DE29918794U1 - Carpule for taking a medicine - Google Patents

Description

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Carpule for holding a medicinal product

The invention relates to a carpule for holding a medicament and to an injection device for the medicament that can be connected to the carpule.

State of the art

&iacgr;&ogr; Carpules of the type in question here are intended for single use; before the carpule is inserted into an applicator, a cannula is attached to the end where the crimp cap is attached, and the needle pierces the membrane attached to the back of the crimp cap and penetrates the interior of the vitreous body and thus the drug. The plastic coating of the cannula locks into a constriction of the crimp cap, which means that the needle is held in place and the injection can begin by operating the applicator.

A ready-to-use functional unit of this previously known type thus contains three components, the carpule, the cannula, which is coupled to the front end of the carpule, and an applicator, which interacts with the piston stopper at the rear end of the carpule to press the drug out of the vitreous body through the needle of the cannula for injection.

Before the device can be used as intended to inject a drug, a number of steps are required, and handling the cannula in particular is unsatisfactory, as it must be sterilized and a risk of injury after the injection cannot be ruled out when it is placed on the cartridge and disposed of.

It is therefore a first object of the invention to further develop a carpule of the type mentioned so that it can be handled more easily and safely. A second object is to design an injection device as an applicator,

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which enables both the puncture and injection procedures in a simple and safe manner.

The first-mentioned problem is solved according to the features of claim 1; with the basic concept of integrating the cannula already in the vitreous body, on the one hand the above-mentioned manually performed preparatory step of placing the cannula on the carpule is transferred to the industrial production area and integrated into the manufacture of the carpule, whereby hygienic requirements can also be optimized and any risk of injury before the injection is excluded.

The integration of the cannula in the vitreous body also enables an injection in which the carpule is placed with its front end (the crimp cap) on the injection site and only then is the puncture procedure carried out, which can be a simplification in certain anise twists.

A particular development of the invention relates to an injection device adapted to the structure of this carpule, the essential feature of which is the successive sequence of the puncture process by a certain puncture path (puncture stroke) and the subsequent injection by advancing the piston stopper by one injection path (injection stroke). By separating these two processes, as already mentioned above, it is possible to use the entire system consisting of the carpule and injection device in the "traditional" way, i.e. the needle is first extended from the carpule and, after locking, inserted into the tissue (for example when used by a dentist). However, it is also possible to use the entire system as an injectomat, in which the end of the carpule (flanged cap) protruding from the injection device is first placed on the injection site without the needle extended and then the needle is inserted and the drug is injected (e.g. for the patient to inject insulin or heparin himself).

Further advantageous designs and embodiments of the carpule and injection device can be found in the subclaims.

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Short description of the drawings

An embodiment of carpule and injection device is explained using drawings, showing:

Figure 1: a perspective view of the carpule according to the invention in its initial state,

Figure 2A: a sectional view of the carpule according to Figure 1 in the initial state,

Figure 2B: a sectional view of the carpule according to Figure 1 after the insertion stroke H1,

Figure 2C: a sectional view of the carpule according to Figure 1 after the injection stroke is H2,

Figure 2D: a cross-section through the carpule in the plane E-E of Figure 2C,

Figure 3: a perspective view of the injection device according to the invention with inserted carpule according to Figure 1 in the initial state,

Figure 4A: a longitudinal section through the injection device according to Figure 3 in the initial state,

Figure 4B: a longitudinal section through the injection device according to Figure 3 after the injection stroke H1,

Figure 4C: a longitudinal section through the injection device according to Figure 3 after the injection stroke H2,
Figure 5A-C: Representations of details XA, XB, XC of Figures 4A-C;

Figure 6A: a detailed section through the housing of the injection device in the initial state, and

Figure 6B: a detailed section through the housing of the injection device after the injection stroke H1.

-A- Description of the implementation examples

The carpule according to the invention consists of a glass body 11, a piston stopper 12 made of rubber, which closes an open end of the glass body 11 and a flanged cap 13, on the inside of which a membrane 14 made of rubber is attached, which seals the constricted end 19 of the glass body 11. A cannula 10 is held within the carpule, which consists of a needle carrier 16 and a needle 17, the needle 17 extending over a holding length HL into the central axis of the needle carrier 16 and is fixed there. The needle 17 has a lateral opening 17A

β, which is realized by a lateral grinding of the needle 17 and which is arranged at the height of a notch 16A in the front side of the needle carrier 16. The front end of the needle 17 is held in the membrane 14.

The needle carrier 16 is axially displaceable in the central axis of the piston stopper 12 by a piercing stroke H1.

