Which statement best describes the flow of current in iontophoresis?

Which statement best describes the flow of current in iontophoresis?

• A. Direct current with fixed polarity; polarity does not reverse
• B. Alternating current with changing polarity
• C. No current used in iontophoresis
• D. Pulsed current with variable polarity

Answer: (A)

The flow used in iontophoresis is direct current with fixed polarity, because a steady electric field provides a consistent directional push that drives charged drug ions from the active electrode into the underlying tissues. If the polarity alternated or reversed, the ions would move back and forth and net delivery would be reduced or lost. No current would mean no ion movement at all, and pulsed current with variable polarity would interrupt the continuous delivery, which is not how iontophoresis is designed to work.

The flow used in iontophoresis is direct current with fixed polarity, because a steady electric field provides a consistent directional push that drives charged drug ions from the active electrode into the underlying tissues. If the polarity alternated or reversed, the ions would move back and forth and net delivery would be reduced or lost. No current would mean no ion movement at all, and pulsed current with variable polarity would interrupt the continuous delivery, which is not how iontophoresis is designed to work.