The drugs can be administered orally, or topically.
It means that the drug can be applied to a body surface (e.g. skin).
A topical medication is a medication that is applied to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes including but not limited to creams, foams, gels, lotions and ointments.
A drug administered topically is applied directly to the part of the body that it is intended to treat. It is contrasted with systemic administration where the drug works by being mixed into fluids that circulate in the body. See Topical Medication at Wikipedia.