There are a number of medications in the clinical world that are administered via a patch applied directly to 1’s skin.
Things like nicotine plus cooling lidocaine patches can be bought over the counter at most drug stores.
The plan is giving a person slow exposure to a single dose of medication over the course of hours longer than if swallowed. A medicated patch also applies the medicine directly to the location of the body that needs to be targeted. If a patient has drastic joint pain, placing the patch directly over the skin above the part with pain will administer the lidocaine exactly where it needs to go. Occasionally it’s to ensure slow absorption of medications that would otherwise process through the body too rapidly. The lethal opiate fentanyl has a short life cycle in the gut, forcing patients to redose after an hour if it’s consumed or given intravenously. Putting it in a patch lets the patient experience the effects from the medicine for hours at a time. All of this reasoning goes into administering cannabis skin patches. A patient gets to experience the medicine in an extended-release format while simultaneously targeting whatever part of the body in which they’re experiencing the most pain. Imagine getting abdominal pain daily from Crohn’s Disease plus having high THC patches that you can place on your skin directly where you’re feeling crampes. You get all day relief while getting the THC right to the affected area. Whenever I have joint pain in my shoulder, I put a THC patch right on top of the affected skin plus it works wonders. I get relief until I unconnect the patch the next day.