Container for metered dispensing of fluids

Abstract

A container for the metered dosing of a sterile fluid, comprising a substantially rotationally symmetrical storage body (12) made of a plastic material with a longitudinal axis (O) and a radial direction (R) extending perpendicular to said longitudinal axis, the storage body (12) comprising a substantially cylindrical or conical casing part (14) having a first wall thickness (S1), a metering part (16), a bottom part (18) and a container neck part (20), characterized in that the metering part (16) is arranged between the casing part (14) and the bottom part (18), the metering part (16) is configured as a collapsible bellows having at least one radially inward fold with joints (36, 38, 40), the wall thickness (S2) of the metering part (16) being 25% to 60% thinner than the first wall thickness S1, at least in the region of the joints (36, 38, 40).

Description

[Technical field]

[0001] The present invention relates to a container for the metered administration of a sterile fluid. [Background technology]

[0002] Sterile fluids, such as eye drops, are either supplied in individual doses or administered from a container containing multiple doses of the sterile fluid. Eye drops are instilled by the user into the conjunctival sac or onto the cornea and must be sterile to prevent eye infections.

[0003] When a sterile fluid is to be administered in a precise, specified dose in the form of a certain number of drops, a container has been proposed in the prior art that allows a defined portion to be administered from the container. For such administration, the reservoir is provided with an elastic side wall, which can be compressed by the user during use, for example, to administer one or more drops. When administering eye drops, the container is generally placed in an upside-down position, so that the administered drops reach the user's eye substantially from above.

[0004] The prior art has also proposed containers with a bottom wall that can assume two defined positions. By applying pressure to this bottom wall, the container bottom, which in a first position is curved towards the outside of the container, can be moved to a second position in which the bottom is curved towards the internal volume of the container. During the movement from the first position to the second position, a defined volume is displaced towards the inside of the container, whereby a defined amount of fluid is dispensed from the dispensing opening. Summary of the Invention [Problem to be solved by the invention]

[0005] Since the functionality of such a base, which can assume a variety of geometrical states, is not intuitively recognizable to a user, there is a need for a container for the metered dispensing of sterile fluids whose operation is prerecognizable and predictable from its shape for the average user, and at the same time, the container must be easy to manufacture since it will be mass-produced. [Means for solving the problem]

[0006] This object is achieved by a container for the metered administration of a sterile fluid having the features of claim 1. Preferred embodiments are evident from the further claims.

[0007] The container for the metered dosing of a sterile fluid according to the invention comprises a substantially rotationally symmetric storage body made of a plastic material with a longitudinal axis and a radial direction extending perpendicular to said longitudinal axis, the storage body comprising a substantially cylindrical or conical casing part with a first wall thickness, a metering part, a bottom part and a container neck part, characterized in that the metering part is arranged between the casing part and the bottom part, the metering part being configured as a folding bellows with at least one radially inward fold with a joint, the wall thickness of the metering part being 25% to 60% thinner than the first wall thickness, at least in the region of the joint.

[0008] The container according to the invention therefore comprises a metering part arranged between the casing part and the bottom part of the container, which metering part is arranged so as to be clearly recognizable in the region of the casing area of ​​the container. The metering part is configured as a folding bellows, so that the radially inward folding is easily visible to the user. The use of the container according to the invention is therefore also intuitively understood by the user. The use of the container is made possible by the fact that the wall thickness of the metering part has a reduced wall thickness at least in the region of the joint of at least one folding part, whereby this wall thickness is 25% to 60% thinner at least in the region of the joint compared to the wall thickness of the substantially cylindrical or conical casing part. The thin wall thickness of the joint allows the integrally manufactured container to be folded in the region of the folding part by the reduction of the height of the container due to the reduction of the height of the metering part when pressure is applied against the bottom part. Preferably, the thin wall thickness is set only in the joint region, so that only a few areas are formed with a thin wall thickness. It is also possible to reduce the wall thickness in the metering part, for example with regard to oxygen penetration by diffusion through the container wall. This is advantageous, since a reduced wall thickness over a large area reduces the stability behavior of products that are particularly sensitive to oxygen. The metering part is arranged between the casing part and the bottom part, which allows the label to be attached to the casing part in the usual way.

[0009] Preferred embodiments emerge from the further claims.

