The various routes of administrations are classified into local route and systemic route. The local route is the simplest mode of administration of a drug at the site where the desired action is required. When the systemic absorption of a drug is desired, medications are usually administered by two main routes: the enteral route and the parenteral route.

Enteral route involves absorption of the drug via the gastrointestinal tract and includes

1. oral route
2. sublingual route, and
3. rectal administration.

Parenteral route, on the other hand, refers to any routes of administration that do not involve drug absorption via the gastrointestinal tract (par = around, enteral = gastrointestinal), including

1. injection routes (e.g., intravenous route, intramuscular route, subcutaneous route etc.),
2. inhalational and
3. transdermal routes.

The main routes of drug administration include:

1. Oral route
2. Sublingual/ Buccal route
3. Rectal route
4. Topical route
5. Transdermal route
6. Inhalational route/ pulmonary route
7. Injection route
   • Subcutaneous (SC)
   • hypodermic
   • Intramuscular (IM)
   • Intradermal (ID)
   • Intravenous (IV)
   • Intra-arterial (IA)
   • Intrathecal (IT)
   • Intraperitoneal (IP)
   • Intravitreal