DE102009053729A1 - Piston-cylinder unit for needle-free injector for providing sterile injection solution, has chamber arranged in cylinder, for receiving injection solution, and front wall having nozzle borehole or outlet element - Google Patents

Abstract

The piston-cylinder unit (1) has a chamber (3) arranged in a cylinder (2), for receiving an injection solution, a front wall (5) having a nozzle borehole or an outlet element (6), and a another piston arranged in such a way that it moves in the chamber. The chamber is made from two parts with a chamber (8) and another concentric chamber (9). The cross-section of the former chamber is larger than the cross-section of the latter chamber. An independent claim is also included for a method for filling a cylinder-piston unit.

Description

The invention relates to a cylinder-piston unit for a needle-free injector, with a chamber arranged in a cylinder for receiving an injection solution, an end wall with at least one nozzle bore or an outlet element and movably arranged in the chamber piston.

The invention also relates to a method for corresponding filling of the cylinder-piston unit.

Cylinder-piston units are used in injectors, for example US 2008/014997 A1 . DE 10 2007 004 211 A1 or DE 10 2007 008 369 A1 are known.

Injection solution is understood to mean liquid medicaments. In the following, the technical terms used will be explained in more detail. The person skilled in the art is familiar with the term drug. This refers to substances or substance mixtures for human or veterinary medicine. They consist of the one or more active pharmaceutical ingredients and other conventional ingredients that make this drug used pharmaceutically, especially water.

From the DE 10 2005 054 600 A1 a cylinder piston unit with a cylinder and a piston guided therein is known, wherein the cylinder and the piston enclose a at least temporarily active agent-fillable chamber and the cylinder has at least one outlet element at its front end. The cross section of the chamber or the cross section of the cylinder inner wall increases at least partially from front to back. The piston has, at least in the - the front part facing - a front, elastic apron, the front outer edge of the unloaded piston spans a cross-sectional area which is larger than a surface which is spanned by an outline which in the region of the transition from the apron is to schürzentragenden piston section.

From the DE 10 1006 040 888 B3 discloses a closure system for containers for storage or administration of liquid, pasty or powdery substances, which consists of a, equipped with a through hole cap and a closure element. In this case, the cap holds the closure element on the container in the region of the opening to be closed by means of a locking element present on the container non-positively and / or positively. The end face surrounding the container opening, on which the closure element rests, has a depression. The closure element is a virus-, bacteria- and spore-dense film which lies on the end face and at least partially over the depression. When placing the cap, an elastomer or adhesive ring is arranged between the closure element and the recess, which fills the depression.

From the DE 10 2006 045 959 B3 is a cylinder piston unit with a cylinder and guided therein, sterile rubber-sealed piston known, wherein the cylinder and the piston enclosing a at least temporarily active agent-fillable chamber and the cylinder has at least one outlet element at its front end. The piston, which is stationary in a rear position, is sealed in a sterile manner with respect to the cylinder by means of a static rear sealing element, wherein both sealing elements rest in a sealing position on the wall of the cylinder and respectively on the wall of the piston. Spatially is behind each static sealing element, the respective sealing element receiving, parking space arranged. When the piston is actuated, the individual static sealing elements are transferred from their respective sealing position into a parking position located in the parking space, wherein each sealing element in the parking position contacts either only the cylinder wall or only the piston wall. Between the two static sealing elements at least one dynamic piston-side sealing element is arranged, which bears against the cylinder inner wall at least when the piston is actuated.

In the known embodiments, the cylinder-piston unit is filled either immediately before use by the user of the disposable injector with the injection solution or the injection solution is filled in the factory in the cylinder-piston unit and then stored in the cylinder-piston unit. Thus, there is a finished solution for injection in the cylinder-piston unit over the possible storage period. A possible preferred type of storage of an active ingredient is to lyophilize the active ingredient solution and to store the active ingredient in the form of a powder. Such a lyophilizate has a longer shelf life than in dissolved form. In order to obtain a finished injection solution prior to injection, the lyophilized active ingredient is dissolved in a solvent such as water. Then there is an injectable solution.

