainly to polarity effects. Otherwise, according to QLQC method, this drug is preferentially solvated by the co-solvent in all the mixtures.

Keywords: Acetaminophen, propylene glycol, solubility, inverse Kirkwood-Buff integrals, preferential solvation.
Download Full Article
Submit to FacebookSubmit to TwitterSubmit to LinkedIn