Roommate Kevin went to some physical therapy this week for his back and got fitted with one of the coolest medicinal devices I’ve seen.
Kevin had this patch applied to his back. The patch has two sides: a positive and a negative.
Kevin’s Patch, close-up.
On the negative side, you’ve got some negatively charged sodium chloride and on the positive side you’ve got a polar, hydrophilic drug. This is, in essence, a battery. The negative side tries to scoot over to the positive side. At the same time, you’ve got the positive drug wanting to seep into the patient’s negatively charged skin.
My MSPaint (props to Viv for some guidance)
Apparently a more primitive application of this occurs in normal drug patches. Nicotine patches for example have a positive charge to attract them to the skin, but they don’t have the negative side of the battery present. This means that the drug just seeps into the skin. This system is not as advanced because you can’t control the rate at which the drug is administered to the patient. It just kinda seeps in at an inconsistent rate.
With the battery setup, you can control the flow from the negative side to the positive side and thus create an even administration of drug to the patient.