Abstract:
Disclosed is a medical device used to prevent the cross-contamination of patients or injectors in which various components placed on the injector minimize or eliminate back splash contamination of the injector.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    Pursuant to 35 U.S.C. §§119(e) and 120, this application is a continuation-in-part application of U.S. application Ser. No. 09/685,499, filed Oct. 10, 2000, which claims priority to Russian Application No. 99121141, filed Oct. 12, 1999 and Russian Application No. 99124268, filed Nov. 23, 1999, and this application claims priority to prior U.S. provisional application No. 60/329,081, filed Oct. 12, 2001, the disclosures of which are incorporated herein by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to a protector cap with an auto-disable feature for needle-free drug delivery devices for animal and human health applications.  
         BACKGROUND OF THE INVENTION  
         [0003]    The most effective measure to prevent many diseases among animals and/or humans is the mass immunization with vaccines. Needle-free injectors have been used to accomplish this task. The traditional needle-free injectors comprise the basic design, a housing with an inner power unit, a medication unit, and a nozzle. The power unit pumps the medication into an under-plunger cavity of the medication unit chamber and expels the medication through the nozzle.  
           [0004]    With the use of a typical jet injector, there exists the possibility of infection transfer from one subject to another by means of fluids (blood, lymph, medication) reflected from the skin surface during injection (“back splash”) that may get on the nozzle and be transferred from one patient to the next. Further, in the injection stage, the contaminated matter can be transferred through the nozzle to inside the injector such as, for example, into the cavity and be transmitted to a new patient through a new cap and nozzle.  
           [0005]    Accordingly, there is a need in the art of needle-free injection devices to solve the problem of cross-contamination during mass vaccinations. More particularly, there is a need for a protector designed for the nozzle head of needle-free injectors, which halts “back splash” contamination, and which is low enough in cost to ensure its practical application as a disposable unit even for mass vaccinations.  
         SUMMARY OF THE INVENTION  
         [0006]    The preceding problems are solved and a technical advance is achieved by the present invention. Disclosed is a protector cap for a needle-free injector having an insert and a baffle integrally joined and a disable device located between the insert and the baffle.  
           [0007]    The protective cap may be a one-shot cap. One purpose of this device is to prevent the multiple use of a cap. This may be achieved through the removal, replacement, and/or destruction of the cap at the later stage of the injection. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0008]    [0008]FIG. 1A demonstrates an exploded view of a simple embodiment of the present invention.  
         [0009]    [0009]FIG. 1B demonstrates the simple embodiment in assembled form.  
         [0010]    [0010]FIG. 2 shows an exploded view of another embodiment of the present invention in which another component is introduced.  
         [0011]    [0011]FIG. 3 shows an exploded view of another embodiment of the present invention in which some components are modified.  
         [0012]    [0012]FIG. 4 shows other embodiments of the present invention in which a protective layer is shown at various positions.  
         [0013]    [0013]FIG. 5 shows yet another embodiment of the present invention in which an intermediate piece is shown.  
         [0014]    [0014]FIG. 6 shows yet another embodiment of the present invention in which a protective layer is shown at various positions.  
         [0015]    FIGS.  7 A-D depict several different embodiments of the protective layer of the present invention.  
         [0016]    [0016]FIG. 8 is one embodiment of the protector cap of the present invention.  
         [0017]    [0017]FIG. 9 is another embodiment of the protector cap of the present invention.  
         [0018]    FIGS.  10 A-C depict the operation sequence of the protector cap and injector during an injection. 
     
    
     DETAILED DESCRIPTION  
       [0019]    [0019]FIG. 1A demonstrates an exploded view of the present invention. An injector assembly  10  is shown. One purpose of the injector assembly  10  is to provide needless injection of medicaments into the skin  12 . As described herein, the injector assembly  10  is provided with a layer, such as protective layer  14 . The protective layer  14  generally comprises a material that is adapted to permit the injection of medicaments in one direction, yet minimize or retard the reverse flow. The source of the medicament jet stream is from an injector  18 . In this regard, the protective layer  14  can serve as a back splash guard. In this particular, exemplary, and non-limiting embodiment, an optional baffle  16  is provided to facilitate the diminution of back splash.  
