CZ2009101A3 - Three-chamber automatic injector - Google Patents

Abstract

The injector for mixing, dissolving, and administering the drug stored in separate compartments consists of a body (1) whose cavity includes a pressure mechanism and a portion with three separate chambers (19, 18 and 30) with an injection needle (16). The chambers (19, 18 and 30) are separated by pistons (10, 11 and 12). A bypass coupling (29) is located in the second chamber (18). In the third chamber (30), an injection needle (16) is attached to the guide roller (17) located below the third piston (12). The guide roller (17) is provided with passages (22) that connect the third chamber (30) to the mouth of the injection needle (16). The third chamber (30) has a second space (21) which has a diameter of 5 to 10% larger than the diameters of the other chambers (18, 19) and is closed with a lettering (13). The section with three separate chambers (19, 18 and 30) is formed by a removable insert (7).

Description

Three-chamber automatic injector.

Technical field

The invention belongs to a group of devices which inject liquids into a living organism in cases where the drug needs to be injected immediately and under conditions not known in advance. BACKGROUND OF THE INVENTION The present invention relates to a three-chamber automatic injector with mutually separated chambers in which the individual components are mixed and mixed prior to injection.

BACKGROUND OF THE INVENTION

A number of manual and automatic devices are currently known which are intended to allow injection of a drug solution into a patient's body or other receiving device. Furthermore, there are cases in which certain individuals need to inject a drug solution at a time that cannot be predicted. These persons should be equipped with injectors which can be activated in a simple and fast manner and which are reliable. For these cases, automatic injectors have been developed. They should meet the storage requirement for several years without changing the chemical or pharmacological properties of the ingredients they contain, regardless of storage temperature. Furthermore, these automatic injectors are exposed to harsh conditions during the time they are worn by potential users. In addition to the shelf life of automatic injectors, their durability under the conditions to which they are exposed is equally important. In this context, it should be noted that the stability of the drug solutions may deteriorate during prolonged storage. This is the case with nerve gas antidotes which are stable in powder form but are difficult to stabilize in solution for a long shelf life. Thus, there is a need to provide a multi-chamber automatic injector for drug solution delivery that is functionally simple, fast and reliable, in which components can be stored separately for long periods of time and which form a drug solution when mixed, and which includes a mechanism that mixing the ingredients and then applying their solution.

Many patents of similar devices are known, e.g. YU-P-616/88. Its disadvantages include the need for five steps in the prescribed order prior to activation. To «· φφ φ φ φ φ φ

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reduces its reliability and the possibility of rapid use in unexpected and unfavorable conditions. Another known device disclosed in EP-A 0 219 899 has the disadvantage that it is intended as a disposable device. If an auto-injector is used, the drug cartridge cannot be replaced and the auto-injector must be discarded after use. Another disadvantage of this device is that the bypass coupling is provided outside the medicament insert, which requires a large inner diameter of the auto-injector and other cartridges allowing the insert to be telescopically moved in the body of the automatic injector.

Further disadvantages of said auto-injectors are the necessity of gripping them with both hands prior to application in order to remove the needle cover, perform a screw movement or exert a certain force resulting in subsequent mixing of the separated components and triggering of the injection device. Significant disadvantages include the fact that the mixing of the separate components and the actual injection of the drug is not carried out by successive steps of one type of operation, but consists of different activities, eg telescopic retraction of the autoinjector body results in mixing the components and subsequently unlocking pawls on the spring-loaded tie rod. In summary, known devices for injecting one, two or multi-component medicaments into the body have the disadvantage that the actual administration of the medicament precedes the need to perform a series of steps in a prescribed order to mix the separate components and to start the auto-injection device. Further disadvantages are that these auto-injectors do not provide protection of the injection needle from contamination, that they do not allow the auto-injectors to be used repeatedly, that they do not allow rapid mixing of the liquid and powder components, that their individual security elements have to be removed before using the auto-injectors , which hinders the preparation of the auto-injector in difficult conditions.

SUMMARY OF THE INVENTION

A three-chamber automatic injector for mixing and administering medicament stored in separate compartments consisting of a body having a cavity comprising a built-in push mechanism and a compartment with separate compartments and a injection needle, according to the invention comprising a compartment with three separate compartments filled with solutions; or a powder of a pharmaceutically active substance. The part with three separate chambers is enclosed in the body. The first chamber is closed from above by a first piston over which a pushing mechanism is placed. The first chamber is separated from the second chamber by the second piston, the second chamber houses a bypass coupling of the second piston, the bypass coupling section being longer than the height of the second piston but shorter than the sum of the heights of the first and second pistons. The third piston separates the second chamber and the third chamber in which the injection needle is mounted in the guide cylinder located below the third piston. The guide cylinder is provided at the top with passageways which connect the third chamber to the mouth of the injection needle. The third chamber consists of a first chamber and a second chamber, the diameter of which is 5 to 10% larger than the diameters of the preceding chambers and its length is shorter than the sum of the heights of the three pistons. The third chamber below the tip of the needle is closed with a blanking plug.

