SYRINGE TIP CAP ASSEMBLY, SYRINGE COMPRISING SUCH A SYRINGE TIP CAP AND METHOD OF SEALING A SYRINGE BARREL

Abstract

A syringe tip cap is provided for retaining a resilient closure at a distal end of a syringe tip of a syringe barrel, comprising a distal cap and a proximal sleeve connected via a coupling strip. An annular first breaking line is formed between the distal cap and the proximal sleeve. Frangible portions are provided as tamper indicator means. The proximal sleeve comprises a second breaking line extending nearly perpendicular to the first breaking line. For opening the cap, first the annular first breaking line is broken so the distal cap and the proximal sleeve can be partially separated. Thereby, the coupling strip serves as a hinge for pivotally coupling the distal cap and the proximal sleeve. Afterwards, the user further pulls down the distal cap in axial direction for breaking the second breaking line. The user may tear-off the syringe tip cap to access to the resilient closure.

Claims

1. A syringe tip cap for retaining a resilient closure at a distal end of a syringe tip on which a collar for coupling with a syringe needle is mounted, comprising: a rigid outer cap having a distal cap member and a proximal sleeve member, wherein an annular first breaking line is formed between the distal cap member and the proximal sleeve member; and tamper indicator means comprising frangible portions which are broken when the annular first breaking line is broken; wherein the distal cap member is cup-shaped for accommodating and covering a distal end of the resilient closure, and configured for pressing the resilient closure toward the syringe tip; and the proximal sleeve member comprises a distal end and a proximal end configured to be coupled with the collar, for coupling the syringe tip cap with the distal end of the syringe tip; wherein the proximal sleeve member comprises a second breaking line extending between the distal end and the proximal end of the proximal sleeve member; the distal cap member and the proximal sleeve member of the rigid outer cap are connected with each other via an axial coupling strip, which bridges and disrupts the annular first breaking line; and the frangible portions of the tamper indicator means are weaker than the coupling strip, so that the distal cap member and the proximal sleeve member of the rigid outer cap can be partially separated by breaking the annular first breaking line and the coupling strip serves as a hinge for pivotally coupling the distal cap member and the proximal sleeve member of the rigid outer cap after the annular first breaking line has been broken.

2. The syringe tip cap as claimed in claim 1, wherein the second breaking line is followed by a first slot, which is formed in the distal cap member and forms a first edge of the axial coupling strip.

3. The syringe tip cap as claimed in claim 2, wherein the axial coupling strip is further delimited by a second slot which is formed in the distal cap member and extends in parallel with the first slot, so that the axial coupling strip is rectangular and extends in axial direction of the syringe tip cap.

4. The syringe tip cap as claimed in claim 1, wherein the second breaking line is slanted at an acute angle relative to the axial direction of the syringe tip cap, wherein the second breaking line comprises frangible portions extending substantially perpendicular to the axial direction of the syringe tip cap.

5. The syringe tip cap as claimed in claim 2, further comprising a third breaking line, said second breaking line and said third breaking line comprising frangible portions which are broken when the second breaking line and third breaking line is broken.

6. The syringe tip cap as claimed in claim 5, wherein the second breaking line and third breaking line preferably extend in parallel with each other.

7. The syringe tip cap as claimed in claim 1, wherein the distal cap member comprises a step portion formed at a side wall of the distal cap member opposite to a position where the coupling strip bridges the second breaking line.

8. The syringe tip cap as claimed in claim 7, wherein the step portion is formed by a vertical side wall extending in the axial direction of the syringe tip cap and a surface extending radially inward perpendicular to or slanted relative to the axial direction, so that by pushing the vertical side wall obliquely upward toward a distal end of the syringe tip cap the distal cap member can be separated from the proximal sleeve member of the rigid outer cap to thereby break the annular first breaking line and partially separate the proximal sleeve member from the rigid outer cap.

9. The syringe tip cap as claimed in claim 1, wherein a pressing member protrudes from an inner surface of the distal cap member of the rigid outer cap at a center thereof, for pressing the resilient closure toward the syringe tip.

10. The syringe tip cap as claimed in claim 9, wherein a transparent portion is provided in a side wall of the distal cap member so that a contact region between the pressing member and the resilient closure and/or an upper surface of the resilient closure is visible from outside the syringe tip cap.

11. The syringe tip cap as claimed in claim 1, wherein a plurality of locking protrusions is formed on an inner side wall of the proximal end of the proximal sleeve member, which are configured for gripping behind an edge of the collar, for coupling the syringe tip cap with the distal end of the syringe tip.

