MXPA06010161A - Needle and hub assembly for automatic injector - Google Patents

Abstract

A needle and hub assembly for an automatic injector and a method for making the needle and hub assembly. The needle and hub assembly comprises a cap or skirt (40), a forward surface of which is interposed between and reinforced by first (42) and second (44) engaged hub portions. A needle (46) is received in a contiguous channel formed in the two hub portions. The method for making the assembly comprises molding the first hub portion, placing the cap over the first hub portion, inserting the needle into a channel in the first hub portion, and then overmolding or otherwise forming the second hub portion on the exterior of the cap such that it is engaged with the first hub portion. An assembly created by this"two-shot"process can be used to seal a relatively large opening, and supports the needle more effectively than a conventional assembly.

Description

NEEDLE ASSEMBLY AND CENTER FOR AUTOMATIC INJECTOR CROSS REFERENCE TO RELATED REQUESTS This application claims priority of the Patent Application American Standard Number 10 / 797,565 filed on March 11, 2004 which is a continuation in part of the Request for US Patent Number 10 / 690,987 filed October 23, 2003 which is a continuation in part of the U.S. Patent Application Number 09 / 897,422, filed July 3, 2001 and 09 / 972,201, filed October 9, 2001. These two applications claim priority of the North American Provisional Requests Numbers 60 / 238,458, 60 / 238,448, and 60 / 238,447, all filed on October 10, 2000. The content of all these applications is incorporated by reference herein in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to drug delivery devices. More particularly, the present invention relates to needle and center assemblies for automatic injection devices. 2. Description of Related Art Many types of syringes and other injection devices are used in the art of medical devices. Typical syringes, for example, using a hollow needle to deliver a drug to a patient subcutaneously, intramuscularly or intravenously. The needle is usually connected to the portion of the syringe that holds the drug through a center assembly. The center assembly holds the needle and also supports it. An automatic injector is an injection device that allows intramuscular (IM) or subcutaneous administration of a dose of medication. In the typical autosampler, a cartridge carries the drug dose and is connected to a needle assembly. The cartridge and the needle assembly are within a frame that also carries a drive assembly. When the drive assembly is activated, the penetration of the needle and its protrusion from the frame is caused and the drug is injected into the patient. Thus, automatic injectors allow a quick and easy IM injection of a drug in emergency situations without the need to measure dosages. In addition, automatic injectors are comfortable for drug self-administration since the user does not see the needle before the device is actuated and there is no need to manually push the needle into the patient. There are three main types of automatic injectors. A first type is the one that carries the drug mixed in liquid form. A second type of automatic injector, known as a "wet / dry" type injector, has two separate compartments and carries the drug in the form of two components, a dry component and a liquid component. When the drive assembly is activated, a structure within the auto-injector cartridge pushes the dry component and the liquid component of the drug to mix. A third type of automatic injector, known as a "wet / wet" type injector, has two separate compartments and carries the drug in the form of two liquid components. The wet / wet type injector includes a structure within the cartridge that can push the two components to mix when the drive assembly is actuated or the automatic injector can supply the fluid consecutively. In a common arrangement of an automatic injector, one of the drug compartments is directly adjacent to the needle assembly. During fabrication, the compartment adjacent to the needle assembly is filled with a medicament component and the needle assembly is installed over the opening in the compartment to seal it. The needle assembly includes a needle center and the needle itself. With this type of arrangement, it is beneficial that the opening in the cartridge and the compartment is as large as possible since large openings allow easier filling of the compartment with the drug, especially when the drug or component is in the form of a dry powder or a lyophilized tablet. However, the size of the opening is limited in practice since it is difficult to make a needle assembly that can seal the compartment well and adequately support the needle. COMPENDIUM OF THE INVENTION One aspect of the present invention relates to a needle and center assembly for an injection device. The needle and center assembly comprises a cap, a first core portion, a needle and a second core portion engaged with the first core portion. The lid has a hooking portion constructed and arranged to engage an outer surface of a cartridge and a needle support portion having a wall that includes an opening therein. The wall defines interior and exterior surfaces. The first