Patent Document

RELATED APPLICATIONS 
     This is a continuation application of copending International Patent Application PCT/EP2008/005867 which was filed on Jul. 17, 2008 and published in English, and claims priority of European Patent Application 07014576.8 filed on Jul. 25, 2007. The entire contents of these priority applications are fully incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The invention relates to an application device for applying a dispensable material that is stored in a cavity of some kind of a receptacle. More particularly, the material may be a liquid, semi-liquid, pasty or powdered material preferably used for medical, diagnostic, cosmetic or dental applications. The application device comprises a closed state and an open state. It may be configured as an injection device configured for single or multiple use and having a closed state and an open state. 
     From US 2005/0215952 A1 an application device configured as a single-use syringe is known which comprises:
         a tubular receptacle enclosing a cavity for receiving a liquid;   a bung made of an elastic material being held at a first longitudinal end of the tubular receptacle and comprising a through channel that is fluidly connected with the cavity;   a holder engaging the bung; and   a needle secured within the holder and comprising a delivery duct fluidly connected with the through channel.       

     The known syringe includes a tubular receptacle provided with sealingly closing-off elements delimiting a chamber, intended to be filled with a liquid, and having a liquid-delivery duct opening into the chamber, a needle-carrying base having a duct for supplying a liquid to the needle and being axially movable between a retracted position in which the delivery duct is closed-off, and an advanced injection position in which it allows the liquid to flow out of the chamber to the needle, a cap having a shape adapted to cover the base and provided with elements for detachable connection to the tubular receptacle, axial-stop elements arranged so as to keep the base in its closing-off position when the latter is covered by the cap, and axial stop elements arranged so as to limit the axial displacement travel of the base, once the cap is removed. 
     The known device suffers from several draw-backs: First of all the opening and closing system of the syringe relies on clips made of hard plastic material that engage recesses provided on the holder. Reliability of the working of these clips is based on plastic molded parts and relative tolerances between these parts. 
     Also the basic principle of this syringe for moving from the closed state to the open state is based on a sliding seal. There is the potential risk of a blocking of the seal after extended storage time. If the axial movement is impeded or blocked in some way, then there is the risk that the syringe may not be activated to allow an injection of the stored liquid to a patient. 
     There is a variety of other so-called “dry needle” application devices, comprising a tubular receptacle containing the liquid to be injected and closed off by a membrane, and a double-point needle which can be displaced axially relative to the tubular receptacle so as to pierce the membrane at the moment of injection. (DE 2 055 840; U.S. Pat. No. 4,720,285; WO 96/013171). 
     The provision of a membrane seal poses a complication of the manufacturing process. In addition, there is always a necessary activation movement either by twisting of the cap or by an axial displacement of the part penetrating the membrane. 
     Again, there is the risk of blocking of the penetrating needle so that the syringe may not be activated. Further there is the risk of generating particles as well. 
     SUMMARY OF THE INVENTION 
     In view of this it is a first object of the invention to disclose an improved application device for applying a material stored within a cavity which is easy to manufacture and can be conveniently and reliably be activated for use. 
     It is a second object of the invention to disclose an improved application device for applying a material which is suitable for long-term storage the material stored within the application device. 
     It is a third object of the invention to disclose an improved application device which can be used as ready-to-use syringe filled with a medical material. 
     It is a forth object of the invention to disclose an improved application device that can be used as a ready-to-use syringe filled with a medical material that avoids leakage after long-term storage. 
     It is a fifth object of the invention to disclose an improved method for manufacturing an application device that is prefilled with a material to be applied. 
     According to the invention these and other objects of the invention are achieved by an application device for applying a dispensable material, the application device having a closed state and an open state and comprising:
         an elastic part made of an elastic material and having a through channel being configured for engaging a cavity of a receptacle;   a holder comprising a support for receiving a dispensing means fluidly connected with the through channel; and   a pinch seal sealing the through channel when being in said closed state.       