12. The syringe tip cap as claimed in claim 11, wherein the locking protrusions are formed at equiangular intervals along the inner side wall of the proximal end of the proximal sleeve member, said locking protrusions having slanted insertion surfaces so that the syringe tip cap can be pushed onto the syringe tip.

13. The syringe tip cap as claimed in claim 12, wherein the diameter of a circle along which the plurality of locking protrusions is disposed is smaller than a maximum outer diameter of the distal end of the resilient closure to be accommodated in the cup-shaped distal cap member so that the resilient closure is retained in axial direction inside the cup-shaped distal cap member by the plurality of locking protrusions.

14. The syringe tip cap as claimed in claim 11, wherein a plurality of ridges are formed on an inner surface of the proximal sleeve member, wherein the ridges are disposed at a distance to the locking protrusions and equiangular intervals along the inner surface of the proximal sleeve member and enclose a circle having a diameter, which is substantially equal to an outer diameter of the collar and/or of the syringe.

15. The syringe tip cap as claimed in claim 1, further comprising a resilient closure, which is accommodated and axially retained in the cup-shaped distal cap member.

16. A syringe tip cap for retaining a resilient closure at a distal end of a syringe tip on which a collar for coupling with a syringe needle is mounted, comprising: a rigid outer cap having a distal cap member and a proximal sleeve member and configured to be coupled with the collar, for coupling the syringe tip cap with the distal end of the syringe tip; and tamper indicator means comprising frangible portions which are broken when the annular first breaking line is broken; wherein the distal cap member is cup-shaped for accommodating and covering a distal end of the resilient closure, an annular first breaking line is formed between the distal cap member and the proximal sleeve member of the rigid outer cap, the proximal sleeve member comprises a second breaking line extending between a distal end and a proximal end of the proximal sleeve member, the second breaking line extends under an acute angle or under an angle of 90 degrees relative to the first breaking line, the second breaking line runs into the first breaking line at a point of intersection, and the distal cap member and the proximal sleeve member of the rigid outer cap are connected with each other via an axial coupling strip, which bridges and disrupts the annular first breaking line at a position adjacent to the point of intersection

17. A syringe comprising: a syringe barrel having a substance receiving chamber and a syringe tip projecting from a distal end of the syringe barrel with a fluid passage extending through said syringe tip; a collar concentrically surrounding the syringe tip, for coupling with a syringe needle; a resilient closure having opposed proximal and distal ends, said proximal end defining a tip engaging portion for sealingly engaging the syringe tip to seal a substance contained in the substance receiving chamber of the syringe barrel; and a syringe tip cap mounted at the distal end of a syringe tip, which engages with the collar and retains the resilient closure at the distal end of the syringe tip, for sealing the syringe tip; said syringe tip cap comprising: a rigid outer cap having a distal cap member and a proximal sleeve member, wherein an annular first breaking line is formed between the distal cap member and the proximal sleeve member; and tamper indicator means comprising frangible portions which are broken when the annular first breaking line is broken; wherein the distal cap member is cup-shaped for accommodating and covering a distal end of the resilient closure, and configured for pressing the resilient closure toward the syringe tip; and the proximal sleeve member comprises a distal end and a proximal end configured to be coupled with the collar, for coupling the syringe tip cap with the distal end of the syringe tip; wherein the proximal sleeve member comprises a second breaking line extending between the distal end and the proximal end of the proximal sleeve member; the distal cap member and the proximal sleeve member of the rigid outer cap are connected with each other via an axial coupling strip, which bridges and disrupts the annular first breaking line; and the frangible portions of the tamper indicator means are weaker than the coupling strip, so that the distal cap member and the proximal sleeve member of the rigid outer cap can be partially separated by breaking the annular first breaking line and the coupling strip serves as a hinge for pivotally coupling the distal cap member and the proximal sleeve member of the rigid outer cap after the annular first breaking line has been broken.