center portion defines a needle receiving channel through the opening in the wall and has a section extending along the inner surface of the wall. The needle is mounted in the needle receiving channel and extends outwards from there. The second center portion is engaged with the first center portion and receives at least a portion of the needle. The second center portion also has reinforcing structures that extend outwardly along the outer surface of the wall. The wall of the needle support portion of the lid is reinforced on the inner surface by the first center portion and on the outer surface by the second center portion. Another aspect of the invention relates to an automatic injector. The automatic injector comprises a frame, a cartridge, a drive assembly, a cover, a first center portion, a needle, and a second center portion, the cartridge is placed in the frame, has at least one opening and contains a drug. The drug is confined backwards by means of a plunger. The drive assembly includes a stored energy source that can be released to drive the plunger through the cartridge. The lid has a hooking portion constructed and arranged to engage an outer surface of the cartridge to cover the opening in the cartridge, and a needle support portion having a wall including an opening therein. The wall defines internal and external surfaces. The first center portion defines a channel that receives a needle through the opening in the wall and has a section extending along the inner surface of the wall. The needle is mounted in the needle receiving channel and extends outwards from there. It is adapted to expel the medication when the plunger is driven through the chamber. The second center portion is engaged with the first center portion and receives at least a part of the needle. The second center portion also has reinforcing structures that extend outwardly along the outer surface of the wall. The wall of the needle support portion of the lid is reinforced on the inner surface by the first center portion and on the outer surface by the second center portion. Another aspect of the present invention relates to a method for forming a needle and center assembly. The method comprises forming a first center portion, supplying a lid having an opening there and placing the first center portion such that a portion thereof extends through the opening in the lid, arranging a needle in a channel defined by the first center portion, and forming a second center portion on an outer surface of the lid such that the second center portion is engaged with the first center portion and is on at least one part of the outer surface of the lid. These and other aspects, features and advantages of the invention will be apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in combination with the following figures in which the same reference numerals designate similar elements in all figures, and wherein: Figure 1 is an open longitudinal cross-sectional view of a cartridge for an automatic injector having a needle and center assembly in accordance with an embodiment of the present invention.; Figure 2 is a perspective view of the center assembly of Figure 1 in isolation; Figure 3 is a partially cutaway perspective view of the needle and center assembly of Figure 1; Figure 4 is a longitudinal cross-sectional view of the needle and center assembly of Figure 1; Figures 5A-5D are perspective views of the needle and center assembly of Figure 1 after each successive manufacturing step; Figure 6 is a high-level schematic block diagram of a process for manufacturing a needle and center assembly in accordance with the present invention; Figure 7 is a perspective view of an auto-injector assembly having the cartridge and needle assembly in accordance with Figure 1; Figure 8 is a partial cross-sectional view of Figure 7 illustrating the cartridge and needle assembly of Figure 1; and Figure 9 is a perspective view of the autoinjector of Figure 7 illustrating the drive assembly.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 is an open longitudinal cross-sectional view of a cartridge and needle assembly generally indicated at 10, for an automatic injector 1, in accordance with one embodiment of the present invention. An example of the auto-injector 1 is illustrated in Figures 7-9. The cartridge and needle assembly 10 is generally of the type shown and described in commonly co-pending US Patent No. 10 / 690,987, even though principles, methods and structures in accordance with the present invention are more broadly applicable to other types of packaging. Cartridge and needle assembly. Typically, the cartridge and needle assembly 10 is contained within an external frame 2 that includes a drive assembly 3 having a stored energy source 4 such as a compressed spring, which is shown in Figure 9. Various types of Automatic injector racks are known in the art and any of these types can be employed with the cartridge and needle assembly 10 in accordance with the present invention. As such, the present invention is not considered limited only for use with the autosampler illustrated in Figures 7-9. In addition, it is contemplated that the needle assembly 14 may be used in a syringe to deliver drug. The cartridge 12 is of the type designed to maintain a liquid medicament component separately from a dry medicament component until the automatic injector is actuated, at which time the two components are mixed. However, a needle and center assembly 14 in accordance with embodiments of the present invention can be used with a wet / dry type cartridge such as cartridge 12, a wet / wet type cartridge, or a cartridge designed to house a drug one component liquid. The cartridge 12 is generally formed of glass, or other rigid material that does not react with the medicament or its components. The cartridge 12 is generally cylindrical and has a smooth cylindrical internal surface. The cartridge 12 is divided into a moist medicament compartment 16 and a dry medicament compartment 18. The medicament contained within the dry medicament compartment 18 may be in powder form, lyophilized, or in any other solid formulation known in the art. . At one end of the cartridge 12, a plunger 20 seals the liquid medicament compartment 16 and, when the drive assembly is actuated, is engaged and propelled forward, and in the liquid medicament compartment 16. A seal structure 22 engages in seal form the walls of the compartment 12 for separating the liquid medicament compartment 16 from the dry medicament compartment 18. The seal structure 22 is of the type disclosed and claimed in the co-pending US Patent Application No. 10 / 690,987 whose disclosure is incorporated specifically here by reference. Although any type of seal structure can be used, and if a wet / wet type cartridge is used, the seal structure 22 can take the form of a membrane that can be broken or another more conventional type of seal structure. The seal structure 22 includes an outer seal member 24, a movable plug 26 fastened within the outer seal member 24, a flow path 28, and a bypass zone 30. When the autosampler is driven, the advancing plunger 20 creates a pressure in the liquid medicament compartment 16 which causes the movable seal plug 26 to move forwardly within the seal structure 22. Once the movable seal plug 26 is moved forwardly within the structure of seal 22. Once the seal plug 26 is displaced forwardly within the seal structure 22, the fluid in the liquid medication compartment 16 can enter the bypass zone 30 and mix with the medicament component in the compartment. of dry medicament 18. Methods for filling the automatic injectors cartridges such as the cartridge 12 are described in US Patent Application Number 10/690, 987 and will not be repeated here in more detail. In summary, a problem with traditional filling methods is that, in the case of a two-compartment cartridge, such as cartridge 12, if both drug components are filled through the same opening, a cross-contamination can happen easily That is, a powder component can be accidentally mixed with a liquid component or vice versa, especially around the opening. Therefore, especially in the case of two-compartment cartridges, it is advantageous for the two compartments to be filled through separate openings in the cartridge 12. As noted above, it is also beneficial that the openings be relatively large. In addition to allowing easier and quicker filling of both dry and powdery drug components, large openings allow a dried drug tablet to be placed directly into a separate container in the dry medicine compartment. cartridge 12, the dry medicament compartment 18 has a relatively wide opening 32 located at the front end of the cartridge 12, adjacent the needle and center assembly 14. In a filling process in accordance with the present invention, once the component dry is loaded in the dry medicament compartment 18, an insert 34 is inserted into the opening 32. The insert 34 has a tapered flow path 26 and acts as a funnel to channel the mixed medicament components towards the needle and center assembly. (ie, forward and inward) when the autosampler is operated. The tapered insert 34 also includes a flange portion 38 that forms a seal between the opening 32 and the needle and center assembly 14. In other filling processes, a needle and center assembly can be directly sealed over the opening 32 without need of an insert or other addressing structure within the cartridge 12. The diameter of the opening 32 may be within a range of 0.7112 centimeter to 1.27 centimeters (0.280 inch to 0.500 inch). Traditionally, a needle and center assembly for this type of cartridge should be formed by inserting a needle into an aluminum center. In general, a 20 to 24 gauge stainless steel needle should be inserted into an aluminum extruded wrap from 0.0254 cm to 0.0381 cm (0.010 inch to 0.015 inch) thick, which opens to cover an opening in the cartridge that has a diameter external from 0.635 cm to 0.762 cm (0.25 inch to 0.30 inch). In the case of an aperture of the size of the opening 32 (eg, 1.19888 centimeters [0.472 inch]), it is difficult to make a traditional extruded aluminum center that can firmly hold the needle and attach it to the cartridge 12. With the purpose of To solve this problem, the needle and center assembly 14 of the present invention includes both traditional extruded components and injection molded components, and is preferably processed through a multi-stage injection molding process, as will be explained below. Specifically, the center