     The object is fully achieved in this way. 
     Namely, the sealing is effected in a very simple way. 
     If possibly after extended storage time there should occur some sticking within the through channel so that the pinch seal is permanently blocked, it may be opened by exerting a pressure. 
     Alternatively, or in addition, the internal surface of the through channel of the elastic said elastic part may comprise a coating made of a material preventing sticking of the internal surface and interaction with any dispensable material filled into the cavity of the receptacle. This coating may, e.g. be a parylene or PTFE coating. 
     So there is no risk that the application device cannot be transferred into its open state even after extended storage life. 
     According to a preferred embodiment of the invention a cap is fitted onto a peripheral portion of the holder for compressing the holder at least partially to effect the pinch-seal. Further, the cap may comprise an end portion that at least partially fits into the collar, in particular into a hollow tubular portion of the collar. 
     These features help to facilitate a long-term sealing of a material obtained within the cavity of the receptacle. While the cap may consist of a material that may be subject to creeping during long-term storage, such possible creeping is prevented by the collar that may consist of a more stable material. 
     According to a further feature of the invention the elastic part comprises a peripheral flange resting against an end portion of the receptacle, the peripheral flange being sealed against said end portion by the holder which at least partially encloses the peripheral flange and secures it to the end portion of the receptacle. 
     Thus the application device includes an integrated sealing of the cavity of the receptacle with the delivery means or needle connected thereto. 
     According to a preferred embodiment of the invention the receptacle is configured as a syringe barrel, cartridge, vial, bottle or bag. 
     According to a further embodiment of the invention the dispensing means is configured as a needle or as a coupling, in particular as a Luer-Lock thread, for attaching a part. 
     So the dispensing means may preferably be coupled to a needle so as to allow an injection of the material stored within the cavity into a patient or into an animal, or to allow a direction into any other part attached by some sort of coupling such as a Luer-Lock thread, a bayonet type connector etc. 
     According to a further development of the invention the elastic part is configured as a bung at least partially received within the holder. 
     This allows for a simple design and easy activation or deactivation of the pinch seal. 
     According to a further embodiment of the invention the application device further comprises:
         a receptacle enclosing a cavity for receiving a dispensable material;   a bung made of an elastic material being held at a first longitudinal end of the receptacle and comprising the through channel that is fluidly connected with the cavity;   a holder engaging the bung; and   a needle secured within the holder and comprising a delivery duct fluidly connected with the through channel.       

     In this way the application device is configured as a syringe. 
     According to a further development of the invention the application device further comprises:
         a removable cap supported on a peripheral portion of the holder when being in the closed state;   wherein the cap, when being in the closed state, compresses the peripheral portion of the holder at least partially, thereby effecting the pinch seal; and   wherein the pinch seal of the through channel is released, when the cap is removed, thereby allowing delivery of the dispensable material from the cavity through the through channel to the dispensing means, in particular through a delivery duct to a tip of a needle.       