[0010] According to a preferred embodiment, the bottom part has a concentrically arranged curvature in the direction towards the measuring part, which has the effect that during use, the thumb of the user, which is often placed on the bottom part to squeeze the measuring part, automatically rests in the central area of ​​said bottom part, resulting in a uniform squeezing of the measuring part over the circumference of the substantially rotationally symmetric storage body of the container.

[0011] According to a preferred embodiment, the entire metering part has a wall thickness less than the first wall thickness, preferably the entire metering part has a wall thickness less than the first wall thickness by 25% to 60%. If the entire metering part has a wall thickness less than the first wall thickness, part of the movement of the collapsible bellows can be realized by the joints and another part of the movement of the collapsible bellows can be realized by bending the walls of the collapsible bellows between the joints, which reduces the mechanical stress on these joints.

[0012] Preferably, the metering portion has a single folding portion comprising a first joint on the casing portion, a second joint on the bottom portion, a first annular joint leg extending radially inward from the first joint and at a first angle relative to the radial direction, a second annular joint leg extending radially inward from the second joint and at a second angle relative to the radial direction, and a third joint connecting the first joint leg to the second joint leg.

[0013] In this regard, the first joint leg and the second joint leg preferably have a substantially straight extension in a cross section perpendicular to the longitudinal axis.

[0014] In this way, the metering portion is formed similarly to a disc spring which can be elastically compressed in the direction of the longitudinal axis when pressure is applied.

[0015] According to a preferred embodiment, the first joint, the second joint, the third joint, and the second joint leg have a wall thickness less than the first wall thickness, and the first joint leg has a wall thickness greater than the second joint leg.

[0016] In this way, when pressure is applied against the base portion, movement of the metering portion takes place substantially in the area of ​​the second annular joint leg which is closer to the base portion.

[0017] According to a preferred embodiment, the first angle is smaller than the second angle.

[0018] This feature also serves to allow the collapsible bellows to deform more in the area of ​​the second joint section adjacent the bottom portion than in the area of ​​the first joint section adjacent the casing portion during compression of the metering portion.

[0019] In this regard, the second angle is preferably greater than twice the first angle, and is preferably between 30° and 40°.

[0020] According to a preferred embodiment of the invention, the second joint is located at a smaller distance from the longitudinal axis than the first joint, this feature also results in that, upon compression, the half of the folding bellows facing the bottom part undergoes a greater movement between the third joint and the second joint than the upper half of the folding bellows, with the result that the metering part, located mainly in the area of ​​the second joint, moves upon compression.

[0021] Preferably, the ratio of the outer diameter of the bottom portion to the inner diameter of the container in the region of the third joint corresponds to a ratio of approximately 2:1.

[0022] In this way, in the area of ​​the metering portion, a fold is formed which is large enough in the area of ​​the collapsible bellows.

[0023] According to a preferred embodiment of the invention, the container further comprises an external thread on the container neck portion, which serves to screw onto a closure cap capable of closing a dispensing opening for dispensing the sterile fluid located in the container neck portion.

[0024] Additionally, the container preferably has a shoulder portion between the casing portion and the container neck portion.

[0025] Such a shoulder portion can improve ease of use by allowing a user of a small-sized container, commonly used for storing and administering eye drops, to hold the shoulder portion with the thumb of one hand and the fingers of the same hand on the exterior of the bottom portion. In the case of a small-sized container, for example a container with a capacity of 5 ml, the container can be held comfortably and the pressure applied to the bottom portion of the container when actuating the metering portion can be absorbed, so to speak, by a counter-bearing while simultaneously holding the shoulder portion.

[0026] According to a preferred embodiment of the invention, the container further comprises circumferential toothing provided on the container neck portion, the circumferential toothing comprising a plurality of substantially tangentially extending inclined surfaces and a plurality of substantially radially extending locking surfaces each adjacent one of the inclined surfaces.

[0027] The teeth on the container neck thus serve to screw the closure cap onto the storage body. This closure cap has a conventional tamper-evident ring which is connected to the closure cap via a thin-walled bridge portion and which can be screwed onto the storage body which is integrally connected to the closure cap via the teeth after the container has been filled, since the tamper-evident ring can be moved on a tangentially extending inclined surface when first screwed on. However, when first opened, the tamper-evident ring is detached from the closure cap, since it abuts against a locking surface and is prevented from following the rotational movement of the closure cap when it is unscrewed. The bridge portion is thus cut off and the tamper-evident ring remains in the region of the teeth, which gives a clear visual indication to the user that the container has already been opened and the contents may no longer be sterile.

