Preliminary filled syringe and method of making them

The invention relates to a pre-filled syringe and a method of manufacturing a pre-filled syringe. In particular, it relates to a plastic syringe.

In medical practice, there is an increasing danger of transmitting various viruses such as HIV and hepatitis, especially when treating many patients. This danger is associated with the repeated use of surgical and other medical devices. There is therefore an increasing need for medical and surgical devices that are reliable and easy to use and that can be disposed of after a single use. This is of particular importance when it comes to hypodermic syringes. As the hypodermic needles come into contact with body fluids, there is a risk of cross contamination if the same syringe is used more than once, and even if the hypodermic needle is thrown away after each use. For these reasons, pre-filled disposable syringes are desired. The single-dose syringe, accurately filled and labeled with the name of the injection fluid, is convenient and safe to use as there is less risk of incorrect dosing. The syringe is used once and thrown away. There is no need to re-sterilize the equipment, and there is no need to carefully transfer the injection fluid from a separate ampoule.

AU 595096 discloses a pre-filled syringe sealed on one side with a stopper and on the other with a closure integrally connected to the syringe. After removing the closure, a hypodermic needle can be attached to the end of the syringe for injection of its contents. The closure is removable by rotation with a suitably shaped tool or by snapping action.

AU patent 635631 discloses a pre-filled syringe which also has an integral closure. The closure breaks away from the end of the syringe after a hypodermic needle has been inserted into the needle attachment on the syringe. The closure moves into the syringe and remains in the chamber at the needle end of the syringe.

While both of the known syringes represent a significant improvement over the previous pre-filled syringes, the present invention relates to a variation of the syringe design that has several advantages (for certain applications) over both of the previously described syringes.

A pre-filled plastic syringe containing an open ended sleeve, one end of which is sealed with a movable stopper and the other end is frictionally connected

178 752 with a syringe closure, and a cap including at least an end of the closure, it is characteristic of the invention that the cap includes closure locking means for holding and retaining at least the end of the closure such that upon removal of the cap from the remainder of the syringe, the closure will be separated from the syringe revealing the closure. injectable content.

Preferably, the overcap is movable at the end of the syringe from a position where the closure remains outside of the closure locking means to a position where the closure is locked inside the locking means.

Preferably, the closure is in the form of a shaft extending from the end of the syringe remote from the stopper.

Preferably, the shank is inserted into a hollow channel inside the cap constituting the locking fixation element.

Preferably, a portion of the hollow channel is conical in shape and has a progressively tapering inward cross section.

Preferably, the hollow channel in the overcap has an actuating portion which, at the point of the maximum cross-section, has a diameter that is at least 0.1 mm smaller than the diameter of the shaft at the point of the maximum cross-section, which is 1.5-2.3 mm.

Preferably, the diameter of the shank at the location with the maximum cross section is 1.8-2.1 mm.

Preferably, the closure has longitudinal grooves separated by ribs.

Preferably, the closure end of the syringe is attached to a hypodermic needle or a luer needle.

Preferably, a closure of the syringe is connected to its end by a plastic bridging portion extending from the inner wall of the exit orifice of the syringe end to the outer wall of the closure.

Preferably, the bridge portion has one section with a minimum cross section and a second section with an increased thickness relative to the minimum section section.

Preferably, the lid is fixed in a position over the closure.

Preferably, the cap has a circumferential skirt extending between the circumferential outer needle mounting wall and a hollow conical portion of the needle mounting or externally extending the circumferential outer needle mounting wall.

Preferably, the syringe is made entirely of polypropylene, polyethylene or polytetrophthalate.

A method for the manufacture of a pre-filled plastic syringe in which, in an aseptic environment, an injection molding of an open ended sleeve, sealed at one end with an integral closure frictionally attached to the sleeve, is then aseptically filled with a medium to be injected in an aseptic environment and injected into the sleeve. in this aseptic environment the pre-sterilized stopper, finally, this stopper fits into the open end of the sleeve in an aseptic environment, according to the invention, it is characteristic in that both before, during and after filling the sleeve, the cap is separately injection molded with the locking elements, then the cover is placed on the closure and connected to it. the other end of the sleeve.

Preferably, the lid is injection molded in the same aseptic environment where the open end sleeve is injection molded and the closure end is joined to the closure end of the sleeve in the same aseptic environment.

