Inhaled and mucosal routes

Learning objective

Distinguish pulmonary, intranasal, sublingual and buccal absorption without treating route comparisons as universal.

Lungs and circulation

The large surface area and blood supply of the lungs can support rapid absorption. The lecture traces pulmonary blood to the left side of the heart and then systemic arteries, including those supplying the brain. Its claim that inhalation is the fastest route should be treated as course framing, not a universal comparison across every compound and formulation.

Mucosal surfaces

Intranasal administration uses nasal mucosa; sublingual delivery uses tissue under the tongue; buccal delivery uses cheek or gum tissue. Absorption at these surfaces differs from swallowing a substance. The deck also introduces possible nose-to-brain transport involving olfactory and trigeminal pathways. That is a distinct, compound- and formulation-dependent research topic, not proof that every nasal drug bypasses the blood-brain barrier.

Sublingual

Delivery under the tongue for absorption through oral mucosa.

Buccal

Delivery at the inner cheek or gum for absorption through oral mucosa.

Pharmacology, kinetics and dynamics

Professor deck 04, PDF pages 10, 11, 12, 13, 14. Course material is paraphrased. Qualifications and excluded clinical generalizations are documented in the Pharmacokinetics editorial record. Source review does not establish clinical validation.

Examples and practice explanations are original study aids, not professor quotations, exam requirements or medication instructions.