LU92112A1 - Delivery nozzle for a jet injector and method of production - Google Patents

Delivery nozzle for a jet injector and method of production Download PDF

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Publication number
LU92112A1
LU92112A1 LU92112A LU92112A LU92112A1 LU 92112 A1 LU92112 A1 LU 92112A1 LU 92112 A LU92112 A LU 92112A LU 92112 A LU92112 A LU 92112A LU 92112 A1 LU92112 A1 LU 92112A1
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LU
Luxembourg
Prior art keywords
hollow tube
conduit
delivery nozzle
device according
device
Prior art date
Application number
LU92112A
Inventor
Gerrit Leon Theodor Henrie Spaas
Michael Kraly
Sergey Schroeder
Original Assignee
Gerrit Leon Theodor Henrie Spaas
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Gerrit Leon Theodor Henrie Spaas filed Critical Gerrit Leon Theodor Henrie Spaas
Priority to LU92112A priority Critical patent/LU92112A1/en
Priority to LU92112 priority
Publication of LU92112A1 publication Critical patent/LU92112A1/en

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Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178Syringes
    • A61M5/20Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically
    • A61M5/2046Media being expelled from injector by gas generation, e.g. explosive charge
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178Syringes
    • A61M5/30Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2207/00Methods of manufacture, assembly or production
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178Syringes
    • A61M5/30Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules
    • A61M5/3007Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules with specially designed jet passages at the injector's distal end

Description

DELIVERY NOZZLE FOR A JET INJECTOR AND METHOD OF PRODUCTION Technical field

The present invention relates to jet injector devices, which use a high velocity skin piercing liquid jet to deliver substances to a human or animal body. In particular, the invention relates to a delivery nozzle for use in a jet injector device and a method for producing such a delivery nozzle. A delivery nozzle is required to finely tune the velocity and steadiness of the delivered liquid jet, and is during operation in direct contact with the liquid that is to be delivered.

Background of the invention

It is well known to use classical syringes to deliver drugs or vaccines to a patient. A syringe is a mechanical device that comprises a tube or container chamber of generally cylindrical shape and a plunger that tightly fits into the tube. The plunger is arranged to slide inside the tube, thereby defining a simple pump.

If the tube comprises a liquid, pushing the plunger into the tube forces the liquid out of the tube through a delivery orifice. A fine hollow sterilized needle is fixed to the delivery office. As the needle is capable of piercing skin tissue, the liquid which is contained in the syringe’s tube may be delivered into a human or animal body. The injection depth of the substance can be adapted by inserting the needle until reaching the appropriate tissue depth or delivery site. As different substances need to be delivered to different delivery sites, the injection depth must be carefully chosen during each application. Every injection using a needle gives rise to a small wound in the skin tissue.

Using a manually operated syringe, it is not possible to generate liquid jet velocities that are high enough to pierce through the skin tissue. Jet injectors have been developed to overcome this drawback. A jet injector is a mechanical device which uses generally pressure-driven actuating means to propel the substance that is to be delivered to very high velocities. The velocities are high enough for the resulting fine liquid jet to pierce the tissue ceneath which the substance is to be delivered. The substance is then decelerated by the :issue, and arrives at the targeted delivery site.

Known jet injector devices use involved mechanisms to achieve the needed acceleration of the substance that is to be delivered. Typically, mechanical piercing means, such as a spring loaded hammer, are triggered. The mechanical constraint achieved by the hammer’s percussion induces a first explosive material to explode. The first material is often referred to as a primer. The explosion of the primer almost instantaneously ignites a second material having explosive properties, which generates a substantial volume of gas inside a variable volume chamber of the jet injector. The pressure of the generated gas pushes on a plunger, which in turn forces liquid to be delivered out of a container chamber of the injector. Finally a delivery nozzle ejects the liquid jet from the device. In comparison with a classical syringe as described above, the gas pressure replaces and amplifies the manual pressure on the plunger of the device. This allows for the generation of higher liquid jet velocities, resulting in a jet that is capable of piercing skin tissue.

