Patent ID: 7272439

Claim:
An iontophoresis working electrode assembly comprising: a working electrode, a medicine containing portion containing an ionic medicine, and a dipolar ion-exchange membrane arranged between said working electrode and said medicine-containing portion, wherein the dipolar ion-exchange membrane comprises a porous film having voids thereon, wherein the voids in the porous film comprise a crosslinking ion-exchange resin into the which have been introduced both anion-exchange groups and cation-exchange groups, wherein the anion-exchange groups are present in an excess amount compared to the cation-exchange groups, or wherein the cation-exchange groups are present in an excess amount compared to the anion-exchange groups, and wherein said dipolar ion exchange membrane contains either the anion-exchange groups or the cation-exchange groups in an amount of 1.01 to 10 times as large as the amount of the other ion-exchange groups.