EP2800597A1

EP2800597A1 - Barrel-plunger unit comprising short cannula

Info

Publication number: EP2800597A1
Application number: EP12797780.9A
Authority: EP
Inventors: Rudolf Matusch
Original assignee: LTS Lohmann Therapie Systeme AG
Current assignee: LTS Lohmann Therapie Systeme AG
Priority date: 2011-11-16
Filing date: 2012-11-16
Publication date: 2014-11-12
Also published as: JP2015501676A; US9599220B2; WO2013072455A1; DE102011119203A1; JP6175066B2; US20140245882A1

Abstract

The invention relates to a barrel-plunger unit comprising at least one barrel, which receives an injection solution and which comprises a discharge opening, and at least one plunger. The barrel or a component mounted upstream of the barrel has an end face from which a short cannula protrudes during the proper emptying process of the barrel-plunger unit, said cannula having a discharge opening at the free end of the cannula. The discharge opening has a surface with a border which has a point or an edge near the base. The point or the edge near the base lies 0.15 - 0.3 mm away from the end face or the front-most end face point or edge. According to the invention, a barrel-plunger unit is developed for a single-use injector, said unit being suitable for penetrating the human skin, among others, in a virtually painless manner in order to apply highly viscous injection solutions.

Description

LTS Lohmann Therapy Systems AG

Cylinder-piston unit with short cannula

The invention relates to a cylinder-piston unit with at least one

Injection solution receiving cylinder with outlet and at least one piston.

From an article in the Journal of Investigative Dermatology (2006) Volume 126 entitled "Precise Microinjection into Skin Using Hollow Microneedles" by Ping M. Wang et al., It is known to apply a group of several smallest hollow glass needles to the skin of one To put on vaccine patients and press against the skin so that the glass needles, with the release of a liquid agent, bring this into the upper layers of the skin. Since the short glass needles have only extremely thin channels, only a small amount of active ingredient can be delivered, which must also be extremely low viscosity.

The present invention is therefore based on the problem of developing a cylinder-piston unit for a disposable injector, which u.a. for a virtually painless penetration of the human skin. for the application highly viscous

Injection solutions is suitable.

This problem is solved with the features of the main claim. The cylinder or a cylinder upstream component has an end face, from the intended emptying of the cylinder-piston unit protrudes a short cannula, which has an outlet opening at its free end. The

Outlet opening has an area whose border has a ground-level point or Ϊ edge near the ground. The ground-level point or the ground-level edge is 0.1 mm away from the face or its foremost point or edge.

With the invention, for example, the cylinder-piston unit of a

Once a injector presented. The disposable injector supports, in addition to the cylinder-piston unit, a drive installed in an injector housing and acting on a piston-actuating ram. Spring drives, gas drives with open gas cartridges or pyrotechnic drives can be used as possible drives. Known spring energy storage use prestressed mechanical or pneumatic springs or spring systems. If a spring energy store is used as the drive, the piston actuating ram is held in a form-fitting manner by at least one support rod or towing hook arranged on or in the injector housing for pretensioning and holding this spring energy store. The one or more support rods or towing hooks are locked by means of one or more triggering elements until the disposable injector in its locked position. To trigger the injector or the

Support rods or towing hooks released so that the piston actuation plunger - under the action of the spring energy storage - can move at least approximately parallel to the center line of the disposable injector to eject the injection solution present in the cylinder of the cylinder-piston unit via at least one short cannula.

According to the invention protrudes from the front side of the cylinder of the cylinder-piston unit out a short short cannula, which penetrates after placing the injector on the skin of the patient during subsequent application of the injection solution only a few tenths of a millimeter into the skin of the patient. The penetration depth is mechanically limited by the front end face of the injector. With the help of the short short cannula, among others, highly viscous protein solutions, eg

Monoclonal antibodies are administered easily and virtually painlessly.