         [0020]    The baffle  16  may further comprises a baffle orifice  20 , which can take any desired shape or size, depending on the intended use. In this regard, the length and cross-section of the baffle orifice  20  will influence how much back splash hits the protective layer  14 . It is contemplated in all embodiments that the size of the baffle orifice  20  can be sized to minimize disruption of the medicament jet stream yet maximize the protection afforded by the protective layer  14 . If the baffle orifice  20  is too small, the baffle  16  may disrupt the jet stream and thereby reduce the energy of the stream. If too much diminution of the stream energy occurs, then the jet stream will not penetrate the skin  12  in the desired fashion to the desired depth.  
         [0021]    Baffle  16  can be sized to accommodate the needed configuration, and may optionally include baffle wings  15  to ensure proper skin stand-off. Of course the length and diameters may vary significantly, but in one example, baffle  16  can be approximately greater than 11 mm in diameter and 5 mm tall. Generally, the diameter of the baffle orifice  20  should be slightly larger than the diameter of the jet stream. Therefore, it does not really matter how large the baffle orifice  20  is so long as it is slightly larger than the jet stream diameter, irrespective of the diameter of the injector orifice  22 .  
         [0022]    Injector  18  has an injector orifice  22  at the distal end of an injector canal  24 . The medication sought to be injected travels through the injector canal  24 , exits through the injector orifice  22  and punctures the protective layer  14 . The medication jet stream then enters the baffle orifice  20  and impacts the skin  12 . The energy of the jet stream is chosen to provide the desired injection, depth, and location. For example, for a deeper injection, a higher energy will be necessary. The medicament jet stream then enters the skin  12  and travels to the desired situs. However, the impact on skin  12  is not without some attendant consequences. One consequence is that surface tissue, fluids, cells, and cellular contents are removed or ablated from the surface of skin  12  and fly about. This back splash of debris can travel back along the jet stream and impact the baffle  16  and protective layer  14 . The debris, though, is generally not traveling fast enough to re-puncture the protective layer  14 . In this regard, the protective layer  14  retards or minimizes the debris back splash into the injector orifice  22  and the injector  18 . One function of the layer  14  is to prevent the contamination of the injector  18 . In this regard, the simple concept of the invention is to protect the injector orifice  22  from contamination. Thus, in the event no baffle  16  is used, the injector  18  itself may bear the protective layer  14 .  
         [0023]    The material chosen for the layer  14  may comprise any material that facilitates a fluid stream puncture in one direction, yet retard the fluid stream puncture in the opposite direction. For example, the layer  14  can comprise a biochemically inert material that is approved for contact with pharmaceuticals, such as but not limited to, at least one of a plastic, rubber, polymer, polyethylene, polytetrafloroethylene, polyurethane, polypropylene, polyolefin, and polysulfone material. In this regard, a material that permits the perforation by the jet stream in one direction but then seals upon itself after the jet stream stops is more desirable. The protective layer or layers are desirably thin, for example greater than 0.001 mm. Preferably and nonexclusively, the thickness can range in the about 0.004 to 0.08 mm range with a further thickness of about 0.2 to 0.5 mm. It should be noted that the thickness chosen is variable. Protective layer  14  may also be textured, woven, braided, or so configured to provide a better adhesion, if necessary, or to provide better attachment, or to prevent or minimize movement. For example, the layer  14  may have grooves of various types. As mentioned, the diameter of the protective layer  14  (if a disc, or the width if a strip) should be slightly larger than the diameter of the jet stream.  
         [0024]    As shown in FIG. 1A, the components are in exploded view. In assembly, the baffle  16  can be designed to fit within the injector  18  and sandwich the layer  14  generally between the baffle  16  and injector  18 . Desirably, the injector orifice  22  and baffle orifice  20  should line up to minimize any diminution of the stream energy. As with any connection and assembly herein, the baffle  16  can be adapted to provide a friction fit, snap fit, screw fit, or bayonet fit. Any component herein can also be heatsealed to fit.  
         [0025]    Protective layer  14  can be also adhered, bonded, or otherwise attached to the injector  18 , baffle  16  or to any part as desired.  
