WO2017076634A2

WO2017076634A2 - Dispensing device with lateral inlet port and advancement mechanism

Info

Publication number: WO2017076634A2
Application number: PCT/EP2016/074952
Authority: WO
Inventors: Andy Greter
Original assignee: Medmix Systems Ag
Priority date: 2015-11-06
Filing date: 2016-10-18
Publication date: 2017-05-11
Also published as: WO2017076634A3

Abstract

A dispensing device comprises a hollow syringe body (100) and a plunger (200). A lateral inlet port (120) is provided for transferring a flowable product into a reservoir inside the syringe body. A check valve (600) in the port permits transfer of the product into the reservoir while preventing the product from leaking from the reservoir. The plunger has a portion configured as a toothed rack (211). An advancement mechanism (140) for the plunger comprises a spring element (141) having an outwardly bent arcuate shape, which engages the toothed rack. Deformation of the spring element into a flattened configuration causes the spring element to advance the plunger in the distal direction. An actuator element (144) converts axial pressure into lateral pressure onto the spring element to advance the plunger.

Description

TITLE DISPENSING DEVICE WITH LATERAL INLET PORT AND ADVANCEMENT

MECHANISM

TECHNICAL FIELD The present invention relates to a syringe-like dispensing device, i.e., a dispensing device comprising a hollow syringe body having a distal syringe outlet and a plunger that is axially displaceable inside the syringe body to expel a flowable product from the syringe body. PRIOR ART

In medicine it is often necessary to transfer a flowable product from a container such as an ampoule or vial into a syringe for application to the human body. Examples include cyanoacrylic tissue adhesives, which are often stored in single-dose ampoules in the form of collapsible tubes. The amount of tissue adhesive contained in each ampoule can be rather small, a typical volume being only 0.5 milliliters. The collapsible tube has a dispensing tip for directly applying the tissue adhesive to lesions of the skin after removing an integrally formed closure cap from the dispensing tip. If, however, the adhesive is to be applied laparoscopically, the adhesive first needs to be transferred to a syringe-like laparoscopic applicator.

Traditionally, flowable products are aspirated into syringes through the distal syringe outlet by retracting the plunger from the syringe body. This, however, can cause significant amounts of air to be trapped inside the syringe, and the air must be purged from the syringe before the product can be expelled from the syringe. If the reservoir inside the syringe has a small cross section of only a few square millimeters, purging the air from the syringe might prove difficult or even impossible because air bubbles will then tend to stay trapped in the syringe due to capillary forces. Another disadvantage of the traditional method of aspirating the product is that usually adapters are needed to transfer the product from a container like an ampoule or vial into the syringe in this manner. Such adapters are usually connected to the syringe via a standard Luer connection. This entails significant dead volumes. With small-volume syringes, the dead volume sometimes exceeds the effective volume that can eventually be dispensed from the syringe at the desired location.

It is further desirable to be able to dispense exactly metered amounts of the flowable substance from the dispensing device after the flowable substance has been transferred into the device. This is particularly desirable for syringe-like dispensers holding comparatively small volumes, e.g., below 1 milliliter, as for instance dispensers for tissue adhesives, since it is notoriously difficult to dispense exactly metered fractions of such small volumes.

SUMMARY OF THE INVENTION In a first aspect, it is an object of the present invention to provide a syringe-like dispensing device that enables a simple transfer of a flowable product into the device while minimizing dead volume.

This object is achieved by a dispensing device having the features laid down in claim 1. Further embodiments of the invention are laid down in the dependent claims.

Accordingly, a dispensing device is provided, comprising:

a hollow syringe body;

a plunger that is axially displaceable inside the syringe body along a distal direction between an initial position in which the plunger delimits a reservoir within the syringe body and a final position in which the piston has been fully advanced along the distal direction to minimize a volume of the reservoir.

In order to facilitate the transfer of a flowable product to the reservoir inside the syringe body, the syringe body comprises a lateral inlet port for transferring the product into the reservoir while the plunger is in its initial position, the lateral inlet port comprising an inlet opening arranged in a circumferential sidewall of the syringe body. By providing a lateral inlet port, a product can be transferred into the reservoir in the syringe body by positive pressure. When the product enters the reservoir, it expels the air that is present in the reservoir through the distal outlet opening of the syringe body. Thereby, any air present in the reservoir is automatically expelled from the reservoir, and a purging operation can be dispensed with.