In the syringe of the invention, the user has a choice of two options, i.e. removing the closure through the lid or breaking the connection of the closure when securing the hypodermic syringe when the lid has already been removed (if not used to remove the closure). This gives the user flexibility in use as the same product can easily be used for connection to a part of an intravenous drip (where no hypodermic needle is attached) or as a hypodermic syringe with simple and efficient opening of the syringe in one of two ways.

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The syringe offers the user considerable flexibility in use. The closure can be removed by retainers in the cap or by placing a hypodermic needle on the needle mount after removing the cap. The syringe may be pre-filled with a marked and known amount of the specified injection fluid for convenience and ease of use.

The subject matter of the invention in the embodiments is reproduced in the drawing, in which Fig. 1 shows the syringe according to the invention with the cap attached to its end, before engaging it with the closure, in section; Fig. 2 is a sectional view of the syringe of Fig. 1 with the cap pressed down and the closure locked in the cap; Fig. 3 shows the cover, enlarged and in section; Fig. 4 is a sectional view of the cap of Fig. 3 after its removal from the syringe with the closure in place; fig. 5 - the end of the syringe on the needle attachment side with the closure in place before its removal, enlarged and in section; Figure 6 is a sectional view of a second embodiment of the syringe having teeth on its body for engaging recesses in the cap in a position prior to engagement and locking the closure to the cap, and Figure 7 is a sectional view of the syringe of Figure 6. 6 with the overcap rotated and pressed in such that the teeth on the syringe body and the recesses on the overcap engage and the closure is secured in the overcap in cross section.

The syringe 1 shown in Fig. 1 comprises a barrel 2 with open ends. The sleeve 2 is sealed on one side by a removable stopper 3 and, on the other side, by a closure 4. The closure 4 is in the form of a shaft which is connected to the end of the syringe 1, which attaches 5 to the needle. A cap 6 is applied to the tip of the closure 4, which is connected to the needle holder 5. The lid 6 has a frangibly attached ring 6a which prevents the lid 6 from moving downward. The ring 6a is connected to the outer wall of the cover 6 by frangible bridges 6b and rests against the end of the needle attachment 5. The lid 6 also includes a hollow channel 7 to hold the closure 7. A cap 6 is attached to the end of the syringe by spot welding.

Fig. 5 shows the luer needle mount 5 in detail. It has a hollow conical portion 8 surrounded by a circumferential outer wall 9. A closure 4 is seated in the hollow conical portion 8 of the attachment 5 by means of a frangible rib portion 10. The bridging portion 10 has one section 11 of minimal cross-section and a second section of increased thickness 12 attached to the inner wall of the conical portion 8. Such a configuration of the bridge part 10 makes the tearing clear and compact when the closure 4 is removed. The end portion 13 of the closure 4 has a conical profile. The inner wall of the conical portion 8 has a stop 14 dimensioned to prevent the closure 4 from falling into the syringe 1 body should it be opened by pushing the closure 4 down in the direction shown by the arrow 15. The other end of the closure 4 has grooves 16 separated by ribs 17. (fig 4).

Figure 1 shows a cover 6 positioned above the closure 4 and connected to the needle attachment 5 by spot welding of the outer wall of the circumferential skirt 18 of the cap 6 to the inner surface 19 of the circumferential wall 9 of the needle attachment 5. The end of the closure 4 is located at the opening of the channel 7.

When using the syringe 1, the cap 6 is turned so as to break its connection with the end of the needle fixture 5. The lid 6 is then pushed in the direction shown by the arrow 21 (Fig. 2) such that the ring 6a is separated from the lid 6, and the closure 4 is pressed into the channel and locks therein. The closure 4 is held tight in the channel as it has a progressively tapering diameter, tapering to an angle of about 1.5 degrees from the opening 20 (Fig. 4).

After the closure 4 has been locked with the cap 6, it is pulled outwards in the direction shown by the arrow 22 (fig. 4), taking the closure 4 with the cap away 4. The closure 4 breaks away from the conical part 8 of the needle holder 5 by tearing the sternum part having a minimum cross-section. 10. Removal of the closure 4 effectively opens the syringe 1 so that the injection fluid contained in the sleeve 2 becomes available.

178 752 nions. A hypodermic needle (not shown) may be attached to the needle mount 5 or, alternatively, the syringe 1 may be attached to a suitable drip injection hole or similar device.