Based on this prior art, the present invention seeks to provide a cylinder-piston unit for receiving an injection solution and a method for filling the cylinder-piston unit, wherein the injection solution of a first component / a first component and a second component / a second component and ready mixed or dissolved shortly before use. Furthermore, a cylinder-piston unit is to be constructed in which can be filled sterile a solution to be freeze-dried injection solution, this can then be freeze-dried and then airtight sterile can be closed. In addition, the solvent for the lyophilisate must be stored in such a way that it can be used as a ready-to-use solution for injection. This solution must be before application gas bubble free in a short-term to 300 bar stable cylinder with a sterile nozzle to be released from it under high pressure needle-free through the skin through to z. B. can be shot into the subcutaneous fat.

• – dass die zweite Kammer durch den zweiten Kolben und die erste Kammer durch einen ersten Kolben verschlossen ausgebildet ist, wobei die erste Kammer von der zweiten Kammer getrennt ist, und
• – dass die erste Kammer mit mindestens einem verschließbaren, axial ausgerichteten Gefriertrocknungskanal und die zweite Kammer mit mindestens einem axial ausgerichteten Überleitungskanal, an den jeweils hinteren Enden der Kammern, ausgebildet ist.

These objects are initially achieved by the device of claim 1. Accordingly, the device described in the introduction is characterized in that the chamber is formed in two parts with a first chamber and a concentric second chamber, wherein the cross section of the first chamber is larger than the cross section of the second chamber,

• - That the second chamber is formed by the second piston and the first chamber is closed by a first piston, wherein the first chamber is separated from the second chamber, and
• - That the first chamber is formed with at least one closable, axially oriented freeze-drying channel and the second chamber with at least one axially aligned transfer channel, at the respective rear ends of the chambers.

The arrangement of the second piston between the second chamber and the first chamber enables separation of the first component / component from the second component / component. By a preferred embodiment of the piston in each case a piston body and an outer piston ring different materials for the piston can be considered. Both the outer piston ring of the first and the second piston are pressed, for example, when inserted into the first chamber so that a channel or a flow edge is formed through which the displaced air can escape from the first chamber without pressure.

For injecting the inner piston body are pushed via a piston rod, for example by a preloaded spring in the second chamber in no time to expel the injection solution under high pressure from the nozzle / -n against a resistance - skin -.

A preferred embodiment provides for forming the inner piston body, which is closest to the nozzle (s), with at least one sealing lip in order to increase the guidance and the tightness between the inner piston body and the wall of the second chamber in a pressure-dependent manner.

The above object is further achieved by a method, taking into account the cylinder-piston unit just described.

• – Befüllen einer zweiten Kammer mit einem ersten Bestandteil/einer ersten Komponente einer Injektionslösung, wobei das Volumen des ersten Bestandteils/der ersten Komponente kleiner ist als das Volumen der zweiten Kammer;
• – Einsetzen eines gequetschten, die Luft entweichen lassenden, zweiten Kolbens in eine erste Kammer bis zur Anlage an eine Ringfläche, um die zweite Kammer zu verschließen, wobei in der zweiten Kammer ein Gaspolster vorliegt;
• – Befüllen der ersten Kammer (8) oberhalb des zweiten Kolbens mit einem Lösungsmittel, z. B. Wasser oder einem zweiten Bestandteil/einer zweiten Komponente,
• – Einsetzen eines ersten gequetschten Kolbens in die erste Kammer und verschließen der ersten Kammer,
• – Einschieben des ersten Kolbens mit nach oben zeigender(n) Düse(n) zur Herstellung der Injektionslösung aus dem Lyophilisat bzw. dem ersten Bestandteil/der ersten Komponente und des Lösungsmittels oder des zweiten Bestandteils/der zweiten Komponente durch einen Kolbenschieber, wobei durch Überdruck in der ersten Kammer ein zweiter innerer Kolbenkörper soweit in einem zweiten äußeren Kolbenring in Richtung zweite Kammer geschoben wird, bis ein bisher verschlossener Überleitungskanal die zweite Kammer mit der ersten Kammer verbindet und das Lösungsmittel oder der zweite Bestandteil/die zweite Komponente vollständig in die zweite Kammer gelangt und sich mit dem Lyophilisat bzw. dem ersten Bestandteil/der ersten Komponente zur fertigen Injektionslösung löst oder mischt,
• – nachfolgendes Einschieben eines ersten inneren Kolbenkörpers gemeinsam mit dem zweiten inneren Kolbenkörper mit Hilfe des Kolbenschiebers durch Eindrehen des Kolbenschiebers in ein Gewinde, Teilgewinde oder Rastelement und Herausdrücken einer Gasblase aus der Zylinder-Kolben-Einheit wobei die Gasblase durch nach oben zeigende/-n Düsenbohrung/-en bzw. Austrittselement/-e aus der zweiten Kammer verdrängt wird und eine am Außenzylinder oder an der Verschlusskappe befestigte Membrane, die sich bei Austritt des Gaspolsters von den Düsenbohrung/-en bzw. Austrittselement/-en abhebt, und
• – nach dem Austritt des Gaspolsters die Düsenbohrung/-en bzw. das/die Austrittselement/-e wieder steril verschließt (Überdruckventil).