The inlet opening is arranged distally from the plunger when the plunger is in its initial position, advantageously immediately adjacent to a distal end surface of the plunger, more particularly, less than 10 mm away from the distal end surface, preferably less than 5 mm away from the distal end surface. More particularly, the distance between the inlet opening and the distal end of the plunger is preferably less than the diameter of the reservoir, preferably even less than half the diameter of the reservoir, in order to avoid that air bubbles can get trapped between the inlet opening and the plunger. In order to avoid leaking of the substance from the dispensing device after the transfer has been completed, the dispensing device can further comprise a check valve or one-way valve arranged in the lateral inlet port, the check valve permitting transfer of the product into the reservoir through the lateral inlet port while preventing the product from leaking from the reservoir through the lateral inlet port after transfer of the product has been completed. The check valve is preferably arranged outside the reservoir and, in particular, outside a circumferential side wall of the syringe body.

The lateral inlet port is advantageously configured to receive an injection tip (i.e., a rigid tubular structure), which may be an integral part of a container holding the product, for introducing the product into the reservoir. The check valve is then preferably configured to be penetrated by the injection tip so as to allow direct access of the injection tip to the inlet opening for transferring the product into the reservoir.

To enable easy penetration of the check valve by the injection tip, the check valve can comprise at least two elastomeric lips configured to touch one another so as to close the check valve in a closed configuration, and the check valve can be arranged in such a manner that the lips are capable of being separated from one another by the injection tip when the injection tip is inserted into the lateral inlet port. In particular, the check valve can be a duckbill valve or a cross-slit valve, both valve types per se being well known in the art.

In order to receive the injection tip in a defined manner, the lateral inlet port can comprise a depression in the outer surface of the circumferential sidewall of the syringe body directly above the inlet opening, the depression being configured (in particular, dimensioned) to receive a free distal end of the injection tip directly above the inlet opening so as to minimize dead volume when the product is transferred into the reservoir. In order to prevent any leaking during the dispensing operation, the plunger can be configured to sealingly cover the inlet opening from the inside of the syringe body when the plunger is axially displaced from the initial position in the distal direction.

The dispensing device can be configured as an endoscopic, in particular laparoscopic, applicator. To this end, the dispensing device can comprise a cannula for transferring the product from the syringe body to a point of application inside a human or animal body. In particular, the cannula can be dimensioned to be passed through a trocar. The cannula can comprise an elastomeric tube defining a fluid channel, the elastomeric tube being radially surrounded by a rigid sleeve. In order to minimize the dead volume at the interface between the syringe body and the cannula, the syringe body can have a distal end in which an axial blind hole is formed, the elastomeric tube being received in the blind hole, the syringe body having a distal outlet opening with reduced cross section (i.e., with a cross section that is smaller than the cross section of the blind hole), the distal outlet opening being formed in a distal end portion of the syringe body, the distal outlet opening connecting the reservoir and the fluid channel of the elastomeric tube in the blind hole so as to transfer a product from the reservoir into the fluid channel when the plunger is advanced along the distal direction.

In a second aspect, it is an object of the present invention to provide a syringe-like dispensing device that facilitates the dispensing of small amounts of the product in a simple manner.

This object is achieved by a dispensing device having the features laid down in claim 9. Further embodiments are laid down in the dependent claims. The first and second aspects of the invention can be readily combined in a single dispensing device.

Accordingly, a dispensing device is provided, comprising:

a hollow syringe body;

a holding structure fixedly connected to the hollow syringe body, the holding structure preferably being configured to facilitate holding the syringe body with a hand of a user; and

a plunger that is axially displaceable inside the syringe body along a distal direction, in particular, between an initial position in which the piston delimits a syringe volume within the syringe body and a final position in which the plunger has been fully advanced along the distal direction to minimize the syringe volume.

In order to facilitate the dispensing of small amounts of the product, the plunger has a portion configured as a toothed rack, and the dispensing device comprises an advancement mechanism for the plunger, the advancement mechanism comprising:

a spring element having a proximal end that is connected to a proximal end portion of the syringe body and a distal end that engages the toothed rack of the plunger, the spring element having an outwardly bent arcuate shape between the proximal end and the distal end and being elastically deformable into a flattened configuration by lateral pressure onto the spring element, and the spring element being configured in such a manner that deformation of the spring element into the flattened configuration causes the distal end of the spring element to advance the plunger in the distal direction; and

an actuator element having a fixed end that is connected to the holding structure and a movable end which is configured as a contact region for contact with the spring element, the actuator element being configured in such a manner that axial pressure onto the actuator element in the distal direction causes the movable end to move radially inward towards the spring element and to exert lateral pressure onto the spring element so as to deform the spring element into its flattened configuration.

