title: On the structure of an aqueous propylene glycol solution.
abstract: Using a combination of neutron diffraction and empirical potential structure refinement computational modelling, the interactions in a 30 mol. % aqueous solution of propylene glycol (PG), which govern both the hydration and association of this molecule in solution, have been assessed. From this work it appears that PG is readily hydrated, where the most prevalent hydration interactions were found to be through both the PG hydroxyl groups but also alkyl groups typically considered hydrophobic. Hydration interactions of PG dominate the solution over PG self-self interactions and there is no evidence of more extensive association. This hydration behavior for PG in solutions suggests that the preference of PG to be hydrated rather than to be self-associated may translate into a preference for PG to bind to lipids rather than itself, providing a potential explanation for how PG is able to enhance the apparent solubility of drug molecules in vivo.
authors.affiliation: Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom.
authors.forename: Natasha H
authors.initials: NH
authors.lastname: Rhys
authors.affiliation: Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Gillams
authors.affiliation: King's College London, Institute of Pharmaceutical Science, London SE1 9NH, United Kingdom.
authors.forename: Louise E
authors.initials: LE
authors.lastname: Collins
authors.affiliation: STFC, ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QU United Kingdom.
authors.forename: Samantha K
authors.initials: SK
authors.lastname: Callear
authors.affiliation: King's College London, Institute of Pharmaceutical Science, London SE1 9NH, United Kingdom.
authors.forename: M Jayne
authors.initials: MJ
authors.lastname: Lawrence
authors.affiliation: Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom.
authors.forename: Sylvia E
authors.initials: SE
authors.lastname: McLain
mesh_terms: D003198:Computer Simulation; D057927:Hydrophobic and Hydrophilic Interactions; D008956:Models, Chemical; D015394:Molecular Structure; D033363:Neutron Diffraction; D019946:Propylene Glycol / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D012996:Solutions; D014867:Water; D019946:Propylene Glycol