     Thus the application device may be configured as a ready-to-use prefilled injection syringe. 
     According to this design the pinch seal can be effected in a very simple way by compressing the bung with the cap when resting on a peripheral portion of the holder so that the through channel extending through the bung is fully blocked. When the syringe shall be made ready for use, only the cap must be taken off, thereby transferring the syringe into the open state. Upon removal of the cap the pressure exerted by the cap on the bung is released so that the bung flexes outwardly under its own elastic force thereby freeing the through channel. 
     In addition, since the pinch seal is merely effected by compressing the elastic bung by the cap being supported on a peripheral portion of the holder, the operation of the syringe is not influenced by any clip tolerances, and activation of the syringe can be effected very reliably. 
     According to a further development of the invention the holder comprises at least one flexible arm that is pressed by the cap against the bung to generate a pinch seal of the through channel when being in the closed state. 
     This feature allows a very effective sealing of the through channel, since the flexible arm allows to generate a high pressure on the bung so as to effect a good pinch seal. 
     According to a further development of this design the at least one flexible arm is biased to the outside so as to release the pinch seal upon removal of the cap. 
     In this way an easy release of the pinch seal is effected upon removal of the cap. So the flexible arm allows to generate an effective pinch seal when being in the closed state and to reliably transition into the open state under its own biasing force. 
     Preferably the holder is made of a hard plastic material that generates a biasing force on the at least one flexible arm when pressed into the closed state. 
     In this way no additional biasing means, such as a spring means, is necessary to effect the desired biasing force. 
     The bung may preferably be made of a polypropylene, a thermo plastic elastomer (TPE), silicone rubber (LSR) or a different rubber type material. 
     Such a material provides the desired resilience to effect a good pinch seal in the compressed state and to release the pinch seal upon release of the outer pressure. Also this material can easily be molded into the desired shape. 
     According to a further development of the invention the tubular receptacle comprises a tubular extension being connected to the reminder of the tubular receptacle by a neck portion, wherein the holder comprises a hollow tubular portion that is mated to the tubular extension and comprises an inner rim portion protruding to the inside and engaging the neck portion for securing the holder on the tubular extension. 
     This allows for a simple and reliable design. 
     According to a further development of this design a collar is fitted onto the periphery of the hollow tubular portion for locking the inner rim portion onto the neck portion. 
     This allows for a simple assembly and a reliable securement of the holder on the tubular extension of the tubular receptacle. 
     According to a further development of the invention the bung comprises a peripheral flange being secured within the hollow tubular portion of the holder abutting the tubular extension of the receptacle. 
     Thereby reliable design and safe seal is facilitated. 
     The cap is preferably made from a rigid material, preferably from a hard plastic material. 
     This design allows an easy manufacture by molding and, in addition, provides sufficient rigidity to effect the necessary pressure for the pinch seal when being seated on the peripheral part of the holder. 
     According to a further development of the invention the cavity of the tubular receptacle is filled with a liquid which is sealed by a piston that is displaceable within the tubular receptacle by a piston rod. 
     In this way the single-use application device is filled with the desired liquid that can be expelled from the tip in the usual manner by exerting pressure on the piston rod for advancing the piston within the tubular receptacle. 
     According to a further embodiment of the invention the application device comprises a plurality of pinch seals coupled to different dispensable materials allowing a mixing of the materials after transfer of the pinch seals into the open state. 
     Thus a series of pinch seals may be used to seal of different dispensable materials and to effect a mixing of the materials when the pinch seals are transferred into the open state. 
     The object of the invention is further solved by a method of manufacturing an application device having a closed state at an end an open state, the method comprising the following steps:
         providing a receptacle enclosing a cavity for receiving a liquid;   attaching a bung made of an elastic material to the receptacle so that a through channel extending through the bung is fluidly connected with the cavity;   providing a holder comprising a support for receiving a dispensing means fluidly connected with the through channel;   attaching the holder to the bung so that the bung is at least partially enclosed from the outside and that the dispensing means is fluidly connected with said through channel;   fitting a collar onto an end portion of the receptacle;   providing a removable cap;   attaching the cap onto a peripheral portion of the holder thereby pressing at least a portion of the holder onto the bung, thereby generating a pinch seal of the through channel; and   securing an end portion of the cap within the collar.       

