Drug delivery device for drug suspensions

Abstract

A drug delivery device is provided herein, the device including a reservoir for containing a medicament. The medicament includes a suspension of solids in a liquid carrier. The device also includes a needle having a distal end for injection into a patient, a proximal end in communication with the reservoir, and a lumen extending between the distal and proximal ends. A path is defined from the reservoir to the distal end of the needle through the lumen, the path having an inner diameter that decreases in the proximal to distal direction along at least a portion thereof. Advantageously, with the subject invention, a flow path may be defined which provides a more gradual transition in diameter from the reservoir to the distal tip of a needle. In this manner, changes in velocity of the suspension may be less abrupt than in the prior art, thus better maintaining solid particles in the suspension.

1 . A drug delivery device comprising:
 a reservoir for containing a medicament comprising a suspension of solids in a liquid carrier; and   a needle having a distal end for injection into a patient, a proximal end in communication with said reservoir, and a lumen extending between said distal and proximal ends, a path being defined from said reservoir to said distal end of said needle through said lumen, said path having an inner diameter that decreases in the proximal to distal direction along at least a portion thereof.   
     
     
         2 . The drug delivery device of  claim 1 , further comprising a fluid inlet port defining a flow control surface, said flow control surface having a proximal end and a distal end, said proximal end of the flow control surface being in contiguous contact with said suspension and disposed proximally of said proximal end of said needle, wherein said proximal end of said flow control surface defines a larger inner diameter than said distal end of said flow control surface, and wherein said proximal end of said flow control surface defines a larger inner diameter than said diameter of said lumen at said proximal end of said needle. 
     
     
         3 . The drug delivery device of  claim 1 , wherein said lumen at said proximal end of said needle has a larger diameter than at said distal end of said needle. 
     
     
         4 . The drug delivery device of  claim 1 , wherein said reservoir has a proximal end and a distal end, said distal end including proximally-facing portions, said proximally-facing portions being disposed to angularly converge towards said needle. 
     
     
         5 . The drug delivery device of  claim 1 , further comprising a cartridge, said cartridge defining said reservoir. 
     
     
         6 . The drug delivery device of  claim 1 , further comprising a needle assembly, said needle assembly including a hub having a proximal end and a distal end, said hub including a fluid inlet port defining a flow control surface, said flow control surface having a proximal end and a distal end, said proximal end of the flow control surface being in contiguous contact with said suspension and disposed proximally of said proximal end of said needle, wherein said proximal end of said flow control surface defines a larger inner diameter than said distal end of said flow control surface, and wherein said proximal end of said flow control surface defines a larger inner diameter than said diameter of said lumen at said proximal end of said needle. 
     
     
         7 . The drug delivery device of  claim 1 , further comprising a septum disposed at a distal end of said reservoir, said septum including a fluid inlet port defining a flow control surface, said flow control surface having a proximal end and a distal end, said proximal end of the flow control surface being in contiguous contact with said suspension and disposed proximally of said proximal end of said needle, wherein said proximal end of said flow control surface defines a larger inner diameter than said distal end of said flow control surface, and wherein said proximal end of said flow control surface defines a larger inner diameter than said diameter of said lumen at said proximal end of said needle. 
     
     
         8 . The drug delivery device of  claim 1 , wherein transitions in diameter along said fluid path are rounded. 
     
     
         9 . The drug delivery device of  claim 1 , wherein said decrease in inner diameter of said path is gradual. 
     
     
         10 . The drug delivery device of  claim 1 , wherein said decrease in inner diameter of said path includes at least one step change in diameter.