In other words, the actuator element (or at least part of it) swivels towards the spring element in response to manual axial pressure so as to laterally act on the spring element and to thereby deform the spring element, which in turn thus advances the plunger. By the cooperation of the actuator element and the spring element, a relatively large swing of the actuator element can be transformed into a comparatively small travel of the plunger in a highly controlled manner. In advantageous embodiments, the actuator element extends, from its fixed end towards its movable end, in an inclined direction, the inclined direction having an axial component extending opposite to the distal direction and a radial component extending radially inwards towards the plunger. In other words, the actuator element can extend along an inclined direction pointing both in a backward direction and towards the plunger. The actuator element can have the shape of a (possibly bent) elastic bar or plate, i.e. it can have a very simple structure.

In order to limit the axial and radial movement of the actuator element when pressure is exerted on it, the actuator element can comprise a stop element configured to abut to the holding structure or to the syringe body so as to limit movement of the movable end of the actuator element when the actuator element is pressed in the distal direction. Since the actuator element cooperates with the spring element to expel the product from the reservoir, the configuration of the stop element determines the amount of product that is dispensed by each stroke of the actuator element. In this manner, an exactly metered amount to be dispensed with each stroke is defined.

In a particularly simple embodiment, the fixed end of the actuator element is fixedly connected to the holding structure, and at least a connection region of the actuator element adjacent to its fixed end is elastically deformable so as to allow a swiveling movement of the movable end of the actuator element against an elastic restoring force in response to axial pressure in the distal direction. In other embodiments, the restoring force may be generated by a separate compression spring, which may be arranged, e.g., between the holding structure and the actuator element. The holding structure may comprise a lateral flange that laterally projects from the syringe body in a region that is arranged distally from the spring element, and the fixed end of the actuator element is connected to the lateral flange. The dispensing device can be manufactured in a particularly simple and cost-effective manner if the spring element is made in one piece (i.e. integrally formed) with the syringe body, and/or if the holding structure is made in one piece with the syringe body, and/or if the actuator element is made in one piece with the holding structure. In particular, the entire unit consisting of the syringe body, the lateral inlet port, the holding structure, the spring element and the actuator element can be made in one piece, for instance by injection molding.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described in the following with reference to the drawings, which are for the purpose of illustrating the present preferred embodiments of the invention and not for the purpose of limiting the same. In the drawings, Fig. 1 shows a perspective view of a laparoscopic applicator;

Fig. 2 shows an exploded view of the applicator in Fig. 1 ;

Fig. 3 shows a central longitudinal sectional view of a portion of the applicator in

Fig. 1;

Fig. 4 shows a central longitudinal sectional view of the portion in Fig. 3 after insertion of an injection tip;

Fig. 5 shows a central longitudinal sectional view of a portion of the applicator in

Fig. 1 during the dispensing operation;

Fig. 6 shows a perspective view of a portion of the applicator together with an ampoule in the form of a collapsible tube during filling of the applicator; Fig. 7 shows a perspective view of a portion of the applicator together with the ampoule and a squeezer;

Fig. 8 shows a side view of a portion of the applicator in an initial position;

Fig. 9 shows a central longitudinal sectional view of a portion of the applicator during the dispensing operation;

Fig. 10 shows a central longitudinal sectional view of a portion of the applicator at the interface between the syringe body and the cannula; and Fig. 11 shows a central longitudinal sectional view of a distal end portion of the applicator. DESCRIPTION OF PREFERRED EMBODIMENTS

In Figures 1 to 11 , an embodiment of a dispenser or applicator 1 according to the present invention is illustrated in several views. As apparent from Figures 1 and 2, the applicator comprises a syringe body 100, a plunger 200, a cannula 300, a dispensing tip 400, a protective sleeve 500, and a check valve (one-way valve) 600.

