Low Cost Syringe with Durable and Disposable Components

Abstract

Insulin injection syringes are disclosed that include two types of components, namely, durable components that that do not contact the fluid path and can be reused, and disposable or single-use components that contact the fluid path and are not reused. The durable components do not contact the fluid path so that sterility is not affected. Two different syringe components include a reusable outer sleeve containing scale markings for the syringe and a reusable syringe plunger are provided as durable components in embodiments of the present invention. Syringes manufactured according to the present invention can employ one or both of these durable components. Methods for making, using and packaging such syringes are also disclosed.

1 . A syringe comprising:
 a barrel assembly comprising a disposable tubular insert forming a fluid reservoir and having a fluid opening at a distal end thereof;   a reusable outer sleeve detachably received on the tubular insert and having visible scale markings thereon, the reusable outer sleeve having a proximal externally threaded end portion;   a threaded collar engaging the externally threaded end portion for detachably retaining the reusable outer sleeve on the disposable tubular insert by moving the threaded collar from a distal position to a proximal position on the externally threaded end portion;   a stopper movably received in the tubular insert for sealing a proximal end of the tubular insert and for displacing fluid into or out of the tubular insert through the fluid opening upon movement of the stopper within the tubular insert; and   a user-operable plunger coupled to the stopper for causing the stopper to move within the tubular insert and thereby displace fluid into or out of the tubular insert through the fluid opening under the control of the user.   
     
     
         2 . The syringe of  claim 1 , wherein the reusable outer sleeve has a distal end wall for engaging the disposable tubular insert and limiting axial movement of the disposable tubular insert toward a distal end of the reusable outer sleeve. 
     
     
         3 . The syringe of  claim 1 , wherein a proximal end portion of the threaded end of the reusable outer sleeve has an outer diameter greater than an outer diameter of a distal end portion of the threaded end of the reusable outer sleeve whereby movement of the collar to the proximal end portion retains the reusable outer sleeve on the disposable tubular insert. 
     
     
         4 . The syringe of  claim 3 , wherein the externally threaded proximal portion of the reusable outer sleeve has axial slits and a variable diameter along its length for allow for inward compression by the internally threaded collar. 
     
     
         5 . The syringe of  claim 1 , wherein a proximal portion of the disposable tubular insert has a proximal portion of the reusable outer sleeve are each formed with adjoining portions of a flange that can be held by a user's fingers when operating the plunger. 
     
     
         6 . The syringe of  claim 1 , wherein the proximal portion of the disposable tubular insert also includes one or both of a flange that can be held by a user's finger when operating the plunger, and an annular collar beneath a thumb press of the plunger. 
     
     
         7 . A syringe comprising:
 a disposable portion comprising a fluid reservoir having a fluid opening at a distal end thereof and a stopper movably received in the fluid reservoir for sealing a proximal end of the fluid reservoir and for displacing fluid into or out of the fluid reservoir through the fluid opening upon movement of the stopper within the fluid reservoir; and   a reusable portion comprising a user-operable plunger detachably coupled to the stopper for causing the stopper to move within the fluid reservoir and thereby displace fluid into or out of the fluid reservoir through the fluid passage under the control of the user.   
     
     
         8 . The syringe of  claim 4 , further comprising a thumb press at a proximal end of the plunger. 
     
     
         9 . The syringe of  claim 4 , further comprising an annular collar at a proximal end of the fluid reservoir. 
     
     
         10 . The syringe of  claim 4 , further comprising a Luer connector at the fluid opening of the fluid reservoir. 
     
     
         11 . The syringe of  claim 4 , further comprising a hollow needle or cannula at the fluid opening of the fluid reservoir. 
     
     
         12 . The syringe of  claim 4  wherein the fluid reservoir comprises a disposable insert that is detachably received within a reusable outer sleeve having visible scale markings thereon. 
     
     
         13 . The syringe of  claim 4 , further comprising a lengthwise slot or window in the reusable outer sleeve through which a fluid level in the disposable tubular insert can be viewed. 
     
     
         14 . A method for performing first and second fluid transfers, comprising:
 performing a first fluid transfer using a first syringe constructed as set forth in claim  22 ;   after the first fluid transfer is complete, detaching the reusable plunger from the stopper of the first syringe and attaching it to the stopper of a second syringe, the second syringe being constructed as set forth in claim  22  but lacking a plunger; and   performing a second fluid transfer using the second syringe having the reusable plunger of the first syringe.   
     
     
         15 . A syringe multipack comprising:
 a plurality of disposable syringe assemblies having syringe barrels lacking at least some of the scale markings required for use of the syringe assemblies; and   one or more reusable outer sleeves releasably attachable to the syringe barrels, the outer sleeves having the required scale markings lacked by the syringe assemblies; and   a package in which the disposable syringe assemblies and reusable outer sleeves are enclosed for sale or use;   wherein the number of disposable syringe assemblies in the package is greater than the number of reusable outer sleeves in the package.   
     
     
         16 . The syringe multipack of claim  30 , further comprising one or more reusable plungers in the package that are releasably attachable to stoppers contained within the syringe barrels of the disposable syringe assemblies, wherein the number of disposable syringe assemblies in the package is greater than the number of reusable plungers in the package. 
     
     
         17 . A syringe multipack comprising:
 a plurality of syringe assemblies comprising syringe barrels having stoppers therein; and   one or more reusable plungers that are releasably attachable to the stoppers in the syringe barrels of the syringe assemblies; and   a package in which the syringe assemblies and the reusable plungers are enclosed for sale or use;   wherein the number of syringe assemblies in the package is greater than the number of reusable plungers in the package.   
     
     
         18 . The syringe multipack of  claim 14 , further comprising one or more reusable outer sleeves in the package that are releasably attachable to disposable inserts in the package to form the syringe barrels of the syringe assemblies, wherein the number of disposable inserts in the package is greater than the number of reusable outer sleeves in the package. 
     
     
         19 . A packaged tubular insert for a syringe, the tubular insert forming a fluid reservoir and having a fluid opening at a distal end thereof and a stopper movably received in the tubular insert for sealing a proximal end of the tubular insert and for displacing fluid into or out of the tubular insert through the fluid opening upon movement of the stopper within the tubular insert, the tubular insert lacking a plunger, printed scale markings, or both. 
     
     
         20 . A method for reducing the effective per-unit cost of a syringe and for reducing the waste and environmental impact resulting from use of the syringe without compromising sterility, comprising using a first syringe to transfer a fluid, disposing of one or more components of the first syringe that contacted a fluid path of the first syringe during such use, and reusing in a second syringe one or more components of the first syringe that did not contact a fluid path of the first syringe during such use.