The bypass coupling is formed by a section in the form of a peripheral recess or groove in the wall of the second chamber having a diameter greater than that of the second piston. Or a section with transfer ducts formed in the inner circumferential wall parallel to the body axis, which are provided with a leading edge allowing the piston to pass smoothly over this edge.

The part with three separate chambers is preferably formed by a replaceable insert placed in the cavity of the body.

The body preferably has the shape of a hollow cylinder and is closed from below by a cap nut.

The third piston has a recess on its front wall for receiving the guide cylinder. The diameter of the guide roller is preferably smaller than the diameter of the pistons.

The cap contacts the union nut, which is provided with an opening for the injection needle passage.

The pushing mechanism consists of a rod, a compression spring and a safety device, the rod being formed by a shaft and in the upper part provided with a first stop and a second stop. The lower part of the shaft is extended, a push-on spring is attached to the rod, which is supported by one end on the lower extended part of the shaft and the other end rests on the bottom of the body cavity. . An opening is provided in the fuse for dropping the first rod stop in the first operating position of the fuse and for dropping the second rod stop at the second operating position of the fuse. The fuse and the upper end of the rod are covered by a cap that is firmly connected to the top of the bottom of the body cavity.

The fuse may be rotatably positioned on the top of the bottom of the body cavity and at the same time form a cap.

In case of need to mix a larger number of substances that require separate storage before spraying, the number of chambers and the number of stops on the rod can be increased.

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A three-chamber automatic injector is a device that allows to automatically inject a drug solution that results from separately positioned three or more components in an insert. With these components separated, the injector can be stored for several years without changing their chemical or pharmacological properties. The automatic injector according to the invention is simply operated with the thumb of one hand. Moving the fuse from one operating position to another will start the mixing phase of one component with the other. In the case of a more than three-chamber embodiment, by returning the fuse, the mixing phase of the next component placed in the next chamber with the drug solution formed in the previous working phase is started. After all components have been mixed, the next step is to move the lock to start the injection phase of the drug solution into the body or other receiving device. At the beginning of this phase, the injection needle extends and the drug solution formed is applied. The automatic injector is again ready for use when the compression spring of the push mechanism is pushed back, the rod lock is locked, the new cartridge with the separate components is inserted and locked.

The advantage of the three-chamber automatic injector according to the invention is, in particular, the ease of handling and use of the auto-injector even under adverse conditions. The injection needle is protected before use by the insert and the blanking plug. It is not necessary to remove the optional needle cover prior to administration, as in the prior art injectors. The phases of mixing, dissolving the active ingredient and injecting the drug into the body can be controlled with one hand. The number of steps required to prepare and start the auto-injector and to mix the liquid component and the powder component takes 3 seconds.

The force required to activate the injector is minimal.

The cartridge with the separate components of the solutions and the powder allows long-term storage of the components in various states that are required for their chemical or pharmacological stability.

The insert is replaceable and allows multiple use of the injector mechanism itself. The construction of the stops and the rod and fuse is very simple and guarantees high reliability of the rod's fuse drop in the first and second working position. The manufacture and assembly of the autoinjector is simple and the manufacturing costs are low.

BRIEF DESCRIPTION OF THE DRAWINGS

Giant. 1 shows a longitudinal section of an automatic injector before use.

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Giant. 2 shows a longitudinal section of the automatic injector after the fuse has been moved to the first operating position in which the liquid component and the powder component are mixed.

Giant. 3 shows a longitudinal section of the automatic injector after the fuse has been moved to the second operating position, where the medicament solution is moved to the area from which it is to be applied,

Giant. 4 shows a longitudinal section of an automatic injector after application of a drug solution to an organism or other receiving device.

Giant. 5 shows a plan view and a side view of a rod with a system of stops formed on its shaft

Giant. 6 shows a plan view and a side view of the fuse.

Giant. 7 shows a detail of the central part of the liner with transfer channels at a 5: 1 scale

Giant. 8 shows a detail of the bottom of the liner at a 5: 1 scale.

