TECHNICAL FIELD

[0001] The present disclosure relates to a tip cap assembly for closing a fluid passageway of a medical injection device and to the injection system including the injection device and the tip cap assembly.

BACKGROUND

[0002] Current medicine uses a wide range of injection devices to deliver fluids into the body of patients. For example, such injection systems may include auto-injectors, medical pens or syringes. Conventional syringes are used because of their common availability, ease of use and limited cost. Syringes may be prefilled or prefillable. Syringes comprise a longitudinal barrel with an open proximal end and a substantially closed distal end including a distally projecting tip. The fluid intended to be injected can be stored in the syringe barrel, and in this case, the open proximal end is closed by a stopper in sliding fluid-tight engagement within the barrel and actuated by a plunger rod. The tip is provided with a fluid passageway extending therethrough to allow the injection of the fluid when a distal pressure is applied on the plunger. The tip can be provided with an attached needle or can be of a luer type, meaning needle-free. Syringe barrels may be made of glass or plastic. Glass may be chosen for its chemical neutrality and low gas permeability whereas plastic may be chosen for its resistance to shocks.

[0003] Almost all fluids can be injected with a syringe. For example, a fluid can be a pharmaceutical solution such as a drug, a vaccine, vitamins or dietary minerals. Syringes are also useful to inject diagnostic solutions, cosmetic fluids, including gels such as hyaluronic acid or silicone compositions. The injection can be performed in every part of the body including skin, hypodermis, muscle and veins, depending on the application.

[0004] Needle-free syringes may be provided with an adaptor to which a device for allowing the transfer of the fluid within the syringe to be dispensed therefrom. In the case of a plastic syringe, the adaptor may be integrally formed with the syringe body. For glass syringes, the adaptor may be separately formed and coupled to the syringe body.

[0005] During the time between the filling of the syringe and its use, needle-free syringes are provided with a tip cap to close a distally extending tip. Examples of tip caps are provided in W02018/011259 and US11013865. The tip cap is engaged with the adaptor provided on the syringe body. As fluids are stored in the prefilled syringe for an extended period of time, such as 6 to 18 months before injection, the injection system remains sealed during this period. The quality of the sealing between the tip cap and the syringe is important as a deficient sealing could damage the nature or the purity of the fluids, leading to waste of valuable fluids, potential unacceptable risks for the patients and potential unacceptable risks for the medical staff according to the nature of the pharmaceutical compositions stored inside the syringes.

[0006] For instance, the outside surface of the distally extending tip should be preserved from contaminants, such as dust or micro-organisms, which may migrate from the tip to the fluid passageway. If these contaminants are injected with the medicinal fluid to a patient, it may trigger an inappropriate immune response, lessen the treatment efficacy and decrease the patient's trust into his treatment. Thus, displacement, in whole or in part, of the tip cap intended to close the fluid passageway may result in contamination of the medicinal fluid.

[0007] The force applied in an attempt to engage a rigid tip cap with the adaptor may be directly transmitted to the adaptor. Crack(s) may be formed in the adaptor and/or the tip cap made of a rigid material due to excessive mechanical stress generated during or after the assembly. Such crack(s) may lead to a poor connection of the adaptor with an intravenous (IV) line, needle hub, or other device for later assembly, may lead to contamination of the fluid within the syringe, and/or may lead to unintended exposure of a user to the fluid within the syringe.

[0008] Moreover, the syringe should be opened easily when required and the tip cap should be removed without excessive effort. A sticking phenomenon may occur when a tip cap is plugged on the tip of a syringe. It has been observed that when two materials are compressed together over an extended period of time, such phenomenon of sticking could occur and prevent a fast and easy opening of a prefilled syringe. Consequently, a tip cap difficult to open would lead to the rejection of the prefilled syringes before use and would constitute an unacceptable economic loss. This could also lead to the death or severe injury of patients requiring an immediate injection.

BRIEF SUMMARY

[0009] An objective of the present disclosure is to a tip cap assembly for closing a fluid passageway extending through a tip of a container of a medical injection device overcoming one or more of the foregoing drawbacks.

