Buccal Drug Delivery Flashcards
What parts of the oral cavity are important for drug delivery?
Sublingual and Buccal Mucosa
What is the Buccal mucosa?
The inside of the mouth that comes in contact with teeth
List the Advantages of Buccal drug delivery
Rich blood supply, so rapid drug absorption
Drug delivery can be stopped by simply removing the delivery system from the mouth
Absorbed drug by-passes the liver (no first pass effect)
Delivery systems can be retained for long times, opportunity for sustained release formulation
What is the oral mucosa?
The outermost lining of the oral cavity
What are the 3 groups of the oral mucosa?
Lining mucosa
Specialised mucosa
Masticating mucosa
What is the lining mucosa?
Lining of the cheeks and inner lips
What is the specialised mucosa?
Regions of the tongue where taste buds exist
For sensory and taste perception
What is the masticatory mucosa?
Hard palate and gingiva
Keratinised
What is the purpose of keratinised mucosa?
Present in regions subject to chemical or physical stress
Makes theses regions more resistant to abrasion
How do keratinised mucosa prevent paracellular transport ?
Intercellular (between cells) lipids of keratinised tissue are in ordered, lamellar state
Hinders ability of molecules diffusing through this paracellular space
Name 3 areas of the oral cavity that are keratinised?
Hard palate
Gingiva
Dorsal surface of the tongue
What is the primary lipid in the keratinised areas of the oral cavity?
Ceramides
Why would Buccal delivery be preferred over delivery through skin?
Organised array of lipids (ceramides) is the main absorption barrier
But lipids in oral cavity are less organised than in skin
Allows less diffusion resistance to drugs
Route of least penetration resistance is usually preferred for drug delivery
Which layer of mucosa is keratinised?
Stratum corneum
What is characteristic of a keratinised area of the mucosa?
Lamellar structure
Organised array of ceramides
What type of cells are present in the oral mucosa epithelium?
Stratified squamous cells
(Characteristic of a tissue which receives wear)
Why is the sublingual Mucosa a good site for drug delivery?
Very thin
Immersed in saliva
Offers most rapid absorption
How does keratinisation affect drug absorption?
Keratinised areas (gingiva, hard palate) are less permeable than non-keratinised areas
How do tight junctions affect drug absorption?
Tight junctions regulate transport through extra-cellular matrix
Their presence slows down drug absorption rates
What type of drug molecules are well absorbed by the Buccal mucosa?
Buccal mucosa acts as a lipid barrier
Small lipophilic molecules are well absorbed
Polar drugs are poorly absorbed
What are the 2 mains roles of saliva?
Maintain a moist environment
Cleansing action
What are the major ions in saliva?
Potassium
Sodium
Bicarbonate
Chloride
Where is mucus produced in the oral cavity?
Buccal sublingual glands
Why is mucus thicker than saliva?
Mucus contain glycoprotein mucin