[0028] Preferably, the container is provided with a corresponding closure cap, which can be screwed onto the reservoir body and, when screwed, closes the container in an airtight manner. Features known in the art serve this purpose, such as, for example, an annular seal on the inside of the upper part of the closure cap, which, after the closure cap is screwed, rests elastically on the outer periphery of the dispensing opening of the container neck, thus sealing the container tightly.

[0029] The invention will now be described, purely by way of example, with the aid of one embodiment of a container according to the invention. [Brief description of the drawings]

[0030] [Figure 1] FIG. 2 is a three-dimensional view of a container according to the invention. [Diagram 2] FIG. 2 is a side view of the container according to FIG. [Diagram 3] 3 is a cross-sectional view of the container according to FIG. 2 along the section line AA. [Figure 4] FIG. 2 is a plan view of the container according to FIG. 1; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] 1 to 4 show one embodiment of a container 10 according to the invention for metered dispensing of a sterile fluid. Preferably, the container is dimensioned so that a predetermined amount of sterile fluid is dispensed by actuating a collapsible bellows, as further explained below.

[0032] The container comprises a reservoir body 12 for a sterile fluid and a closure cap, not shown, which can be screwed onto the reservoir body. The reservoir body has a longitudinal axis O and is formed substantially rotationally symmetrical about said longitudinal axis O. A radial direction R, shown by way of example in FIG. 4, extends perpendicular to the longitudinal axis.

[0033] The reservoir body 12 comprises a casing part 14, which in this embodiment is substantially cylindrical, but can also be conically configured, and has a first wall thickness S1. A metering part 16 is integrally adjacent to the casing part 14, and a bottom part 18 is integrally adjacent to the metering part 16. Furthermore, the reservoir body 12 comprises a container neck part 20 having a dispensing opening 22 for dispensing a sterile fluid. Molded on the container neck part 20 is an external thread 24, which serves for a screwing connection to a closure cap (not shown). A circumferential collar 26, also shown in the figures, serves to allow retention of the reservoir body during fluid filling, in particular as part of an industrial filling process.

[0034] The container according to this embodiment further comprises a tamper-evident ring 28, which is provided between the external thread 24 and the casing part 14. The tamper-evident ring 28 serves to separate the tamper-evident ring, which is attached to the closure cap in the usual manner via the bridging web, from the closure cap when the container is first opened by unscrewing the closure cap, and to make it visually recognizable to the user if the container has already been opened. The tamper-evident ring 28 can be configured in any way. In this example, a toothing 30 is provided, which comprises a number of substantially tangentially oriented inclined portions 32 and a locking portion 34 arranged substantially radially between the inclined portions 32. As is clear from the plan view in FIG. 4, the closure cap can initially be screwed in clockwise with the tamper-evident ring, since the tamper-evident ring moves together with the closure cap via the inclined portions 32 due to the action of the ratchet. On the other hand, when the closure cap is opened for the first time, the tamper-evident ring is prevented from moving in the counterclockwise direction in Fig. 4 by the locking portion 34, so that the web-shaped bridge between the closure cap and the tamper-evident ring is torn and the tamper-evident ring remains on the teeth after the closure cap is unscrewed, which then allows the closure cap to be unscrewed. However, the tamper-evident ring used in the illustrated embodiment can be replaced by another tamper-evident ring known in the art in the same way within the scope of the invention.

[0035] The dimensions of the dispensing opening 22, and in particular its diameter, are preferably adapted to the size of the formed droplets of sterile fluid and in the case of aqueous fluids can have an opening diameter of between 8.1 mm and 8.3 mm.

[0036] The metering portion 16, which is arranged between the casing portion 14 and the bottom portion 18, is arranged in a position that does not interfere with the attachment of a label on the casing portion 14 and is therefore clearly recognizable by the user. The metering portion 16 is configured as a folding bellows and can have one or more folding portions. In the present embodiment, a single folding portion is provided. To this end, the metering portion 16 has a first joint 36, a second joint 38 and a third joint 40. The first joint 36 corresponds to the transition between the casing portion 14 and the metering portion 16. The second joint 38 corresponds to the transition between the bottom portion 18 and the metering portion 16. The third joint 40 is provided inside the folding portion.