The method comprises at least the following steps:

• - filling a second chamber with a first component / a first component of an injection solution, wherein the volume of the first component / the first component is smaller than the volume of the second chamber;
• - inserting a squashed, venting, second piston into a first chamber until it engages an annular surface to close the second chamber, with a gas cushion in the second chamber;
• - filling the first chamber ( 8th ) above the second flask with a solvent, e.g. Water or a second ingredient / component,
• Inserting a first crimped piston into the first chamber and closing the first chamber,
• - Insertion of the first piston with upwardly pointing (n) nozzle (s) for producing the injection solution of the lyophilisate or the first component / the first component and the solvent or the second component / the second component by a piston valve, wherein by overpressure in the first chamber, a second inner piston body is pushed so far in a second outer piston ring in the direction of the second chamber until a previously closed transfer passage connects the second chamber to the first chamber and the solvent or the second component / the second component completely into the second chamber and dissolves or mixes with the lyophilizate or the first component / the first component to form the finished injection solution,
• - Subsequent insertion of a first inner piston body together with the second inner piston body by means of the piston valve by screwing the spool into a thread, partial thread or locking element and pushing out a gas bubble from the cylinder-piston unit wherein the gas bubble by upward pointing / -n nozzle bore or -en or outlet element / -e is displaced from the second chamber and a membrane attached to the outer cylinder or on the cap, which stands out at the outlet of the gas cushion of the nozzle bore / -en or outlet element / -en, and
• - After the exit of the gas cushion, the nozzle bore / -en or the / the outlet element / -e again sterile closes (pressure relief valve).

As a rule, the finished injection solution is metered in a sterile manner into the second chamber closed with the closure cap and the membrane. Then, the second piston with the piston ring is placed so that the entire gas space above the injection solution through at least one freeze-drying channel has contact to the outside. Then it is freeze-dried. After lyophilization, the second piston is advanced with the piston ring to the annular surface, so that the lyophilisate is sealed protected against moisture and oxygen. Thereafter, the solvent (eg., Water) is filled sterile in the first chamber and with the first piston z. B. with squeezed piston ring, without pressure on the solvent, sealed.

Further features and details of the invention will become apparent from the claims and the following description of an embodiment of the invention shown in schematic drawings. Show it:

1 in a sectional side view of a cylinder with two diameters and pressure-stable outer cylinder of a cylinder-piston unit with a diaphragm mounted on a cap;

1a in plan view, the location of the channels 1 ;

2 in cut side view of the cylinder 1 with the injection solution to be lyophilized and the second plunger in a position such that the gas space above the injection solution is in contact with the outside;

3 in a sectional side view of the known cylinder with the second piston, which closes the lyophilisate sterile and gas-tight;

4 in cut side view of the cylinder 3 with a solvent and the gas-tight and sterile occluding first piston;

5 in a sectional side view of the known cylinder with open overflow channel, reconstituted solution for injection and gas cushion;

6 in a sectional side view of the known cylinder with the screwed-in piston slide to the freedom of air bubbles advanced inner first and inner second piston body;

7 in a sectional side view of the injection-ready cylinder-piston unit with the cap and remote membrane removed;

8th the system after injection with a closed nozzle;

9 in bottom view, the cylinder-piston unit with a nozzle;

10 in bottom view, the cylinder-piston unit with four nozzles;

11 a cross section of the four-nozzle model through two diagonally opposite nozzles;

In the following description of an embodiment, the front end of the cylinder-piston unit means the end closest to the surface of a patient. The rear end of the cylinder-piston unit is the end that is removed from the surface of the patient when the unit is applied.

In all figures, the same technical elements are designated by the same reference numerals.

