- Drugs are absorbed across the mucous membranes
- Transmucosal administration includes sublingual, nasal and rectal routes
- Sublingual: here the tablet or pellet containing the drug is placed under the tongue. It dissolves and the drug is absorbed across the sublingual mucosa, e.g. nitroglycerine, nifedipine, buprenorphine
- Absorption is rapid – within minutes the drug reaches the circulation.
- First pass metabolism is avoided
- After the desired effect is obtained, the drug can be spat out to avoid the unwanted effects.
Buccal ulceration can occur.
Nasal drugs can be administered through nasal route either for systemic absorption or for local effects. For example:
- Oxytocin spray is used for systemic absorption
- For local effect – decongestant nasal drops, e.g. oxymetazoline; budesonide nasal spray for allergic rhinitis.