In the embodiment shown, the lengths of the cannula 10 and the glass body 11 are selected such that the cannula is held completely in the glass body 11 in its initial state, with the end of the needle carrier 16 opposite the needle 17 protruding from the piston stopper 12 at least by the insertion stroke H1 or the glass body 11 protruding beyond the piston stopper 12 by approximately the insertion stroke H1.

The crimp cap 13 has a recess 13A in the area of the needle 17, so that when the cannula 10 is axially acted upon from the stopper-side end of the glass body 11, the needle 17 pierces the membrane 14 and is pushed outwards until the predetermined final value of the piercing stroke H1 is reached. During this movement, the piston stopper 12 and needle carrier 16 are coordinated with one another in terms of their choice of material and shape so that the frictional force between the piston stopper 12 and the glass body 11 that arises when the piercing stroke H1 is carried out is so great that the piston stopper 12 maintains its axial position in the glass body 11, so that the drug 50 located in the glass body 11 between the membrane and the piston stopper 12 remains pressure-free.

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After the injection stroke H1 has been carried out, the piston stopper 12 is displaced in the longitudinal axis L and carries out the injection stroke H2, during which it moves towards the opening 17A of the needle 17 and presses the drug 50 into the needle via the opening 17A of the needle, so that the injection of the drug 50 takes place at the front end of the inserted needle 17 (Figure 2C).

An essential prerequisite for the operation of the carpule according to the invention is that the piercing stroke H1 and the injection stroke H2 do not overlap, i.e. that it is ensured that the injection stroke H2 only pushes out the drug 50 after the piercing stroke H1 has been completed, with the needle 17 then stationary. To ensure this, the carpule according to the invention can be coupled to an injection device 20 which successively axially acts on the needle carrier 16 and the piston stopper 12 in the functional direction F in order to first carry out the piercing stroke H1 and then the injection stroke H2.

In its front section, the injection device has a trough-like receptacle 20A into which the carpule can be inserted and fixed in such a way that its longitudinal axis L is aligned with the functional axis F of the injection device 20.
20

For axial fixation of the position of the carpule, the front semicircular face of the receptacle 2OA surrounds the carpule in a constriction 19 of the vitreous body 11, so that an axial movement is excluded on the one hand by the widened section of the vitreous body 11, and on the other hand by the annular vitreous body-side face of the crimp cap 13.

For the lateral alignment of the longitudinal axis L with the functional axis F, snap hooks 28 are formed in the area of the side walls of the trough-like holder 2OA, which press the carpule onto the bottom of the holder 2OA. In this position, shown for example in Figure 3, the carpule is in a state ready for injection. After carrying out the insertion stroke H1 and injection stroke H2 and, if necessary, retracting the cannula into the vitreous body, the carpule can be removed again, for which purpose lateral recesses 27 are provided for gripping under the carpule and for

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are provided for pulling out of the trough-like receptacle when the snap hooks 28 are retracted.

The trough-like receptacle 2OA of the injection device 20 is followed by a substantially cylindrical housing 2OB in which a plunger 21 is mounted so as to be axially displaceable by the total stroke of the injection stroke H1 and the injection stroke H2, in which a needle ejector 25 is in turn held so as to be axially displaceable by the injection stroke H1.

&iacgr;&ogr; The plunger 21 is guided in a cylindrical bore of the housing 20B and in turn consists of a hollow cylindrical, rear section 21A with a lateral longitudinal slot 21C and a front, also cylindrical section 21B with a reduced inner diameter compared to the rear section 21A, which is selected such that the front section 21B can be inserted over its entire length into the glass body 11 of the carpule and its annular front side acts on the opposite annular front side of the piston stopper 12.

The needle ejector 25 is guided inside the plunger 21 and also has a rear section 25A and a front section 25B. The rear section 25A is dimensioned such that it can be moved in the rear section 21A of the plunger 21, the front section 25B is enclosed by the front section 21B of the plunger 21. This means that the diameter of the rear section 25A of the needle ejector 25 is also larger than the diameter of the front section 25B. This creates two adjacent annular shoulders in the transition area between the respective front section and rear section of the plunger 21 and needle ejector 25.

In the rear section 25A of the needle ejector 25, a sliding block 24 is held so as to be movable transversely to the functional axis F, so that it engages either in the rear end 21A of the plunger 21 or in a fixing part 26 in the housing 20B. This coupling is designed in such a way that after the piercing stroke H1 has been carried out, the coupling of the needle carrier 16 with the plunger 21 is removed by the sliding block 24 being ejected from the plunger 21 via a correspondingly bevelled shape of the wall of the

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plunger 21 is pushed out and into the fixing part 26, whereby the needle ejector 25 is coupled to the housing 20B, with the result that a certain axial position of the needle ejector 25 and thus a predetermined insertion length of the needle 17 is defined and fixed.