[0037] Further, a first joint leg 42 is provided connecting the first joint 36 to the third joint 40. A second joint leg 44 connects the third joint 40 to the second joint 38. In this example embodiment, the joint legs 42 and 44 are configured in an annular shape and have a substantially linear extension when viewed in a cross section perpendicular to the longitudinal axis (O) as illustrated in FIG.

[0038] The wall thickness (S2) of the metering part is 25% to 60% less than the first wall thickness (S1). However, it is also possible to configure the first joint leg 42 and the second joint leg 44 with the same wall thickness S1 as the casing part, and to make the wall thickness correspondingly thinner only in the region of the joints 36, 38, 40, thereby increasing the deformation of the metering part 16 in these regions.

[0039] As is evident from FIG. 3, the angle at which the first joint leg 42 on the one hand extends relative to the radial direction R and the angle at which the second joint leg 44 on the other hand extends relative to the radial direction R are formed with different magnitudes. In this particular embodiment example, the angle β between the second joint leg 44 and the radial direction is more than twice the angle α between the first joint leg 42 and the radial direction. In this particular example, the angle α can be between 10° and 15°, and the angle β can be between 30° and 40°. The difference in these angles ensures that, when the metering part 16 is actuated by external pressure on the bottom part, as will be further explained below, the action takes place mainly in the area of ​​the second joint 38 and the second joint leg 44. However, it is also possible, according to an alternative embodiment, to modify the configuration of FIG. 3 in such a way that the actuation takes place in a substantially uniform manner via the first joint leg and the second joint leg, or substantially only via the first joint leg.

[0040] Furthermore, it has proven advantageous for the inside diameter Di of the container in the region of the third joint 40 to be selected to be approximately half the outside diameter Da of the bottom part 18 in the region of the second joint 38 .

[0041] Furthermore, it is advantageous if the second joint 38 is arranged at a smaller radial distance from the longitudinal axis O than the first joint 36 between the casing part 14 and the metering part 16. As a result, the radius of the bottom part 18 is smaller than the radius of the casing part 14. This shape, together with the ratio of dimensions Da:Di, has proven to be particularly advantageous with regard to the best possible force transmission and force application. This force is applied in the direction of the arrow B via the bottom part 18. Due to the cylindrically symmetric shape of the bottom part 18 and the curvature 46 of this bottom in the direction towards the internal volume of the container, the force is transmitted approximately concentrically. This curvature 46 is advantageous because, to perform the actuation, the user automatically pushes in the direction towards the lowest position of the curvature 46 and thus the concentricity of the force application is improved. However, the lever arm also plays a decisive role for the amount of force required. An excessively small lever arm makes the system stiff and requires a larger actuation force. However, if the length of the lever is too long, the metering part will be too soft depending on the wall thickness selected and not enough force will be applied to activate the metering part configured in the form of a Belleville spring. As a result, the excess pressure required to form the droplets will be too low and the droplets will not leave the dosing opening 22 acting as a drip hole at all. The selection of a lever arm with a ratio of 2:1 between the outside diameter Da of the base and the inside diameter Di of the folded part has therefore been found to be very suitable for achieving an optimal application of force to form the droplets.

[0042] However, according to an alternative configuration, the radius of the base portion can also match the radius of the casing portion.

[0043] Additionally, the base portion 18 itself has some flexibility such that if sufficient pressure is applied to the base, the droplets may still be expelled even if only the base of the bottle is squeezed.

[0044] The configuration of the metering portion 16 also allows containers according to the invention to be made from more rigid plastic materials, such as HDPE and PP, that are sometimes used because of their resistance to sterile fluids.

[0045] It plays a crucial role that at least these joints have a thin wall thickness for the purpose of the spring function. Moreover, it may be advantageous to only make the wall thickness of the joints thinner, since this reduces the diffusion of oxygen through the outer wall of the container, and therefore results in a better stability behavior for oxygen-sensitive products. This shape also makes it intuitively clear to the user how to activate the container. If the user presses on the center of the bottom part 18 to compress the metering part 16, it has been found to be advantageous to provide a shoulder part 48 between the casing part 14 and the container neck part 20. This shoulder part 48 acts like a counter bearing and facilitates the activation of the application of force to the bottom part.