18. A method of sealing a syringe barrel for administering a liquid containing a pharmaceutical drug, comprising the steps of: providing the syringe barrel having a syringe tip at a distal end thereof on which a collar for coupling with a syringe needle is mounted; sealing the syringe tip with a resilient closure; providing a syringe tip cap; and pushing the syringe tip cap in axial direction on the distal end of the syringe barrel until the proximal end of the syringe tip cap is coupled with the collar and the resilient closure is pressed on the distal end of the syringe tip, for sealing the syringe tip; said syringe tip cap comprising: a rigid outer cap having a distal cap member and a proximal sleeve member, wherein an annular first breaking line is formed between the distal cap member and the proximal sleeve member; and tamper indicator means comprising frangible portions which are broken when the annular first breaking line is broken; wherein the distal cap member is cup-shaped for accommodating and covering a distal end of the resilient closure, and configured for pressing the resilient closure toward the syringe tip; and the proximal sleeve member comprises a distal end and a proximal end configured to be coupled with the collar, for coupling the syringe tip cap with the distal end of the syringe tip; wherein the proximal sleeve member comprises a second breaking line extending between the distal end and the proximal end of the proximal sleeve member; the distal cap member and the proximal sleeve member of the rigid outer cap are connected with each other via an axial coupling strip, which bridges and disrupts the annular first breaking line; and the frangible portions of the tamper indicator means are weaker than the coupling strip, so that the distal cap member and the proximal sleeve member of the rigid outer cap can be partially separated by breaking the annular first breaking line and the coupling strip serves as a hinge for pivotally coupling the distal cap member and the proximal sleeve member of the rigid outer cap after the annular first breaking line has been broken.

19. The method of sealing a syringe for administering a liquid containing a pharmaceutical drug as claimed in claim 18, wherein the steps of sealing the syringe tip with a resilient closure and providing a syringe tip cap further comprise: inserting the resilient closure in the cup-shaped distal cap member so that the resilient closure is accommodated and axially retained in the cup-shaped distal cap member before pushing the syringe tip cap in axial direction on the distal end of the syringe barrel; and wherein the syringe tip cap together with the resilient closure accommodated and axially retained in the cup-shaped distal cap member is pushed in axial direction on the distal end of the syringe barrel until the resilient closure seals the syringe tip, the proximal end of the syringe tip cap is coupled with the collar and the resilient closure is pressed on the distal end of the syringe tip, for sealing the syringe tip.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The invention will now be described by way of example and with reference to the accompanying drawings, from which further features, advantages and problems to be solved will be-come apparent. In the drawings:

[0039] FIG. 1 shows a typical syringe barrel to be sealed by a resilient closure, for use with a syringe tip cap of the present invention;

[0040] FIGS. 2a and 2b show in a perspective front and rear view a syringe barrel with a luer collar and a resilient closure mounted on the syringe tip;

[0041] FIGS. 3a to 3c show a syringe tip cap according to a first embodiment of the present invention in two perspective side views and a perspective bottom view;

[0042] FIGS. 4a and 4b show in a perspective front and rear view the syringe barrel of FIGS. 2a and 2b with the syringe tip cap of the first embodiment of the present invention;

[0043] FIGS. 4c and 4d show in a front and rear view the syringe barrel of FIGS. 2a and 2b with the syringe tip cap of the first embodiment in an enlarged view;

[0044] FIGS. 5a to 5c show in different perspective top views the condition of a syringe tip cap of the first embodiment of the present invention after breaking a first annular breaking line at a first stage of removing the syringe tip cap from the syringe barrel;

[0045] FIGS. 6a to 6c show in different perspective top views the condition of a syringe tip cap of the first embodiment of the present invention after breaking a second breaking line at a second stage of removing the syringe tip cap from the syringe barrel, subsequent to the first stage of FIGS. 5a to 5c;

[0046] FIGS. 7a and 7b show a syringe tip cap according to a second embodiment of the present invention in a perspective side view and a bottom view;

[0047] FIG. 7c shows in a side view the syringe barrel of FIGS. 2a and 2b with the syringe tip cap of the second embodiment in an enlarged view; and

[0048] FIGS. 8a to 8c show in different perspective top views the condition of a syringe tip cap of the second embodiment of the present invention after breaking the second and third breaking lines at a second stage of removing the syringe tip cap from the syringe barrel.

[0049] In the drawings, the same reference numerals designate identical or substantially equivalent elements or groups of elements.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0050] As shown in FIG. 1, the syringe 6 includes a syringe barrel 60 which is formed from glass or plastic and is preferably transparent. The syringe barrel 60 includes a proximal end 61 having a flange 67, a distal end 62 and is a cylindrical body defining a substance receiving chamber which may be pre-filled with a selected dose of medication in either dry or liquid form, as well as other substances such as water or diluent for use in reconstituting a medicament. The distal end 62 of syringe barrel 60 includes a tip 64 having a passage extending therethrough and communicating with the substance receiving chamber. A plunger rod assembly (now shown) may extend into the proximal end 61 of the syringe barrel 60 via the filling opening 68, and include a stopper, which may slide in fluid-tight engagement inside the cylindrical wall. The syringe barrel 60 may be used with a standard needle assembly (not shown), which is generally known from the prior art.

