buccal delivery

Buccal delivery means absorbing a drug through the lining of the cheek — you tuck a tablet, film, or spray against the inside of your cheek and let it soak in, rather than swallowing it. The whole point is that drug going straight from the cheek into the bloodstream skips the trip through the stomach and the liver.

The cheek lining (buccal mucosa) is reasonably thick but well supplied with blood, and crucially its veins drain into the general circulation, not into the portal vein that funnels gut-absorbed drug through the liver. So buccal absorption avoids the first-pass effect, which can destroy much of a swallowed dose before it reaches the body. The mucosa is also robust and tolerant, allowing dosage forms that stay in place for minutes to hours, often using mucoadhesive (sticky) polymers to hold them against the cheek.

Buccal delivery suits drugs that are inactivated in the gut or heavily metabolized by the liver, and it offers a steadier, more prolonged release than the quicker sublingual route. Its constraints are the modest surface area, the barrier of the mucosal lining (which limits large or very polar molecules), the dilution and washing effect of saliva, and the simple risk that the patient swallows the dose. Permeation enhancers and mucoadhesives are common tools to overcome these.