NO301453B1 - The unit dosage container - Google Patents

Abstract

A liquid containing thermoplastic unit dose container (1) which comprises a body portion (2), a neck portion (3) and an outlet opening (7) at the end of neck portion (3) which is sealed by a non re-sealable cap (4). The outside wall of the neck portion (3) comprises a thread engagement portion (8) which is located at or proximate the outermost edge of the neck portion (3) so that after removal of cap (4) thread engagement portion (8) is adapted to engage within an inwardly facing screw thread channel (14) at the end of a syringe. This enables sealing connection of the container (1) to the syringe so that liquid within container (1) may be directly transferred from the container (1) to the syringe.

Description

The present invention relates to a liquid-containing unit dose container made of thermoplastic which includes a main part, a neck part and an outlet opening at the end of the neck part which is sealed with a non-resealable cap.

The invention is suitable for use in holding and transferring injectable solutions to a syringe.

There are many different types of syringes available today for use in the medical professions. The most appropriate syringe design for any given situation depends to a large extent on the particular circumstances of use, the nature of the solution to be injected and the location of the intended injection.

A definite design difference between different syringes is the way in which the open end is shaped to receive a hypodermic or subcutaneous needle. The two most popular forms of pin assembly are the friction fit assembly (such as the cap-drop assembly) and the combination of screw thread and friction engagement assembly (such as the cap-lock assembly). The screw thread engagement assembly of interest in connection with the present invention is a female assembly which has an internal thread such as in the case of the luer lock assembly and all references to screw thread engagement assemblies on syringes in the following are referred to female assemblies or fittings. A screw-thread engagement assembly is the assembly preferred where the circumstances of use indicate that there is something that says the needle is dislodged with the syringe body (ie, epidural injections). This invention particularly relates to containers suitable for transferring injectable solutions to syringes having a screw thread engagement assembly.

In the past, the common practice of surgeons or other medical practitioners using subcutaneous syringes has been to transfer an injection solution to a syringe from a glass ampoule using a wide bore needle attached to the syringe body. After transfer, this wide bore needle has been removed from the syringe and replaced with a subcutaneous needle with a narrower bore suitable for injecting the solution into the patient. It will be understood that this past practice has necessitated the use of a number of separate components. Since the solution transferred for injection into humans requires careful sterilization of the components, this prior practice has required that separate sterilization measures be taken for each step.

To avoid problems with such transfer, it has previously been proposed to deliver ampoules or small bottles containing a single dose. These single-dose bottles have been designed to fit as cartridges in a syringe body onto which a subcutaneous needle can be mounted. Such unit dose bottles have usually been made of glass and sealed with a rubber membrane and the bottle is punctured by attaching a double-sided needle to the syringe body.

An alternative arrangement is shown in Australian patent 556,483 where a unit dose container is described which is made of a thermoplastic material which is arranged to be opened and cooperatively inserted directly into a needle assembly of a syringe into which it is desired to transfer the injection fluid. While this patent describes a satisfactory arrangement for use with a standard friction fit needle fitting such as a luer slip assembly, it does not address the problems associated with syringes utilizing screw thread engagement systems such as the luer lock system.

It is an object of the present invention to provide a container suitable for use with a syringe having a screw thread engagement assembly to enable safer, easier and more dexterous transfer of an injection solution to a syringe having a screw thread engagement assembly than what which until now has been possible.

In accordance with the present invention, a liquid-containing unit dose container made of thermoplastic is provided which includes a main part, a neck part and an outlet-soap at the end of the neck part which is sealed with a non-resealable cap, characterized in that the outer wall of the neck part comprises a thread engagement portion located at or near the outermost edge of the neck portion so that after removal of the cap, the thread engagement portion is adapted to engage an inwardly facing screw-threaded channel at the end of a syringe, thereby enabling sealing connection of the container to the syringe so that liquid in the container can be directly transferred from the container to the syringe.

The cap is preferably attached to the outlet opening along a weakened part so that it can be quickly detached by a wiggling or twisting action. Preferably, the outer wall of the container neck includes a thread engagement portion and a non-engagement portion. In such an embodiment, the thread engagement portion has a cross-sectional diameter greater than the distance between the top of the thread on opposite sides of the syringe assembly and is adapted to engage the screw thread channel of the syringe to enable coupling.

The diameter of the non-engaging portion is equal to or preferably less than the distance between the top of the thread on opposite sides of the syringe assembly so that it effectively clears the thread when the neck is pulled on the screw thread of the syringe upon engagement of the thread engaging portion in the thread channel.