[0051] The syringe barrel 60 generally does not have an integral collar for engaging the mounting hub of the needle assembly. As shown in FIGS. 2a and 2b, for this purpose a collar 4, particularly a luer collar, is mounted to the syringe tip 64 at the distal end 62 of the syringe barrel 60. The collar 4 includes a generally cylindrical body 40, having locking members 43 at a proximal end 42 thereof, configured for engagement with the syringe tip 64, e.g. with a groove or ridge 64 (see FIG. 1) provided on the outer surface of the syringe tip 64.

[0052] The needle assembly may be maintained separate from the syringe barrel 60, and may be mounted to the syringe barrel 60 a short time prior to usage of syringe 6. In this way, the syringe barrel 60 may be pre-filled with medication, and stored in its pre-filled condition prior to mounting needle assembly 30 thereto. To prevent contamination or leakage of medication stored in syringe barrel 60, a resilient closure 5 shown in FIGS. 2a and 2b seals the syringe tip 64. The resilient closure 5 is preferably made of an elastomeric material and comprises a cylindrical body (not shown), which is inserted into the syringe tip 64 to seal it. The distal end of the resilient closure 5 is of cylindrical shape and of a larger diameter, which usually corresponds to the outer diameter of syringe barrel 60. On the upper surface 51 of the distal end 50 and annular protrusion 52 is formed that can be used by a pressing member to exert a controlled and uniformly spread pressure onto the resilient closure 5, for pressing the resilient closure 5 in a controlled manner on syringe tip 64.

[0053] In order to keep the resilient closure 5 in place, in a proper engagement with the syringe tip 64 and to prevent a contamination of the resilient closure 5 during storage, a tip cap assembly generally denoted by reference numeral 1 is provided on the syringe tip 64 of the syringe barrel 60, as generally shown in FIGS. 4a and 4b.

[0054] The tip cap 1 is generally cup-shaped and suited to fully accommodate at least the distal end 50 of the resilient closure 5, for preventing a contamination of the distal end 50. The tip cap 1 is made of a rigid or sufficiently stiff plastic material, preferably by plastic injection molding. The tip cap 1 generally is a tubular member and preferably has a closed upper surface 20 at a distal end thereof, for covering the entire distal end of closure 5. More specifically, the tip cap 1 consists of a distal cap member 2 and a proximal sleeve member 3 that are connected with each other via frangible, web-like portions 11 disposed along a first annular breaking line 10 formed between the distal cap member 2 and the proximal sleeve member 3. These frangible, web-like portions 11 serve as tamper indicator means, as outlined below in more detail.

[0055] As shown in FIGS. 3a to 3c, the distal cap member 2 of the first embodiment of the present invention is generally cup-shaped, for fully accommodating the entire distal end of the resilient closure. When mounted on the distal end of syringe barrel 60, the annular first breaking line 10 is preferably below the position of the distal end 50 of closure 5, to provide full access to the closure 5 once the annular first breaking line 10 is broken and the distal cap member 2 is partially separated from the proximal sleeve member 3, as outlined below in more detail.

[0056] As shown in FIG. 3a, the distal cap member 2 is a cup-shaped cylindrical body having a closed upper surface 20, which is surrounded by a rounded upper rim 21 connecting with the circumferential side wall. The inner diameter of the distal cap member 2 is slightly larger than the outer diameter of the distal end 50 of closure 5 so that the closure 5 can be easily inserted and accommodated with radial play inside the distal cap member, when it is not compressed.

[0057] The annular first breaking line 10 is not fully circumferential, but disrupted by a coupling strip 29, which bridges the annular first breaking line 10 and couples the distal cap member 2 with the proximal sleeve member 3. The frangible portions 11 are weaker than the axial coupling strip 29. Hence, when the frangible portions 11 are broken by tilting the distal cap member 2 about coupling strip 29, the coupling strip 29 will continue coupling the distal cap member 2 with the proximal sleeve member 3. Thus, after breaking the annular first breaking line 10, the distal cap member 2 and the proximal sleeve member 3 will be separated only partially, but remain coupled with each other via coupling strip 29. The coupling strip 29 will thus serve as a hinge for pivotally coupling the distal cap member 2 and the proximal sleeve member 3 of the rigid outer cap 1 after the annular first breaking line 10 has been broken.