         [0026]    [0026]FIG. 1B demonstrates a simple embodiment of the present invention. As one can see, the protective layer  14  can be generally sandwiched between baffle  16  and the injector  18 . The protective layer  14  can be totally sandwiched or partially sandwiched between the components described herein. As the medication is injected out through injector canal  24  and injector orifice  22 , it will penetrate through the layer  14  and through the baffle orifice  20 .  
         [0027]    It should be noted that in any embodiment of the present invention, the medication need not be liquid. In addition to aqueous solutions, the present invention may employ suspensions, aqueous gels, emulsions, or controlled release injectable medications. One other dosage form includes powder. For example, Powderject Pharmaceuticals, of Oxford, United Kingdom, and/or Powderject Vaccines (Madison, Wisc.) have developed an injector that propels medicine in powder form in the same manner as traditional needle-free injectors. For example, see, U.S. Pat. Nos. 5,733,600; 6,053,889; and 5,899,880; the disclosures of which are expressly and entirely incorporated herein. Since the powder form of drugs take up less than 1% of the volume of drugs in liquid form, adapting the powder injectors to be used in accordance with the present invention is also contemplated.  
         [0028]    Generally, but not exclusively, the powder particles of one dose can range in size but are generally 50 microns wide, as compared to a 500 micron wide syringe needle. In other words, powder form vaccines, such as recombinant DNA based vaccines, including Hepatitis B and HIV vaccines, and other medications for treating influenza, tetanus, erectile dysfunction, allergies, pain, cancer, etc., are contemplated. Such powder forms may be admixed with small amounts of sterile water or other physiologically acceptable diluents (e.g., about 1-10%) to form pastes or suspensions. Therefore, adapting the powder injectors to have a protective cap and/or film consistent with the present invention is within the ordinary skill in the art.  
         [0029]    [0029]FIG. 2 demonstrates another embodiment of the present invention. The injector assembly  10  is shown having a baffle  16  and an insert  26 . The insert  26  can be adapted to form an insert reservoir  27 . Insert  26  also has an insert distal orifice  28 . Insert  26  can be adapted to fit with baffle  16  such that the insert  26  provides an additional benefit of back splash protection, during or after the injection is completed. Insert  26  can be adapted to fit with baffle  16  such that insert  26  helps to properly tension the skin for the injection type (intramuscular, subcutaneous, or intradermal). As shown in this particular, exemplary, and non-limiting embodiment, the protective layer  14  is generally located between, either partially or completely, the baffle  16  and the injector orifice  22 . In this configuration, the jet stream will exit the injector orifice  22 , penetrate through the layer  14 , and exit through the baffle orifice  20  and insert distal orifice  28  to impact the skin  12 . The skin debris will back splash against the insert  26  and any debris that flies into the insert distal orifice  28  will likely be stopped by the baffle  16 . In the event that debris trajectory permits debris to travel through the baffle orifice  20 , the debris will impact the distal surface  29  of layer  14 .  
         [0030]    In this regard, the injector orifice  22  is protected against contamination. The debris that hits the protective layer distal surface  29  will likely fall into the insert reservoir  27  and collect there. Insert  26  can be adapted to fit into the baffle  16  as needed. One benefit of the insert configuration is the disposability of the unit. As for configuration, the injector orifice  22  can be varying distances away from the skin  12 . For example, it can be adjacent the skin  12  (where a baffle or insert is not used and the layer  14  is attached directly to the injector  18 ), or millimetres away, such as 2-15 mm away. Naturally the distance chosen will reflect on the stream energy. Desirably, the injector orifice  22  distance from the skin  12  is chosen with this in mind. In some configurations, the proximal face of the baffle  16  could be millimetres away from the skin, such as 2-15 mm and desirably 2-7 mm. Insert orifice  28  diameter is also sized accordingly, such as 0.001 mm or greater. In one commercial embodiment, however, the insert  26 , baffle  16 , and protective layer  14  can be discarded as a unit upon contamination.  