The syringe body 100 comprises a lateral inlet port 120 for transferring a flowable product into a reservoir in the interior of the syringe body 100, as will be described in more detail in conjunction with Figures 3 to 7. A holding structure 130 is integrally formed with the syringe body 100. The holding structure 130 comprises a first flange 131 on the lower side of the syringe body 100, on which a ring structure 132 for receiving one or two fingers of the user is formed, and a second flange 133 on the upper side of the syringe body 100. An advancement mechanism 140, to be described in more detail below in conjunction with Figures 8 and 9, is integrally formed with the syringe body 100 and the first flange 131.

The plunger 200 is slidingly received in the syringe body 100 for axial displacement along a distal direction D. The distal end 212 of the plunger 200 is configured as a piston, which sealingly delimits a reservoir in the interior of the syringe body 100. The plunger has a portion configured as a toothed rack 211, the toothed rack 211 extending over most of the length of the plunger 200. The teeth of the toothed rack 211 have a sawtooth shape, with a comparatively flat leading flank and a much steeper trailing flank. At its proximal end, the plunger 200 is provided with a thumb rest 213.

The cannula 300 is connected to the distal end of the syringe body 100, as will be shown in more detail in Fig. 10. It comprises a rigid sleeve 310 made of stainless steel, in which an elastomeric tube 320 made of silicone rubber is received. The dispensing tip 400 is connected to the distal end of the cannula 300, as will be shown in more detail in Fig. 11.

The protective sleeve 500 is made of an elastomeric material like silicone rubber. It is significantly shorter than the cannula 300. At its proximal end, it is provided with a circumferential collar 511. The protective sleeve 500 serves to protect a trocar (not shown in the drawings) from being contaminated with a tissue adhesive that is to be dispensed by the applicator 1. To this end, the protective sleeve 500 will initially be in the position shown in Fig. 1, i.e. arranged immediately adjacent to the distal end of the syringe body, the circumferential collar 511 abutting to the distal end of the syringe body 100. The applicator will be inserted into the trocar in this configuration. When the adhesive has been applied and the applicator is retracted from the trocar, the protective sleeve 500 will remain in the trocar until the applicator has been completely removed from the trocar, and will be retracted from the trocar only thereafter. In this manner, any adhesive that might still be present on the dispensing tip 400 will only contaminate the protective sleeve 500, while the trocar will be kept clean.

In Figures 3 to 7, the lateral inlet port 120 and the check valve 600 are illustrated. The lateral inlet port 120 is arranged on the circumferential sidewall 110 of syringe body 100. It comprises a transfer opening 124 in the sidewall 110 immediately adjacent to the distal end 212 of the plunger 200. Above the transfer opening 124 along the radial direction and concentrically with the transfer opening, a recess or depression 123 in the form of a blind hole is arranged. A cylindrical wall 121 extending laterally away from the syringe body 100 concentrically surrounds the depression 123 at a certain distance. At its upper end, the cylindrical wall 121 has an annular inner step structure 122.

The check valve 600 is inserted into the lateral inlet port 120. In the present embodiment, the check valve 600 is a duckbill valve, as it is well known in the art. A duckbill valve is manufactured from an elastomeric material like silicone rubber and is shaped like the beak of a duck. It is commonly used in medical applications to prevent backflow. In the present embodiment, the check valve 600 comprises an annular circumferential collar 610, which is received in the complementary annular step structure 122 of cylindrical wall 121 and from which two elastomeric lips 621 extend downwardly towards the depression 123 and the transfer opening 124. The lips 621 touch one another so as to close the check valve in a closed configuration. When pressure is applied from above, the lips open, and fluid can pass through the valve 600 and through the transfer opening 124 into the reservoir 101 in the interior of syringe body 100. If, on the other hand, pressure is applied from below, the lips will remain closed and will prevent fluid from leaking from the lateral inlet port 120. Instead of a duckbill valve, another type of valve can be employed, for instance a cross slit valve, which has four elastomeric cuspids instead of two elastomeric lips. Figures 4 and 6 illustrate how a flowable product is transferred from an ampoule 700 in the form of a collapsible tube through the lateral inlet port 120 into the reservoir 101 and the inside of syringe body 100. The ampoule 700 has a dispensing tip 710, which here acts as an injection tip for injecting the product into the reservoir 101. To this end, the dispensing tip 710 is pushed through the duckbill valve 600 until its free end is received in depression 123. By exerting pressure on the collapsible tube of ampoule 700, the flowable product is transferred through the dispensing tip 710 and the transfer opening 124 into the reservoir 101. Since the free end of dispensing tip 710 is seated in circular depression 123 directly above transfer opening 124, dead volume is reduced to the absolute minimum possible. Once the product has been transferred from ampoule 700 into the reservoir 101, dispensing tip 710 is retracted from the lateral inlet port 120. Thereby, duckbill valve 600 automatically closes, and the product is prevented from leaking to the outside through the lateral inlet port 120. Subsequently, the product is dispensed from the syringe body 100 by advancing plunger 200 in the distal direction D, as illustrated in Fig. 5. As soon as the plunger has been advanced by an amount that approximately corresponds to the diameter of the lateral inlet port 120, it sealingly covers transfer opening 124 from the inside of syringe body 100, thereby preventing any substance from leaking through transfer opening 124 altogether.

