System and method for delivery of a therapeutic agent to the inner ear

Abstract

Embodiments of the invention provide systems and methods for delivering therapeutic compositions to the inner-ear to treat inner-ear disorders. An embodiment of such a system comprises a sheath for insertion into the auditory canal and a cannula which can be inserted through the sheath. The cannula can include a tip for piercing the tympanic membrane and delivering the composition to an inner-ear tissue surface. The system may also include a therapeutic composition comprising a therapeutic agent and a thixotropic material which allows the composition to be delivered (e.g., by injection) through the cannula in liquid form and transition to gel-form once delivered to the tissue surface. A method for using the system comprises introducing the sheath into the ear, introducing the cannula through the sheath to pierce the tympanic membrane and position the tip adjacent an inner-ear tissue surface; and delivering the composition through the cannula to adhere to the tissue surface.

What is claimed is: 
     
         1 . A system for delivering a therapeutic composition to the inner ear, the system comprising:
 a delivery sheath having a lumen; and   a cannula configured to be inserted through the lumen of the delivery sheath, the cannula including a lumen for delivery of the therapeutic composition and a distal tip for piercing the tympanic membrane and delivery of the therapeutic composition to the round window membrane so as to have the composition adhere to the round window membrane.   
     
     
         2 . The system of  claim 1 , further comprising:
 a therapeutic composition for delivery through the cannula, the composition comprising a therapeutic agent for treating an inner ear disorder and a thixotropic material which allows the therapeutic composition to exist in a liquid form while being injected through the cannula and a gel form once positioned on the round window membrane.   
     
     
         3 . The system of  claim 1 , wherein the cannula distal tip is configured to be substantially atraumatic to the round window membrane. 
     
     
         4 . The system of  claim 3 , wherein at least a portion of the cannula distal tip comprises a material which transforms upon contact with fluid to make the distal tip atraumatic to the round window membrane. 
     
     
         5 . The system of  claim 4 , wherein the transformable material comprises a hydrogel which is configured to swell upon contact with fluid to make the cannula distal tip atraumatic. 
     
     
         6 . The system of  claim 4 , wherein the transformable material transforms upon contact with fluid in the inner ear. 
     
     
         7 . The system of  claim 1 , further comprising a device for measurement of a drop size of therapeutic composition positioned on the round window membrane, the drop size measurement device coupled to the cannula. 
     
     
         8 . The system of  claim 7 , wherein the measurement device comprises a gauge for measurement of a diameter of the drop, the gauge coupled to the cannula distal tip. 
     
     
         9 . The system of  claim 8 , wherein the gauge comprises a marker, a radio-opaque marker or echogenic marker.