[0010] The tip cap assembly comprises a rigid outer cap and an elastomeric inner cap. The rigid out cap has a distal portion and a proximal portion. An inner surface of the distal portion defines a cavity configured to retain the elastomeric inner cap therein. An inner surface of the proximal portion defines a cavity configured to surround the tip of the container when the tip cap assembly is assembled with the container. An elastomeric sealing ring is bonded to the inner surface of the proximal portion of the rigid outer cap. An inner surface of the sealing ring configured to engage the tip when the tip cap assembly is assembled with the container. The elastomeric inner cap is disposed within the cavity of the distal portion of the rigid outer cap. The inner cap abuts against a distal surface of the tip of the container when the tip cap assembly is assembled with the container.

[0011] Certain preferred but non-limiting features of the tip cap assembly described above are the following, taken individually or in combination:

[0012] the inner surface of the sealing ring comprises a plurality of ribs, and a surface of the ribs is configured to engage an outer surface of the tip of the container;

[0013] an inner diameter of the sealing ring is less than an outer diameter of the tip on which the tip cap assembly is configured to be disposed;

[0014] a height of the sealing ring is less than a height of the tip on which the tip cap assembly is configured to be disposed, preferably the height of the sealing ring is 40% of the height of the tip;

[0015] the elastomeric sealing ring comprises a thermoplastic elastomer; and/or

[0016] the rigid outer cap is made of a rigid polymer, the rigid polymer preferably being polypropylene, polyethylene, polyvinylchloride, polystyrene, polycarbonate, acrylonitrile butadiene styrene or styrene acrylonitrile.

[0017] A method of forming the tip cap assembly includes comolding the sealing ring to the inner surface of the proximal portion of the rigid outer cap.

[0018] Another objective of the present disclosure is to an injection device comprising the tip cap assembly as previously described, a container, and an adaptor. The container has a barrel and atip distally projecting from the barrel. The tip comprises a fluid passageway extending longitudinally therethrough. The adaptor is disposed circumferentially about the tip of the container.

[0019] Certain preferred but non-limiting features of the injection device described above are the following, taken individually or in combination:

[0020] an outer surface of the proximal portion of the rigid outer cap has a threaded surface;

[0021] the adaptor comprises a distal portion having an inner surface that is threaded, the threaded surface of the proximal portion of the rigid outer cap engaged with the threaded inner surface of the adaptor; [0022] the elastomeric sealing ring of the tip cap assembly is radially compressed between the rigid outer cap and the adaptor;

[0023] the elastomeric inner cap is disposed on the tip of the container to sealingly close the fluid passageway; and/or

[0024] the elastomeric inner cap is axially compressed between protrusions of the rigid outer cap that extend radially inwardly and the tip of the container to sealingly close the fluid passageway.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The illustrations presented herein are not meant to be actual views of any particular component, device, or system, but are merely idealized representations which are employed to describe embodiments of the present invention. Other features, goals, and advantages of the present invention will appear more clearly upon reading of the detailed description that follows and with references to drawings provided by way of non-limiting examples wherein:

[0026] FIG. 1 is a cross-sectional view of an outer cap of a tip cap assembly;

[0027] FIG. 2 is a side view of the outer cap of FIG. 1;

[0028] FIG. 3 is a side view of an inner cap of the tip cap assembly;

[0029] FIG. 4 is a cross-sectional view of the outer cap of FIG. 1 including the inner cap of FIG. 3 disposed therein;

[0030] FIG. 5 is a cross-sectional view of a container having an adaptor disposed thereon; and

[0031] FIGS. 6 and 7 are a side view and a cross-sectional view, respectively, of a container having a tip cap assembly disposed thereon.

DETAILED DESCRIPTION

[0032] As used herein, the term “proximal” refers to a location, such as a proximal end, that is nearer to a point of reference such as a point of contact of a user applying a force to a plunger rod of an injection device as described herein. As used herein, the term “distal” refers to a location, such as a distal end, that is farther from a point of reference such as a point of contact of the user applying a force to the plunger of the injection device as described herein. Thus, the terms “proximal” and “distal” refer to, for example, directions nearer to and farther from, respectively a user administering a medicinal fluid to a patient. [0033] As used herein, the terms “axial,” “axially,” “longitudinal,” and “longitudinally” generally mean and refer to a direction along or parallel to a longitudinal axis of an element(s) of the injection device described herein.