         [0031]    [0031]FIG. 3 represents another embodiment of the present invention. Shown are the baffle  16 , insert  26 , protective layer  14 , and injector  18 . In this configuration the baffle  16  is adapted to provide a greater surface area exposed to potential back splash. The insert  26  is also adapted to minimize back splash contamination. For example, insert  26  has an insert inner surface  30  and an insert outer surface  32 . As shown in dotted lines, the insert  26  can be configured to form “wings” in which the insert  26  will cooperate with the baffle  16 . Baffle  16  has a baffle inner surface  34  that cooperates with the insert  26 . As shown in this embodiment, the insert outer surface  32  is in cooperation with the baffle inner surface  34 . The wings of the insert  26  come into proximity of each other to form an insert proximal orifice  36 . In this embodiment, any back splash of skin debris entering the insert distal orifice  28  will likely hit the insert inner surface  30 , or the baffle inner surface  34 , or the distal surface  29  of protective layer  14 . In the event insert  26  is configured to not have wings, any debris can still hit the insert inner surface  30 , the baffle inner surface  34 , or the distal surface  29  of protective layer  14 .  
         [0032]    [0032]FIG. 4 demonstrates yet another embodiment of the invention. Shown is a plurality of protective layers  14  shown in phantom  38 . In this exemplary and non-limiting embodiment, the protective layer  14  is shown covering the baffle orifice  20 . The protective layer  14  can be integrally formed with the baffle  16  or can be separately affixed to the baffle  16 . In this embodiment, the removal of the baffle  16  facilitates disposability.  
         [0033]    Also shown is that multiple protective layers  14  are present. Protective layers  14  can be generally found proximal the skin, coincident with the insert distal orifice  28 , proximal to the insert distal orifice  28 , distal to the baffle  16 , distal to the baffle orifice  20 , coincident with the baffle orifice  20 , or proximal to the baffle orifice  20 . The number of protective layers can be chosen to maximize the jet stream energy for puncture purposes, but diminish back splash contamination potential. Also shown in FIG. 4 is the assembly in which the insert  26  and baffle  16  are within the injector assembly  18 . Where multiple layers are used, the layers can be attached using bonding, heatsealing, or sandwiching the layers.  
         [0034]    As seen in FIGS.  7 A-D, it should be noted that in any embodiment herein, the protective layer  14  or film need not be a separate piece. Rather it may be integrally formed with a component, such as a septum. For example, the protective layer  14  may be part of the baffle  16  in which that area that will be punctured by the jet stream is adapted to give way during injection. For example, if the baffle  16  is made of plastic, then the area that will serve as the protective layer can be integral with the baffle  16  yet be “ground” down slightly to make it thinner or more easily adapted to perforation. In yet another embodiment, the layer  14  may be separately manufactured then adhered in some fashion to a component, such as the baffle  16 . In yet another embodiment as shown in FIG. 7D, a plurality of films may also be used (as shown in phantom lines).  
         [0035]    [0035]FIG. 5 demonstrates yet another embodiment of the present invention. Baffle  16  is provided with a plurality of baffle legs  40 . The baffle legs  40  can be adapted to cooperate with an intermediate piece  42 . The intermediate piece  42  has a proximal and distal end such that various components can be attached to either or both ends. In this particular, exemplary, and non-limiting embodiment, intermediate piece  42  has an intermediate piece orifice  44  therethrough. This intermediate piece orifice  44  can be formed by one or more intermediate piece extensions  46 . As with any orifice described herein, the size and shape of the orifice  44  may determine the potential back splash contamination and the interruption of the jet stream energy. Intermediate piece  42  can be connected to injector  18  and/or baffle  16  and/or insert  26  via an intermediate piece connector  48 . The intermediate piece connector  48  can include any mechanism to attach one piece to another, and can further include a friction fit, bayonet, or screw fitting.  
         [0036]    Therefore, as medication is extracted from the medication vial  50 , it is drawn into the injector chamber  52  wherein the injection system  10  then delivers the medication through the injector canal  24 , through the injector orifice  22 , into the intermediate piece  42 , through the intermediate piece orifice  44 , and then through the various distal components.  
         [0037]    As shown in FIG. 5, upon exiting the intermediate piece orifice  44 , the medication will penetrate the protective layer  14  and then enter the baffle  16  via the baffle orifice  20 , then through the insert reservoir  27 , through the insert distal orifice  28 , to then impact the skin  12 .  
