Enhanced stylet for drug depot injector

Abstract

A pellet delivery system is provided that comprises a needle having an inner surface defining a passageway. The needle has a first portion that extends along a longitudinal axis and a curved second portion comprising an opening that is in communication with the passageway. The second portion extends transverse to the longitudinal axis. A pellet is positioned in the passageway. A plunger is slidably positioned in the passageway. The plunger comprises a shaft having a rounded tip configured to push the pellet through the first and second portions and out of the opening without the pellet becoming stuck within the passageway or the opening. Implants, systems, constructs, instruments and methods are disclosed.

1 . (canceled) 
     
     
         2 . A system for delivering a plurality of solid drug pellets, the system comprising:
 an epidural Tuohy needle configured to create a pathway to an epidural space, the needle comprising:
 a proximal end, 
 a distal end comprising an opening, and 
 a passageway in communication with the opening; and 
   a plurality of solid drug pellets in the passageway;   a rigid plunger slidable in the passageway and the configured to push the plurality of solid drug pellets through the passageway and out of the opening, the plunger comprising:
 a first end, 
 a second end, 
 a shaft portion extending from the first end to a position proximate the second end, and 
 a tip portion extending from the position proximate the second end to the second end, the tip portion having a bullet-nose shape comprising a progressively decreasing diameter from a maximum diameter at or adjacent the shaft portion to a minimum diameter at the second end so that a chamfer angle extends at an angle of 10° to 45° relative to a longitudinal axis of the plunger. 
   
     
     
         3 . The system of  claim 2 , wherein the plunger is configured to push the plurality of solid drug pellets through the passageway and out of the opening without the plurality of solid drug pellets becoming stuck in the passageway or the opening. 
     
     
         4 . The system of  claim 2 , wherein a shape of the tip portion allows the tip portion to move into the passageway a greater distance than if the tip portion comprised a planar end surface. 
     
     
         5 . The system of  claim 2 , wherein each of the plurality of solid drug pellets comprises:
 a length of 4 mm;   a diameter of 0.75 mm, the diameter being 0.01 inches to 0.1 inches less than a maximum diameter of the passageway or 0.2 inches to 0.5 inches less than a maximum diameter of the passageway;   clonidine; and   a biodegradable polymer.   
     
     
         6 . A system for delivering a drug depot, the system comprising:
 a needle comprising:
 a proximal end, 
 a distal end comprising an opening, and 
 a passageway in communication with the opening; 
   a drug depot positioned in the passageway; and   a rigid plunger slidable in the passageway and the configured to push a drug depot through the passageway and out of the opening, the plunger comprising:
 a first end, 
 a second end, 
 a shaft portion extending from the first end to a position proximate the second end, and 
 a tip portion extending from the position proximate the second end to the second end, the tip portion having a bullet-nose shape comprising a progressively decreasing diameter from a maximum diameter at or adjacent the shaft portion to a minimum diameter at the second end. 
   
     
     
         7 . The system of  claim 6 , wherein the plunger is configured to push the drug depot through the passageway and out of the opening without the drug depot becoming stuck in the passageway or the opening. 
     
     
         8 . The system of  claim 6 , wherein the needle is an epidural Tuohy needle configured to create a pathway to an epidural space. 
     
     
         9 . The system of  claim 6 , wherein a chamfer angle of the tip portion is 10° to 45°. 
     
     
         10 . The system of  claim 6 , wherein the drug depot comprises a plurality of pellets. 
     
     
         11 . The system of  claim 6 , wherein the drug depot comprises a therapeutically effective amount of clonidine and a biodegradable polymer. 
     
     
         12 . The system of  claim 6 , wherein the plunger is configured to push a drug depot through the passageway and out of the opening without the drug depot becoming stuck in the passageway or the opening, wherein the needle is an epidural Tuohy needle configured to create a pathway to an epidural space, wherein the plunger is rigid, wherein a shape of the tip portion allows the tip portion to move into the passageway a greater distance than if the tip portion comprised a planar end surface, and wherein the drug depot comprises a solid pellet having a length of 4 mm and a diameter of 0.75 mm. 
     
     
         13 . A system for delivering a drug depot, the system comprising:
 a needle comprising:
 a proximal end, 
 a distal end comprising an opening, and 
 a passageway in communication with the opening; and 
   a plunger slidable in the passageway and the configured to push a drug depot through the passageway and out of the opening, the plunger comprising:
 a first end, 
 a second end, 
 a shaft portion extending from the first end to a position proximate the second end, and 
 a tip portion extending from the position proximate the second end to the second end, the tip portion having a bullet-nose shape. 
   
     
     
         14 . The system of  claim 13 , wherein the plunger is configured to push a drug depot through the passageway and out of the opening without the drug depot becoming stuck in the passageway or the opening. 
     
     
         15 . The system of  claim 13 , wherein the needle is an epidural Tuohy needle configured to create a pathway to an epidural space. 
     
     
         16 . The system of  claim 13 , wherein a chamfer angle of the tip portion is 10° to 45°. 
     
     
         17 . The system of  claim 13 , further comprising a drug depot positioned in the passageway. 
     
     
         18 . The system of  claim 17 , wherein the drug depot comprises a pellet having a length of 4 mm and a diameter of 0.75 mm. 
     
     
         19 . The system of  claim 17 , wherein the drug depot comprises a therapeutically effective amount of clonidine and a biodegradable polymer. 
     
     
         20 . The system of  claim 17 , wherein the drug depot comprises a plurality of pellets. 
     
     
         21 . The system of  claim 13 , wherein the plunger is configured to push a drug depot through the passageway and out of the opening without the drug depot becoming stuck in the passageway or the opening, wherein the needle is an epidural Tuohy needle configured to create a pathway to an epidural space, wherein the plunger is rigid, wherein a shape of the tip portion allows the tip portion to move into the passageway a greater distance than if the tip portion comprised a planar end surface, and wherein a chamfer angle of the tip portion is 10° to 45° relative to a longitudinal axis of the plunger.