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Drug delivery systems . Michael G. Stewart, MD, MPH Professor and Chairman Department of Otorhinolaryngology. Paranasal sinuses & middle ear. Frequent sites of infection, inflammation Lined by mucous membrane (mucosa) with good capacity for absorption Current surgical management
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Drug delivery systems Michael G. Stewart, MD, MPH Professor and Chairman Department of Otorhinolaryngology
Paranasal sinuses & middle ear • Frequent sites of infection, inflammation • Lined by mucous membrane (mucosa) with good capacity for absorption • Current surgical management • Opening, ventilation, irrigation • Potential problems & issues • Access to cavity • Maintenance of medication dose
Other potential locations • Into abdominal cavity • Into chest cavity • Intra-vascular • Directly into tissue, joint, muscle
Sinus: clinical diseases • Chronic inflammatory sinus disease • Chronic infection • Nasal polyps • Fungal sinusitis • Cystic fibrosis • Other diseases of mucus and cilia transport
Problems – sinus disease • Access to sinus cavities • Mucosa is source of inflammation, polyp regrowth • Inhaled solutions go directly to back of nose • Irrigated solutions go partially into some sinuses • Oral or intravenous meds go to mucosa • Problems with long-term use of steroids and antibiotics, antifungal meds
Problems – sinus disease 2 • Fungal particles trapped in sinus cavity • “inside the sinus, outside the body” • Surgery to ventilate sinus is only part of solution • Bacterial overgrowth in sinus cavity • Impairment in mucus, cilia function
Potential solutions - sinuses • Topical delivery system • Implantable delivery system • Slow-dissolving “gel” into sinus? • Positive pressure aerosol? • Other method of delivery • Long-term dosing directly to area • High topical dose, limited systemic absorption • Constant dosing
Ear disease • Middle ear • Persistent effusion • Recurrent infection or effusion • Eustachian tube block
Ear disease • Inner ear – middle ear could be source of drug delivery • Meniere’s disease (recurrent vertigo) • Autoimmune inner ear disease • Sudden hearing loss • Ototoxic systemic medications • Noise trauma
Issues – ear disease • Easier access • Problems • requires puncturing eardrum • requires multiple procedures, doses • long-term problems, want preventative treatment in some cases
Delivery system • Prolonged release • Steady dosing (not bolus) • Remain in situ • Not interfere with hearing
Summary • Paranasal sinus and ear disease are very common problems • Can get access to site of disease • Need better long-term delivery and distribution of medication doses