+0
To prevent the wound from becoming infected, apply this medicine and then keep it dry.

As I have only heard "apply this ointment on the wound" but not "apply this medicine," I wonder if it sounds right.
+0
It's a bit odd, perhaps, but completely understandable.

CJ
+0
Angliholic
Thanks, CJ.

That means "apply this ointment to the wound" sound better, right?
Right. "medication/medicine" generally refers to something ingested.
Students: Are you brave enough to let our tutors analyse your pronunciation?
Comments  
Thanks, CJ.

That means "apply this ointment to the wound" sound better, right?
 Philip's reply was promoted to an answer.
Teachers: We supply a list of EFL job vacancies