What type of substances are included in external medications?

External medications are substances that are applied to the skin or mucous membranes for therapeutic effects. This includes creams, ointments, and transdermal patches, which are designed to deliver medication through the skin into the bloodstream or to provide localized treatment for conditions such as skin irritation, inflammation, or infections.

This type of medication is specifically formulated to be administered externally rather than orally or by injection. The effectiveness of external medications comes from their ability to interact directly with the affected area, making them an essential part of treatment regimens for a variety of conditions.

The other options refer to forms of medication that are taken internally or administered in a manner different from topical application, which makes them unsuitable when discussing external medications.