title: The effect of the nature of H-bonding groups on diffusion through PDMS membranes saturated with octanol and toluene.
abstract: The permeation of a series of structurally related compounds across silicone membranes (PDMS) was studied. The PDMS was saturated either with toluene, to mimic a functionally inert barrier, or octanol, to mimic the polar/hydrogen bonding environment of the stratum corneum lipid barrier. Phenol, salicylic acid, benzoic acid, anisole, phenylethanol and benzyl alcohol were chosen in an attempt to relate permeation to their different H-bonding capabilities. The flux was lower through the octanol system suggesting retardation by polar/H-bonding interactions. Separation of the permeability coefficient into its thermodynamic (partition coefficient) and kinetic (diffusion coefficient) terms suggests that the effect of altering polarity within the membrane has a greater impact on the diffusion of permeant rather than its chemical potential within the membrane.
authors.affiliation: Pharmaceutics, School of Pharmacy, Potchefstroom University for CHE, Potchefstroom, South Africa. fmsjdp@puknet.puk.ac.za
authors.forename: Jeanetta
authors.initials: J
authors.lastname: Du Plessis
authors.forename: W John
authors.initials: WJ
authors.lastname: Pugh
authors.forename: Anja
authors.initials: A
authors.lastname: Judefeind
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hadgraft
mesh_terms: D004058:Diffusion; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D006860:Hydrogen Bonding; D008567:Membranes, Artificial; D009757:Nylons / Q000737:chemistry*; D000442:Octanols / Q000737:chemistry* / Q000493:pharmacokinetics; D010539:Permeability; D012995:Solubility; D012997:Solvents; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014050:Toluene / Q000737:chemistry* / Q000493:pharmacokinetics
chemical_list: D004129:Dimethylpolysiloxanes; D008567:Membranes, Artificial; D009757:Nylons; D000442:Octanols; D012997:Solvents; C085707:poly(dimethylsiloxane)-polyamide copolymer; D014050:Toluene