In 1 is a sectional side view of a cylinder-piston unit 1 shown. A chamber 3 a water vapor and oxygen blocking cylinder 2 is through a first chamber 8th and a second concentric chamber 9 formed, wherein the cross section of the first chamber 8th is greater than the cross section of the second chamber 9 , The second chamber 9 is at the first chamber 8th opposite side with an end wall 5 formed, the at least one nozzle bore or at least one outlet element 6 having. Each nozzle bore or each outlet element 6 ends on the outside 12 the pressure-stable and the second chamber 9 enveloping outer cylinder 13 in a raised dull cone 29 and has on its inside 28 the front wall 5 a discharge funnel 30 on. On the outside 12 the pressure-stable outer cylinder 13 one is above the exit element (s) 6 cocked and preferably from the cap 11 carried water vapor and oxygen barrier membrane 26 For example, made of rubber or transparent silicone. Alternatively, the membrane 27 on the outer cylinder 13 be mounted (see 2 ). The pressure-stable outer cylinder 13 is with optional retaining elements 32 shaped like slot, threaded flange or bayonet. For example, pull hooks 33 into the slot (compare 8th ).

Between the first chamber 8th and the second chamber 9 a transition region is formed, preferably as an annular surface 18 , A first embodiment of the transition region thereby sees radii (not shown) in the transition from the cylindrical wall of the first chamber 8th to the ring surface 18 and from the ring surface 18 to the cylindrical Wall of the second chamber 9 in front. A second embodiment of this area provides bevels (not shown). Other configurations, including combinations of, for example, radii and bevels, negative or positive camber or concave or convex, can be taken into account. The embodiments help on the one hand during filling of the solution for injection 4 or the first component 14 , please refer 2 , and on the other hand in the production of the cylinder 2 , which is made for example in one-component or two-component plastic injection molding or glass. By the embodiments described above, the flow behavior of the considered water vapor and oxygen barrier material is supported to a cylinder 2 with the given properties such as squareness, concentricity, wall thickness, etc. to obtain.

The drug intended for injection becomes the cylinder-piston unit 1 held for a long time. It is known that drugs are stored until injection in two components / components, as z. B. the durability is extended. That from a first component / a first component 14 and a second component / component 15 existing medicines are mixed and / or dissolved shortly before injection. At the component (s) 14 it can be a liquid - like a solution for injection 4 - or act a powder. A powdery component / component is e.g. B. a lyophilisate 17 , A second component / component 15 lies like the solvent 19 in liquid form. Other forms of components / ingredients 14 . 15 are explicitly considered.

At the back of the chamber 8th and the chamber 9 is in the cylinder wall 35 in each case at least one freeze-drying channel 34 (in chamber 8th ) and a transfer channel 36 (in chamber 9 ) formed.

The cross-section of the freeze-drying channel / freeze-drying channels 34 or the transfer channel (s) 36 is, viewed from the rear end, in the form of a rectangle. However, other shapes are also conceivable, in particular those which take into account the flow behavior and the strength of the cylinder.

See the 1a ,

In a first step, shown in 2 , becomes the sterile solution for injection 4 or the first component / component 14 in the second chamber 9 of the sterile cylinder 2 sterile filled. Subsequently, a sterile second piston 7 in the first chamber 8th inserted so sterile that the freeze-drying channel 34 in the cylinder wall 35 between the chamber 3 and the environment stays open.

All other components and work steps are sterile, without being addressed again in the text.

The one in the second chamber 9 submitted injection solution 4 or component / component 14 is subsequently freeze-dried and remains as a lyophilisate 17 in the second chamber 9 , as in 3 shown. For storage over a longer period of time, the lyophilisate 17 in the second chamber 9 sealed gas- and moisture-tight. For this purpose, the second piston 7 so in the first chamber 8th pushed in that second piston 7 at a transition area, the ring area 18 , between first chamber 8th and second chamber 9 is applied.

After the lyophilisate 17 in the second chamber 9 by means of the second piston 7 is included, as in 4 shown, above the second piston 7 , and thus in the first chamber 8th , the second component / component 15 of the drug. The second component / component 15 is for example a solvent 19 , In a preferred embodiment, water is used as the solvent 19 used and in use for dissolving the as lyophilisate 17 present first component / first component 14 used to form a liquid drug - the solution for injection 4 - be able to inject. After filling the second component / the second component 15 in the first chamber 8th , this is done by a first piston 10 sealed liquid-tight. This is the first piston 10 , For example, by lateral squeezing, depressurized in the first chamber 8th used.