The pressure profile generated by the second gas generating propellant generally follows the pressure profile of the shockwave that has been generated by the explosion of the primer, as schematically illustrated in Figure 1. A very high pressure peak at time tmax, marking the explosion at t0 is followed by a steady pressure decay. As a result, the force acting on the plunger that drives the liquid out of the container chamber is generally not applied continuously at the same intensity. Similarly, the generated jet velocity of the liquid stream is generally not steady and tends to decay over time. However, the injection depth of the substance that is to be delivered depends among other factors on the velocity of the injection jet when it contacts the skin. As the velocity is not constant, it is difficult to precisely target a specific tissue depth or delivery site using such a known jet injection device. Moreover, if the generated jet that contacts the skin is turbulent and not steady, it may not readily pierce the skin and some liquid may not enter the skin appropriately.

Furthermore, the containing chamber of the jet injector is required to withstand a very high internal pressure corresponding to the initial explosion peak. Provision and certification of material that is able to withstand such high pressures, and which is to be used in direct contact with injectable medicaments, are both costly and lengthy to obtain,

Technical problem to be solved

It is an object of the present invention to provide a delivery nozzle for a jet injector, and a corresponding jet injector, which overcome at least some of the disadvantages of the prior art.

Summary of the invention

According to a first aspect of the invention, an actuating device for a jet injection device is provided. The actuating device comprises ignition means that are configured to ignite a gas generating propellant in a controlled manner. The ignition means comprise an electrical heating element. As the propellant is ignited and consumed in a generally controlled manner, gas is generated at a generally constant rate during the timespan in which the propellant is consumed at a regular rate.

The gas generating propellant may preferably be comprised in a propellant chamber of said ignition means.

The propellant may preferably be nitrocellulose.

Advantageously, the electrical heating element may comprise a resistor connected to two electrodes. The resistor may preferably be arranged in direct contact with the propellant. The resistor may be connected to electrodes, which may be connected to a power source, for example a battery. The voltage difference between the electrodes leads to the circulation of an electrical current through the resistor, which is thereby heated. Alternatively, the voltage difference may be generated by other means, such as a piezo element, or an appropriate electrochemical reaction, for example.

Preferably, the device may further comprise a housing or body and an actuating piston, and the piston may be arranged to slideably move in said housing under the action of gas pressure generated by said propellant. The housing may preferably be made out of ceramics, of a plastic material, or of a metal. The term plastic material is used to signify any synthetically produced material, including material comprising carbon.

The housing may preferably have the general shape of a hollow cylinder, and the piston head of said piston may be arranged to provide a gas proof fit with the inner wall of the cylinder. A seal may preferably be provided on a circumference of said piston head in order to provide the gas proof fit.

According to a further object of the present invention, there is provided a jet injector device or injecting a liquid substance into a tissue. The device comprises a trigger for triggering actuating means, which are arranged for cooperating with a first end of a container chamber, and a delivery nozzle which is attached to a second end of said container chamber, and said actuating means conform to the present invention as described.

According to yet another aspect of the present invention there is provided a delivery nozzle for a jet injector. The delivery nozzle comprises a body, and an inlet leading into at least one conduit. Each conduit is defined by a hollow tube.

The inlet may preferably have a diameter corresponding to the outlet diameter of a drug containing ampule or cartridge. The diameter of the inlet may preferably be of at least 2 mm. Alternatively, the diameter may be of at least 5 mm. Each conduit may preferably have a length of at least 2 mm and an outlet diameter comprised between 0.05 mm and 1 mm. Alternatively, the conduit length may be of at least 5 mm. The outlet diameter of the conduit may alternatively be comprised between 0.05 mm and 0.5 mm.

Each conduit may preferably have a constant cross section and extend along a straight line.

The delivery nozzle body may preferably comprise an abutment surface comprising the opening of each conduit.

Each conduit may preferably be defined by a hollow tube, such as a needle made of metal. Each hollow tube may even more preferably be a needle that is certified for use in drug administration.

Preferably, the delivery nozzle body may have the general shape of a cylinder.

Each conduit may be arranged at an angle with respect to the axis of the cylinder

The body of the delivery nozzle may preferably be moulded from a metal or a plastic material. The material of the delivery nozzle’s body may alternatively be ceramic.

According to a further aspect according to the present invention, there is provided a jet injector device for injecting a liquid substance into a tissue. The device comprises a trigger for triggering actuating means, which are arranged for cooperating with a first end of a container chamber, and a delivery nozzle which is attached to a second end of said container chamber. The delivery nozzle conforms to the device of the present invention, as described.

