Final answer:
Iontophoresis uses direct current (DC) to deliver medication through the skin, providing a steady and unidirectional flow of electric charge.
Step-by-step explanation:
The type of current waveform used in iontophoresis is direct current (DC). Iontophoresis utilizes a steady flow of electric charge in one direction, without changing its magnitude or reversing direction, which is characteristic of DC. This method contrasts with alternating current (AC), where the current periodically reverses direction and varies in magnitude. In iontophoresis, direct current is preferred for delivering medication through the skin by using electric charge to drive the therapeutic ions into the body.
Direct current is the flow of electric current in only one direction. It refers to systems where the source voltage is constant. Unlike alternating current (AC), which changes direction periodically, direct current maintains a consistent flow of current in a single direction.