For many people, electricity for treatment by a physiotherapist has long been nothing new and is more or less part of the standard program for treating knee problems, for example. But using electricity to transport substances into the body is new for many of us. But that is exactly what iontophoresis does.
But how does it manage to transport the substances through our greatest protective shield, the skin? In order to understand the principle, one must first be aware of a few things about electricity. Electricity consists of very small flowing particles, the ions (hence the name IONtophoresis).
Like a magnet, there are two different types of particles, comparable to a plus and a minus pole. Those with much positive (plus) charge and those with less positive, namely negative charge. These also do not “like” each other and repel each other.
Positive “plus” particles are also repelled by a plus pole and attracted by the minus pole, as with a magnet. The opposite is true for “minus” particles, which are attracted by the positive pole. Transferred to current, the poles are called electrodes.
In this case the positive pole is the anode, the negative pole is the cathode. If current is applied to these two electrodes, the particles start to flow. That the current, when it flows, can also penetrate into the inside of the body is well known, because who hasn’t got a stroke on the fence.
So the current somehow manages to overcome the skin as our protective shield to flow to its plus or minus pole without any wrong ways. Iontophoresis uses electricity as a transporter. So you take similarly charged particles as the current and they flow when you apply current (just like their related particles) in the current to the negative or positive pole.
You can modify drugs to get a positive charge and then move to the negative pole (anode) when you apply current, or of course you can change them to be negatively charged and flow to the positive pole (cathode). As it is well known that current penetrates every structure of the body, drugs can also reach very deep structures and tissue or even the blood. The longer it is used and the larger the area on which it is applied together with the medication, the more medication can penetrate the body and develop its effect.
How the current gets into the body in iontophoresis is different. Either one sticks the electrodes directly onto the body or one lets the current flow into the body through water. The adhesive position for direct current delivery can be selected so that the distance between the electrodes covers the area on which the drug is to act.
The second indirect method is tap water iontophoresis. Here, one or more chambers of a bath are filled with water and the two electrodes are immersed in the water and the current flows through the water. In this way, complete hands or feet can be treated by immersion in water.
All articles in this series:
