Complexation of 5-Fluorouracil with -Cyclodextrin and Sodium Dodecyl Sulfate: A Useful Tool for Encapsulating and Removing This Polluting Drug.

The formation of complexes of the drug 5-fluorouracil (5-FU) with -cyclodextrin (-CD) and sodium dodecyl sulphate (SDS) was studied through experimental measurements of the ternary mutual diffusion coefficients (, , , and ) for the systems {5-FU (component 1) + -CD (component 2) + water} and {5-FU (component 1) + SDS (component 2) + water} at 298.15 K and at concentrations up to 0.05 mol dm by using the Taylor dispersion method, with the objective of removing this polluting drug from the residual systems in which it was present. The results found showed that a coupled diffusion of 5-FU occurred with both -CD and SDS, as indicated by the nonzero values of the cross-diffusion coefficients, and , as a consequence of the complex formation between 5-FU and the -CD or SDS species. That is, 5-FU was solubilized (encapsulated) by both carriers, although to a greater extent with SDS (K = 20.0 (±0.5) mol dm) than with -CD (K = 10.0 (±0.5) mol dm). Values of 0.107 and 0.190 were determined for the maximum fraction of 5-FU solubilized with -CD and SDS (at concentrations above its CMC), respectively. This meant that SDS was more efficient at encapsulating and thus removing the 5-FU drug.