[0034] As used herein, the terms “radial,” “radially,” “lateral,” and “laterally” generally mean and refer to a direction perpendicular to the central, longitudinal axis of the element(s) of the injection device described herein.

[0035] As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

[0036] As used herein, the term “configured” refers to a size, shape, material composition, material distribution, orientation, and arrangement of one or more of at least one structure and at least one apparatus facilitating operation of one or more of the structure and the apparatus in a pre-determined way.

[0037] The tip cap assembly 100 disclosed herein comprises a rigid outer cap 102 and an inner cap 130. FIGS. 1 and 2 illustrates the rigid outer cap 102 of the tip cap assembly 100.

[0038] The outer cap 102 comprises a distal portion 104 and a proximal portion 106. The outer cap 102 has a longitudinal axis 101 extending between a distal end 103 and a proximal end 105 thereof. The outer cap 102 is a hollow body having an opening at each of the distal end 103 and the proximal end 105 thereof.

[0039] The distal portion 104 comprises a cavity 110 defined by an inner surface 108. As illustrated in FIG. 4, the cavity 110 is configured to retain an inner cap 130 therein. The inner surface 108 of the distal portion 104 decreases in width as the cavity 110 extends from the distal end 103 toward the proximal end 105. A shoulder 107 is defined by the inner surface 108 of the distal portion 104 at which the width of the cavity 110 is reduced in a stepped manner. The shoulder 107 is configured such that a portion of the inner cap 130 is disposed thereon when the inner cap 130 and the outer cap 102 are assembled together.

[0040] The distal portion 104 of the outer cap 102 may comprise at least one protrusion 140 proximate to the distal end 105. The protrusion(s) 140 extends radially inward toward and longitudinally along the longitudinal axis 101 of the outer cap 102. A proximal end 141 of the protrusion 140 may be referred to as an abutment surface and is configured to abut against a distal surface 133 of the inner cap 130 when the inner cap 130 is disposed therein.

[0041] The proximal portion 106 comprises a cavity 114 defined by an inner surface 112 thereof. The cavity 114 of the proximal portion 106 is continuous with the cavity 110 of the distal portion 104. As illustrated in FIG. 7, the cavity 114 is configured to receive and surround a tip 22 of a container 10 therein when the tip cap assembly 100 is assembled with the container 10.

[0042] A sealing ring 120 is bonded to the inner surface 112 of the proximal portion 106 of the outer cap 102. The sealing ring 120 is made of a material such that the sealing ring 120 is radially compressible.

[0043] The sealing ring 120 is bonded to the inner surface 112 of the proximal portion 106 of the outer cap 102. The sealing ring 120 and proximal portion 106 may be bonded by a comolding or overmolding process depending on the material compositions of the sealing ring 120 and outer cap 102. In a co-molding process, the sealing ring 120 and the outer cap 102 may be substantially simultaneously formed by an injection molding such that, as the molten materials of the sealing ring 120 and the outer cap 102 solidify after injection into a mold, the sealing ring 120 and the outer cap 102 are bonded together. In an overmolding process, the outer cap 102 may be injection molded and solidified prior to injection of the sealing ring 120 material into the mold, and the sealing ring 120 is bonded onto the outer cap 102 when the molten material of the sealing ring 120 solidifies.

[0044] The sealing ring 120 may be made of an elastomeric material. The elastomeric material may be a thermoplastic elastomer. By way of non-limiting example, the sealing ring 120 may be made of natural rubber, synthetic rubber, thermoplastic elastomers, or combinations thereof.

[0045] The inner surface 122 of the sealing ring 120 is configured to directly engage the tip 22 of the container 10 when the tip cap assembly 100 is assembled with the container 20. The sealing ring 120 comprises a plurality of ribs 124 separately longitudinally by valleys, which are axially recessed surfaces relative to the ribs 124. As explained in further detail below, the surface of the ribs 124 (e.g., the surface area of the sealing ring 120 in contact with the tip 22) may be selected to modify the force to be applied by a machine and/or a user to axially displace the tip cap assembly 100 onto and/or off of the container 10.