An alternative embodiment of the syringe is shown in Fig. 6. The end of the syringe 1, constituting the needle attachment 5, is similar to that shown in Fig. 1. The same reference numerals are used here for parts with the same features as the embodiment of the syringe shown in Fig. 1 and 2. In this syringe, the cap 6 is wider and the circumferential skirt 18 is outside the circumferential outer wall 9 of the needle mount 5. The circumferential skirt 18 of the lid 6 has two recesses 23 and 24 (FIG. 7). The needle mount 5 has two teeth 25 and 26 which are of such a length that they abut or very close to the peripheral wall 27 of the circumferential skirt 18 when the cover 6 is positioned with the closure 4 at the entrance of the channel. In the configuration shown in Figure 6, the recesses 23 and 24 are slightly spaced from the teeth 25 and 26. The lid 6 is spot welded so as to be attached to the syringe 1 in the orientation shown in Figure 6.

When using the syringe 1, the user rotates the cap 6 to break the spot welding and then remove the cap 6. The cap 6 rotates to a position where the recesses 23 and 24 are aligned along the teeth 25 and 26. In this position, the cap 6 is pushed. in the direction of arrow 21 to the position shown in Fig. 7. The closure 4 is then seated and fixed in the channel constituting the locking element 7. As in the syringe embodiment shown in Figures 1 and 2, sliding the cap 6 in the direction of the arrow 22 will remove the closure 4 and expose the contents of the syringe to be injected.

The opposite end of the syringe 1 shown in Figures 6 and 7 is made so as to reduce the possibility of the syringe 1 being manipulated by unauthorized persons and the contents removed from the syringe. The plug 3 is attached to the piston rod 28 and the piston assembly slides through the open end 29. In the illustrated construction, the bore of the sleeve 2 is surrounded by a flange 30, the free edge 31 of which is bent towards the inside of the inner wall of the sleeve 2. In this way, the open end 29 through which the piston assembly passes is tapered in relation to the opening of the chamber. Adjacent to the plug 3, the piston rod 28 has an outer stop 32, and a further disk 33 is spaced from this disk 32. Both these disks 32 and 33 and the flange 30 work together to prevent an unauthorized person from removing the injection solution from the inside of the syringe.

The closure 4 can be held and fixed in the locking means 7 in a number of ways. For example, either the shank or the bore may include ribs or the like to cooperate with a groove in the latter. The shaft, when pushed far enough into the channel, will lock into the lid 6. An appropriate force applied to the lid 6 during its removal will break the seal of the closure 4 with the syringe 1 such that the lid 6 and closure 4 will be removed in one operation.

In such an embodiment, applying a downward force to the cap 6 is used to move the cap 6 down and push the end of the closure 4 tightly into the channel, before applying a force to remove the cap 6 (and closure 4) from the end of the syringe. Where the locking element 7 of the closure 4 is a hollow channel and the closure 4 is an outwardly projecting shank, the entrance of the channel is at least 0.1 mm wider than the shank and the channel has a tapered portion which has a taper of 1-3 ° (most preferably about 1.5 °). Alternatively, the channel may have a substantially uniform cross-sectional diameter and the shank may be tapered.

In these designs, the end of the closure 4 has a plurality of longitudinal grooves 16 or slots and is made of a compressible but resilient plastic material. In this embodiment, the closure 4 also has a plurality of ribs 17 which are easier to squeeze into a channel in the cap 6. This helps to lock the closure 4 into the channel as it is removed from the tip of the syringe 1.

In one embodiment of the syringe 1, its closure end 4 has a straight exit opening through which the contents of the syringe 1 are pressed after the closure 4 is removed.

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In an alternative embodiment, the closure end of the syringe 4 has a fastening 5 to a hypodermic needle placed in a plastic holder. The fastening 5 at the end of the syringe 1 is in the form of a hollow conical part 8 surrounded at a distance by a circumferential skirt 18. The inner surface of the circumferential skirt 18 may have the same threads as in a standard luer needle mounting. In this embodiment, the closure 4 is sealed to the conical part 8 of the needle holder 5 and projects beyond the end of the needle holder 5. Preferably, the closure 4 also extends inwardly into the hollow conical part 8 and is frangibly connected to the inner wall of the conical part 8 at a distance. from the inner end of the closure 4.

The connection of the closure 4 to the end of the syringe should be strong enough to withstand an accidental impact or fall of syringe 1 when cap 6 has been removed, but also brittle enough to break when force is applied to pull cap 6 when distal end of closure 4 has already been locked in place. locking elements 7 closure 4. When the closure 4 is compressed inside the channel in the cap 6, the frictional force of the shaft in the channel should be greater than the force needed to break the frangible connection between the closure 4 and the end of the syringe 1.