Both the second and the first piston 7 . 10 are each made up of at least one inner piston body 7.1 . 10.1 and an outer piston ring 7.2 . 10.2 formed, wherein the inner piston body 7.1 . 10.1 in the outer piston rings 7.2 . 10.2 are slidably arranged. The present embodiment with two separate closed chambers 8th . 9 serves to store the otherwise unstable solution for injection 4 in the form of the separately present lyophilisate 17 and also separately present solvent 19 ,

Before injecting the solution for injection 4 must be the lyophilisate 17 with the solvent 19 mixed and go into solution, which can take up to 30 minutes to be awaited. Only then will the remaining gas cushion 31 with upwardly pointing nozzle (s) 6 pushed out.

In 5 is shown as the solvent 19 from the first chamber 8th of the cylinder 2 in the second chamber 9 arrives. For this purpose, the cylinder-piston unit 1 , which is located in an injector, preferably rotated about 180 ° about the horizontal axis. This increases the gas bubble 31 in the direction of the nozzle or outlet element 6 , Furthermore, the first piston 10 by means of a piston valve 20 Sitting and being operated in the injector, towards the front wall 5 of the cylinder 2 moves as indicated by the arrow. When inserting the first piston decreases 10 the first chamber 8th , whereby over the solvent 19 a pressure on the second piston 7 is exercised. Because the outer piston ring 7.2 of the second piston 7 on the ring surface 18 rests and can not be displaced, is due to the applied pressure of the inner piston body 7.1 of the second piston 7 in the direction of the face 5 pressed. In this and the following manipulation, the nozzle must point upwards. At the moment when the rear edge 21 of the inner piston body 7.1 of the second piston 7 in the cylinder wall 35 trained overflow channel 36 releases, the solvent flows 19 from the first chamber 8th in the second chamber 9 and mixes with the lyophilisate 17 , Only after complete dissolution of the lyophilisate 17 is the solution for injection 4 for injection. To improve the dissolution process, the second chamber is not completely filled with the solvent 19 and the lyophilisate 17 filled. In the second chamber 9 there is a gas cushion for this purpose 31 , before injection by further advancing the piston valve 20 must be removed.

In 6 is shown as the first inner piston body 10.1 completely in the second chamber 9 of the cylinder 2 is inserted and at the already completely in the beginning of the second chamber 9 stuck second inner piston body 7.1 is applied. The solvent 19 is completely in the second chamber 9 as an injection solution 4 , The piston valve 20 of only partially in 8th injector shown, has been arranged axially freely longitudinally displaceable in the injector. For this purpose, it has a diameter which is smaller than one in a flange 22 arranged threaded hole 23 and smaller than the diameter of the second chamber 9 (please refer 8th ). The piston valve 20 is guided axially in the injector and the smaller diameter portion is designed so that when the solvent 19 completely in the chamber 9 conveyed position of the first inner piston body 10.1 the area of the piston valve 20 that's a thread 24 complementary to the threaded hole 23 has, is just in contact with this. Then, by screwing the thread of the spool 20 further into the cylinder-piston unit 1 pushed, the air cushion is removed and the power transmission of the energy storage on the spool 20 will be produced. The Ausdrück- or ejection energy of the disposable injector, for example, by a spring 25 caused.

For this purpose, the first inner piston body 10.1 of the first piston 10 in the longitudinal direction on the front wall 5 of the cylinder 2 pushed down until the thread 24 of the piston valve 20 into the threaded hole 23 of the flange 22 can be screwed. When inserting and subsequently screwing in the spool valve 20 displace the successive inner first and second piston bodies 10.1 and 7.1 the gas bubble 31 from the second chamber 9 through the nozzle or the outlet element 6 , Upon further insertion of the piston valve 20 escapes the gas bubble 31 from the second chamber 9 , where the cap 11 with a membrane 26 is formed, which at an overpressure in the second chamber 9 the nozzle or the outlet element 6 releases. The complete pushing out of the gas bubble from the second chamber 9 by further screwing the thread is visually by the user through opposite window (not shown) in the membrane 26 and through the crystal-clear cap 11 supervised. Also, the inflow of the solvent 19 can already with screwing in the then correspondingly longer thread of the piston valve 20 be accomplished.