and needle assembly 14 comprises a rigid cap or skirt 40, which can be formed of metal, a first molded center portion 42, a second center portion 44, a needle 46, and a needle cover 48. If the skirt 40 is formed of metal, it will typically be extruded, although it can also be cast or otherwise formed. Although the first molded center portion and second portion 42, 44 are separately described in some of the following paragraphs to facilitate description, they are preferably fused together during manufacture and function as a single component, as will be explained. Further, even when the skirt 40 is described as being formed of metal, it can also be formed of a plastic material having sufficient stiffness. The components of the needle and center assembly 14 can be seen more clearly in FIGURE 4 which is a longitudinal cross-sectional view of the components of the needle and center assembly 14 in isolation, as well as in FIGURES 2 and 3, which are a perspective view and perspective view partially in section, respectively, of the needle and center assembly 14. As shown in the views of FIGURES 3 and 4, the skirt 40 is a generally cylindrical shaped component of a diameter sufficient to fit on the outer side of the cartridge 12 to close the opening 32 in the dry compartment 18. The skirt 40 has one or more hemispherical inner protuberances 45 designed to fit under pressure in the surface 47, which is shown in Figure 1. The lower portion 49 of the skirt 40 is wound or snapped into the slot 13 in the cartridge 12 in order to hold the needle and center assembly 14 on the cartridge 12. needle support end or needle support portion 50 of skirt 40, which is in a position opposite the end or portion of skirt 40 that engages cartridge 12, comprises a closed wall except or as to a central hole 52. As can be seen more clearly in FIGURE 4, the needle support end 50 of the skirt 40 is essentially "sandwich" between the first molded center portion 42 and the second center portion. molded 44. This positioning of the needle support end 50 of the skirt 40 between the first molded center portion 42 and the second molded center portion 44 mutually reinforces and promotes rigidity of the entire structure. The first molded center portion 42 is positioned along the inside of the needle support end 50 of the skirt 40 such that a flange portion 54 of the first molded center portion 42 is adjacent to the support end of the molded center portion 42. 50 needle of the skirt 40 and a front portion 56 of the first molded center portion extends through the hole 52 in the needle support end 50 of the skirt 40. The needle 46 is mounted within a central channel 58 of the first molded center portion 42 just beyond the hole 52 in the skirt 40. The needle 46 extends to a retainer 58a, shown in Figure 4, formed in the channel 58 such that the needle can be reliably inserted therein. depth during manufacturing. The detent 58a limits the depth of insertion of the needle 46 into the first molded center portion 42. Only a short segment of the needle 46 is clamped within the first milled center portion 42. As can be seen in the FIGURES 3 and 4, the first molded center portion 42 of the illustrated embodiment defines a chamber 60 substantially hemispherical in shape. The channel 58 supporting the needle 46 opens into the chamber 60. A filter 62 covers the wide opening of the chamber 60. The chamber 60 and the filter 62 are provided to direct the flow from the cartridge 12 to the needle 46 and to allow a more fully developed "back" flow of the filter 62. The particular characteristics and advantages of these components were described in co-pending US Application No. 10 / 690,987, of which said request is a continuation in part. It will be understood that the chamber 60 and the filter 62 are optional components and do not have to be included in embodiments of the present invention. In addition, as will be readily understood by a person skilled in the art, the first molded center portion 42 may include any contour or structural feature necessary for the internal arrangement of the autosampler with which it is designed to be used. In general, the structural features of the first molded center portion 42 in the skirt 40 are not critical to the present invention, provided that the first molded center portion 42 includes structures of sufficient extension to retain it in position of the skirt 40 and to reinforcing the skirt 40. The second molded center portion 44 is positioned on the outer side of the needle support end 50 of the skirt 40. It abuts against the outer surface of the needle support end 50 and creates a fusion zone 64 in where the pieces 42 and 44 are permanently joined. During the formation of the center portion 44, the first molded center portion 42 is fused again so that the portions 42 and 44 are joined together. As can be seen more clearly in FIGURES 2 and 3, the second molded center portion 44 includes a number of radially extending ribs 66 that bear against the outer surface of the needle support end 50 and extend outwardly. going through it. The ribs 66 act to stabilize and reinforce the supporting end 50 of the skirt 40 and to prevent its distortion or otherwise deformation due to the stresses encountered during the operation. automatic