Fig. 7 illustrates a variant wherein a squeezer clip 800 is used to facilitate expulsion of the substance from ampoule 700. The squeezer clip 800 comprises a first wing 810 and a second wing 820 connected via a film hinge 801. The ampoule 700 is placed between the wings 810, 820, and the wings are compressed towards one another. A latch 811 keeps the wings in their compressed position.

Figures 8 and 9 illustrate the advancement mechanism 140. The advancement mechanism comprises a spring element 141 that is formed in one piece with the syringe body and has an outwardly bent arcuate shape. With its proximal end 142, the spring element is fixedly connected to a proximal end portion 113 of syringe body 100. With its free distal end 143, the spring element 141 engages the toothed rack 211 of the plunger 200. When lateral pressure is exerted on the spring element 141, the spring element elastically deforms from its outwardly bent arcuate shape shown in Fig. 8 into a more flattened (less bent) configuration as shown in Fig. 9. Since the free distal end 143 of the spring element 141 engages the toothed rack 211, the spring element will thus advance the plunger 200 in the distal direction. In order to facilitate the exertion of lateral pressure onto the spring element 211, the advancement mechanism further comprises an actuator element 144 that is connected to (and integrally formed with) the first flange 131 of the holding structure 130. The actuator element 144 has essentially the shape of an elastic bar or plate having a first end 145 that is fixedly connected to the flange 131 and having a slightly bent, movable second end 146 that is configured as a contact region for contact with the spring element 141. The plate-or bar-shaped portion of the actuator element 144 essentially extends away from the flange 131 along an inclined direction E, which has an axial component A that extends opposite to the distal direction D and a radial component R that extends radially inwards towards the plunger. As a consequence of this arrangement of the actuator element 144, axial pressure onto the actuator element 144 in the distal direction D causes the movable free end 146 to move radially inwards towards the spring element 141. In this manner, the actuator element 144 exerts lateral pressure onto the spring element 141, so as to cause an elastic deformation of the spring element into its flattened configuration and to thereby advance the plunger 200 in the distal direction. The overall effect of the actuator element 144 is therefore to convert manual axial pressure along the distal direction D into lateral pressure onto the spring element along a radial direction in order to axially advance the plunger 200.

In order to enable the dispensing of exactly metered amounts of the product from the syringe body 100, the actuator element 144 comprises a stop element 147 (here in the form of a nose or cam) that is configured to abut to flange 131 of the holding structure 130 when the actuator element 144 is pressed in the distal direction D. In this manner, the stop element 147 limits movement of the movable end 146 of the actuator element 144. In consequence, the spring element 121 will be compressed by an exactly defined the amount, and therefore the free end 143 of spring element 141 will move by an exactly defined amount. Thereby the plunger 200 will be advanced by an exactly defined amount, and an exactly defined amount of substance will be dispensed from the reservoir 101. Advantageously the amount by which the plunger 200 is moved corresponds to the distance between two adjacent teeth of the toothed rack 211, or to an integer multiple of this distance. The stop element 147 is formed in one piece with the rest of the actuator element 144.

Because of the elastic properties of the actuator element 144, in particular, of its connection region 148 (see Fig. 9), the actuator element 144 will automatically return to its initial position once pressure is released from the actuator element. Thereby, pressure will also be released from the spring element 141, and the spring element 141 will return to its original arcuate shape. Because of the sawtooth shape of the teeth of the toothed rack 211, the free end 143 of spring element 141 will slide backwards over the toothed rack 211 so as to engage with the next tooth.