[0046] Radially innermost surfaces of the ribs 124 engage a lateral surface of the tip 22 when the tip cap assembly 100 is assembled therewith. The radially innermost surfaces of the inner sealing ring 120 define an inner diameter D120 of the sealing ring 120. The inner diameter D120 of the sealing ring 120 is less than the outer diameter D22 of the tip 22 of the container 20. The inner diameter D120 of the sealing ring 120 is adjustable as the sealing ring 120 is radially compressible. [0047] The proximal portion 106 comprises an outer surface 118 having threading thereon. The threaded outer surface 118 is configured to engage with threading of an adaptor 50 as discussed in further detail below.

[0048] The outer cap 102 is made of a rigid polymer. By way of non-limiting example, the outer cap 102 is made of polypropylene, polyethylene, polyvinylchloride, polystyrene, polycarbonate, acrylonitrile butadiene styrene or styrene acrylonitrile.

[0049] The outer cap 102 may also comprise a ring 121 defining a portion of the exterior surface 105 thereof. The ring 121 defines a proximal surface 123 that abuts against an adapter 50 when the tip cap assembly 100 is coupled thereto. The ring 121 may define the largest radial dimension of the outer cap 102.

[0050] FIG. 3 illustrates an inner cap 130 of the tip cap assembly 100, and FIG. 4 illustrates the inner cap 130 disposed within the outer cap 102.

[0051] The inner cap 130 comprises a distal portion 132 and a proximal portion 134. A longitudinal axis 131 of the inner cap 130 extends between a distal surface 133 and a proximal surface 135 of the inner cap 130.

[0052] When the inner cap 130 is disposed within the outer cap 102, the longitudinal axis 131 of the inner cap 130 may be coaxial with the longitudinal axis 101 of the outer cap 102.

[0053] The distal portion 132 may be generally cylindrical in shape with a planar distal surface 133. The proximal portion 134 may be have a first portion 134a that is generally cylindrical in shape immediately adjacent to the distal portion 132 and a second portion 134b that is frustoconical in shape at a proximal end thereof.

[0054] In some embodiments, the first portion 134a may have a bulbous portion that increases in width proximate to the second portion 134b. The bulbous portion is radially compressed when the inner cap 130 is disposed within the outer cap 102 in order to retain the inner cap 130 within the cavity 110. The proximal portion 134 comprises a planar proximal surface 135.

[0055] The distal portion 132 has a width (e.g., diameter) that is greater than a width of the proximal portion 134. The width of the proximal portion 134 and the distal portion 132 may such that the inner cap 130 is radially compressed by the inner surface 108 of the cavity 110 when the inner cap 130 is disposed in the outer cap 102.

[0056] The inner cap 130 is separately formed from and assembled with the outer cap 102. The inner cap 130 may be inserted into the outer cap 102 by passing the inner cap 130 through the opening at the distal end 103 of the outer cap 102 and into the cavity 110 of the distal portion 106 of the outer cap 102.

[0057] When the inner cap 130 is disposed within the outer cap 102, the distal surface 133 of the distal portion 132 may abut against the abutment surface 141 of the protrusion 140 of the outer cap 102. The proximal surface 137 of the distal portion 132 may abut against the shoulder 107 of the outer cap 102.

[0058] The inner cap 130 may be formed of an elastomeric material. Suitable materials for the inner cap 130 may include natural rubber, acrylate-butadiene rubber, cis-polybutadiene, chloro or bromobutyl rubber, chlorinated polyethylene elastomers, polyalkylene oxide polymers, ethylene vinyl acetate, fluorosilicone rubbers, hexafluoropropylene-vinylidene fluoridetetrafluoroethylene terpolymers, butyl rubbers, poly isobutene, synthetic polyisoprene rubber, silicone rubbers, styrene-butadiene rubbers, tetrafluoroethylene propylene copolymers, thermoplastic-copolyesters, thermo-plastic elastomers, or the like or a combination thereof.

[0059] The outer cap 102 having the inner cap 130 disposed therein may be assembled with an injection device 1. FIGS. 5-7 show an injection device 1 in the form of a luer syringe according to an aspect of the disclosure. The tip cap assembly 100 of the present disclosure could be used with any other types of injection systems, such as a pen, or an infusion system, provided they include a distally projecting tip. For sake of clarity, the present disclosure will only be described with a luer syringe.

