Iontophoresis is a type of transdermal drug delivery facilitated by electrotherapy devices utilising Direct Current, such as electric stimulators and microcurrent machines. Iontophoresis means a ‘transfer of ions’.
During iontophoresis, a medicinal or other bio-active substance is delivered non-invasively into tissues through the skin. Due to its non-invasive nature, the iontophoretic drug delivery has been sometimes referred to as a ‘needle-less injection’.
Iontophoresis has therapeutic applications. Depending on a medicine used, iontophoresis can be used to achieve a variety of therapeutic effects, such as acute and chronic pain relief, reduction of inflammation and swelling, muscle relaxation, muscle spasm relief, healing of ulcers and open wounds, local circulation enhancement and suppression of sweating.
Active substances and medications that are to be delivered to the tissues during iontophoresis treatment must be in ionic solution form – either of positive or negative polarity charge. Subsequently, care must be taken to use the electrode of the same polarity to drive the active substance into the tissue. This means that the ionised substances in aqueous solutions consisting of positive ions must be placed under the positive polarity electrodes and the ionised substances in solutions consisting of negative ions must be placed under the negative polarity electrodes.
The electrode under which the ionised solution is placed is referred to as the active electrode, whist the other inactive electrode (i.e. also called indifferent) - placed on the opposite side of the treated area - completes the circuit.
During iontophoresis the ions are pushed into the skin beneath the active electrode through the pores, sweat glands ducts and hair follicles and penetrate tissues up to circa 1 mm depth. Thereafter the ionised actives travel to local tissues for targeted localised effects and also enter general circulation for systemic effects around the body.
The ionic solutions used in iontophoresis are selected by their therapeutic effects required. Unless already supplied as an iontophoresis ready solution, it is exceedingly important to dilute the active substance to the correct aqueous solution concentration, using distilled water. It is also equally important to know the polarity of the ionised solution for correct administration. Information on the correct dilution for iontophoresis can be obtained from a doctor or a pharmacist. Information on the polarity can be found on the packaging or in the medication data sheet available to your doctor and pharmacist. Ask your doctor or your pharmacist for guidance on iontophoresis.
Unless already experienced with iontophoresis therapy, it is important that before embarking upon the iontophoresis treatment, a medical guidance is sought.
You can find more information about Iontophoresis on the Electrotherapy website run by Professor Tim Watson.