DETAILED DESCRIPTION OF THE INVENTION

The three-chamber automatic injector shown in the figures consists of a hollow cylindrical body 1, in the upper part of which there is a pushing mechanism consisting of a draw bar 2, a steel compression spring 3 and a fuse 4. .

An insert 7 is inserted into the cavity of the cylindrical body 1 with separate chambers 19, 18 and 30 filled with solutions and / or a powder of a pharmaceutically active substance. The liner 7 in the body 1 is secured from below by a union nut 6. The lower widened part 26 of the rod 2 rests on the first piston 11, which closes both the liner 7 and the first chamber 19 from above. In the cylindrical wall of the second chamber 18 there are formed transfer channels 14, which are provided with a leading edge 15 allowing a continuous passage of the piston 11 over this edge 15. The third, last piston 12 separates the second chamber 18 and the third chamber 30 The diameter of the guide cylinder 17 is smaller than the diameter of the pistons 10, 11 and 12. The guide cylinder 17 is provided at the top with passages 22 which connect the outer space of the guide cylinder 17 and the third chamber, respectively. The third chamber 30 is formed by a first compartment 20 and a second compartment 21, which is in the lower of the part below the tip of the needle 16 closed by a blanking plug

13. The second space 21 has a diameter 7% larger than the diameter of the other chambers of the insert 7. The plug 13 touches the union nut 6 described above.

The push rod 2 is formed by a stem 23 and is provided with a first stop 24 and a second stop 25 in the upper part. The lower part 26 of the stem 23 is extended, a steel compression spring 3 is mounted on the stem 2. On the upper side of the body cavity bottom 27, there is a fuse 4 through which the shaft 23 of the rod 2 with stops 24 and 25 extends. The rod 2 further extends through the cavity of the cylindrical body 11 and the lower widened portion. 26 of the stem 23 presses on the first piston 10. An opening 28 is provided in the fuse 4 for dropping the first stop 24 of the draw bar 2 in the first operating position of the fuse 4 and for dropping the second stop 25 of the draw bar 2 in the second operating position of the fuse 4 connected to the top of the bottom 27 of the body cavity 4

In the first chamber 19 there is a solvent necessary to form a solution of the drug from the powder component, which is located in the second chamber 18 in the middle part of the liner 7 between the pistons 11 and 12. The third chamber 30 is filled with a suitable liquid and gas phase. The three-chamber injector described above in an arrangement in which it is stored and ready for use is shown in Figure 1.

The injector can be operated with one hand by sliding the fuse 4 from its rest position (Fig. 1) to the first working (mixing) position (Fig. 2). By moving the fuse back (the second fuse working position is the same as the initial rest position), the injector gets into the second working position (injection) (Figs. 3 and 4).

By sliding the fuse 4 from the rest position to the first working position, the first stop 24 of the drawbar 2 will fall through the opening 28 in the fuse 4. By pushing the compression spring 3 onto the drawbar 2, the first piston 10 is moved. with a bypass coupling which is formed by overflow channels 14 formed in the inner circumferential wall of the chamber 18 parallel to the axis of the body 1. The length of the channels 14 is equal to five quarters of the height of the second piston 11.

The pressure on the third piston 12 is partially compensated by the gas layer in the third chamber 30 in the first chamber 20. Through the passageways 14, liquid enters the first chamber 19 into the second chamber 18, where it dissolves the powdered medicament form (Fig. 2).

The travel length of the first piston 10 and the second piston 11 is dependent on the distance of the first stop 24 and the second stop 25.

By moving the fuse 4 to the opposite, second operating position, or in this case to the original rest position, the second stop 25 falls through the opening 28 of the fuse 4 and the rod 2 pushes the piston 10 up to the piston 11 by pressing the spring 3. 44 444 «

4 * 4 4 · 4 4 4 4 4 4 44 * 44 · 44 • 4 «· 4« · «4 4 44444 * ·· The injection needles 16 through the filler 13. (FIG. 3) Further, the pistons 10 and 11 move to the piston

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At the point of piercing of the plug 13, the gaseous phase leaks through the passages 20 formed in the guide cylinder 17 into the mouth of the injection needle 16. Finally, the solution from the third chamber 30 from the first space 20 enters the injection needle.

At the moment when the piston 12 arrives in the expanded space 21, all the above-described spaces that were created in the individual working phases are connected into one common. The contents of the third chamber 30 are mixed with the solution from the second chamber 18.

The drug solution flows through the passages 22 at the top of the guide cylinder 17 into the mouth of the injection needle 16 and through it into an organism or other receiving device.