The front end of the injector can also be the front end of a - the short-tubule during storage of the injector occlusive - elastomer or

Adhesive disc, which is slidably mounted in the direction of the longitudinal extent of the injector on the cylinder.

Further details of the invention will become apparent from the dependent claims and the following descriptions schematically illustrated embodiments.

Cylinder-piston unit with short cannula protective housing;

Cut the short cannula after placing it on the skin of the patient before completely piercing the elastomer disc;

like Figure 2, but after the complete penetration of the

Elastomer disk;

Section through the front portion of the cylinder-piston unit after delivery of the injection solution;

Cut through the elastomeric disc bonded to the skin after removal of the injector;

perspective view of the projecting from the elastomer disc short cannula;

perspective view of a short-necked tube with a tapered tip;

Perspective view of a short cannula with square cross section. FIG. 1 shows a cylinder-piston unit (10) of a disposable injector. The cylinder-piston unit (10) consists of a cylinder (20) and an example two-piece piston (80). The cylinder (20), at its front end one of a

Adhesive disc (110) carries sealed and protected short cannula (61)

for example, additionally surrounded by a protective housing (150). Above the piston (80), the lower part of a piston actuating punch (7) is shown, which belongs to the disposable injector, not shown here. The cylinder (20) is fastened to the injector by means of its external thread (22) present in the rear region or by means of slots (23). Between the cylinder (20) and the protective housing (150), an adhesive disk (110) is additionally arranged in the cylinder bottom area.

The e.g. one-piece cylinder (20) consists of a housing adapter (21), a

Pipe section (28) and a bottom portion (33). The housing adapter (21) fixes the cylinder (20) in an injector housing (not shown). For this purpose, its radial outer wall on an external thread (22) and at least two opposing slots (23). The slots (23) have e.g. a depth of 2 mm. They are located at the end of the thread in the immediate vicinity of the pipe section (28). The width of the slots (23) is e.g. 0.6 mm.

Between the slots (23) and the pipe section (28) is a

Stop ridge (24) whose outside diameter is e.g. identical to the

Thread outside diameter can be. The outside diameter of the

Pipe section (28) is more than twice the diameter of the

Inner wall (31).

To the housing adapter (21) closes the cylinder wall (29) of the

Pipe section (28). The cylinder wall (29) along the pipe section length, for example, a constant wall thickness of 3.25 mm. The bottom section (33) comprises an outwardly flat bottom plate (34), which corresponds to the average wall thickness of the cylinder wall (29) in the region of the pipe section (28). In the outer region of the bottom plate (34), for example, a cylindrical tube-shaped annular web (51) is integrally formed. The ring bridge (51), the one

Adhesive disk receiving space (53) spans, for example, as high as the wall thickness of the bottom plate (34). The height is e.g. 3 mm. The wall thickness of the annular web (51) is about one third of the wall thickness of the cylinder wall (29) of the pipe section (28).

The cylinder inner wall (31) is cylindrical at least in the pipe section (28). It has there, e.g. an inner diameter of 5.5 mm. In the region of the housing adapter (21), the cylinder inner wall (31) widens.

truncated cone-shaped on. The cone angle of this expansion (25) is e.g. 50 degrees. The length of the widening (25) corresponds to approximately one third of the length of the housing adapter (21).

In the area of the bottom section (33), the cylinder inner wall (31) terminates in a cylinder bottom (45) whose cone angle is e.g. 160 degrees is. In the center of the bottom portion (33) a short cannula (61) is arranged. Its center line runs e.g. congruent to the center line (5) of the cylinder-piston unit (10). The short cannula (61) extends in the bottom portion (33) e.g. between the cylinder bottom (45) and the flat end face (46). It is either inserted during the injection process of the cylinder (20) in its injection mold for mounting or it is subsequently pressed or glued into the finished cylinder (20).

