What is the purpose of a buccal medication in pharmacology?

October 9, 2025 •

5 min read

Did you know that buccal medication can begin to work in as little as 5 to 10 minutes, significantly faster than many traditional pills? This rapid delivery method raises the question: What is the purpose of a buccal? It is a targeted approach used to achieve high bioavailability and rapid onset of action for various medications.

Quick Summary

Buccal administration involves dissolving medication between the cheek and gum, allowing rapid absorption into the bloodstream. It bypasses liver metabolism, enhances bioavailability, and is suitable for patients with swallowing issues.

Key Points

Bypasses Liver Metabolism: Buccal drugs enter the bloodstream directly, avoiding first-pass metabolism in the liver, which increases bioavailability and allows for lower doses.
Rapid Onset of Action: The rich blood supply in the oral mucosa allows for quick absorption, providing rapid therapeutic effects, which is especially useful in emergency situations.
Accommodates Swallowing Difficulties: This non-invasive method is an ideal alternative for patients who have trouble swallowing pills, such as children, the elderly, or those who are unconscious.
Reversible Therapy: In case of an adverse reaction, the medication can be easily removed or spat out, allowing for a swift stop to drug absorption.
Local and Systemic Effects: The buccal route can be used to treat local conditions, like mouth ulcers, or to deliver medication systemically for effects throughout the body.
Enhanced Drug Stability: With less enzymatic activity and a neutral pH compared to the stomach, drugs delivered buccally are less susceptible to degradation.

Understanding the Buccal Route

The term 'buccal' refers to the inner lining of the cheeks and lips within the mouth. The buccal mucosa, the mucous membrane lining this area, is highly vascularized, meaning it contains a dense network of tiny blood vessels. This unique physiological feature provides an effective pathway for administering certain medications, allowing the drug to be absorbed directly into the systemic circulation. When a buccal dosage form, such as a tablet, film, or liquid, is placed in the cheek, the active pharmaceutical ingredient (API) diffuses through the oral mucosa and enters the bloodstream without first passing through the digestive system. This is the fundamental purpose behind the buccal route of administration.

The Mechanisms of Buccal Drug Absorption

The absorption of medication through the buccal mucosa is primarily driven by passive diffusion, with the route of transport depending on the drug's physicochemical properties. There are two main pathways for drugs to cross the buccal epithelium:

Transcellular pathway: This route is preferred by lipophilic (fat-soluble) drugs. The drug passes directly through the epithelial cells, crossing the cell membrane.
Paracellular pathway: This route is utilized by small, hydrophilic (water-soluble) drug molecules. They diffuse through the intercellular spaces between the cells.

Unlike the gastrointestinal tract, the buccal mucosa has a relatively neutral pH (6.2–7.4) and lower enzymatic activity, which helps maintain the drug's stability. The rate-limiting barrier to permeation is typically the uppermost layer of epithelial cells and the lipids that fill the intercellular spaces. To overcome this barrier for less-permeable drugs, formulations often include permeation enhancers and mucoadhesive polymers. Mucoadhesive polymers extend the drug's contact time with the mucosa by adhering to the surface, counteracting the natural flushing action of saliva.

Key Advantages of Buccal Drug Administration

The purposeful design of buccal medications offers several significant benefits over traditional oral tablets or injections:

Avoids First-Pass Metabolism: One of the most important advantages is bypassing the hepatic first-pass metabolism, where the liver can significantly break down or metabolize a drug before it reaches the systemic circulation. For drugs with high first-pass metabolism, this means a larger proportion of the drug reaches its target, increasing its bioavailability and reducing the required dose.
Rapid Onset of Action: Due to the oral mucosa's rich blood supply, medications can be absorbed quickly, leading to a faster therapeutic effect. This makes the buccal route ideal for emergency situations where rapid action is needed, such as for pain relief or seizures.
Patient-Friendly Administration: The buccal route is non-invasive and can be used for patients who have difficulty swallowing, including young children, the elderly, or unconscious individuals. It is also a viable option for patients experiencing nausea or vomiting, as it avoids the gastrointestinal tract.
Controlled and Sustained Release: Depending on the formulation, buccal dosage forms can be designed for either rapid or controlled, sustained drug release. Mucoadhesive films or patches can prolong the drug's exposure to the mucosa, leading to more consistent therapeutic levels over an extended period.
Reversible Therapy: In the event of an adverse reaction, a buccal medication can be easily removed from the patient's mouth, quickly stopping further absorption of the drug.