[0060] The injection device 1 includes a container 10. The container 10 comprises a barrel 11 extending axially along a longitudinal axis A. The container 10 is configured to contain a medicinal fluid therein. The barrel 11 comprises a flange 12 at a proximal end and a tip 22 at a distal end. The tip 22 includes a fluid passageway 14 extending therethrough, a distal surface 15 and a lateral surface 16 which is substantially tubular. While not illustrated in FIGS. 6 and 7, the injection device 1 may further comprise a stopper coupled to a plunger. In operation, a user depresses the plunger so to displace the stopper and dispense a medicinal fluid from the container

10 through the fluid passageway 14 of the tip 22.

[0061] The tip 22 may be configured to be connected to an additional element such as a needle hub or intravenous (IV) line, thereby allowing the medicinal fluid contained in the barrel

11 to be expelled and further injected into an intended target through the fluid passageway 14.

[0062] The barrel 11 and tip 22 may be made of glass or plastic.

[0063] An adaptor 50 is securely engaged with the tip 22. The adaptor 50 may be separately formed and fixedly attached to the injection device 1 by clipping, screwing, welding, an adhesive, or the like. Alternatively, the adaptor 50 may be integrally formed with the barrel 11 such as by molded.

[0064] The adaptor 50, which is best illustrated in FIG. 5, surrounds the tip 22 so as to define an annual space 52 therebetween for receiving the proximal portion 106 of the outer cap 102. An inner surface 54 of the adaptor 50 comprises threading to engage with threading on the outer surface 118 of the proximal portion 106 of the outer cap 102.

[0065] The adaptor 50 may be made of a plastic material. By way of non-limiting example, the adaptor 50 may be made of acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polyoxymethylene (POM), polystyrene (PS), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PE), polyamide (PA), thermoplastic elastomer (TPE) and their combinations.

[0066] The tip cap assembly 100 is coupled to the adaptor 50 by engaging the threaded outer surface 118 of the outer cap 102 with the threaded inner surface 54 of the adaptor 50. When assembled together, the proximal portion 106 of the outer cap 102 is disposed in the annular space 52 and surrounds the tip 22 of the injection device 1.

[0067] When assembled, the proximal surface 107 of the ring 121 of the outer cap 102 abuts against a distal end of the adapter 50.

[0068] When assembled, the inner cap 130 is axially compressed between the tip 22 of the injection device 1 and the abutment surface 141 of the protrusion(s) 140 of the outer cap 102. More particularly, the proximal surface 135 of the inner cap 130 abuts against the distal surface 15 of the tip 22 and the distal surface 133 of the inner cap 130 abuts against the abutment surface 141 of the protrusion 140 of the outer cap 102. The seating of the inner cap 130 between the protrusion 140 and the tip 22 maintains the inner cap 130 in position within the outer cap 102 during a sterilization process and during subsequent storage of the device 1 until a user is ready to use the device 1 to dispense medical fluid therefrom.

[0069] The proximal portion 134 of the inner cap 130 may partially protrude into the fluid passageway 14 of the injection device 1. The positioning of the inner cap 130 against the tip 22 seals the fluid passageway 14 of the injection device 1 and prevents fluid from flowing out of the injection device 1. The engagement of the inner cap 130 and the tip 22 also prevents any contamination of the medical fluid disposed within the container 10 from the outside environment, thereby assuring the container closure integrity.

[0070] In addition, the inner cap 130 is dimensioned to be radially compressed along at least a portion of its length. For example, the bulbous portion of the proximal portion 134 may be radially compressed to a greater degree relative to the remainder of the first portion 134a. Radially compression of the inner cap 130 maintains the inner cap 130 in position within the outer cap 102 within the outer cap 102 during a sterilization process and during subsequent storage of the device 1 until a user is ready to use the device 1 to dispense medical fluid therefrom. Maintaining the inner cap 130 within its seated position with the outer cap 102 maintains the fluid seal of the inner cap 130 and the tip 22 to avoid contamination of the medicinal fluid in the container 10.

