Transport of drugs across porous ion exchange membranes

Effect of ion-exchange fiber structure on the binding and release of model salicylates

“…13 In dilute salt solutions, the Donnan potential between the extracting solution and the fiber is high and the fiber pulls the compounds back to the charged fiber. 5,13,15,16 By raising the electrolyte concentration, the Donnan potential decreases and, hence, the electrostatic interaction between the bound compounds and the fiber is smaller, thus releasing the compounds more easily into the external solution.…”

Controlled transdermal delivery of leuprorelin by pulsed iontophoresis and ion-exchange fiber

“…One possibility to enhance peptide transport from the cation-exchange fibers would be to increase the release from fibers. Using higher Na + concentrations or multivalent cations in the external solution would lead to a decrease in Donnan potential, resulting in more extensive peptide release from ion-exchanger [37]. At the same time the presence of higher amounts of small and more mobile co-ions means higher competition for the peptide in the iontophoretic transport.…”

Donnan Equilibrium of Ionic Drugs in pH-Dependent Fixed Charge Membranes: Theoretical Modeling

“…Determining the partition equilibrium of an ionic drug between a membrane solution and an external electrolyte solution (1-15) constitutes a difficult problem not only because of the multi-ionic character of the system (the ionic drug, the salt ions, and the hydrogen and hydroxide ions) but also due to the great 1 To whom correspondence should be addressed. E-mail: smafe@uv.es.…”