Lecture 20 Buccal Drug Delivery Flashcards
Describe the parts included in the oral cavity.
The oral cavity includes the lips, inner cheek, hard palate, soft, retromolar trigone, front two-thirds of the tongue, gingiva, buccal mucosa, and floor of the mouth under the tongue.
What are the most important parts of the oral cavity for drug delivery purposes?
The sublingual and buccal mucosa are crucial for targeting drug delivery.
Define buccal mucosa.
The buccal mucosa is the lining of the cheeks and the back of the lips, the area inside the mouth that comes in contact with the teeth.
List the advantages of Buccal Drug Delivery (BDD).
Advantages include rapid absorption into systemic circulation, bypassing liver metabolism, rapid curtailment by removal, and the ability to be retained at the site for extended periods.
Describe the different types of oral mucosa.
Oral mucosa is divided into lining mucosa, specialised mucosa (taste buds on the tongue), and masticatory mucosa (covering the hard palate and attaching gingiva).
Explain the characteristics of non-keratinized mucosa.
Non-keratinized mucosa provides flexibility and elasticity necessary for mastication and speech, with intracellular lipids in an amorphous state allowing easier diffusion of molecules.
Detail the features of keratinized mucosa.
Keratinized mucosa, found in regions subject to stress, is more resistant to abrasion. It has intracellular lipids in an ordered lamellar state, hindering the diffusion of molecules through intercellular space.
Describe the difference between non-keratinised and keratinised mucosa in terms of epithelium structure and drug diffusion barrier.
Non-keratinised mucosa has amorphous and non-organised intracellular material with low ceramide content, providing a lower barrier to drug diffusion compared to the keratinised mucosa.
What are tight junctions in keratinised areas of the mucosa?
Tight junctions are multi-protein complexes.
What is the role of tight junctions in keratinised areas of the mucosa?
They mediate cell-cell adhesion, regulate transportation through the extracellular matrix, and slow down drug absorption in keratinised areas.
How do membrane coating organelles in stratified squamous epithelium contribute to barrier function?
What do they produce and how does it work ?
Lamellar bodies in stratified squamous epithelium produce lipid ceramides, acting as a barrier against foreign substances by discharging their contents into the intercellular space.
Absorption
Define the structure of absorption sites in the buccal mucosa.
What does the buccal mucosa act as ?
The buccal mucosa acts as a lipid barrier where absorption is mainly passive, allowing well absorption of small lipophilic molecules but poor absorption of polar drugs and highly ionised substances at oral cavity pH.
Describe the characteristics of sublingual mucosa in terms of absorption and permeability.
Sublingual mucosa is very thin, constantly immersed in saliva, making it the site of most absorption. It is less permeable compared to keratinised areas due to the absence of certain organelles like lamellar bodies.
Describe the role of saliva in the human body.
Saliva maintains a moist environment, provides cleaning action, and contains major ions like potassium, sodium, chloride, and bicarbonate. It helps in moistening food, aiding in chemical digestion, chewing, swallowing, lubricating, and cleaning, among other functions.
What are some functions of saliva in the digestive process?
Saliva moistens food to form a bolus for easy swallowing, aids in chemical digestion, helps in chewing and swallowing, has a lubricating and solvent effect, and provides antibacterial and pH buffering effects.