[0058] In order to ease a breaking of the annular first breaking line 10, a handling section is formed at the distal cap member 2 at a position opposite to the coupling strip 29 and slightly offset toward the distal end 20 of the distal cap member 2, so that a pivoting force will be exerted on the distal cap member 2 when operating the handling section, to ease a pivoting of the distal cap member 2 about the hinge formed by the coupling strip 29. More specifically, this handling section may be formed by a stepped portion on the outer surface of the distal cap member 2, as shown in FIG. 3a. This stepped portion is formed by a planar, vertical side wall 23, which extends from the distal end 20 toward the step 25, which is a substantially horizontal surface near the proximal end 26 of the distal cap member 2 and is connected with the vertical side wall 23 via a rounded horizontal edge 24. This stepped portion can be operated easily by a finger, preferably by a thumb, while holding the syringe barrel 60 with a hand. It is preferred to operate the tip cap 1 with only one hand, in which case the syringe barrel 60 will be held with the fingers of one hand, while the stepped portion will be pushed radially inward and toward the distal end 20 under an acute angle with respect to an axial middle line of the syringe barrel 60 so that a pivoting force will be exerted onto the distal cap member 2, which will finally break the frangible portions 11 of the first annular breaking line 10 and will finally result in the condition shown in FIGS. 5a to 5c.

[0059] As shown in FIG. 3b, the rectangular coupling strip 29 of the distal cap 2 is integrally connected with an opposite, rectangular coupling strip 39 of the proximal sleeve 3. More specifically, the coupling strips 29, 39 have a wedge-shaped profile, if viewed in a cross-sectional view, so that a film hinge is formed at the region where the two coupling strips 29, 39 are connected with each other. As shown in FIG. 3b, this film hinge is at the center of the first breaking line 10 and thus eases and guides the pivoting of the distal cap 2 about the proximal sleeve 3.

[0060] As shown in FIG. 3b, the coupling strip 29 is laterally delimited by two rectangular slots 28a, 28b and 37b, 38, respectively, which both extend in axial direction and are formed in the side wall of both the distal cap member 2 and the proximal sleeve member 3. More specifically, a first slot 28a is formed at a first side of the coupling strip 29 in the distal cap member 2 and a second slot 28b is formed at a second side of the coupling strip 29, in parallel with the first slot 28a. Directly opposite to these two slots 28a, 28b two corresponding slots 37b, 38 are formed at the distal end 31 of the proximal sleeve member 3. The first slot 37b communicates with a second breaking line 35 formed in the proximal sleeve member 3, extending between the distal end 31 and proximal end 30 thereof. Web-shaped second frangible portions 36 extend horizontally across the second breaking line 35. It is noted that the second breaking line 35 preferably extends under an acute angle with respect to the axial direction, preferably at an angle in the range between 45 degrees and 5 degrees, more preferably at an angle in the range between 30 degrees and 5 degrees and even more preferably at an angle in the range between 20 degrees and 10 degrees. It is also noted that the first slot 37b of the proximal sleeve member 3 extends in axial direction and can be considered as an extension of the first slot 28a of distal cap member 2.

[0061] As indicated by the dashed lines in FIG. 4d, the slot 38 in the proximal sleeve member 3 opposite to the axial slot 28b is optional and may also be omitted.

[0062] As shown in FIG. 3c, a plurality of locking protrusions 34 is formed on the inner surface of the proximal sleeve member 3 at a proximal end 30 thereof. The locking protrusions 34 are preferably disposed at equiangular distances to each other and protrude in radial direction inwards and each have an upper surface (not shown), which extends substantially perpendicularly to the side wall of proximal sleeve member 3, and a slanted insertion surface, which is directed toward the proximal end 30 for guiding the tip cap 1 when it is pushed over the distal end of the collar 4, as outlined below in more detail. After the tip cap 1 has been mounted on the syringe tip, the locking protrusions 34 grip behind the distal end of the collar 4, for coupling the tip cap 1 with the syringe 6 by latching or locking.

