Advantages with nasal systemic drug delivery

The nasal cavity is covered by a thin mucosa which is well vascularised [1]. A drug molecule can therefore quickly be transferred across the single epithelial cell layer directly to the systemic blood circulation without first-pass hepatic and intestinal metabolism. The effect is often reached within 5 min for smaller drug molecules [2]. Nasal administration can therefore be used as an alternative to oral administration of for example tablets and capsules if a fast effect is desired or if the drug is extensively degraded in the gut or liver.