Micro-Wick and Mierocatheter sustained release devices are used in:
Ans. d. Delivering drug to the round membrane Micro Wick and Micro catheter are methods of delivery of medications directly to the inner ear (AIIMS November 2008 Repeat).Intratympanrc Direct Therapy for Inner Ear DiseaseIntratympanic direct therapy for inner ear disease has several advanges over the conventional systemic and indirect therapy:* Increased therapeutic concentrations in the inner ear* Reduced side-effects* Can be used when systemic therapy is contraindicated* Can be used when systemic therapy fails.In direct therapy to the inner ear, the drug is delivered at the Round window membrane.Round window membrane separates the middle ear from the inner ear. A large range of substances are able to cross the RWM, including antimicrobials, corticosteroids, anesthetics etc.Delivery methodsTypical intratympanic injectionGelfoam methodMechanical sustained release devicesFully implantable micropump system* Drug is administered directly around RWM. using injection after a myringotomy.* Drawbacks: Injected medication my leak down the Eustachian tube, escape out of the external auditory canal, or be sequestered in the middle ear* In order to address these problems, several sustained release vehicles have been developed.* A dry' gelfoam pad can be placed directly in the round window niche.* The medication is directly injected over the gelfoam pad.* The Silverstein micro wick: It is made of polyvinyl acetate. It is wick measuring 1x9 mm small enough to fit through a tympanostomy tube. The wick absorbs medication which can be instilled into the external auditory canal by the patient at home and delivers it to the RWM.* The Intra Ear Microcatehter: Consists of an electronic pump connected to catheter tip that is placed directly on the RWM Implantation of the Microcatheter is more invasive and requires the elevation of tympanomeatal flap.* This device is made from pure titanium, polyethylene, and silicone and is designed for life-long implantation in humans.* To place the device, a cavity is drilled in the mastoid bone to house the pump and the reservoir system.* This device can deliver drugs which require chronic and continuous application.
Drooling of saliva
Frey's syndrome
Control of epistaxis
Delivering drug to the round membrane
Ear