     Such a pre-manufactured application device may be filled with a drug material by a drug manufacturer by filling the cavity with the liquid, pasty or powdered material and sealing the filled cavity to the outside by inserting a piston held displaceably within the tubular cavity at an end of a piston rod. The application device is suitable for long-term storage of materials, such as drug materials. 
     The holder may support an injection needle or some kind of coupling such as a Luer-Lock thread or a bayonet-type connection. 
     Prior to filling the application device may be sterilized either in an assembled state or in a pre-assembled (open) state. 
     It is understood that the features of the invention mentioned above and those yet to be explained below can be used not only in the respective combinations indicated, but also in other combinations or in isolation, without leaving the scope of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the invention will become apparent from a preferred embodiment of the invention which will be described hereafter with reference to the drawings which are of merely exemplary nature without limiting the scope of the invention and in which: 
         FIG. 1  shows a perspective view of an application device according to the invention; 
         FIG. 2  shows an enlarged longitudinal partial section of the application device according to  FIG. 1  in the region of the cap and the adjoining longitudinal end of the tubular receptacle, shown in the closed state with the cap attached; and 
         FIG. 3  shows the application device of  FIG. 2  in its open state, after removal of the cap. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In  FIG. 1  a single-use application device according to the invention is shown in perspective view and depicted in total with reference numeral  10 . 
     The application device  10  comprises a tubular receptacle  12  which is configured as a glass cylinder, having a first longitudinal end  13  and a second longitudinal end  14  and enclosing a cavity  15  that can be filled with a liquid. The cavity  15  is sealed to the outside by a piston  18  held at the end of a piston rod  20  and sealed against the interior wall of the cavity  15  by suitable sealing rings (not shown). 
     The application device  10  is shown in  FIG. 1  in its closed state in which the cavity  15  is sealed against a needle supported on the first tubular end  13  of the tubular receptacle  12  and surrounded by a collar  24  and an attached cap  22 . 
     For transferring the application device  10  from its closed state shown in  FIG. 1  to an open state in which a liquid can be injected through the needle  32  shown in  FIGS. 2 and 3 , merely the cap  22  needs to be removed and thereafter the piston  22  can be advanced within the cavity  15  by pressing the end of the piston rod  20  with one finger while holding the tubular receptacle  12  at a gripping flange  16  provided on the second longitudinal end  14  with two fingers. 
     The details of the application device that allow a sealing of the cavity  15  against the needle  32  when being in its closed (or “dry”) state and for transferring the application device into its open state in which liquid stored within the cavity  15  can be injected through a tip  38  of the needle  32  will be explained hereinafter with reference to  FIGS. 2 and 3 . 
     According to  FIG. 2  the tubular receptacle  12  comprises a tubular extension  45  having a smaller diameter than the reminder of the tubular receptacle  12  and being connected to the remainder of the tubular receptacle  12  by a neck portion  44  defining a circumferential recess. Held within the inner wall of the tubular extension  45  is a bung  46  made of a polypropylene material or from TPE. The bung is of generally cylindrical shape resting with a peripheral flange  50  against the end surface of the tubular extension  45  and having a central through channel  48  that opens into the cavity  15  at one end and opens into a delivery duct  36  of the needle  32  at the other end. 
     In  FIG. 3  the bung  46  is shown in its released state so that the central through channel  48  is not blocked by a pinch seal effected in the closed state shown in  FIG. 2 . 
     A holder  26  preferably made of a hard but elastic plastic material is attached onto the outer surface of the bung  46  and comprises an enlarged portion  40  having a larger outer diameter with a hollow tubular portion  41  that is fitted onto the peripheral flange  50  of the bung  46  and onto the tubular extension  45  of the tubular receptacle  12 , thereby pressing the peripheral flange  50  of the bung  46  against the tubular extension of the receptacle  12 . To effect a proper securement, the enlarged portion  40  comprises an inner rim portion  42  at its end remote from the needle  32  engaging the neck portion  44  of the tubular receptacle  12 . To finally secure the holder  26  against removal from the tubular receptacle  12 , in addition, a collar  24  is pressed onto the peripheral wall of the enlarged portion  40  using a press fit and rests against a rim portion protruding outwardly at the end of the enlarged portion  40 . 
     The needle  32 , usually made of stainless steel is fitted into a central opening  28  of the holder  26  and secured by an adhesive  30  or by another means so that the inner end of the needle  32  rests about flush with the through channel  48  of the bung  46 . 
     The holder  26  at one side comprises a flexible arm  34  extending from a portion near the inner end of the needle  32  and having a free end remote from the needle  32 . The flexible arm  34  has a cross section of a wedged shape having a larger thickness at its free end than at its other end that is connected to the remainder of the holder  26 . The holder  26  is made from a hard but elastic plastic material that allows to bias the flexible arm  34  into the position shown in  FIG. 3  so that the bung  46  is not compressed in the open state indicated by numeral  10 ′ in  FIG. 3 . 
     For transferring the application device into a closed state in which the central through channel  48  of the bung  46  is sealed by the pinch seal  52  as shown in  FIG. 2 , the cap  22  needs to be attached on the holder  26 . The cap  22  is inserted onto a peripheral portion of the holder  26  resting with its end within a slot provided between the peripheral portion of the holder  26  and the collar  54  and abutting against the enlarged portion  40  of the holder  26 . In this closed state shown in  FIG. 2  the flexible arm  34  is pressed by the cap  22  to the inside against the bung  46  thereby effecting the pinch seal  52  of the through channel  48 , whereby the through channel  48  is effectively blocked. 
     This closed state shown in  FIG. 2  is the ready-to-use state of the application device filled for instance with a medical drug by a drug manufacturer. The liquid containing the drug solution within cavity  15  is sealed against the needle  32  by the pinch seal  52 . When the application device needs to be used, merely the cap  22  is pulled off from the holder  26  while holding the application device at the tubular receptacle  12 . Once the cap  22  is removed, as shown in  FIG. 3 , the flexible arm  34  flexes to the outside under its own bias thereby releasing the central through channel  48  so that the drug solution contained in cavity  15  may then ejected out of the needle tip  38  by advancing the piston rod  20  thereby expelling the drug solution through the needle tip  38 . 
     In case after a long storage period there should be some tendency of sticking between the two adjacent parts of the inner wall of the bung  46  effecting the pinch seal  52 , the pressure generated by advancing the piston  18  into the cavity  15  will effectively remove any potential blockage of the pinch seal  52 . 
     Alternatively, or in addition, the inner wall surface of the bung may comprise a coating (not shown) that is made from a material that prevents sticking and that prevents interaction with any drug material. Such a coating may, e.g. consist of parylene of PTFE (polytretrafluorethylene). This leads to a very reliable design.

Technology Category: a