Yet a further object of the present invention is a method for producing a delivery nozzle for a jet injector. The method comprises the steps of: - providing at least one hollow tube; - inserting said at least one hollow tube into a mould that is adapted for injection moulding a delivery nozzle body; - overmoulding said at least one hollow tube using a moulding material, thereby creating at least one conduit, which leads from the nozzle inlet to an outlet. Each conduit of the nozzle is formed by a hollow tube.

The moulding material may preferably be a metal, ceramic or plastic material, such as polypropylene (PP).

The hollow tube or needle may preferably have a length of at least 1 mm and an outlet diameter comprised between 0.05 mm and 1 mm. Alternatively, length of each hollow tube may be of at least 2 mm. The outlet diameter of the hollow tube may alternatively be comprised between 0.05 mm and 0.5 mm.

The hollow tube may be made of metal, of a ceramic material or a plastic material, and have a constant cross section. It may preferably be a straight hollow tube. The hollow tube may preferably be a needle that is certified for use in drug administration.

The actuating device for a jet injector according to the present invention allows generating controlled pressure profiles that are constant over a prolonged time period, without exhibiting pressure peaks typically associated with the uncontrolled explosion of primer material. This allows designing a jet injector device capable of delivering a constant rate tunable liquid jet of desired velocity over the corresponding time period. As the jet velocity is a key parameter for targeting a specific delivery site, the proposed device improves the delivery precision of drugs to specific tissue depths as compared to the state of the art, while avoiding the use of involved mechanical parts and relying on elements that are easily produced. As no pressure peak is generated during the delivery process, drug containing ampules for use in the proposed jet injector device do not require the ability to withstand very high pressures. Known standard drug ampules or cartridges may be used with the device without requiring Further modifications or certifications.

rhe delivery nozzle for a jet injector according to the present invention allows stabilizing a nigh velocity jet so that it easily enters skin tissue at a desired depth. The manufacturing method according to the present invention allows for the provision of small bore stabilizing conduits in the delivery nozzle using relatively simple and readily available constituent parts. The conduits of the nozzle are formed by needles which have already acquired certification for use in drug delivery applications.

Brief description of the drawings

Several embodiments of the present invention are illustrated by way of figures, which do not limit the scope of the invention, wherein:

Figure 1 schematically illustrates a pressure profile varying in time, as generated by a known jet injector device.

Figure 2 shows a perspective section of an actuating device for a jet injector according to a preferred embodiment of the present invention.

Figure 3 shows a perspective section of an actuating device for a jet injector according to a preferred embodiment of the present invention.

Figure 4 schematically illustrates various pressure profiles varying in time, as generated by actuating devices according to preferred embodiments of the present invention.

Figure 5 shows a perspective section of a delivery nozzle for a jet injector according to a preferred embodiment of the present invention.

Figure 6 shows a perspective section of a delivery cartridge in cooperation with a delivery nozzle for a jet injector according to a preferred embodiment of the present invention.

Figure 7 illustrates an assembly comprising an actuating device for a jet injector according to a preferred embodiment of the present invention, in cooperation with a delivery cartridge and a delivery nozzle for a jet injector according to a preferred embodiment of the present invention.

Figure 8 illustrates an assembly comprising a trigger device, an actuating device for a jet injector according to a preferred embodiment of the present invention in cooperation with a delivery cartridge and a delivery nozzle for a jet injector according to a preferred embodiment of the present invention.

Detailed description of the invention

This section describes the invention in further detail based on preferred embodiments and on the figures. Concepts that are similar across several embodiments will be denoted by similar reference number, for example, the reference numbers 130, 230, 330, 430 each denote a different embodiment of a delivery nozzle according to the present invention.

According to a first aspect of the present invention, an actuating device 110 for a jet injector, as illustrated in Figure 2, is proposed. The jet injector 110 comprises ignition means 112 that are configured to ignite a gas generating propellant 116. The ignition means 112 comprise an electrical heating element.