Fig. 4 shows the position of the individual parts of the automatic injector; and Fig. 8 shows a detail of the lower part of the insert 7 at a scale of 5: 1 after application of the drug solution. Fig. 5 shows the rod 2 and Fig. 6 the fuse 4 for the three-chamber version of the automatic injector.

This results in the individual phases required for the operation of the automatic injector, which is, in the case of a three-chamber embodiment, the formation of a drug solution from a liquid and solid component in the form of a powder and its subsequent injection into an organism or other receiving device.

The internal by-pass coupling allows immediate mixing of the powder and liquid components. Further mixing and homogeneity of the injected active ingredient is ensured by expanding the diameter of the second space 21 in the third chamber 30 and the turbulence in the passages 22.

The injection needle 16 is protected from use by the insert 7 and the blanking plug 13. Before application, it is not necessary to remove the optional needle cover as in the prior art injectors.

The design of the stops 24 and 25 of the tie rod 2 and of the fuse 4 is very simple and guarantees high reliability of the drop of the tie rod 2 with the fuse 4 in both the first and second operating positions.

Industrial applicability

The three-chamber automatic injector according to the invention is useful in the pharmaceutical industry for the preparation of a medicament for emergency situations.

Claims (11)

Patent claims A three-chamber automatic injector for mixing and administering a medicament stored in separate compartments consisting of a body, the cavity of which comprises a built-in push mechanism and a compartment with separate compartments with a syringe needle, characterized in that the compartment with three separate compartments (19, 18); 30) the filled solutions and / or powder of the pharmaceutical active is enclosed in the cavity of the body (1), the first chamber (19) is closed from above by the first piston (10) above which the pushing mechanism is located and separated from the second chamber (18) a bypass (29) of the second piston (11) is located in the second chamber (18), the bypass coupling section being longer than the height of the second piston (11) but shorter than the sum of the heights of the first piston (10) and a second piston (11), the third piston (12) separating the second chamber (18) and the third chamber (30) from which it is in the guide cylinder (17) located below the third p the syringe needle (16) is attached by the piston (12), the guide roller (17) is provided in the upper part with passages (22) connecting the third chamber (30) with the mouth of the injection needle (16), the third chamber (30) (20) and the second chamber (21), the second chamber (21) having a diameter of 5 to 10% greater than the diameters of the first chamber (19) and the second chamber (18) and its length is shorter than the sum of the slits of all three pistons ( 10, 11 and 12), the second space (21) is closed at the bottom under the tip of the needle (16) by a blanking plug (13). A three-chamber automatic injector according to claim 1, characterized in that the bypass coupling is formed by a section in the form of a peripheral recess or groove in the second chamber (18) having a larger diameter than the diameter of the piston (11). A three-chamber automatic injector according to claim 1, characterized in that the bypass coupling is formed by a section with transfer channels (14) formed in the inner circumferential wall parallel to the axis of the body (1), which are provided with a leading edge (15). A three-chamber automatic injector according to claims 1 to 3, characterized in that the part with three separate chambers (19, 18, and 30) is formed by a replaceable insert (7) located in the cavity of the body (1), A three-chamber automatic injector according to claims 1 to 4, characterized in that the diameter of the guide cylinder (17) is smaller than the diameter of the pistons (10, 11 and 12). • · The three-chamber automatic injector according to claims 1 to 5, characterized in that the third piston (12) is provided on its face with a recess for receiving the guide cylinder (17). A three-chamber automatic injector according to claims 1 to 6, characterized in that the body (1) has the shape of a hollow cylinder and is closed from below by a cap nut (6). The three-chamber automatic injector according to claim 1 to 7, characterized in that the plug (13) contacts the union nut (6), which is provided with an opening for the passage of the injection needle (16). The three-chamber automatic injector according to claims 1 to 8, characterized in that the pushing mechanism consists of a rod (2), a compression spring (3) and a fuse (4), a compression spring (3) is fitted on the rod (2). In this part, the rod (2) is provided with two stops (24 and 25) for successively dropping the rod (2) through the opening (28) formed in the fuse (4) to the first working position and to the second working position. The three-chamber automatic injector according to claim 9, characterized in that the fuse (4) is located on the upper part of the bottom (27) of the cavity of the body (1), is covered by a cover (5) in which it slides. firmly attached to the body (1). The three-chamber automatic injector according to claim 9, characterized in that the fuse (4) is placed on the upper part of the bottom (27) of the cavity of the body (1) rotatably and at the same time forms a cover (5).