Oral quick relief formulations Flashcards
advantages of taking medicines by mouth
Convenience
Onset time—fast drug release and absorption.
disadvantages of taking medicines by mouth
absorption barriers—e.g. mucus, vascularity. • Residence time.
advantages of oromucosal drug delivery:
– Rapid absorption and onset—suited for emergencies. – Mild environment—avoids drug degradation.
– No first-pass hepatic metabolism—excellent bioavailability. – Non-invasive and discreet—well accepted by patients. – No swallowing needed—can be used by dysphagic patients. • Disadvantages: – Need to avoid eating or drinking
disadvantage of oromucosal drug delivery
• Disadvantages: – Need to avoid eating or drinking
how much of the mucosal surface area is available for drug absorption
60%
what is keratinised sublibgual or buccal
none
does sublingual or buccal have very good permeability
sublingual
what is the thickness of sublingual
100-200
what is the thickness of buccal
500-600
what is the surface area of sublingual
25
what is the surface area of buccal
50
what is the turnover time in days of sublingual
20
what is the turnover time in days of sublingual
20
what is the blood flow of sublingual
12
what is the blood flow of buccal
0.2
what is the residence time of sublingual
poor
what is the residence time of buccal
intermediate
give the flow of oromucosal drug absorption
Oral mucosa
Submucosal capillaries
Jugular veins
Seuperior vena cava
Arterial circulation
challenges of oromucosal drug absorption
Permeability • pH • Dissolution – limited fluid volume • Enzyme activity • Retention time – salivary washout • Taste
saliva key facts:
pH
how much we make
resting value
Ph is 5.5-7
We make 0.5-2L daily
Resting value is 1mL
what is mucus important for
mucoadhesion of dosage forms
thickness of mucus
40–300 µm
what characteristics do you want in the formulation
Low effective dose. – Good stability in saliva. – Acceptable taste. – Rapid dissolution and absorption across oral mucosa.
is fentanyl lipophillic
yes
is fentanyl basic
yes
is fentanyl through first pass
yes
actiq buccal lozenges are in what form
It is in ionised form so its absorbed more rapidly than the non-ionised form in the mouth
citric acid acidifies what
acidifies saliva to enhance dissolution of basic drugs
orally dispersible tablets have what
Disintegrate rapidly in mouth. • Low hardness. • Porous. • Uncoated. • Rapid disintegration activated by water: – Superdisintegrant. – Effervescent system.
what does super disintegrate mean
Crosslinked polymers. • Hygroscopic. • Rapid 3D swelling. • High swelling capacity. • Typically used at 2–5%.