The short cannula (61) is, for example, a thin-walled tube (62), which is produced, for example, from a stainless steel. It has, for example, an outer diameter of 0.5 mm. The wall thickness is usually 0.05 mm, 0.06 mm or 0.07 mm, cf. DIN 13097-4, appendix A, issue August 2009. The cannula (62) has at its free, front End including a single cut, a facet cut or a

Relief. The respective main grinding angle is between 9 and 18 degrees, cf. DIN 13097-4, appendix B, issue August 2009. In the present case, a main grinding angle of 18 angular degrees, cf. Figure 1, or an even larger angle preferred because with increasing angle, the maximum length of the opening cross section is smaller. According to Figures 2 and 3, the angle is 45 degrees.

The cannula tip (64) is dependent on the wall thickness and elasticity of the adhesive disc (110) used - e.g. 1 to 1, 5 mm over the ring web (51) over.

Between the short cannula (61) and the annular web (51), according to FIG. 1, an adhesive disc (110) is arranged in the front region of the adhesive disc receiving space (53). It has a material thickness at least 0.4 mm larger than the depth of the

Adhesive Disk Storage Room (53). According to FIG. 1, the adhesive disc (110) is attached to the short cannula (61) in such a way that it does not penetrate the front third of the adhesive disc (110). As a result, in front of the tip (64) there is a sealing area (117) closing the short cannula (61) at the front.

The substantially cylindrical outer wall of the adhesive disk (110) is guided on the cylindrical inner wall (52) of the annular web (51). According to FIG. 1, the adhesive disk (110) has a radial, for example, in the upper area of its outer wall. 0.5 mm, protruding circumferential web (123), via which it rests elastically on the front inner edge (59) of the annular web (51).

For positioning of the adhesive disk (110) on the annular web (51) of the bottom portion (33), the latter can also have a radially inwardly projecting web formed in the front region of the annular web (51) and inserted in a corresponding annular groove

Adhesive disc (110) protrudes elastically. The adhesive disk (110), for example made of rubber or another elastomer, is provided with an adhesive layer (121) consisting of a pressure-sensitive adhesive, for example, on its flat front end face. The remaining surface areas have a good lubricity, since the adhesive disk (110) is treated or teflonized at least partially with silicone oil. The adhesive of the adhesive disc (121) is designed so that its adhesive force to the adhesive disc (110) is greater by at least 50% compared to a disinfected skin surface (201).

Possibly. the adhesive disk (110) laterally has at least one notch oriented parallel to the center line (5) which, upon insertion of the sliding disk (110) into it

Adhesive disc receiving space (53) allows the existing air easily displace. The air can also be connected to the ring bridge (51) near the

End face (46) of the bottom portion (33) arranged bore escape.

Figures 2 and 3 show a short cannula (61) having a wall thickness of 0.05 mm with an outer diameter of 0.5 mm and which has a single cut with a bevel angle of e.g. 45 degrees. According to FIG. 2, the needle tip (64) is just in the adhesive disc (110) during the pressing of the injector onto the patient skin (200).

According to FIG. 3, the short cannula (61) has reached its application depth. By the attachment of the adhesive disc (110) on the skin surface (201), the short cannula (61) has penetrated so deeply that its outlet opening (71), cf. Also Figure 6, in the upper region of the dermis (205) opens. The outlet opening (71) has an elliptical border (72) in the single cut. The farthest, ground-level point (74) of this

The border (72) has passed through the horny layer (203). The foremost point (73) is positioned in the dermis (205) according to FIG. The area centroid (77) of the area (71) enclosed by the border (72) is only at the transition of the epidermis (202) to the dermis (205) by way of example. This is the ground level point (74) of the End face (113) of the adhesive disc (1 0) in the range of 0.15 0.3 mm away.

If the short cannula (61) in a cylinder-piston unit (10) are used, which uses neither an adhesive disc (110) nor a ring land (51), the projecting

Short cannula (61) out of the front face of the cylinder. If this

If the end face is arched or cone-shaped, the distance dimension (0.15-0.3 mm), instead of a flat surface (113), is related to the edge corresponding to the penetration curve of the short cannula (61) and the cylinder end face.

