Iontophorese

Iontophoresis is a noninvasive technique that uses a small electrical current to drive charged drug molecules through the skin or other membranes. The method relies on electrophoresis, which moves ions in an electric field, and on electroosmosis, a solvent flow that can enhance transport across the skin’s barrier. The resulting transport enables localized delivery of certain ionic drugs with limited systemic exposure.

Method and devices: A solution or gel containing the drug is applied to a delivery electrode (the active electrode) on the skin, while a counter electrode completes the circuit. When power is applied, the drug ions migrate toward the opposite electrode and penetrate the skin’s outer layers. Devices typically include a power source, two electrodes, and conductive medium to maintain contact and minimize irritation.

Applications: Iontophoresis is used to deliver anti-inflammatory and analgesic agents (such as lidocaine or dexamethasone), antibiotics, and other ionic compounds for localized treatment. It is employed in clinical settings for pain and inflammation relief, wound care, and certain dermatologic therapies, and is actively researched for expanding transdermal drug delivery possibilities.

Advantages and limitations: The approach offers noninvasive, targeted delivery with potential for controlled dosing and reduced systemic exposure. Transport is mainly superficial and limited to ionizable or small molecules; effectiveness varies with skin impedance and individual factors. Possible adverse effects include local skin irritation or burns at the electrode site and, less commonly, allergic reactions to gels or drugs.

Safety and regulation: Used under clinical or research supervision with approved devices. Iontophoresis is contraindicated on damaged or inflamed skin and should be used with caution in individuals with implanted electrical devices or conditions sensitive to electrical currents.