For injecting the solution for injection 4 becomes the latched cap 11 from the outer cylinder 13 deducted. The dull cone 29 the exit element 6 is now pressed on or on the previously disinfected body part into which the solution for injection 4 to be injected. By means of a tripping device, not shown, the prestressed spring 25 released, causing the spool 20 on the first inner piston body 10.1 of the first piston 10 fast and the first inner piston body 10.1 and the second inner piston body 7.1 of the second piston 7 in the second chamber 9 in the longitudinal direction on the front wall 5 to rush ahead. The solution for injection 4 Escapes at very high speed through the at least one nozzle bore or through the outlet element 6 from the second chamber 9 , as in 7 shown.

If the solution for injection 4 completely out of the second chamber 9 is pressed, is the second inner piston body 7.1 on the front wall 5 on and close the nozzle (s) 6 , as in 8th shown. Also shown is an embodiment in which at least one freeze-drying channel 16.1 in a slot ring 7.2b is trained. The freeze-drying channel described above 34 becomes functional through the illustrated freeze-drying channel 16.1 replaced. In the chamber 9 there is at least one transfer channel 36 ,

It goes without saying that the number of channels 16.1 . 34 and 36 can vary.

Instead of the transfer channel 36 In a further embodiment, at least one transfer channel in the second outer piston ring 7.2 be educated. Thus, there is the possibility of the channels, depending on the requirement or possibility, either only in the cylinder wall 35 or in the cylinder wall 35 and the second outer piston ring 7.2 train.

9 shows in bottom view, that is from the front end to the rear end of the cylinder-piston unit 1 a version with a blunt cone 29 and a nozzle 6 ,

10 shows in bottom view a version of the cylinder-piston unit 1 with four blunt cones 29 and four nozzles 6 ,

The version out 10 is in 11 shown in cross-section, with two diagonally opposite outlet elements 6 in the vertical section plane.

LIST OF REFERENCE NUMBERS

1

Cylinder-piston unit

2

cylinder

3

chamber

4

injection

5

bulkhead

6

Nozzle bore or outlet element

7

second piston

7.1

second inner piston body

7.2

second outer piston ring

7.2a

Quadring

7.2b

split ring

8th

first chamber

9

second chamber

10

first piston

10.1

first inner piston body

10.2

first outer piston ring

11

Locking cap with locking element

12

Outside of the pressure-resistant outer cylinder 13

13

Outer cylinder, pressure-stable with locking groove

14

first component / first component

15

second component / second component

16.1

Freeze-drying channel, alternatively in the second outer piston ring 7.2 results in slot ring 7.2b

17

lyophilisate

18

ring surface

19

solvent

20

spool

21

rear edge of the piston body 7.1

22

threaded

23

threaded hole

24

thread

25

feather

26

Membrane on cap 11

27

Diaphragm alternatively on outer cylinder 13

28

Inside of the chamber 9 or the discharge funnel 30

29

Cone, duller

30

outflow funnel

31

Gas cushion, gas bubble

32

retaining element

33

spring hooks

34

Freeze drying channel

35

cylinder wall

36

Crossover passage

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2008/014997 A1 [0003]
• DE 102007004211 A1 [0003]
• DE 102007008369 A1 [0003]
• DE 102005054600 A1 [0005]
• DE 101006040888 B3 [0006]
• DE 102006045959 B3 [0007]

Claims (11)