Is instead of a short cannula (61) with a circular cross-section a

Short cannula used with rectangular or square cross-section, cf. For this figure 8, the front (73) and the rear point (74) by a near-ground (76) and a front edge (75) is replaced.

FIG. 7 shows a short cannula (61) whose front end has a cannula taper (63) shortly before the cut (65) or in front of the outlet opening (71). In the area of the taper (63) the diameter is e.g. 0.1 mm smaller than in the rear needle area. The front generated, for example, by material diving

Needle section has a minimum length which is in the range of half to twice the needle diameter.

A pot-shaped protective housing (150), a sterile closure surrounds according to Figure 1, the pipe section (28) and the bottom portion (33) with the inserted

Adhesive disc (110) of the cylinder (20). It consists of a tubular

Sheath (151) and a flat bottom (152). In the embodiments shown, the protective housing (150) is made, for example, from the plastic cycloolefin copolymer (COC) due to its shape. This material has a particularly low Gas and water vapor permeability. For a simpler design, the protective housing (150) can be made of glass.

In the region of the pipe section (28), the distance between the

Outer wall (32) of the pipe section (28) and the inner wall (155) of the

Protective housing (150) e.g. 1, 5 mm. The axial distance between the bottom (152) of the protective housing (150) and the adhesive disk (110) is according to FIG. 1 e.g. 1 mm.

On the cylinder (20), the protective housing (150) is releasably fixed in two places. The first point is at the transition between the pipe section (28) and the stop web (24) of the cylinder (20). There is, according to Figure 1, a in a notch of

Cylinder (20) seated O-ring (161) over which the protective housing (150) relative to the cylinder (20) is sealed. At the same time the O-ring (161) centers the

Protective housing (150) on the cylinder (20). Instead of a conventional O-ring (161), a quadring, a profile ring or the like can be used.

The sealing ring (161) is clamped during assembly between the protective housing (150) and the cylinder (20), so that it can easily take over a centering and holding function in addition to the sealing function. Possibly. the sealing ring (161) can also be replaced by a sealing, viscous adhesive.

The second point for supporting the protective housing (150) on the cylinder (20) is located in the bottom (152) of the protective housing (150). For radial support, the protective housing (150) comprises e.g. five radially oriented support ribs (159). This am

Circumference of the shell (51) equidistantly distributed support ribs (159) are formed, for example, on the bottom (152) and on the jacket (151). The support ribs (159) have radial inner surfaces, with which they on the cylindrical outer surface (119) of the

Adhesive disc (110) abut. For axial support of the adhesive disc (110) is also on the bottom (152) a

annular support web (153) arranged, which rests with its upper, circular edge on the adhesive disk (110), in the central region thereof. The edge is in this case so narrow that it develops only a slight adhesive force with respect to the adhesive disk (110).

According to Figure 1, the cylinder (20) is filled with an injection solution (1). Of the

Liquid level (2) of the injection solution (1) is located in the transition region between the housing adapter (21) and the pipe section (28). On the

Liquid level (2) is bubble-free and sterile disc-shaped sealing body (100) placed on the sealing under a radial clamping action on the

Cylinder inner wall (31) is applied. Behind the sealing body (100) a cup-shaped drive body (81) is arranged. The propellant body (81) partially rests on the sealing body (100) or it is at a distance of e.g. 0.2 to 0.5 mm.

The sealing body (100) is here a disc whose undeformed diameter e.g. twice as big as its slice thickness. At the periphery, for example, the disc (100) has a groove profile (107), e.g. has two grooves (108). The

Grooved profile (107) is here, for example, designed so that the sealing body (100) in cross-section on both sides as a sectional profile has a wavy line with two, the grooves (108) forming troughs. The wavy line here is circular arcs

composed.

Since the sealing body (100) is an elastomer body, the wave crests of the set sealing disc are flattened, cf. FIGS. 1 and 4.

