Which route is described by administration by mouth?

• A. Cream
• B. Oral
• C. Ointment
• D. Transdermal

Answer: (B)

Oral administration means giving the drug by mouth, where it is swallowed and absorbed from the gastrointestinal tract. This route is distinct from topical forms like creams or ointments, which are applied to the skin, and from transdermal delivery, which passes through the skin into the bloodstream. When a drug is taken by mouth, its absorption occurs mainly in the small intestine and it may undergo first-pass metabolism in the liver, which can affect how much drug reaches systemic circulation. Oral dosing is convenient and noninvasive, but the amount that becomes available can vary with food, gastric pH, and transit time, so formulations often address stability and release in the GI tract. Therefore, the administration by mouth corresponds to the oral route.