In this work we have analyzed the conditions leading to a kinetic demixing of species in ceramics exposed to an electrical potential gradient. Mathematical expressions have been derived from the expression of the cationic fluxes. They have allowed us to relate the driving force of diffusion to the cation concentration profiles. Time dependent cation redistribution profiles have been estimated for (Co, Mg)O and (ZrO2, Y2O3) solid solutions. The computed data are compared to the experimental results.