The lid 6 should be of such a size and shape as to cover and protect the closure 4 from accidental tampering. It is desirable that the cover 6 includes a gripping part at its end to facilitate removal, e.g. a finger grip or a flange tilted outwards. The cap 6 is fixed in position above the closure 4 by spot welding the cap 6 to the end of the syringe 1.

In cases where it is desired to prevent contamination of the outer peripheral surface of the outer wall 9 of the attachment 5, the cover 6 has an outer circumferential skirt 18 which has a diameter such that it covers the outer surface of the peripheral outer wall 9 of the attachment 5. If greater sealing accuracy is required, the cap may have two joined peripheral shell portions spaced apart slightly greater than the thickness of the peripheral outer wall 9 and positioned to fit on both sides of the peripheral outer wall 9. The outer surface of the cap shell 6 is attached to the inner peripheral surface of the outer wall 9 by spot welding.

The lid 6 is fitted in a position above the closure 4, and the end of the closure 4 is in the channel entrance but not yet engaged with the locking means 7 of the closure 4.

In one embodiment, the cap 6 has a circumferential skirt 18 positioned to fit between the tapered portion 8 and the circumferential outer wall 9 of the luer attachment 5, and has an outer ring 6a fracturedly connected to the top edge of the circumferential skirt 18. The outer ring 6a is positioned to abut the top of the peripheral outer wall 9 when the cap 6 is placed on the closure 5 with the end of the closure 5 being in the channel entrance but not engaged with the locking means 7 of the closure 4. In this way, the syringe 1 can be opened in an easy two-step operation in which the lid 6 is first pressed (to break the frangible ring 6a from the lid 6 and insert the end of the closure 5 into the retaining means 7 of the closure 4) and then pull it out (to remove the lid 6). and closure 4 and reveal the contents of syringe 1 for injection).

In an alternate embodiment of the syringe 1 with a luer fitting, the peripheral skirt 18 is spot-welded to the peripheral outer wall 9 and the syringe 1 is opened in a three-step operation. The cap 6 is first turned (to break the seal with the end of the syringe), pressed (to insert the end of the closure 4 into the locking means 7 of the closure 4) and then pulled out (to remove the cap 6 and closure 4 and expose the contents of the syringe for injection).

In this embodiment, the connection of the syringe body 1 to the cap 6 can be made in the form of engaging teeth 25 and 26 and recesses 23 and 24, offset

178 752 with respect to each other where the lid 6 is welded to the peripheral outer wall 9. A pair of teeth 25 and 26 are formed on opposite sides of the peripheral outer wall 9 and the cover 6 has mating recesses 23 and 24 which are offset with respect to their respective teeth 25 and 26 when the cover 6 is welded. If, in this position, the teeth 25 and 26 abut the peripheral wall 27 of the circumferential skirt 18, this prevents accidental engagement of the closure 4 in the cover 6, as it cannot then be pressed in. However, when the user intends to open the syringe 1 for use, the cap 6 must be turned to break the connection with the end of syringe 1. The mating teeth 25 and 26 and the recesses 23 and 24 will align with each other to allow the user to press down on the cap 6 to engage the end of the closure 4 with the locking means 7 of the closure 4.

Each of the listed syringe embodiments is partially or completely manufactured in an aseptic environment to ensure the sterility of the contents of the syringe 1.

The barrel 2 of the syringe 1 and the cap 6 are separately injection molded in an aseptic environment. The syringe 1 is then filled with a pre-sterilized injection fluid. After filling the syringe 1, a pre-sterilized stopper 3 is inserted into the aseptic environment, which is inserted into the open end of the sleeve 2 of the syringe 1. At the end of the closure 4, the cap 6 is put on and it is welded (e.g. ultrasonically) to the end of the sleeve 2 from the closure side 4 . All these operations are performed in an aseptic environment. The syringe 1 is then removed from the sterile area and sent to the final sterilization. Finally, the syringe 1 is placed in the piston rod insertion machine 28. At this stage, the complete pre-filled syringe 1 can be transferred to the final sterilizer if desired. The process can be further carried out such that the insertion of the piston rod 28, labeling and inspection are also performed in the sterile area.

The attachment and shaping of the lid 6 need not be performed in an aseptic environment.

The protective cap 6 of the syringe serves to remove the integral closure 4 from the pre-filled syringe. Such a cap also applies in combination with a syringe disclosed in AU 635631.

The syringe according to the invention is particularly suitable for cases where the pre-filled syringe is intended for use without a hypodermic needle, e.g. when introducing a pharmaceutical solution from a syringe into an intravenous drip.