The thread engagement portion may be of any shape that will engage the screw thread channel of the syringe assembly. Most advantageously, the thread engagement portion of the neck is located at the edge of the outlet opening and includes a shoulder shaped to fit into the screw thread channel of the syringe fitting. An example of a particular embodiment of the invention is a container having a cylindrical neck portion (which is the non-engaging portion) with a circumferential shoulder at the edge of the outlet opening which forms the engaging portion. In other words, it is possible to form the container with parallel sides. If the screw thread assembly includes a central cone such as in the luer lock assembly, it is preferred that these sides are sized to seal against the luer cone. Alternatively, the container may have an inverted truncated conical neck portion with the leading edge designed to engage the thread of a syringe assembly (the threaded engaging portion) and the rear portion of the truncated cone forming the non-engaging portion of the neck.

The container according to the present invention is particularly applicable for use with syringes having screw thread engagement fittings such as the luer lock fitting. The Luerlock fitting includes a central male cone, an outer circumferential wall and a lower wall. The outer wall of the cone, the lower wall and the inside of the circumferential wall together define an annular channel. A screw thread is arranged on the inside of the circumferential wall. When used in conjunction with a syringe having a fitting similar to that of the luer lock, it is necessary that the outlet opening from the container be sufficiently large to accommodate the central male cone of the syringe.

As the container according to the invention is made of a thermoplastic material, it is capable of slight deformation and the diameter of the neck part in at least one position is most advantageously slightly smaller than the outer diameter of the syringe in order to fit tightly against the cone at this place or places .

Where sealing engagement is made possible in this way, it is not necessary that the engagement portion of the container neck also provides a seal with the fitting, although this is desirable. However, it is very important that the sealing engagement takes place either between the engaging part of the neck and the circumferential wall of the fitting or alternatively between a part of the inside of the container neck and the central male cone. If there are no sealing connections, it is possible for non-sterilized air to enter the container and this can lead to contamination of the contents of the syringe container.

Sealing between the container and the syringe fitting is also increased if the engaging part of the neck is somewhat larger in cross-sectional diameter than the internal diameter of the annular channel. This means that when the container engages with the syringe, the engaging part deforms slightly and rests tightly against the inside of the circumferential wall.

The main part of the container can be of any shape. However, it is preferred that the top of the main part is formed hexagonally. The hexagonal shape makes it easier to connect the syringe to the container as it strengthens the container in such a way that it can withstand radial and axial loads better. The hexagonal upper part of the main body is then further strengthened by a yoke on each side. The yokes also reduce the risk of the containers being punctured during manufacture.

The transfer of the injection solution in a container manufactured in accordance with the invention takes place in the following way: First, the non-resealable container cap is removed with a wriggling or twisting movement and separates from the container along the weakening part near the outlet opening. The container is held in a vertical position and the syringe into which it is intended to transfer the solution is positioned so that the screw thread engagement fitting is flush with the outlet opening. The plunger in the syringe must be inserted completely. The container is then sealingly contacted with the syringe fitting by rotating the syringe and container relative to each other until the container has fully engaged the screw thread of the syringe. When it is connected in this way, the contents of the container can be suitably drawn into the syringe with a backward movement of the plunger in the syringe body, and if necessary help for this fluid transfer can be provided by partial deformation of the outer walls of the container.

The invention is further described below with reference to preferred embodiments of the invention shown in the attached drawings where: Figure 1 shows a front view of a unit dose container manufactured in accordance with the invention sealed with a non-releasable cap; Figure 2 shows the upper part of the unit dose container according to Figure 1 with the cap removed from the outlet opening; Figure 3 shows the upper part of an alternative embodiment of the invention. Figure 4 shows the unit dose container of Figure 2 with a syringe connected to its outlet opening; and

Figure 5 shows an exploded view of the connection between the outlet opening and the syringe fitting as shown in Figure 4.

Figure 1 shows a container 1 made of thermoplastic material which can be easily deformed. Suitable materials for making such containers are well known in the art, but include polyethylene and polypropylene. The container 1 includes a main part 2 and a neck part 3. At the end of the neck part there is arranged a non-resealable cap 4 connected to the end of the neck 3 along the weakening line 5. The neck part 3 is in the form of a truncated cone which widens outwards and this feature is easier to identify in Figure 2.

Figure 3 shows an alternative embodiment of the invention where the top of the body is shaped hexagonally and the main part is strengthened with a yoke 6 on each side.

The non-resealable cap 4 can be removed from the neck portion 3 by. a rocking or twisting movement and separates from the neck portion 3 along the weakening line 5. After removal of the non-resealable cap, an outlet opening 7 is exposed at the end of the neck portion 3 through which the liquid held in the container 1 can pass.

