Buccal, from the Greek for “on the stomach,” refers to the oral route of delivery by which pharmacologically active substances diffuse in the bloodstream through the stomach which is primarily responsible for the absorption of fluids from the gastrointestinal tract.
Buccal can also refer to the oral or nasal routes by which ingested substances are transported to other regions.
Buccal is a direct absorption of oral materials that are delivered directly into the bloodstream from the stomach or intestinal tract. Buccal also includes the trans-bronchial and the trans-gastric routes. Sublingual delivery of substances, on the other hand, takes place through the mouth or nose and is more indirect, delivering oral agents to areas distant from the oral cavity. Sublingual delivery can also take place in the small intestine through the bile duct.
Most oral drugs can be absorbed into the bloodstream if they are ingested in their oral route. Oral drugs that can reach the bloodstream include analgesics, antihistamines, anti-anxiety, antidepressants, anti-seizures, anti-cancer, anti-fungals, anti-diarrheals and anti-toxic drugs. Buccal delivery of oral drugs also includes oral contraceptives. In most cases, these medications do not pass directly into the bloodstream, but they may be absorbed into the bloodstream by diffusion in the gastrointestinal tract.
In most cases, the absorption of drugs into the bloodstream depends on the site of entry of drugs via the sublingual route. Oral drugs, as their name suggests, are taken orally; the sublingual route includes oral drug absorption by diffusion in the upper digestive tract or the stomach.
Sublingual drug absorption also depends on the amount of drug present in the substance. Drugs that contain substantial amounts of water tend to be absorbed better than those that are hydrophilic.
Absorption of drugs in the oral cavity depends on the location of drug in the oral cavity. Drug particles enter the buccal cavity when they are passed into the throat or the mouth.
The absorption of drugs via the sublingual route can also be influenced by factors such as the surface area of the buccal wall, the oral cavity’s composition and structure and the oral cavity’s pH level. Factors such as smoking, alcohol intake, food intake, sex and certain types of gum also affect the absorption of oral drugs. Some drugs that cannot be absorbed directly into the bloodstream include prescription drugs.
Oral absorption of drugs through sublingual routes is also influenced by the oral tissues and mucosal layers. The thickness and composition of the mucosal layer is one important factor affecting absorption. Oral drugs can also be reduced or enhanced by a change in the oral flora in the gut.
It is possible that some drugs that cannot be absorbed via the oral cavity can be absorbed via sublingual routes. These drugs include medications used in chemotherapy, for instance, antibiotics and radioactive materials. Inhalation of drugs into the lungs can also enhance their absorption.
The presence of some drugs in the oral cavity and the mucosal layers can help to improve absorption of oral drugs.
Oral drugs can be absorbed into the body through different ways including inhalation (inhalation) and exhalation (exhalation). There are several oral routes of drug absorption, all of which have their own advantages and disadvantages.
Absorption is normally carried out through a passive exchange, through diffusion, and by either the active or inactive exchange. There is generally no physical transfer of drugs between substances.
Passive exchange occurs when the drug enters the digestive tract or the stomach and is metabolized into its active form. Active exchange occurs when the drug is metabolized into carbon dioxide, water, glycogen, lactate and urea. by a mechanism known as autophosphorylation. Active exchange occurs because it is more effective than passive exchange in reducing the rate of drug absorption. The inactive form of a drug can also be reduced in the intestines by the activity of bacteria in the colon.
Passive exchange is more efficient in reducing drug absorption than active exchange, which increases the chances of drug absorption. Autophagy occurs when a drug passes from the stomach to the small intestine without being metabolized. In this process, active drug molecules pass from the stomach back into the stomach where they can be excreted in the urine.