injection. A tapered portion 68 extending forward and supporting the needle 46 over a greater portion of its length is contiguous with the ribs 66. Thanks to the first molded center portion 42 and the second molded center portion 44, the end of the molded center portion 44 Needle support 50 of skirt 40 is reinforced and needle 46 itself is well supported. The needle assembly 14 in accordance with the present invention is more advantageously manufactured using a multi-stage injection molding process. The first molded center portion 42 and the second molded center portion 44 can be made of ABS, polyethylene, polypropylene, or another well-known medical grade polymer. The injection molding process for the needle assembly 14 will be described below with reference to FIGS. 5A-5D, which are seen in perspective of the needle assembly 14 in various manufacturing steps, and FIG. 6, a block diagram of FIG. something level of the steps involved in the process. An injection molding apparatus suitable for these processes is well known in the art. An example of an appropriate injection molding apparatus that can be used in a process according to the present invention is the Arburg Model 270 All Rounder. The manufacturing process 100 for needle assembly and center 14 starts at S102. Before starting the molding process per se, the user must prepare the equipment and provide appropriate mold parts for the components. The process continues in S104. In S104, the user injects heated plastic material heated into a mold component having a cavity defining the shape of the first molded center portion 42. The fluid plastic is cooled inside the mold cavity to become the first center portion molded 42, as shown in FIGURE 5A. The center portion 42 is then injected from the mold. Process 100 advances to S106. In S106, a needle 46 is placed in the channel 58 in the first molded center portion 42, as shown in FIGURE 5B until the needle 46 contacts a detent 58a. Once the needle 46 is placed in the channel 58, the process 100 advances to S108, where an extruded metal skirt 40 is placed on the outside of the first molded center portion 44. Once the skirt 40 is placed and the needle 46, the assembly, which is shown in FIGURE 5C, is removed from the first mold and placed in a second mold. Cavities in the second mold define the shape of the second molded center portion. Once the assembly is in place, the process 100 advances to S110, where the second molded center portion 44 is over-molded in the assembly, forming the complete needle and center assembly 14 shown in perspective in FIG. FIGURE 5D. As discussed above, during the molding of the center portion 44, a portion of the surface area of the center portion 42 is fused back to form a melting zone 64 such that the portions 42 and 44 are fused together to form one piece. Process 100 ends at S112 and can be repeated as many times as desired. When the second molded center portion 44 is overmoulded in the step S110 of the process 100, the second molded center portion 44 is fused with the first molded center portion 42 along the melting zone 46 as it cools, forming a fused integral component. For this reason, it is typically profitable to mold the first molded center portion 42 and the second molded center portion 44 of the same material so that they can be fused together effectively. However, two thermally compatible materials can be used for the first molded center portion 42 and the second molded center portion 44. The process 100 also offers certain additional advantages compared to more conventional methods of manufacturing a water assembly and center . For example, even though the components illustrated in the Figures could be separately molded, assembled and joined, welded or press-fitted together, the process 100 offers much stricter tolerances than would be possible to use any of these more conventional processes. Even though the invention has been described in relation to certain embodiments, these embodiments are contemplated as examples only and should not be considered as limiting the present invention. Modifications and variations to the invention described herein may be within the scope of the appended claims. 24 wherein the wall of the needle support portion of the lid is reinforced on the inner surface by the first center portion and on the outer surface by the second center portion. The automatic injector according to claim 10, wherein the first center portion and the second center portion are fused. 12. The automatic injector according to claim 11, wherein the first center portion and the second center portion are plastic. 13. The automatic injector according to claim 12, wherein the first center portion and the second center portion are from the same plastic. 14. The automatic injector according to claim 10, wherein the lid is made of metal 15. The automatic injector according to claim 14, wherein the lid is made of aluminum. 16. The automatic injector according to claim 10, wherein the refuerso structures are ribs that extend radially. The automatic injector according to claim 10, wherein the second center portion further comprises a support portion extending along the needle. 18. The automatic injector in accordance with

Claims (10)

