Drug delivery to the Ear

Question 1

In what conditions does drugs need to be administered to the ear

Answer 1

• Bacterial infections (otitis externa) – antibiotics, steroids, analgesics
• Eczema of ear canal – corticosteroids
• Excess earwax – earwax softeners

Question 2

Drug delivery to the external ear

Answer 2

Variant of topical delivery to the skin

Ear drops, creams, ointments

Question 3

Drug delivery to the middle ear

Answer 3

Not accessible by ear drops (stopped by eardrum) Systemic delivery or injection through eardrum

Question 4

Drug delivery to the internal ear

Answer 4

High doses by systemic delivery

Delivery to middle ear

Question 5

Formulation of ear drops

Answer 5

Non-aqueous

• Water promotes bacterial growth in ear canal
• Earwax is hydrophobic and viscous

Oils, glycerol, propylene glycol

• Soften wax → better drug penetration

Glycerol, PG are hygroscopic → Reduce oedema (swelling)