Local concentration management system

Abstract

The invention provides a local concentration management system (LCMS) for delivery of highly concentrated therapeutic agent formulations. The LCMS comprises a device comprising an elongate body defining a lumen between its proximal and distal ends, and a diffuser element, a dilutor element, or both. The diffuser element, which is selectively permeable to the agent, is operatively associated with the elongate body so that agent flows through the elongate body, and into and through the diffuser element to exit the system. The dilutor element can be operatively associated with the system to be in fluid communication with the elongate body lumen, a diffusion space defined by a diffuser element inner wall, or both. The dilutor element is selectively water permeable, but substantially impermeable to agent, to provide for dilution of the agent during transit through the system. The LCMS system is designed to disperse and/or dilute the drug delivery stream.

1 .- 28 . (canceled)  
   
   
       29 . A drug delivery device comprising: 
 an elongate body defining a lumen and a delivery outlet, wherein said lumen and delivery outlet are in fluid communication; and    a diffuser element secured to an outside portion of the elongate body and in fluid communication with the delivery outlet;    wherein flow of a formulation through the lumen, through the delivery outlet, and through the diffuser element provides for diffusion of the formulation over an area defined by the diffuser element.    
   
   
       30 . The device of  claim 29 , wherein said diffuser element is detachable from said elongate body.  
   
   
       31 . The device of  claim 29 , wherein the elongate body comprises a material substantially impermeable to water.  
   
   
       32 . The device of  claim 29 , wherein the diffuser element comprises a semi-permeable membrane.  
   
   
       33 . The device of  claim 29 , wherein the elongate body lumen is adapted for delivery of agent at a low volume rate.  
   
   
       34 . The device of  claim 29 , wherein the diffuser element has a Diffusion Coefficient (DC) value in the range between 4.1×10 −6  and 3.3×10 −5  μg/cm/sec.  
   
   
       35 . A drug delivery system comprising the device of  claim 29  operably attached to a drug reservoir.  
   
   
       36 . The drug delivery system of  claim 35 , wherein the elongate body lumen is adapted for delivery of agent at a low volume rate.  
   
   
       37 . The drug delivery system of  claim 36 , wherein said drug is delivered in microliter or submicroliter quantities per day.  
   
   
       38 . The drug delivery system of  claim 35 , wherein the drug reservoir contains sufentanil.  
   
   
       39 . A method for delivery of a drug to a delivery site in a subject, the method comprising the steps of: 
 implanting at the delivery site of a subject a drug delivery device comprising: 
 an elongate body defining a reservoir containing a drug formulation, a lumen, and a delivery outlet, wherein said lumen and delivery outlet are in fluid communication with a reservoir; and  
 a diffuser element secured to an outside portion of the elongate body and in fluid communication with the delivery outlet;  
   wherein flow of the drug formulation from the reservoir, through the lumen, through the delivery outlet, and through the diffuser element provides for diffusion of the drug formulation over an area defined by the diffuser element.    
   
   
       40 . The method of  claim 39 , wherein the drug is delivered at a low volume rate.  
   
   
       41 . The method of  claim 40 , wherein said drug is delivered in microliter or submicroliter quantities per day.