[0071] The inner cap 130 is shaped and dimensioned such that the inner cap 130 does not surround the lateral surface 16 of the tip 22. Rather, the lateral surface 16 of the tip 22 is engaged with ribs 124 of the sealing ring 120 of the tip cap assembly 100. As the inner cap 130 does not engage with the lateral surface 16 of the tip 22 when the tip cap assembly 100 is assembled with the container, the inner cap 130 is less prone to displacement from its seated position within the cavity 112 of the rigid cap 102 compared to an inner cap having a proximal portion that is configured to at least partially surround the lateral surface 16 of the tip 22 when assembled therewith.

[0072] A seal may be formed between the radially innermost surfaces 122 of the ribs 124 of the sealing ring 120 and the lateral surface 16 of the tip 22 to ensure container closure integrity such that any contamination of the medical fluid disposed within the container 10 from the outside environment is inhibited.

[0073] Radially innermost surfaces 122of the ribs 124 directly contact the lateral surface 16 of the tip 22 of the container 10. When assembled, the sealing ring 120 of the tip cap assembly 100 is radially compressed between the rigid outer cap 102 and the adaptor 50 when the tip cap assembly 100 and injection device 1 are assembled together. The sealing ring 120 is radially compressed by virtue of the relative dimensions of the inner diameter D120 of the sealing ring 120 and the outer diameter D22 of the tip 22 on which the tip cap assembly 100 is disposed. More particularly, the inner diameter D120 of the sealing ring 120 is less than the outer diameter D22 of the tip 22. By way of non-limiting example, the inner diameter D120 may be 5 to 20% less than the outer diameter D22 of the tip 22.

[0074] The height L120, or the axial dimension, of the sealing ring 120 is less than the height L22 of the tip 22 of the container 10. In some embodiments, the height L120 of the sealing ring 120 may be between 30 and 50% and, more particularly, 40% of the height L22 of the tip 22 of the container 10. Valleys between the ribs 124 on the inner surface 122 of the sealing ring 120 are also provided to reduce the contact area between the sealing sing 120 and the tip 22, which also reduces the force necessary to remove the tip cap assembly 100 from the container 10. The surface area of the ribs 124, which defines the contact area of the sealing ring 120 in direct contact with the tip 22, may be selected to modify the force to be applied by a machine and/or a user to axially displace the tip cap assembly 100 onto and/or off of the container 10.

[0075] The provision of the sealing ring 120 made of a compressible material absorbs some of the compressive forces existing between the adaptor 50, the proximal portion 106 of the rigid cap 102, and the tip 22 when assembled together. By providing the compressible material of the sealing ring 120, the proximal portion 106, which is made of a rigid polymeric material, is less prone to cracking as a result of the compressive forces compared to a rigid cap having a proximal portion is a unitary piece of a rigid material having threading on an outer surface in contact with the adaptor 50 and ribs on an inner surface in contact with the lateral surface 16 of the tip 22. Cracking of the rigid cap 102 jeopardizes the container closure integrity. This tip cap assembly 100 according to the present disclosure is therefore less prone to cracking when the tip cap assembly 100 is assembled with the container 10 that is made of glass or plastic.

[0076] The tip cap assembly 100 is assembled onto the container 10 by engaging the threaded surface 188 of the outer cap 102 with the threaded inner surface 54 of the adaptor 50. As the tip cap assembly 100 is rotated to engage with the adaptor 50, the sealing ring 120 glides along lateral surface 16 of the tip 22 of the container 10. Various dimensions of the sealing ring 120 may be selected to control the frictional forces between the sealing ring 120 and the tip 22 and, thus, the torque force that is applied to engage and disengage the tip cap assembly 100 with the adaptor 50 and the container 10.

[0077] While the present disclosure has been described herein with respect to certain illustrated embodiments, those of ordinary skill in the art will recognize and appreciate that it is not so limited. Rather, many additions, deletions, and modifications to the illustrated embodiments may be made without departing from the scope of the disclosure, including legal equivalents thereof. In addition, features from one embodiment may be combined with features of another embodiment while still being encompassed within the scope of the invention as contemplated by the inventors.