In summary, by exerting axial pressure on actuator element 144 in the distal direction D until stop element 147 abuts to flange 133, plunger 200 is advanced by exactly one tooth of toothed rack 211 (or by exactly two, three, four etc. teeth).

Fig. 10 illustrates how the elastomeric tube 320 and the rigid sleeve 310 are connected to the distal end of syringe body 100. An inner axial blind hole 112 that is open in the distal direction D is formed in the distal end of syringe body 100. The proximal end of elastomeric tube 320 is received in inner blind hole 112. In the distal end portion of syringe body 100, a distal outlet opening 102 with reduced cross-section is formed, which opens out from reservoir 101 into inner blind hole 112. Distal outlet opening 102 thereby connects reservoir 101 and a fluid channel 321 in elastomeric tube 320 received in inner blind hole 112 so as to transfer the product from reservoir 101 into fluid channel 321 when plunger 200 is advanced. This configuration minimizes the dead volume, especially if compared to a traditional connection via a Luer cone. Rigid sleeve 310 is received in a concentrically arranged outer blind hole 111 that has larger diameter, but is less deep than inner blind hole 112. Fig. 11 illustrates how dispensing tip 400 is connected to elastomeric tube 320 and rigid sleeve 310. To this end, dispensing tip 400 has a holding structure 410 comprising a holding ring 411 that extends into the annular interspace between rigid sleeve 310 and elastomeric tube 320. Fluid channel 321 opens out into a fluid channel 401 of dispensing tip 400, which ends at an outlet 402.

It will be apparent from the above description that a large number of modifications are possible without leaving the scope of the present invention. In particular, the holding structure 130 can be configured in an entirely different manner. Different types of valves 600 may be used. The container from which the product is transferred into the applicator may be different from an ampoule in the form of a collapsible tube as shown in Figures 6 and 7. In particular, the container may itself be a syringe.

LIST OF REFERENCE SIGNS dispensing device 211 toothed rack syringe body 212 distal end reservoir 213 thumb rest distal outlet opening 300 cannula sidewall 310 rigid sleeve outer blind hole 320 tube

inner blind hole 321 fluid channel proximal end portion 400 outlet tip inlet port 401 fluid channel cylindrical wall 402 outlet step 410 holding structure depression 411 holding ring transfer opening 500 protective sleeve holding structure 511 collar first flange 600 check valve ring structure 610 collar second flange 611 inlet opening advancement mechanism 621 lip

spring element 700 ampoule proximal end 710 injection tip distal end 800 squeezer clip actuator element 801 film hinge lower end 810 first wing contact region 811 latch/snap arm stop element 820 second wing connection region

plunger

Claims

A dispensing device comprising:

a hollow syringe body (100);

a plunger (200) that is axially displaceable inside the syringe body (100) along a distal direction (D) between an initial position in which the plunger (200) delimits a reservoir (101) within the syringe body (100) and a final position in which the plunger (200) has been fully advanced along the distal direction (D) to minimize a volume of the reservoir (101),

characterized in that the syringe body (100) comprises a lateral inlet port (120) for transferring a flowable product into the reservoir (101) when the plunger (200) is in its initial position, the lateral inlet port (120) comprising an inlet opening (124) arranged in a circumferential side wall (110) of the syringe body (100).

The dispensing device of claim 1, wherein the reservoir (101) has a reservoir diameter, and wherein the inlet opening (124) is arranged at a distance from a distal end (212) of the plunger (200) that is less than the reservoir diameter when the plunger (200) is in its initial position.

The dispensing device of claim 1 or 2, wherein the dispensing device further comprises a check valve (600) arranged in the lateral inlet port (120), the check valve (600) permitting transfer of the product into the reservoir (101) through the lateral inlet port (120) while preventing the product from leaking from the reservoir (101) through the lateral inlet port (120) after transfer of the product has been completed.

The dispensing device of claim 3, wherein the lateral inlet port (120) is configured to receive an injection tip (710), and wherein the check valve (600) is configured to be penetrated by the injection tip (710) so as to allow direct access of the injection tip (710) to the inlet opening (124) for transferring the product into the reservoir (101).