The neck portion 3 comprises a thread engagement portion which is the shoulder 8 located around the circumferential edge of the outlet 7. The neck portion also includes a non-engagement portion 9 with a reduced cross-sectional diameter. Figures 4 and 5 show the connection of such a container to a syringe in order to facilitate the transfer of liquid in the container to the syringe. These figures show a syringe having a luer lock needle fitting 10. This fitting has a central male cone 11, an outer circumferential wall 12 and a lower wall 13. These walls form the boundary of an annular channel 14. A screw thread 15 is provided on the inner side of the circumferential wall 12. The central luer cone 11 is arranged with a transfer channel 16 which is open at its outermost end 17.

In Figure 3, the engaging part has a less sharply defined edge. This shoulder is adapted to grip the screw thread fitting, but may require continued application of force during connection with the screw thread to ensure engagement. The neck is strengthened by yoke 6 and the top of the pack is hexagonally designed.

The container 1 is adapted to engage with the luer lock fitting 10 as follows. After the non-resealable cap 4 is removed from the container 1, it is held in a vertical position and the syringe fitting 10 is located close to the outlet opening 7 from the container 1 whereby the central luer cone 11 is introduced into the outlet opening 7. By relative rotation of the container with respect to the syringe fitting , the thread engagement shoulder 8 on the neck 3 is caused to engage with the thread 15. To assist the first engagement, the syringe fitting can be pushed somewhat down into the outlet opening 7. As soon as the thread takes hold, the shoulder 8 fits behind the thread 15 and rests against the underside 17' of the thread and inside the circumferential wall 12. The non-engaging part 9 of the neck 3 is of smaller cross-section, so that it does not come into conflict with the thread 15, but can move freely in the channel 14 while the container is screwed onto the syringe fitting.

The inner diameter of the neck 3 at the point 19 is somewhat smaller than the outer cross-sectional diameter of the cone 11. As can be seen in figure 5, this ensures sealing engagement between the components at the area generally denoted by the number 20. The extent of the seal at 20 improves as the container screwed onto the luer lock fitting as in a standard luer cone, the side wall of the cone is slightly inclined where the bottom part of the cone is of a slightly increased diameter in relation to the top of the cone.

Accordingly, as the container 1 is screwed onto the screw thread fitting 10, this part of the neck, indicated by position 19, is pushed outwards to increase the internal diameter of the neck at this position. This results in tensions in the neck which result in a closer and tighter contact of the part 19 against the outer wall of the cone 11 as the container is screwed onto the needle fitting.

In figure 5, the position of the container when it is completely screwed onto the needle fitting is also shown with dashed lines. In this position, the top of the outlet opening 7 lies against the bottom part 13 of the needle fitting to further ensure sealing engagement of the container on the needle fitting.

When the container has been completely attached to the needle fitting, transfer of the injectable solution in the container is carried out in a simple way by moving backwards with the plunger in the syringe body. Most advantageously, the side walls of the container are sufficiently flexible so that the container can partially collapse when the injection solution is withdrawn. Transfer of the solution can be remedied by squeezing the outer walls of the container 21.

The container according to the present invention can be filled with a solution of any drug suitable for injection, but is particularly advantageous for use with aqueous solutions of pressure-boiled local anesthetics such as lidocaine, prilocaine, mepivacaine, bupivacaine, etidocaine or other drugs used during conditions where the need for easy handling and sterility is particularly high.

Claims (7)

1. Liquid-containing unit dose container (1) of thermoplastic which includes a main part (2), a neck part (3) and an outlet opening (7) at the end of the neck part which is sealed with a non-resealable cap (4), characterized in that the The outer wall of the neck part comprises a thread engagement part (8) which is located at or near the outermost edge of the neck part (3) so that after removal of the cap (4) the thread engagement part (8) is adapted to engage in an inwardly facing screw-threaded channel ( 15) at the end of a syringe, which thus enables a sealing connection of the container (1) to the syringe so that liquid in the container can be directly transferred from the container to the syringe. 2. Container according to claim 1, characterized in that the thread engagement part (8) is connected to a non-engagement part (9), which thread engagement part (8) is adapted to grip the screw-threaded channel (15) at the end of the syringe and the non-engagement part (9) is designed so that it does not come into conflict with the screw thread when the container (1) is connected to the syringe. 3. Container according to claim 2, characterized in that the threaded engagement portion (8) is located at the edge of the outlet opening (7) and comprises a shoulder designed to fit in the screw-threaded channel (15) at the end of the syringe. 4. Container according to claim 3, characterized in that the non-engaging part (9) is in the form of an inverted truncated cone and the edge of the shoulder is shaped to engage with the screw-threaded channel (15) at the end of the syringe. 5. Container according to claim 2 or 3, characterized in that the non-engaging part (9) has parallel sides. 6. Container according to any of the preceding claims 2-5, characterized in that the neck part together with the non-engaging part is strengthened with a yoke (6) on two opposite sides. 7. Container according to any one of the preceding claims, characterized in that the threaded engagement portion (8) is shaped so that it is adapted to engage screw-like with a luer lock fitting.