This method is promising as a means of administering insulin and vaccines in the future without using needles. It is based on a technique called iontophoresis. By applying a weak voltage of several volts or several hundred microamperes through two electrodes attached to the skin, charged drugs are transported into the skin by the voltage. Iontophoresis has already been practically applied as a method for penetrating the skin with ionized drugs or cosmetics. As a pharmaceutical, a lidocaine local anesthetic agent for use with iontophoresis is available on the market in the United States.
However, to pass through the interstices between dense corneocytes in the skin, the drugs that can currently be used are limited to those with small molecules. Antigens administered to the body and used as vaccines to elicit immune strength have large molecular sizes, and therefore, administration of these antigens is not currently practical.
Painless Vaccinations with Iontophoresis
