Lecithin-based emulsions for potential use as saliva substitutes in patients with xerostomia – viscoelastic properties

摘要: The purpose of the present study was to investigate lecithin-rice bran oil rheological properties with view consider these as potential saliva substitutes in patients severe xerostomia and salivary hypofunction. Pseudo-ternary phase diagrams rice oil, lecithin water mixtures were constructed characterised using polarising light microscopy. Viscoelastic properties, which we hypothesise are important determinants product performance, analysed both flow oscillatory rheology. Rheological influenced by composition, frequency shear stress. Frequency-dependent viscoelasticity observed some formulations where viscosity dominated (tanδ>1) at frequencies under 5 Hz elasticity (tanδ<1) higher frequencies. Threshold determined for each formulation, a peak loss tangent observed, coinciding reduction storage modulus increase modulus. frequency-dependent behaviour emulsions interest because combinations exhibit viscous low frequencies, may improve lubrication oral cavity rest, whereas increased retention during higher-shear tasks such swallowing speaking.