Flashcards in Oral Transmucosal Delivery Deck (26):
What is buccal delivery?
Drug administered through the mucous membrane on the side of the cheek (buccal mucosa)
What is sublingual delivery?
Drug delivered through the mucosal membranes lining the bottom of the mouth
What is gingival delivery?
Drug delivered through the gingiva (gums)
Describe what the keratinised epithelium is and where it's normally found?
1. Dehydrated, mechanically tough and chemically resistant
2. Found in areas subjected to mechanical stress
3. Gingiva (gums) and hard palate (roof of mouth)
Describe what non-keratinised epithelium is and where it's normally found?
1. Relatively flexible
2. Found on soft palate (ball on back of throat)
3. Floor of the mouth
4. Lips and cheeks
What are the functions of saliva?
2. Digestion- amylase in salvia breaks down starch to lower molecular weight molecules
3. Protection- lysozyme acts on lyze bacteria
Where is the permeability of the oral mucosal epithelium?
Intermediate between that of the skin epithelium and the gut
Describe in general Buccal delivery as well as its permeability, absorption and thickness?
1. Lower permeability
2. Slower absorption
3. Expanse of smooth muscle
4. Relatively immobile
5. Thickness 500-800 μm
Describe in general sublingual delivery as well as its permeability, absorption and thickness?
1. Higher permeability
2. Faster absorption
3. Constant production of saliva washes it
4. Thickness 100-200 μm
What is Buccal more suitable for?
1. Useful for sustained delivery applications
2. Peptide drugs and delivery of less permeable molecules
What is sublingual more suitable for?
1. Useful for short dosing requirement drugs
2. Infrequent dosing
3. Continuous pain medication (after dental treatment)
What are cell membranes usually made of and what drug molecule form is best to diffuse?
1. Lipid membrane
2. Lipid soluble drugs or unionised form in solution can cross most easily
What molecules will cross the non-kertinised buccal membrane more easily?
1. Unionised Lipid molecules
2. Lower molecular weight molecules
Explain why phenobarbitone is absorbed better in high pH?
1. Phenobarbitone is a weak acid that reacts with the high pH to dissociate the H portion
2. Leads to the molecule being charged so it's absorbed better
What are the factors that favour drug absorption in the oral mucosa?
1. Low molecular weight
2. Soluble in water and liquid membranes of the body
3. Should be unionised and not bind to the oral mucosa
Describe how drugs are adsorbed via the oral route?
1. Solid drug powder tablet
2. Dissolved drug in buccal fluid
3. Dissolved drug in buccal membrane
4. Drug in Lymphphatic circulation
5. Drug in blood circulation
What are the indications of nitroglycerin?
1. Prophylaxis of angina and left ventricular failure
2. Relieves pain within 2 minutes of dissolution
How are the anti-anginal effects prolonged in nitroglycerin?
Sustained release tablet using mucoadhesive cellulose tablets
What are the two various patches buccal delivery?
1. Multi-directional patches
2. Unidirectional release patch
What are the disadvantages of a multi-directional patch?
1. Drug can be washed by the saliva and swallowed away
2. Drug is not protected by the physical environment as it's released in the mouth
What are the disadvantages of a uni directional patch?
1. Only one direction so area is limited
2. May cause discomfort as there's a decrease in flexability
What ingredient is used for the most suitable form of a buccal dosage form?
Carbopol as it lasts 15 minutes in terms of disintegration time
The drug Buccastem M in higher and lower doses are used for what?
1. Higher: Psychiatric illnesses
2. Lower: Nausea and vomiting that's involved in migraines
What are the requirements to mucoadhesive buccal films?
1. Flexibility, elasticity, softness
2. Should not swell or disintegrate too much which may cause discomfort
3. Good mucoadhesive ability to remain in the mouth for long enough
4. Adequate strength to withstand breakage
What are the advantage of buccal, sublingual and gingival administration?
1. Avoids exposure to the GI system
2. Provides direct route to systemic circulation
3. Bypasses the liver
4. Rapid absorption if possible
5. Ease of administration and termination