Aural and Nasal Routes Flashcards
Advantages of the nasal route (4)
easy to administer
non invasive, painless
direct route to brain is possible
low enzymatic activity
Absorption occurs across..
turbinates and septum
Lipophilic drugs transported …
Lipophilic drugs transported transcellularly by concentration- dependent passive diffusion, by receptor/carrier mediated and vesicular transport mechanisms
Polar drugs pass through…
Polar drugs pass through epithelium via gaps between cells (tight junctions)
The olfactory mucosa is in direct contact with..
the brain and cerebral spinal fluid.
Drug delivery – systemically can be used…
emergency situations where rapid onset of action is required
Factors affecting systemic absorption
solubility
lipophillicity/ hydrophilicity
molecular size
degree of ionisation - unionised with a higher logo is better absorbed than ionised form
enzymatic activity
nasal epithelium permeability
mucosal contact time
Common devices include…
nasal sprays - easy and fast, exact nose, multi dose or unit dose
dropper/squeezers
although this requires skill to apply, If delivered too quickly causes cough
nasal tube
for creams, gels, ointments
messy to apply
uncontrolled dose
Drug treatments for the ear can be broadly categorised as follows:
Antibiotics – eg, gentamicin.
– Anti-inflammatories – eg, hydrocortisone. – Antiseptics (not common now).
– Cleansing solutions eg, urea.
– Wax softeners – eg, docusate sodium.
Dosage forms (in the ear) (3(
drops
sprays
washes
Ear wax..
Wax is a normal bodily secretion which provides a protective film on the meatal skin.
- It needs only be removed if it causes deafness or interferes with a proper view of the ear drum.
- Composition of ear wax is mostly lipophilic substances
Cerumenolytics act by…
softening the cerumen and lubricating the canal, thus facilitating ear wax removal from the ear canal
or by disintegrating it.
Otitis externa
Inflammatory reaction of the meatal skin.
- Mostly caused by bacteria or fungus.
- Many cases recover after thorough cleansing of the external ear canal by suction or dry mopping.
An astringent is…
An astringent is a substance that causes shrinking or constriction of body tissues, usually locally after topical medicinal application.