Ternary mutual diffusion coefficients (D-11, D-22, D-12 and D-21) measured by the Taylor dispersion method are reported for aqueous solutions of levodopa (L-dopa) (1) in the presence of 2-Hydroxypropyl-beta-cyclodextrin (HP-beta-CD) (2) at 25 degrees C and 37 degrees C and concentrations up to 0.005 mol . dm(-3). The effects of HP-beta-CD (HP-beta-CD) on the transport of L-dopa are assessed by comparing the binary diffusion coefficient of aqueous L-dopa solutions with the main diffusion coefficient (D-11) measured for ternary {L-dopa (1) + HP-beta-CD (2)} solutions. H-1 NMR spectroscopy suggests no significant complexation between HP-beta-CD and L-dopa. However, coupled diffusion of L-dopa and HP-beta-CD occurs, as indicated by non-zero values of the cross-diffusion coefficients, D-12 and D-21. HP-beta-CD concentration gradients produce significant co-current coupled flows of L-dopa. (C) 2016 Elsevier Ltd. All rights reserved.