Dosage control electrode for iontophoresis device

An electrode assembly for an associated iontophoresis device in the transcutaneous administration of an active therapeutic species comprising:

• (a) a base layer of a conductive base material which is electrochemically consumed preferentially to water oxidation or reduction;
• (b) a first upper layer of sacrificial electrode material coated on a first portion of said base layer wherein said sacrificial electrode material is electrochemically consumed preferentially to said conductive material of said base layer;
• (c) a second upper layer of non-conducting material coated on a second portion of said base layer, said second upper layer being spaced from said first upper layer, a narrow exposed linking area of said base layer conductive base material remaining therebetween, wherein said exposed linking area of said base layer extends across said base layer;
• and
• (d) wherein, during operation of an associated iontophoresis device, consumption of said sacrificial material is ordered with said first upper layer of sacrificial electrode material being consumed first, said exposed linking area of conducting base material of said base layer being consumed second with consumption of said linking area of conducting base material severing said base layer thereby breaking electrical circuit continuity in said base layer.