[0063] As shown in FIG. 3c, a plurality of axial ridges 32 is formed on the inner side wall 33 of proximal sleeve member 3 and disposed at a distance to the locking protrusions 34 and at equiangular intervals along the inner side wall 33 of proximal sleeve member 3. The ridges 32 enclose a circle having a diameter, which is substantially equal to an outer diameter of the collar 4 and/or the syringe 6, so that the collar 4 and/or the syringe 6 may abut with these ridges 32 in a mounted position. The ridges 32 serve for precisely centering the syringe in the tip cap 1 and for reducing friction when mounting the tip cap 1.

[0064] As shown in FIGS. 3b and 4b, the second breaking line 35 extends under an acute angle relative to the annular first breaking line 10. This acute angle may be in the range between 5 degrees and 45 degrees, more preferably in the range between 7.5 degrees and 30 degrees, even more preferably in the range between 10 degrees and 20 degrees. However, the angle of intersection between the second breaking line 35 and annular first breaking line 10 may also be 90 degrees or nearly 90 degrees. As shown in FIGS. 3b and 4b, the second breaking line 35 runs into the first breaking line 10 at a point of intersection, which is basically formed by the axial slots 37b and 28a. The axial coupling strip 29 bridges the first breaking line 10 at a position directly adjacent this point of intersection. Thus, once all frangible portions 11 of the first breaking line 10 are broken, the distal cap member 2 and the proximal sleeve member 3 remain to be connected with each other via the axial coupling strip 29, which can then be used as a pulling tab for breaking the second breaking line 35 by pulling the axial coupling strip 29 basically along the direction of the second breaking line 35, until finally all frangible portions 36 of the second breaking line 35 are broken and the syringe tip cap 1 can be removed from the syringe by unwinding the proximal sleeve member 1 from the collar at the distal end of the syringe.

[0065] In the following, two methods according to the present invention for mounting the tip cap 1 on the syringe tip and sealing a syringe are described with reference to FIGS. 1 to 3c. According to a first embodiment of the method, first the resilient closure 5 is put on the syringe tip 64. Afterwards, the tip cap 1 is pushed on the distal end 62 of the syringe barrel 60, until the slanted insertion surfaces of the locking protrusions 34 get in contact with the distal edge of the collar 4. Then, the tip cap 1 is further pushed onto the distal end of syringe barrel 60 so that the front ends of the locking protrusions 34 slide over the outer surface of collar 4, until the locking protrusions 34 grip behind the proximal end of collar 4 to thereby retain the tip cap 1 on syringe barrel 60. In this position, the distal end 20 of tip cap 1 may slightly compress the resilient closure 5 and press it on syringe tip 64 to seal the syringe tip 64 safely. For exerting a controlled pressure on the upper surface 51 of the resilient closure 5 and properly spread this pressure over the upper surface 51, a cylindrical protrusion 27 (see FIG. 5a and FIG. 7b) may be formed on the inner surface of the distal end 20 of the distal cap member 2, in which case the pressure exerted on the upper surface 51 of the resilient closure 5 may be controlled by the axial length of the cylindrical protrusion.

[0066] According to a second embodiment of the method, first the resilient closure 5 is inserted into the tip cap 1. Because the diameter of a circle along which the plurality of locking protrusions 34 is disposed on the inner side wall 33 of proximal sleeve member 3 is smaller than a maximum outer diameter of the distal end 50 of the resilient closure 5 the resilient closure 5 is retained in axial direction inside the cup-shaped distal cap member 2 by the plurality of locking protrusions 34. Afterwards, the syringe tip cap 1 together with the resilient closure 5 are pushed in axial direction on the distal end 62 of syringe barrel 60 until the slanted insertion surfaces of the locking protrusions 34 get in contact with the distal edge of the collar 4. Then, the tip cap 1 is further pushed onto the distal end of syringe barrel 60 in the same manner as outlined in the previous section, until the locking protrusions 34 grip behind the proximal end of collar 4 to thereby retain the tip cap 1 on syringe barrel 60.

[0067] Because the resilient closure 5 is fully accommodated in the cup-shaped distal cap member 2, particles from outside cannot contaminate the upper surface 51 of the resilient closure 5. FIGS. 4a and 4b show the syringe 6 with the syringe tip cap 1 according to the present invention mounted at the distal end of syringe 6. FIGS. 4c and 4d show the syringe 6 with the syringe tip cap 1 according to the present invention mounted at the distal end of syringe 6 in an enlarged partial view.