Challenges and Considerations for Buccal Delivery

While offering many benefits, the buccal route is not without limitations:

Small Absorption Area: The surface area of the buccal mucosa is relatively small compared to the vast surface area of the small intestine, which limits the total dose that can be administered.
Effect of Saliva: The constant production and washing effect of saliva can dilute or prematurely remove the drug, affecting its absorption and potentially leading to variable therapeutic effects.
Patient Discomfort: Some formulations may cause localized irritation or have an unpleasant taste, which can affect patient compliance.
Limited Drug Candidates: Not all drugs are suitable for buccal delivery. Ideal candidates must have sufficient potency (low dose required) and an optimal balance of solubility and lipophilicity to cross the mucosal barrier effectively.
Interference from Eating/Drinking: Eating, drinking, or smoking can disrupt the medication's contact with the mucosa and interfere with proper absorption.

Common Buccal Medications

A variety of drugs are administered via the buccal route, capitalizing on its specific advantages:

Buprenorphine and Fentanyl: These opioids are used for managing severe chronic pain and are available as buccal films (e.g., Belbuca).
Midazolam: An anticonvulsant used for acute epileptic seizures, often administered as a liquid in the buccal pouch.
Nitroglycerin: Used for chest pain (angina), sometimes available as a buccal spray.
Asenapine: A psychiatric drug for schizophrenia and bipolar disorder.
Nicotine: Patches or films used for smoking cessation.
Hydrocortisone: Used to treat oral ulcers.

Comparison: Buccal vs. Oral Administration


Feature	Buccal Administration	Oral (Swallowed) Administration
Absorption Pathway	Oral mucosa, directly into the bloodstream.	Gastrointestinal tract, then through the liver via the portal vein.
Onset of Action	Rapid, often within minutes, as it bypasses the digestive system.	Slower, as it must go through digestion and metabolism.
Bioavailability	High, since it avoids first-pass hepatic metabolism.	Can be lower due to drug degradation in the GI tract and liver metabolism.
Dose Size	Generally limited to small doses due to the small absorption surface area.	Can accommodate a wide range of doses.
Patient Suitability	Suitable for patients with swallowing difficulties, nausea, or who are unconscious.	Requires the ability to swallow effectively.
Discontinuation	Therapy can be quickly reversed by removing the dosage form.	Discontinuation is not immediate after swallowing.
Drug Stability	Higher stability due to the relatively neutral pH and lower enzyme activity of the oral cavity.	Susceptible to degradation by stomach acid and digestive enzymes.

Conclusion

In summary, the primary purpose of a buccal is to serve as an effective, alternative route for drug delivery that offers significant advantages over traditional methods, particularly oral administration. By allowing medication to be absorbed directly into the bloodstream through the highly vascularized oral mucosa, it enables a rapid onset of action and increases drug bioavailability by circumventing the liver's first-pass metabolism. This makes it a critical tool in clinical settings for emergency treatments, managing certain chronic conditions, and improving patient compliance, especially for those with swallowing difficulties or gastrointestinal sensitivities. As pharmacological research progresses, innovations in formulation science continue to address existing challenges, such as optimizing drug absorption and managing the effects of saliva, further solidifying the buccal route as a promising option for future drug therapies. For more information on proper administration, resources from reputable health organizations like Gillette Children's Hospital offer detailed guidance.

Frequently Asked Questions

To properly administer a buccal medication, place the tablet or film between your gums and the inside of your cheek. Hold it in place and allow it to dissolve naturally. You should not chew, swallow, or move the medication with your tongue.

Buccal administration involves placing medication between the cheek and gum, while sublingual administration is done by placing it under the tongue. While both bypass the liver, sublingual absorption is generally faster due to a thinner, more permeable mucosa, but buccal offers slower, more sustained release.

If a buccal medication is accidentally swallowed, it is not harmful, but it will not work as effectively. The drug will then be processed through the gastrointestinal tract and liver, which can reduce its bioavailability and delay its effect.

Common examples of buccal medications include fentanyl and buprenorphine for pain, midazolam for seizures, nitroglycerin for angina, and asenapine for psychiatric conditions.

No, it is important to avoid eating, drinking, or smoking until the buccal medication has completely dissolved. Doing so can disrupt the medication's contact with the mucosa and interfere with its absorption.

While buccal medication is beneficial for many patients, it is not suitable for everyone. It is not ideal for high-dose medications and can cause irritation for some individuals. A healthcare provider should determine if it is the right option for a patient's specific needs.

The dissolution time for a buccal medication can vary depending on the specific product, but it typically dissolves within 30 minutes. Always follow the instructions provided by your doctor or pharmacist for the particular medication.