[0046] The storage body 12 of the container according to the invention can be made in one piece from plastic material, which makes the container very suitable for mass production. By selecting the wall thickness of the metering part, the angle of the first joint leg relative to the radial direction and the angle of the second joint leg relative to the radial direction, and the ratio of the outside diameter Da of the base to the inside diameter Di of the folding part, it is possible to set an actuation force that is always almost the same for the user, independent of the volume of the container, the other wall thicknesses of the container and even the selected plastic material. [Explanation of symbols]

[0047] 10 containers 12 Storage unit 14 Casing part 16 Measuring part 18 Bottom part 20 Container neck 22 Dispensing opening 24 Male thread 26 Circumference Color 28 Tamper evident ring 30 Teeth 32 Slope section 34 Lock section 36 First Joint 38 Second Joint 40 Third Joint 42 First Joint Leg 44 Second Joint Leg 46 Curved section 48 Shoulder part

Claims

1. 1. A container for metered administration of a sterile fluid, comprising: A substantially rotationally symmetric storage body (12) made of a plastic material, having a longitudinal axis (O) and a radial direction (R) extending perpendicular to said longitudinal axis. The storage body (12) is provided with: a substantially cylindrical or conical casing portion (14) having a first wall thickness (S1); A measuring portion (16); A bottom portion (18); A container neck portion (20) and A container comprising: the metering portion (16) is disposed between the casing portion (14) and the bottom portion (18); the metering portion (16) is configured as a collapsible bellows having at least one radially inwardly folded portion having a joint (36, 38, 40); A container, characterized in that the wall thickness (S2) of said metering portion (16) is 25% to 60% thinner than said first wall thickness S1, at least in the area of ​​said joints (36, 38, 40).

2. 2. The container according to claim 1, characterized in that the bottom portion (18) has a curved portion (46) arranged concentrically in a direction towards the metering portion (16).

3. Container according to claim 1 or 2, characterized in that the entire metering portion (16) has a wall thickness (S2) which is thinner than the first wall thickness (S1), preferably the entire metering portion (16) has a wall thickness which is 25% to 60% thinner than the first wall thickness (S1).

4. The metering portion (16) has a single folded portion, the folded portion having: a first joint (36) on said casing portion (14); a second joint (38) on the bottom portion (18); a first annular joint leg (42) extending radially inwardly from the first joint (36) at a first angle (α) relative to the radial direction (R); a second annular joint leg (44) extending radially inwardly from the second joint (38) at a second angle (β) relative to the radial direction (R); a third joint (40) connecting the first joint leg (42) to the second joint leg (44); Container according to any one of claims 1 to 3, characterized in that it comprises:

5. 5. The container according to claim 4, wherein the first joint (36), the second joint (38), the third joint (40) and the second joint leg (44) have a wall thickness less than the first wall thickness (S1), and the first joint leg (42) has a wall thickness greater than the second joint leg (44).

6. 6. A container according to claim 4 or 5, characterized in that the first joint leg (42) and the second joint leg (44) have a substantially straight extension in a cross section perpendicular to the longitudinal axis (O).

7. 7. The container according to claim 6, characterized in that the first angle (α) is smaller than the second angle (β).

8. 8. The container according to claim 7, characterized in that the second angle (β) is greater than twice the first angle (α), preferably the second angle (β) is between 30° and 40°.

9. 9. The container according to claim 4, wherein the second joint (38) is arranged at a smaller radial distance from the longitudinal axis (O) than the first joint (36).

10. Container according to any one of claims 4 to 9, characterized in that the ratio between the outer diameter (Da) of the bottom part (18) in the area of ​​the third joint (40) and the inner diameter (Di) of the container corresponds to a ratio of approximately 2:

1.

11. 11. The container of any one of claims 1 to 10, further comprising an external thread (24) on the container neck portion (20).

12. Container according to any one of the preceding claims, further comprising a shoulder portion (48) between the casing portion (14) and the container neck portion (20).

13. 13. A container according to any one of claims 1 to 12, further comprising circumferential teeth (30) provided on the container neck portion (20), the circumferential teeth (30) comprising a plurality of substantially tangentially extending inclined surfaces (32) and a plurality of substantially radially extending locking surfaces (34) each adjacent one of the plurality of inclined surfaces (32).

14. Container according to any one of claims 1 to 13, further comprising a corresponding closure cap which can be screwed onto the storage body (12) and which, when screwed, tightly closes the container.

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