5. The dispensing device of claim 4, wherein the check valve (600) comprises at least two elastomeric lips (621) configured to touch one another so as to close the check valve (600) in a closed configuration, and wherein the check valve (600) is arranged in such a manner that the lips (621) are capable of being separated from one another by the injection tip (710) when the injection tip (710) is inserted into the lateral inlet port (120).

6. The dispensing device of any one of the preceding claims, wherein the lateral inlet port (120) comprises a depression (123) in the circumferential sidewall (110) of the syringe body (100) directly above the inlet opening (124), the depression (123) being configured to receive a free distal end of the injection tip (710) directly above the inlet opening (124) so as to minimize dead volume when the product is transferred into the reservoir (101).

7. The dispensing device of any one of the preceding claims, wherein the plunger (200) is configured to sealingly cover the inlet opening (124) when the plunger (200) is axially displaced from the initial position in the distal direction (D).

8. The dispensing device of any one of the preceding claims, further comprising a cannula (300) comprising an elastomeric tube (320) defining a fluid channel (321) and a rigid sleeve (310) that surrounds the elastomeric tube (320), wherein the syringe body (100) has a distal end in which an axial blind hole (112) is formed, the elastomeric tube (320) being received in the blind hole (112), the syringe body (100) having a distal outlet opening (102) with reduced cross section, the distal outlet opening (102) being formed in a distal end portion of the syringe body (100), the distal outlet opening (102) connecting the reservoir (101) and the elastomeric tube (320) in the blind hole (112) so as to transfer a product from the reservoir (101) into the fluid channel (321) of the elastomeric tube (320) when the plunger (200) is advanced along the distal direction.

9. A dispensing device, in particular, the dispensing device of any one of claims 1-8, comprising: a hollow syringe body (100);

a holding structure (130) fixedly connected to the hollow syringe body (100); and

a plunger (200) that is axially displaceable inside the syringe body (100) along a distal direction (D),

characterized in that the plunger (200) has a portion configured as a toothed rack (211), and that the dispensing device further comprises an advancement mechanism (140) for the plunger, the advancement mechanism comprising:

a spring element (141) having a proximal end that is connected to a proximal end portion (113) of the syringe body (100) and a distal end that engages the toothed rack (211) of the plunger (200), the spring element (141) having an outwardly bent arcuate shape between the proximal end and the distal end and being elastically deformable into a flattened configuration by lateral pressure onto the spring element (141), and the spring element (141) being configured in such a manner that deformation of the spring element (141) into the flattened configuration causes the distal end of the spring element (141) to advance the plunger (200) in the distal direction; and

an actuator element (144) having a fixed end (145) that is connected to the holding structure (130) and a movable end (146) which is configured as a contact region for contact with the spring element (141), the actuator element (144) being configured in such a manner that axial pressure onto the actuator element (144) in the distal direction (D) causes the movable end (146) to move radially inward towards the spring element (141) and to exert lateral pressure onto the spring element (141) so as to deform the spring element (141) into its flattened configuration.

10. The dispensing device of claim 9, wherein the actuator element (144) extends, from its fixed end (145) towards its movable end (146), in an inclined direction (E), the inclined direction (E) having an axial component (A) extending opposite to the distal direction (D) and a radial component (R) extending radially inwards towards the plunger (200).

11. The dispensing device of claim 9 or 10, wherein the actuator element (144) comprises a stop element (147) configured to abut to the holding structure (130) or to the syringe body (100) so as to limit movement of the movable end (146) of the actuator element (144) when the actuator element (144) is pressed in the distal direction (D).

The dispensing device of any one of claims 9-11, wherein the fixed end (145) of the actuator element (144) is fixedly connected to the holding structure (130), and wherein a connection region (148) of the actuator element (144) adjacent to its fixed end (145) is elastically deformable so as to allow movement of the movable end (146) of the actuator element (144) against an elastic restoring force in response to axial pressure in the distal direction (D).

The dispensing device of any one of claims 9-12, wherein the holding structure (130) comprises a lateral flange (131) that laterally projects from the syringe body (100) in a region that is arranged distally from the spring element (141), and wherein the fixed end (145) of the actuator element (144) is connected to the lateral flange (131).

The dispensing device of any one of claims 9-13, wherein

the spring element (141) is made in one piece with the syringe body (100); and/or

the holding structure (130) is made in one piece with the syringe body (100); and/or

the actuator element (144) is made in one piece with the holding structure

(130).