[0068] For permitting a visible inspection of the contact area between the pressing member 27 (see FIG. 5a) on the inner surface of the distal end 20 and the upper surface 51 of the resilient closure 5, a transparent window (not shown) may be provided in a side wall of the distal cap member 2, particularly in the vertical side wall 23, so that the upper surface 51 of resilient closure 5 and/or a pressing member provided on the inner surface of the distal cap member 2 (cf. FIG. 7b) is visible from outside the syringe tip cap 1. This transparent window may be integrally formed with the tip cap 1, particularly by two-component plastic injection molding.

[0069] In the following, a process for giving access to the resilient closure 5 by partially separating the distal cap member 2 from the proximal sleeve member 3 and even for completely removing the tip cap 1 will be described with reference to FIGS. 4a to 6c.

[0070] At a first stage, a force directed obliquely toward the distal end of the syringe 6 is exerted on the distal cap member 2 by a user, particularly by pushing the vertical side wall 23 obliquely upward toward the distal end with the thumb of the user. This force will finally break the frangible portions 11 of the first annular breaking line 10 which hence serve as a tamper indicator means to provide such tamper evidence, as an integral and unmistakable evidence of tampering with the syringe barrel 60 and the medication therein. When the annular first breaking line 10 is broken, the distal cap member 2 is pivoted about the coupling strip 29, which is disposed opposite to the vertical side wall, until the condition shown in FIGS. 5a to 5c is reached. In this condition access is gained to the upper surface 51 of the resilient closure 5, which may be sufficient for administering the medication inside syringe barrel 60.

[0071] To gain full access to the entire resilient closure 5, the tip cap 1 may also be removed completely, which will be described with reference particularly to FIGS. 6a to 6c in the following.

[0072] For tearing off the tip cap 1 completely, the user may proceed further by gripping the distal end of syringe 6 with two fingers of one hand, particularly with the thumb and forefinger, and gripping the distal cap member 2 with two fingers of the other hand, particularly with the thumb and forefinger of the other hand. The user will continue tearing the distal cap member 2 into the same direction as previously pushing the distal cap member 2. In this condition, the distal cap member 2 will further pivot about the coupling strip 29 opposite to the vertical side wall 23. Finally, the distal cap member 2 is pivoted to such an extent about the coupling strip 29 that the coupling strip 29 basically serves as shackle to ease breaking the second breaking line 35 and completely tearing off the tip cap 1. This function is enhanced, because the two axial slots 37b and 38 that delimit the coupling strip 29 in the side wall of the proximal sleeve 3 enable pulling the coupling strip 29 a distance away from the side wall of the proximal sleeve member 3. Finally, the coupling strip 29 can be pulled in axial direction toward the proximal end of the proximal sleeve member 3, because the slot 37b serving as the distal end of the second breaking line 35 also extends in axial direction.

[0073] Then, the user continues pulling the coupling strip 29 toward the proximal end 30 of proximal sleeve member 3 so that one frangible portion 36 of the second breaking line 35 after the other is finally broken, as shown particularly in FIG. 6b, so that the proximal sleeve 3 can be unwound finally from the distal end of syringe 6, as shown particularly in FIG. 6c. That rim of the second breaking line 35 that is provided on the same side of the second breaking line 35 as the coupling strip 29 may thus serve as a pulling tab 13, as shown in FIG. 6c, for further pulling the proximal sleeve member and unwind the proximal sleeve member 3 from the distal end of the syringe 6. For this purpose, the user may grip the side of the proximal sleeve member 3 opposite to this pulling tab 13 and continue pulling the coupling strip 29, until all frangible portions 36 of the second breaking line 35 are broken and the proximal sleeve member 3 is finally unwound from the distal end of the syringe 6. Then, full access is gained to the resilient closure 5 on the distal end of syringe 6, for further handling, such as puncturing the closure 5 with a needle etc.

[0074] As will become apparent to a person skilled in the art, the above procedure for breaking the first breaking line, pivoting the distal cap member and finally complete removal of the syringe tip cap may of course also be performed with the fingers of a single hand.

[0075] To enable the above handling of the tip cap 1, the material of the tip cap 1 should be sufficiently flexible, particularly in the region of the coupling strip 29 bridging the annular first breaking line 10.