The pot-shaped drive body (81) whose length corresponds, for example, its outer diameter, consists of a disk-shaped impact plate (83) and a molded apron (90), the thickness of the impact plate (83) is slightly larger than the length of the skirt (90), see. FIG. 1

The impact plate (83), on the triggering of the disposable injector

Piston actuation punch (7) hits, has at least one e.g. central

Bore (97), which located in front of and behind the drive body (81)

Cylinder space areas (11, 12) with each other with minimal throttle effect connects. The bore (97) whose minimum diameter is between 1 and 2 mm ends according to the embodiments at the rear end face (85) of the drive body (81), e.g. in a channel cross (88) of two channels intersecting in the area of the bore (97). The channels of the channel cross (88) each have a semicircular cross section, the diameter of the cross sections being e.g. corresponds to the diameter of the bore.

At the front end face (84) of the striking plate (83), the skirt formed as an elastic sealing lip (90) connects. The wall of the skirt (90) tapers, starting from the end face (84), towards the front, outer sealing edge (91), which bears elastically against the cylinder inner wall (31) in each operating state of the injector. When installed, the skirt (90) and the front enclose

Front side (84) an immersion cavity (96). The latter essentially has the shape of a truncated cone whose cone angle is e.g. Measures 20 degrees.

The combination of the drive body (81) and the sealing body (100), the

Piston (80), allows a simple bubble-free filling and a sterile closing of the cylinder-piston unit (10) in conjunction with a

Ejecting process when triggering the disposable injector, the very high

Compaction shock of up to 350 * 10 ⁵ Pa withstands. When the injector is prepared for injection, the protective housing (150) is withdrawn forward of the cylinder (20), eg, by manual force. This remains the

Adhesive disc (110) in the bottom portion (33) of the cylinder (20) adhere. Also, the sealing ring (161) remains on the outer wall (32) of the cylinder (20) back.

In order to be able to carry out the application of the injection solution, the injector with the adhesive disk (110) is placed in advance on the skin surface (201) of the patient. In this case, the adhesive disc (110), which is still in its installed position (111), adheres via its adhesive layer (121) to the skin surface (201).

By the contact pressure of the injector, the adhesive disk (110) is loaded, with overcoming the blocking effect of the circumferential web (123) and with a piercing of the adhesive disc (110) - along the short cannula (61) in the direction of the bottom portion (33) slips to with its rear end face (115) on the end face (46) of the bottom portion (33) to apply. The adhesive disk (110) is now in its application position (112). She now fills the

Adhesive disc receiving space (53) completely made. For example, she stands in front 0.5 mm over the annular web (51). In the Anpressvorgang is by increasing the

Pressure on the one hand, the bonding between the adhesive layer (121) and the skin of the patient reinforced and on the other, the short cannula (61) protrudes a few tenths of a millimeter from the adhesive disc (110), see. Figures 3 and 4, in the

Skin (200).

At the same time, the injector is triggered by pressing on the skin (200). The e.g. preloaded by means of a mechanical or pneumatic spring

Piston actuation plunger (7) abruptly loads the two-part piston (80) in order to introduce the injection solution (1) via the short cannula into the upper layers of the skin (200) of the patient, cf. FIG. 4. The generated inflow channel (211), which is formed by the liquid jet shooting out of the short cannula (61), usually ends only in the

Subcutaneous tissue (206). In the fatty tissue rich in capillaries

Connective tissue of the subcutis (206) then forms an injection solution accumulation (210) fed by the liquid jet, cf. FIG. 5.

This pressurized injection solution pool (210) will at least substantially empty itself via the inflow passage (211) as the injector is lifted off the skin (200) with all its parts. In the present case, after removing the injector, the adhesive disk (110) remains behind due to its adhesive layer (21) until it is removed separately.

