An electrotransport apparatus using dispersed ion exchange material (19,83) is disclosed. The ion exchange material (19,83) may be dispersed in either the donor electrode assembly (10), the counter electrode assembly (10) or both electrode assemblies. The dispersed ion exchange material (83) comprises mobile ionic species (84-2) and substantially immobile ionic species (P). The dispersed ion exchange material (83, 84-2) interacts with competitive species (86) generated during electrotransport to render those species substantially immobile (87). Electrotransport devices exhibiting reduced polarization are also disclosed.