Which route is usually through buccal tissue or rectum?

• A. Sublingual route
• B. Mucus membrane route
• C. Transdermal route
• D. Topical route

Answer: (B)

Mucous membrane route.

Buccal tissue (the inside of the cheek) and rectal mucosa are examples of mucous membranes. These surfaces are moist and well vascularized, so drugs can diffuse through them quickly and enter the systemic circulation. This pathway often allows faster absorption than swallowing a pill and can bypass much of the stomach’s environment and, to some extent, first‑pass metabolism in the liver. While sublingual administration also uses a mucous membrane, the general category for absorption through buccal tissue or rectum is the mucous membrane route, distinct from skin routes like transdermal or topical.