         [0038]    Skin debris, if it has the correct trajectory, can enter the insert  26 -baffle  16  component. Debris can either strike the baffle  16 , such as baffle splash guards  54 , or insert  26  itself, or can strike the protective layer distal surface  29 . In the event that the debris has sufficient energy to re-puncture the layer  14 , debris will then strike the intermediate piece  42 , such as the intermediate piece extensions  46 . In this manner, the only manner in which the injector tip is contaminated is if the debris enters the intermediate piece  42  at such a precise trajectory that is flies through the orifice  44  and directly hits the injector orifice  22 .  
         [0039]    However, although not shown in FIG. 5, a plurality of protective layers  14  can be used at various stages along the insert  26 , baffle  26 , or intermediate piece  42 . Intermediate piece  42  can also include an optional intermediate piece channel  56 , which fluidly communicates with the atmosphere and the intermediate piece lumen  57 . This permits an equalization of pressure in the lumen  57  and also permits any debris in the lumen  57  to be evacuated. As for size, intermediate piece channel  56  can be approximately any size but may be about 1 mm.  
         [0040]    Therefore, the injector assembly  10  provides increased resistance to contamination using a variety of components. It is noted that in any and all embodiments described herein, no individual component is critical or necessary for accomplishing the invention.  
         [0041]    For example, the embodiment of FIG. 5 can be configured so that it does not have an insert  26 , a baffle  16 , a protective layer  16 , or the intermediate piece  46 . In FIG. 5, the addition of the insert  26  and baffle  16  provide added benefit.  
         [0042]    [0042]FIG. 6 demonstrates yet another embodiment of the present invention. In this embodiment, an insert  26  plays many roles. First, the insert  26  is provided with an insert connector  60 , shown here by example only, as a screw fitting. The intermediate piece  42  is provided with an intermediate piece distal connector  62 , as shown by example only, as a screw fitting. Accordingly, the intermediate piece distal connector  62  cooperates with the insert connector  60  to provide a detachable attachment. The, insert  26  is adapted to provide the same characteristics as the baffle  16  (not shown) in that it can be adapted to also have an insert splash guard  64 . While the protective layer  14  is shown proximal to the insert  26 , the intermediate piece  42  can also include an intermediate piece protective layer  66  located anywhere along the intermediate piece  42 . This intermediate piece protective layer  66  is shown in phantom either distal to the intermediate piece orifice  44 , coincident with the orifice  44 , or proximal to the orifice  44 . In this regard, the intermediate piece protective layer  66  is distal to the injector orifice  22 . In operation, the debris that enters the insert  26  will likely impact the insert splash guard(s)  64 , the protective layer  14 , the intermediate piece extension(s)  46 , or the intermediate piece protective layer  66 . In this regard, the disposability of the components is enhanced in that the intermediate piece inner surface  68  remains generally clean in that most debris stays within the insert  26  or strikes the protective layers  14 , 66 .  
         [0043]    [0043]FIG. 8 depicts another embodiment of the present invention. The baffle  16  and the insert  26  may be heat-sealed or otherwise bonded to form an integral protector cap  100  with an insert reservoir  27 . The baffle  16  may be a flat sheet or may have a dome shape, as depicted in FIG. 8 to facilitate intra-dermal injections, for example. In one embodiment, the baffle  16  and the insert  26  cannot be taken apart or modified without destroying the protector cap  100 . The baffle  16  includes a flange  80  to which the insert  26  is bonded. In one embodiment, the baffle  16  may include ribs  81  on the flange  80  to stiffen the cap structure and ensure proper placement of the baffle layer against the skin and prevent slippage. The protective cap  100  may further include a disable device. In one embodiment, the disable device is a central washer  82  located between the baffle  16  and the insert  26  in the insert reservoir  27 . The central washer  82  may also include a washer orifice  84  that lines up with the baffle orifice  20  and the insert orifice  28  when the central washer  82  is in an installed position. For use during an injection, the central washer  82  must be located in the installed position. Thus, the protector cap  100  creates four challenges for blood or debris to enter the injector canal  24 : the insert orifice  28 , the washer orifice  84 , the baffle orifice  20 , and the injector orifice  22 .  