A status indicator is held in the housing 2OB, which in the embodiment shown consists of a rocker arm 27, the first leg of which interacts with the annular shoulder between the two sections 21A and 21B of the plunger 21 and the second leg of which, running at a right angle to this, can be swung out of a display opening 27A in the surface of the housing 2OB when the insertion stroke H1 is completed and the needle 17 is stationary. This informs the treating personnel, for example the dentist, that the insertion stroke H1 is now completed, the needle 17 is stationary and further actuation of the plunger 21 consequently leads to the injection of the drug 50.

A working cycle of the injection device is now explained in more detail using Figures 4A to 4C:

The carpule is inserted, the plunger 21 is in its rear starting position, in which the coupling between the plunger 21 and the needle ejector 25 is established via the sliding block 24 (Figure 4A, the sectional view of Figure 4A corresponds to the perspective view of Figure 3).

If a sufficient actuating force is now exerted in the functional direction F on the rear end face of the plunger 21 (whereby the injection device is held with two fingers by means of the handles 22 and 23), the plunger 21 and needle ejector 25 jointly carry out the piercing stroke H1, during which the end face of the needle ejector 25 acts on the end face of the needle carrier 16, whereby the latter is pushed forward in the piston stopper 12 and the needle 17 pierces the membrane 14, so that in the embodiment shown in the drawing, after the piercing stroke H1 has been carried out, the needle 17 protrudes from the crimp cap by approximately the length of the piercing stroke H1.

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Shortly before the end of the piercing stroke H1, the ring shoulder of the plunger 21 hits the first leg of the rocker arm 27 and pivots it by an angle of about 20°, so that the other leg pivots out of the display opening 27A and can be felt there. At the same time, the coupling between the plunger 21 and the needle ejector 25, which was brought about by the sliding block 24 during the piercing stroke H1, is canceled by the sliding block 24 being pushed out of the recess provided for this purpose in the rear section 21A of the plunger 21 and is now pushed into the fixing part 26. In this end position shown in Figure 4B after the end of the piercing stroke H1, the needle ejector 25 is now connected to the

&iacgr;&ogr; housing 20B, with the result that the needle 17 is stationary and this state is communicated to the operating personnel through the pivoted arm of the rocker arm 27.

The injection device is now ready for injection:

When further force is applied to the plunger 21 in the functional direction F, the injection stroke H2 now begins, during which the front side of the front section 21B of the plunger 21 pushes the piston stopper 12 forwards within the glass body 11, with the sliding block 24 sliding backwards within the longitudinal slot 21C. During the injection stroke, the drug 50 is pressed out of the glass body 11 through the injection needle 17. At the end of the injection stroke H2, the constellation shown in Figure 4C then arises, in which the plunger 21 is completely pressed into the housing 20B and the piston stopper 12 has arrived at the front end of the glass body in the region of the constricted end 19.

The details of the described movement sequences at the front end of the receptacle 2OA are shown in Figures 5A to 5C.

This completes the injection process and the injection device with the needle 17 can be withdrawn from the patient's body, whereby the functional sequence described above takes place in reverse order:

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The sliding block 24 slides back into its other coupling position and the plunger 21 and needle ejector 25 are pulled out together until the state shown in Figure 4A (apart from the position of the piston stopper 12) is reached again, in which the carpule can be removed from the trough-like receptacle 2OA as described above and a new carpule can be inserted.

In the embodiment shown, the needle 17 is not retracted into the carpule, but it is easily possible to achieve a corresponding coupling by means of a corresponding coupling of the needle ejector 25 and the needle carrier 16, for example by locking them in place, so that when the plunger 21 is retracted, the needle 17 also disappears back into the glass body 11, which reduces the risk of injury when disposing of the carpule.

Claims (23)