[0076] FIGS. 7a and 7b show a syringe tip cap 1 according to a second embodiment of the present invention. As shown in FIG. 7a, the second breaking line 35a extends basically in the axial direction of the syringe tip cap 1, but stops a short distance before reaching the proximal end 30 of the proximal sleeve member 3. According to this second embodiment, a third breaking line 35b extends in parallel with the second breaking line 35a, and may extend until the proximal end 30. Both the second and third breaking line 35a, 35b are formed by a linear groove which is bridged by web-shaped frangible portions 36 that are broken when breaking the second and third breaking line 35a, 35b. The second and third breaking line 35a, 35b is each followed by a respective short slot 28a, 28b formed in the distal cap member 2 at an opposite side of the annular first breaking line 10. As shown in FIG. 7a, the coupling strip 29 does not necessarily comprise a hinge as for the above first embodiment. Of course, such a hinge may be provided also in the second embodiment.

[0077] Once the annular first breaking line 10 is broken and the distal cap member 2 is pulled down toward the proximal end 30 the frangible portions 36 of the second and third breaking line 35a, 35b are broken, one after the other, so that a pulling tab of rectangular shape is formed between the second and third breaking line 35a, 35b, which acts as a lever for more efficiently break the second and third breaking line 35a, 35b when the distal cap member 2 is pulled down further toward the proximal end 30. FIGS. 8a to 8c show this pulling tab 13 at the second stage of removing the syringe tip cap 1 from the syringe barrel 60 by pulling down the distal cap member 2 toward the proximal end 30.

[0078] FIG. 7c shows the syringe tip cap 1 of the second embodiment in a rear side view, when mounted on the syringe barrel 60. Of course, the second and third breaking line 35a, 35b may also extend under an acute angle relative to the axial direction of the syringe tip cap 1, just as in the case of the first embodiment described above.

[0079] FIG. 7b shows a bottom view of the syringe tip cap 1 of the second embodiment. The pressing member formed in the bottom of the cap 1 consists of two concentric circular protrusions 27a, 27b, which may be of identical height, but which may also have different heights. The diameter of the outer pressing member 27b may be similar or slightly smaller than the diameter of protrusion 52 (see FIGS. 2a and 2b) of the resilient closure. The inner pressing member 27a is used to exert a controlled pressure at a central part of the upper surface 51 of resilient closure 5. The cooperation of the inner and outer pressing member 27a, 27b ensures a reliable sealing of the ejection opening 66 (see FIG. 1) of syringe barrel 60.

[0080] FIGS. 8a to 8c show in different perspective top views the condition of the syringe tip cap of the second embodiment of the present invention after breaking the second and third breaking lines at a second stage of removing the syringe tip cap from the syringe barrel. After breaking the first breaking line a pulling tab is formed between the second and third breaking line 35a, 35b, which is used to further break the frangible portions of the second and third breaking line 35a, 35b by pulling. After breaking all or nearly all frangible portions of the second and third breaking line 35a, 35b, a slight tilting of the distal cap member 2 relative to the syringe barrel is induced, because the third breaking line 35b is shorter in length than the second breaking line 35a. This tilting induces a circumferential motion component, which causes a widening of the gap between the edges of the second breaking line so that the syringe tip cap is finally unwound by a spiral-shaped movement.

[0081] While the preferred embodiments of the present invention have been described so as to enable one skilled in the art to practice the device of the present invention, it is to be understood that variations and modifications may be employed without departing from the concept and intent of the present invention as defined in the appended claims. Accordingly, the preceding description is intended to be exemplary and should not be used to limit the scope of the invention. The scope of the invention should be determined only by reference to the appended claims.

TABLE-US-00001 List of reference numerals 1 syringe tip cap 2 distal cap member 3 proximal sleeve member 4 collar 5 resilient closure 6 syringe 10 annular first breaking line 11 frangible portion/coupling web 12 gap 13 pulling tab 20 upper surface/distal end 21 rounded upper rim 22 edge 23 vertical side wall 24 edge 25 step/slanted surface 26 proximal end 27 pressing member 27a outer pressing member 27b inner pressing member 28a first slot 28b second slot 29 coupling strip 30 proximal end 31 distal end 32 inner ridge 33 inner side wall 34 locking protrusion 35 second breaking line 35a second breaking line 35b third breaking line 36 frangible portion/coupling web 37a proximal end of second breaking line 37b distal end of second breaking line 38 slot 39 coupling strip 40 cylindrical body 41 ridge 42 proximal end of collar 4 43 locking member 50 distal end of resilient closure 5 51 upper surface 52 protrusion 53 step 60 syringe barrel 61 proximal end 62 distal end 63 tip shoulder 64 syringe tip 65 groove 66 ejection opening 67 flange 68 filling opening