         [0044]    Upon injection, the baffle  16  of the protector cap  100  becomes distorted due to the pressure created by the subject&#39;s skin  12  or by an injector component, as described below. The baffle  16  may also become distorted during packaging and shipping if not handled carefully. When the baffle  16  becomes distorted, the central washer  82  dislodges in the insert reservoir  27 . As a result, the washer orifice  84  no longer lines up with the baffle orifice  20  and the insert orifice  28 , thereby disabling the protector cap  100  for further use. As a result, entry of the debris or blood into the injector canal  24  is even more difficult because the orifices  28 ,  84 ,  20  and  22  are no longer aligned. In one embodiment, the central washer  82  is tinted to a different color than the insert  26  or baffle  16  so that the user can determine whether the central washer  82  is in the installed or disabled position.  
         [0045]    In another embodiment of the protector cap  100  depicted in FIG. 9, the shape of the baffle  16  may be modified to ease the disabling of the protector cap  100 . The insert  26  may include a hinge  88  having a lug  90  for holding the central washer  82  in the installed position. The hinge  88  produces a double hinge line that allows the baffle  16  to deflect as shown in the operation sequence of FIG. 10A-C. The hinge  88  provides for programmed deflection of the baffle  16  to ensure that the central washer  82  is dislodged before the cap  100  is ejected from the injector  18 . Upon application of pressure, the baffle  16  distorts and pops the central washer  82  from its installed position on the lug  90  (FIG. 10A) to a dislodged position (FIG. 10B). In one embodiment, a bead  92  has been added near the flange  80  of the baffle  16 . The bead  92  locks into a grove or other locking feature of a cap receiver  110  on the injector  18 .  
         [0046]    In the operation sequence of FIG. 10, pressure from the cap receiver  110  of the injector  18  distorts the baffle  16  rather than pressure from placement against the skin  12 . A sliding sleeve  112  in the cap receiver  110  contacts the hinge  88  of the baffle  16 , causing the hinge line of the hinge  88  to flex and knocking the central washer  82  out of its installed position. Once the central washer  82  is loose in the insert reservoir  27  of the protector cap  100 , the protector cap  100  is disabled and will not allow a stream from the injector  18  to penetrate. After being disabled, the sliding sleeve  112  continues to move forward towards subject and pops the protector cap  100  free of the cap receiver  110 . In one embodiment, the injector  18  cannot be fired unless the protector cap  100  is in the cap receiver  110 .  
         [0047]    The protector cap  100  may further include a protective layer  14 , as described above. The protective layer  14  may cover the insert orifice  28 , the washer orifice  84 , the baffle orifice  20 , or the injector orifice  22  or may be suspended within the insert reservoir  27 . In another embodiment, the protector cap  100  may further include an upper washer  86  that holds the protective layer in place when the protective layer is made from a material that can not adhere to the material of the baffle  16 .  
         [0048]    Protector caps  100  may be packaged individually or in packets. In one embodiment, protector caps  100  are packaged as part of a kit. The protector caps  100  may be packaged in individual or numerous rows. A cradle with a separate well for each protector cap  100  may be sealed with an adhesive strip to provide a contamination free environment.  
         [0049]    Although the present invention is described by reference to a single and exemplary embodiments, and the best mode contemplated for carrying out the present invention has been shown and described, it is to be understood that modifications or variations in the structure and arrangements of these embodiments other than those specifically set forth may be achieved by those skilled in the art and that such modifications are to be considered as being within the overall scope of the present invention. It is to be further understood that the following pending patent applications owned by the assignee of the instant application are hereby incorporated by reference in their entirety as if fully set forth herein: U.S. Ser. No. 09/685,499; PCT/US00/41122; U.S. Ser. No. 09/685,633; PCT/US00/27991; U.S. Ser. No. 09/717,548; PCT/US00/32186; U.S. Ser. No. 09/717,559; PCT/US00/32187; U.S. patent application Attorney Docket No. 02033872 for “Jet Injector System with Hand Piece” filed on Oct. 11, 2002.