The opening of the elastomeric body (110) initially punctured by the short cannula (61) closes completely immediately after the removal of the injector. The patient removes the adhesive disc (110) - including the adherent

Adhesive layer (121) - only when the injection-related curvature of the

Skin (200) has largely regressed. This is the case when the

Injection solution (1) into which the injection solution accumulation (210) surrounding

is.

LIST OF REFERENCE NUMBERS

1 injection solution

2 liquid levels

3 Arrow direction for injector release

5 center line

7 piston actuating punch

9 Environment 10 cylinder-piston unit

11 cylinder chamber area, in front of the piston

12 cylinder space area, behind the piston

20 cylinders

21 housing adapter

external thread

ring groove

stop web

Expansion, inside

pipe section

cylinder

Inner wall, radial

Outer wall, radial

bottom section

baseplate

Edge on (46)

Cylinder bottom, inside of the cylinder bottom End face of the bottom section, front ring bridge

Inner wall, cylindrical

Adhesive disk recording room

Edge, front

Short cannula, miniature needle

cannula tube

cannula rejuvenation

cannula tip

Cut, single cut

Outlet opening, exit surface

Edge of the exit surface, border point, front

Point, behind, near the ground

Edge, front

Edge, behind, ground level

Center of gravity of the exit surface

Piston, combination of (81) and (100)

Blowing body; Body, cup-shaped

impact plate

Front side, front

Front side, rear

cross channel Apron, elastic; sealing lip

Sealing edge, edge

Flattening, notch

Immersion cavity, cavity

Recess, bore, central sealing body, sealing washer

Front side, rear

Outer wall, profiled

groove profile

Groove adhesive disc, elastomeric disc

installation position

application position

Front side, front; Face, flat surface

Front side, rear

sealing area

Outer surface, radial Adhesive layer, front, pressure-sensitive adhesive, adhesive coating Circular bar Protection uss sheath, tubular

Floor, plan

Support bridge, inside

Inside wall

support ribs O-ring skin

skin surface

epidermis

Horny layer (stratum corneum)

Horn formation and regeneration layer Papillary and plexus layer (dermis) Subcutis (subcutis) Injection solution collection

inflow

Claims

LTS Lohmann Therapy Systems AG

Cylinder-piston unit with short cannula

claims:

1 cylinder-piston unit (10), with at least one injection solution

receiving cylinder (20) with outlet opening (71) and at least one piston (80),

characterized,

- That the cylinder (20) or a cylinder (20) upstream component (110) has an end face (46, 113) from which protrudes during normal emptying of the cylinder-piston unit (10), a short cannula (61) has an outlet opening (71) at its free end;

- That the outlet opening (71) has a surface whose border (72) has a ground-level point (74) or a near-bottom edge (76) and

- That the ground-level point (74) or the near-bottom edge (76) from the end face (46, 113) or the foremost point or edge (44) is 0.15 - 0.3 mm away.

2. Cylinder-piston unit according to claim 1,

characterized,

the flow cross section of the short cannula (61) is in a range of 0.03 to 0.1. Cylinder-piston unit according to claim 1

characterized,

that the short cannula (61) at the front has a single cut with short-cut design according to DIN 13097-4, August 2009.

Cylinder-piston unit according to claim 1,

characterized,

in that a component upstream of the cylinder (20) is an elastomer disc (110) which is attached to the short cannula (61) and / or to the bottom portion (33) of the

Cylinder (20) in the direction of the center line (5) of the cylinder-piston unit (10) longitudinally guided between an installation position (11) and a

Application position (112) is arranged slidably.

Zyfinder piston unit according to claim 4,

characterized,

that the elastomeric disc (110) in the installed position (111) at least one sealing element or a sealing region (117) for closing the

Short cannula (61) whose effect in the application position (112) is no longer present.

Cylinder-piston unit according to claim 4,

characterized,

in that the elastomeric disc (110) adjoins the bottom portion (33) of the

Cylinder (20) facing away from end face (113) has an adhesive coating (121).