1. Carpule for holding a drug, with a cylindrical glass body, the front end of which is closed with a membrane and can be pierced by a cannula and the rear end of which is sealed by an axially displaceable piston stopper, when the piston is moved towards the front end the drug is pressed through the cannula, characterized in that the cannula ( 10 ) is held within the glass body ( 11 ) and guided axially. 2. Carpule according to claim 1, characterized in that the cannula ( 10 ) consists of a needle carrier ( 16 ) and a needle ( 17 ). 3. Carpule according to claim 1 and 2, characterized in that the needle ( 17 ) is held in the membrane ( 14 ). 4. Carpule according to claim 1 and 2, characterized in that the needle carrier ( 16 ) is held axially displaceably in the piston stopper ( 12 ) by an insertion stroke (H1). 5. Carpule according to claim 4, characterized in that the needle ( 17 ) extends into the central axis of the needle carrier ( 16 ) over a holding length (HL) and is fixed there. 6. Carpule according to claim 4, characterized in that the total length of needle carrier ( 16 ) and needle ( 17 ) is slightly less than the length (L) of the carpule ( 10 ). 7. Carpule according to claim 1, 4 and 6, characterized in that the end of the needle carrier ( 16 ) opposite the needle ( 17 ) projects out of the piston stopper ( 12 ) at least by the insertion stroke (H1) in the starting position. 8. Carpule according to claim 1, characterized in that the cannula ( 10 ) is held completely in the vitreous body ( 11 ) in its initial position. 9. Carpule according to claim 7 and 8, characterized in that the glass body ( 11 ) projects beyond the piston stopper ( 12 ) approximately by the insertion stroke (H1). 10. Carpule according to claim 6, characterized in that the needle ( 17 ) has at least one lateral opening ( 17A ) in the region between the needle carrier ( 16 ) and the membrane ( 14 ), through which the drug enters the needle ( 17 ) in the injection state. 11. Carpule according to the preceding claims, characterized in that the piston stopper ( 12 ) and the needle carrier ( 16 ) are coordinated with one another with regard to choice of material and shape such that the frictional force between the piston stopper ( 12 ) and the glass body ( 11 ) which arises when the piercing stroke (H1) is carried out is so great that the piston stopper ( 12 ) maintains its axial position in the glass body ( 11 ). 12. Carpule according to claim 4, characterized in that the membrane ( 14 ) contains a blind bore ( 14A ) for holding the needle ( 17 ), which extends so far to the outside that the remaining material thickness is pierced by the needle ( 17 ) when the piercing stroke (H1) is initiated. 13. Carpule according to claim 1, characterized in that the membrane ( 14 ) is part of a crimp cap ( 13 ) which has a recess (13A) in the region of the passage opening of the needle ( 17 ). 14. Carpule according to claim 1, characterized in that, in order to carry out the piercing stroke (H1) and the subsequent injection stroke (H2), it can be coupled to an injection device ( 20 ) which successively axially acts on the needle carrier ( 16 ) and the piston stopper ( 12 ). 15. Injection device for actuating a carpule according to claim 14, characterized in that it contains a trough-like receptacle (20 A) into which the carpule ( 10 ) can be inserted and fixed in such a way that its longitudinal axis (L) is aligned with the functional axis (F) of the injection device ( 20 ). 16. Injection device according to claim 15, characterized in that the receptacle ( 20 A) is followed by a housing ( 20 B), in which a plunger ( 21 ) is mounted so as to be axially displaceable by the total stroke of the injection stroke (H1) and the injection stroke (H2), in which a needle ejector ( 25 ) is in turn held so as to be axially displaceable by the injection stroke (H1). 17. Injection device according to claim 16, characterized in that the plunger ( 21 ) and needle ejector ( 25 ) are coupled to one another and to the housing ( 20 B) in such a way that after the piercing stroke (H1) has been carried out by loading the needle carrier ( 16 ) by means of the needle ejector ( 25 ), the coupling of the needle carrier ( 16 ) to the plunger ( 21 ) is canceled by actuating the plunger ( 21 ) and a coupling to the housing ( 20 B) takes place, so that the following injection stroke (H2) takes place by loading the piston stopper ( 12 ) by the plunger ( 21 ) with the needle ( 17 ) stationary. 18. Injection device according to claim 17, characterized in that the alternating coupling of the needle ejector ( 25 ) takes place by means of a sliding block ( 24 ) which is held displaceably perpendicular to the functional axis (F) in the needle ejector ( 25 ) in such a way that it engages either in the plunger ( 21 ) or in the housing ( 20 B). 19. Injection device according to claim 17 and 18, characterized in that after completion of the injection stroke (H1) the plunger ( 21 ) after the sliding block ( 24 ) has engaged in the housing ( 20B ) actuates a visually, acoustically and/or haptically perceptible status display in the housing ( 20B ). 20. Injection device according to claim 19, characterized in that the status indicator includes a rocker arm ( 27 ), one end of which is pivoted out of the surrounding housing surface through an indicator opening ( 27A ) when the injection stroke (H1) is completed and the needle ( 17 ) is stationary. 21. Injection device according to claim 17, characterized in that during the piercing stroke (H1), in particular towards the end of the piercing stroke (H1), a coupling between the needle ejector ( 25 ) and the needle carrier ( 16 ) is activated, by means of which the needle ( 17 ) is retracted back into the glass body ( 11 ) when the plunger ( 21 ) is retracted. 22. Injection device according to claim 15, characterized in that the receptacle ( 20A ) has lateral snap hooks ( 28 ) for fixing the carpule. 23. Injection device according to claim 15, characterized in that the receptacle ( 20A ) has at least two opposite recesses ( 27 ) for gripping underneath the carpule for removal.