What isinvasive medication?

Invasive medication is the one in which you administer a drug in such a way that you have to make a breach in the continuity of the skin to reach the deeper tissues.

for eg. administering a drug orally in the form of a tablet is a non-invasive medication whereas, administering the drug via an injection (be it intradermal, intravenous or subcutaneous) is an invasive procedure.

Thus administration of a drug by oral, rectal, inhalational, or topical (direct application on skin) route are non-invasive medications while administering via injection is invasive medication