Taylor dispersion technique as a tool for measuring multicomponent diffusion in drug delivery systems at physiological temperature

Abstract The Taylor dispersion technique was used to measure quaternary diffusion coefficients, 123 D 11 , 123 D 22 , 123 D 33 , 123 D 12 , 123 D 13 , 123 D 21 , 123 D 23 , 123 D 31 , and 123 D 32 , in aqueous solutions of 2-hydroxypropyl-β-cyclodextrin (HP-βCD) + KCl + caffeine (CAF) + water, and 2-hydroxypropyl-β-cyclodextrin (HP-βCD) + KCl + theophylline (THP) + water at T  = 310.15 K at different carrier concentrations of 0.002, 0.005 and 0.010 mol · dm −3 , for each solute. The behaviour diffusion of these multicomponent systems and the coupled flows occurring in the solution can be explained on the basis of salting-out effects, as well as the possible interactions between both (cyclodextrin + xantine) or (cyclodextrin + metal ion) interactions, lead us in this way to obtain a better understanding of the structure of these systems.