Buccal administration

Buccal administration is a topical route of administration by which drugs held or applied in the buccal (ˈbʌkəl) area (in the cheek) diffuse through the oral mucosa (tissues which line the mouth) and enter directly into the bloodstream. Buccal administration may provide better bioavailability of some drugs and a more rapid onset of action compared to oral administration because the medication does not pass through the digestive system and thereby avoids first pass metabolism. As of May 2014, the psychiatric drug asenapine; the opioid drugs buprenorphine, naloxone, and fentanyl; the cardiovascular drug nitroglycerin; the nausea medication prochlorperazine; the hormone replacement therapy testosterone; and nicotine as a smoking cessation aid were commercially available in buccal forms, as was midazolam, an anticonvulsant, used to treat acute epileptic seizures. Buccal administration of vaccines has been studied, but there are challenges to this approach due to immune tolerance mechanisms that prevent the body from overreacting to immunogens encountered in the course of daily life. Buccal tablets are a type of solid dosage form administered orally in between the gums and the inner linings of the cheek. These tablets, held within the buccal pouch, either act on the oral mucosa or are rapidly absorbed through the buccal mucosal membrane. Since drugs "absorbed through the buccal mucosa bypass gastrointestinal enzymatic degradation and hepatic first-pass effect", prescribing buccal tablets is increasingly common among healthcare professionals. Buccal tablets serve as an alternative drug delivery in patients where compliance is a known issue, including those who are unconscious, nauseated, or having difficulty in swallowing (i.e. dysphagia). A wide variety of these drugs are available on the market to be prescribed in hospitals and other healthcare settings, including common examples like Corlan®, Fentora®, and Buccastem®. The most common route for drug transport through the buccal mucosa is the paracellular pathway.