Paediatricsniche
An 8-year-old boy who had a right tympanostomy tube inserted last year has a two-week history of an itchy, discharging right ear after swimming lessons. He has already completed one course of ear drops obtained elsewhere. Pressure on the tragus is painful, and the canal is oedematous and lined with fluffy white debris and black specks; the tube cannot be seen. He is afebrile and the pinna is normal. Aural toilet is performed. Which one of the following preparations should now be instilled?