1. CLAIMS 1. A needle and center assembly for an injection device, comprising: a cap having a hook portion adapted to engage an outer surface of a cartridge, and a needle support portion having a wall that includes a cap opening there, the wall defines an internal surface and an external surface; a first center portion defining a channel that receives a needle through the opening in the wall and having a section extending along the inner surface of the wall; a needle mounted in the needle receiving channel and extending outward therefrom; and a second center portion engaged with the first center portion and receiving at least a portion of the needle, the second center portion having reinforcing structures extending outwardly along the external surface of the wall; wherein the wall of the needle support portion of the lid is reinforced on the inner surface by the first center portion and on the outer surface by the second center portion. The needle and center assembly according to claim 1, wherein the first center portion and the second center portion are fused together. 3. The needle and center assembly according to claim 2, wherein the first center portion and the second center portion are made of plastic. 4. The needle and center assembly according to claim 3, wherein the first center portion and the second center portion are from the same plastic. 5. The needle and center assembly according to claim 2, wherein the lid is made of metal. 6. The needle and center assembly according to claim 5, wherein the lid is made of aluminum. The needle and center assembly according to claim 2, wherein the reinforcing structures are ribs that extend radially. The needle and center assembly according to claim 1, wherein the second center portion further comprises a support portion extending along the needle. The needle and center assembly according to claim 1, wherein the needle receiving channel provides a continuous flow path from the inner side of the cap to the outer side of the cap. 10. An automatic injector comprising: a frame; a cartridge placed in the frame, the cartridge has at least one opening there and contains a drug, the drug is confined back by a plunger; an actuator assembly that includes a stored energy source that can be released to drive the plunger in the cartridge; a lid having a hooking portion adapted to engage an outer surface of the cartridge to cover the opening in the cartridge, and a needle support portion having a wall including an opening therein, the wall defining an inner surface and a surface external; a first center portion defining a needle receiving channel through the opening in the wall and having a section extending along the internal surface of the wall; thereafter, the needle is adapted to eject the drug when the plunger is pushed through the cartridge; and a second center portion engaged with the first center portion and receiving at least a portion of the needle, the second center portion having reinforcing structures extending outwardly along the external surface of the wall; Claim 10, wherein the channel receiving the needle provides a continuous flow path from the inner side of the cap to the outer side of the cap. 19. The automatic injector according to claim 10, wherein the cartridge has two compartments for medicament. 20. The automatic injector according to claim 19, wherein one of the medication compartments is adapted to house a wet medicament compartment and the other medication compartment is adapted to accommodate a dry medicament compartment. 21. The automatic injector according to claim 20, wherein the at least one opening in the cartridge is in the dry medicament compartment. 22. A method for forming a needle and center assembly, said method comprising: forming a first center portion; provide a lid that has an opening there; placing the first center portion such that the first center portion has a portion thereof extending through the opening in the lid; placing a needle in a channel defined by the first center portion; and forming a second center portion on an outer surface of the lid such that the second center portion engages the first center portion and extends over at least a portion of the outer surface of the lid. The method according to claim 22, wherein the formation of the first center portion comprises the injection molding of the first center portion. The method according to claim 22, wherein the formation of the second center portion comprises the injection molding of the second center portion. The method according to claim 22, further comprising, after inserting the needle into the channel and before forming the second center portion, moving the assembly to a second mold having cavities that define the second portion of center. 26. The method according to claim 22, wherein a portion of the first center portion melts during the formation of the second center portion such that a melting zone is formed that holds the first center portion on. the second portion of center. 27. A method for assembling an automatic injector, comprising: filling a dry medicament compartment with a dry medicament component using an opening in the dry medicament compartment; and sealing the opening in the dry medicament compartment by placing the needle and center assembly of claim 22 on the opening.