Delivery devices for nasopharyngeal mucosa targets

Abstract

A system for delivering a therapeutic agent to nasopharyngeal mucosa tissue has a shaft, a porous pad of compliant material coupled to the shaft near the distal end, and a drug reservoir. The porous pad is configured to expand from a contracted configuration to an expanded configuration. The expanded configuration is adapted to engage and conform to the mucosa tissue in a nasal cavity, and the contracted configuration has a size suitable for introduction into the nasal cavity. The drug reservoir holds a therapeutic agent and is at least partially covered by the porous pad. The drug reservoir is configured to release a fixed volume of the therapeutic agent into the porous pad within a period of less than about 120 minutes, and has a wall with a plurality of channels fluidly coupled with the porous pad.

What is claimed is: 
     
         1 . A system for delivering a therapeutic agent to nasopharyngeal mucosa tissue, said system comprising:
 a shaft having a proximal end and a distal end;   a porous pad of compliant material coupled to the shaft near the distal end, wherein the porous pad is configured to expand from a contracted configuration to an expanded configuration, the expanded configuration being adapted to engage and conform to the mucosa tissue in a nasal cavity, and the contracted configuration having a size suitable for introduction into the nasal cavity; and   a drug reservoir holding a therapeutic agent, the drug reservoir being at least partially covered by the porous pad, the drug reservoir having a wall with a plurality of channels fluidly coupled with the porous pad.   
     
     
         2 . The system of  claim 1 , wherein the drug reservoir is configured to release a fixed volume of the therapeutic agent into the porous pad within a period of less than about 120 minutes. 
     
     
         3 . The system of  claim 1 , wherein the elongate central member comprises an elongate shaft. 
     
     
         4 . The system of  claim 3 , wherein the elongate shaft comprises a central lumen extending therethrough. 
     
     
         5 . The system of  claim 3 , wherein the elongate shaft has a lumen extending between the proximal and distal ends, the lumen fluidly coupled to the drug reservoir. 
     
     
         6 . The system of  claim 5 , wherein control of fluid pressure applied to the lumen controls the flow of the therapeutic agent out of the drug reservoir. 
     
     
         7 . The system of  claim 1 , further comprising a sheath slidably disposed over the porous pad, the sheath constraining the porous pad in the contracted configuration, and wherein removal of the sheath from the porous pad allows expansion thereof into the expanded configuration when the therapeutic agent wets the porous pad. 
     
     
         8 . The system of  claim 1 , wherein the porous pad expands from the contracted configuration to the expanded configuration when wetted by the therapeutic agent. 
     
     
         9 . The system of  claim 7 , wherein the porous pad in the expanded configuration exerts a force against the mucosa tissue. 
     
     
         10 . The system of  claim 1 , further comprising a stiffening element extending at least partially from the proximal end to the distal end of the elongate central member, the stiffening element providing a desired rigidity and stiffness to the elongate central member so that the elongate central member may be delivered to a desired location. 
     
     
         11 . The system of  claim 1 , wherein the porous pad comprises a sponge. 
     
     
         12 . The system of  claim 1 , wherein the porous pad comprises a foamed polymer. 
     
     
         13 . The system of  claim 1 , wherein the porous pad comprises a plurality of channels extending radially outward therefrom, the channels configured to direct the therapeutic agent toward an external surface of the porous pad. 
     
     
         14 . The system of  claim 1 , wherein the porous pad comprises a plurality of fingers extending outward therefrom. 
     
     
         15 . The system of  claim 1 , wherein the porous pad comprises a looped section. 
     
     
         16 . The system of  claim 1 , wherein the porous pad comprises a plurality of protuberances spaced axially apart from one another and separated by a gap therebetween. 
     
     
         17 . The system of  claim 1 , wherein the porous pad comprises a plurality of axial elements extending distally of the elongate central member, each axially extending element having a portion of the porous pad disposed thereover, and each axially extending element in fluid communication with the drug reservoir. 
     
     
         18 . The system of  claim 1 , wherein the porous pad comprises a plurality of radial elements extending laterally from the elongate central member, each radial element having a portion of the porous pad disposed thereover, and each radial element in fluid communication with the drug reservoir. 
     
     
         19 . The system of  claim 1 , wherein the porous pad comprises a sheet of porous material wrapped around the elongate central member. 
     
     
         20 . The system of  claim 19 , wherein the sheet of porous material is helically wrapped around the elongate central member. 
     
     
         21 . The system of  claim 1 , wherein the porous pad comprises a support member disposed therein, the support member configured to provide support to the porous pad in the expanded configuration. 
     
     
         22 . The system of  claim 1 , wherein the porous pad comprises a plurality of fibers extending radially outward from the central member, the fibers configured to be loaded into a syringe in the contracted configuration, and wherein the fibers expand into engagement with the mucosa tissue when discharged from the syringe and in the expanded configuration. 
     
     
         23 . The system of  claim 1 , further comprising a hydrophobic layer of material disposed between the drug reservoir and the porous pad, the hydrophobic layer of materials having a plurality of channels disposed therein, the channels configured to direct the therapeutic agent from the drug reservoir to the porous pad. 
     
     
         24 . The system of  claim 1 , wherein the drug reservoir comprises a plurality of pores, the pores configured to allow the therapeutic agent to flow from the drug reservoir toward the porous pad. 
     
     
         25 . The system of  claim 24 , further comprising a plurality of valves fluidly coupled with the plurality of pores, the valves configured to control flow through the pores. 
     
     
         26 . The system of  claim 1 , further comprising a hydrophilic cover surrounding at least a portion of the drug reservoir, the hydrophilic cover configured to facilitate transport of the therapeutic agent from the drug reservoir toward an external surface of the porous pad. 
     
     
         27 . The system of  claim 1 , wherein the drug reservoir comprises a plurality of loops extending distally from the elongate central member, the loops having a central reservoir extending therethrough. 
     
     
         28 . The system of  claim 27 , wherein at least some of the loops comprise a stiffening member extending therethrough, the stiffening member configured to maintain patency of the central reservoirs. 
     
     
         29 . The system of  claim 1 , wherein the drug reservoir comprises an expandable member, and wherein expansion of the expandable member advances the porous pad toward the mucosa tissue. 
     
     
         30 . The system of  claim 1 , wherein the drug reservoir comprises an expandable member, and wherein expansion of the expandable member forces the therapeutic agent out of the drug reservoir. 
     
     
         31 . The system of  claim 1 , wherein the therapeutic agent comprises a toxin configured to inhibit mucus secretions. 
     
     
         32 . The system of  claim 31 , wherein the toxin comprises botulinum toxin.