Piston-cylinder unit ( 1 ) for a needle-free injector, for example, to provide a sterile solution for injection, with one in a cylinder ( 2 ) arranged chamber ( 3 ) for receiving an injection solution ( 4 ), an end wall ( 5 ) with at least one nozzle bore or an outlet element ( 6 ) and one in the chamber ( 3 ) movably arranged second piston ( 7 ), characterized in that - the chamber ( 3 ) in two parts with a first chamber ( 8th ) and a concentric second chamber ( 9 ), wherein the cross section of the first chamber ( 8th ) is larger than the cross section of the second chamber ( 9 ), - that the first chamber ( 8th ) by a first piston ( 10 ) and the second chamber ( 9 ) through the second piston ( 7 ) is formed closed, wherein the first chamber ( 8th ) of the second chamber ( 9 ), and - that the first chamber ( 8th ) with at least one closable, axially oriented freeze-drying channel ( 34 ) and the second chamber ( 9 ) with at least one axially aligned transfer channel ( 36 ), at the respective rear ends of the chambers ( 8th . 9 ), is trained. Cylinder-piston unit according to claim 1, characterized in that the second piston ( 7 ) as an inner second piston body ( 7.1 ) with an outer second piston ring ( 7.2 ) and the first piston ( 10 ) as an inner first piston body ( 10.1 ) with an outer first piston ring ( 10.2 ) is trained. Cylinder-piston unit according to claim 2, characterized in that the inner first piston body ( 10.1 ) frictionally engaged with the outer first piston ring ( 10.2 ) and the inner second piston body ( 7.1 ) frictionally engaged with the outer second piston ring ( 7.2 ) is formed connected. Cylinder-piston unit according to one of the preceding claims, characterized in that between the first chamber ( 8th ) and the second chamber ( 9 ) a transition region as an annular surface ( 18 ) is trained. Cylinder-piston unit according to one of the preceding claims, characterized in that the closure cap ( 11 ) with a membrane ( 26 ) or alternatively the membrane ( 27 ) separately on the outer cylinder ( 13 ) is attached. Cylinder-piston unit according to one of the preceding claims, characterized in that the closure cap ( 11 ) directly or indirectly with the outer surface of the outer cylinder ( 13 ) is formed connected. Cylinder-piston unit according to one of the preceding claims, characterized in that the second inner piston body ( 7.1 ) of the second piston ( 7 ) at the second chamber ( 9 ) facing edge is formed with at least one sealing lip. Cylinder-piston unit according to one of the preceding claims, characterized in that the closed in the storage state transfer channel ( 36 ) by displacing the second inner piston body ( 7.1 ) and the first chamber ( 8th ) with the second chamber ( 9 ) connects. Method for filling a cylinder-piston unit ( 1 ) for a needle-free disposable injector, comprising at least the following steps: - filling a second chamber ( 9 ) with a first constituent / component ( 14 ) an injection solution ( 4 ), wherein the volume of the first component (s) ( 14 ) is smaller than the volume of the second chamber ( 9 ); Inserting a squeezed, air-escape, second piston ( 7 ) into a first chamber ( 8th ) until it abuts an annular surface ( 18 ) to the second chamber ( 9 ), whereas in the second chamber ( 9 ) a gas cushion ( 31 ) is present; - filling the first chamber ( 8th ) above the second piston ( 7 ) with a solvent ( 19 ), z. As water or a second component / a second component ( 15 ), - inserting a first pinched piston ( 10 ) into the first chamber ( 8th ) and close the first chamber ( 8th ), - insertion of the first piston ( 10 ) with upwardly pointing nozzle (s) ( 6 ) for the preparation of the injection solution ( 4 ) from the first constituent / component ( 14 ) and the solvent ( 19 ) or the second component (s) ( 15 ) by a piston valve ( 20 ), due to overpressure in the first chamber ( 8th ) a second inner piston body ( 7.1 ) so far in a second outer piston ring ( 7.2 ) in the direction of the second chamber ( 9 ) is pushed until a previously closed transfer channel ( 36 ) the second chamber ( 9 ) with the first chamber ( 8th ) and the solvent ( 19 ) or the second component (s) ( 15 ) completely into the second chamber ( 9 ) and interacts with the first component (s) ( 14 ) to the finished injection solution ( 4 dissolves or mixes; - Subsequent insertion of a first inner piston body ( 10.1 ) together with the second inner piston body ( 7.1 ) with the help of the piston valve ( 20 ) by screwing in the piston valve ( 20 ) in a thread, partial thread or locking element and pushing out a gas bubble ( 31 ) from the cylinder-piston unit ( 1 ) wherein the gas bubble ( 31 ) by upwardly pointing nozzle bore (s) or exit element (s) ( 6 ) from the second chamber ( 9 ) is displaced and one on the outer cylinder ( 13 ) or on the cap ( 11 ) attached membrane ( 26 ), which at the outlet of the gas cushion ( 31 ) from the nozzle bore (s) or exit element (s) ( 6 ) lifts off, and - after the exit of the gas cushion, the nozzle bore (s) or the exit element (s) ( 6 ) closes again sterile (pressure relief valve). Method according to claim 9, characterized in that the first component (s) ( 14 ) in the second chamber ( 9 ) is freeze-dried. A method according to claim 9, characterized in that the complete outlet of the gas cushion ( 31 ) is controllable.

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