In a preferred embodiment of the actuating device, the body 129 is made of a heat and pressure resistive material. The material may for example be ceramics, the production of which is friendly to the environment. Alternatively, the body may be moulded from a plastic material, such as polypropylene (PP). Other materials suitable for moulding elements that are heat and pressure resistive to a certain degree will be known to the skilled person. The body 129 has preferably the general shape of a cylinder, possibly with different sections of different diameters. At its center it comprises a propellant chamber 118 with an opening 119 that is oriented axially. When the device is not ready for use, the opening 119 of the propellant chamber is preferably covered with a sheet, so as to hermetically enclose the propellant and shield it from the environment. The sheet is removed prior to using the device.

The propellant 116 which is comprised in the propellant chamber 118 is preferably nitrocellulose, but any other suitable gas generating substance that may be ignited through heating is suitable and within the scope of this invention. Nitrocellulose is known to be a flammable compound, formed by nitrating cellulose through exposure to either nitric acid or other powerful nitrating agents. The propellant chamber 118 has preferably the shape of conical frustum, with its large base corresponding to the opening 119.

The ignition means 112 are arranged in close vicinity of propellant chamber, so as to heat the nitrocellulose 116 when they are triggered. The device does not rely on the explosion of a primer material in order to ignite the gas generating compound. It is advantageous to arrange the heating element of the ignition means in direct contact with the nitrocellulose, inside the propellant chamber 118. The ignition means are electrical ignition means and comprise an electrical heating element. In a preferred embodiment, the ignition means comprise a set of electrodes 114 which are connected by a heating resistor 113 passing through the chamber 118. The resistor may be made of any conducting material that presents a relatively low conductivity and a high resistance. When an electrical potential difference U is applied to the contacts 115 of the electrodes 114, the power that is dissipated by the resistor 113 can be quantified by the relation P = l2R (Watt), where I is the current flowing through the resistor 113 in Ampere and R the resistivity of the resistor in Ohm. Therefore, the heating temperature of the ignition means can be tuned by adjusting the current I, or by adjusting the resistor 113.

During operation of the actuating device 110, a potential difference is applied to the contacts 115, which are directly connected to the electrodes 114. As a consequence, an electrical current passes through the heating element 113, which heats up until a critical temperature is reached. The heating element heats the environment directly surrounding it in the propellant chamber 118, which is filled with nitrocellulose 116. At the critical temperature, the nitrocellulose is ignited and burns by generating a volume of gas. As the propellant 116 is not ignited by an explosion, but by use of a controlled and gradual heating, it burns regularly until it is entirely consumed. By burning regularly, the propellant generates gas at a more substantially constant rate. This is in contrast to the case in which a propellant is ignited through an uncontrolled explosion of a primer material, and in which a large quantity of gas is released in a short initial period of time.

In another preferred embodiment of the actuator device, illustrated by Figure 3, the device 210 further comprises a piston 220, which is arranged inside a corresponding elongated structure of the body 229. The elongated structure may be produced separately from the part containing the ignition means, or the two may be produced as a single piece. The piston 220 comprises a piston head 222, which is oriented towards the opening of the propellant chamber 218. The piston head is dimensioned to provide a gas tight fit with the inner wall of the cylindrical structure that surrounds it. A seal may be provided at a contour of the piston head 222 to ensure the gas tightness. The piston may slide inside the body 229 along the axial direction. It further comprises a rod or plunger 224 of smaller diameter, having an actuating end 225. The space between the opening of the propellant chamber 218 and the facing piston head 222 defines a variable volume chamber. Before the actuating means have been triggered, it encompasses generally no volume, as shown in Figure 3. Once the propellant inside the chamber starts burning and generating gas, the generated gas pressure pushes with a generally constant intensity on the piston head, as the gas is generated at generally constant rate. As a consequence, the chamber between the opening of the propellant chamber and the piston head increases its volume and the plunger 224 is propelled at a substantially constant speed along the axis of the body 229. The variable volume chamber may comprise a non-illustrated pressure valve, which opens a conduit that leads through the body to the external environment of the device if the internal pressure exceeds a predetermined pressure threshold value. This ensures that in any case, the pressure acting on the piston head is well controlled.

Figure 4 schematically illustrates a pressure profile (solid line) generated by igniting the gas generating propellant as described and in conformity with the present invention. After ignition at time t0, the gas pressure increases slowly. This is in contrast to the known case in which a gas generating propellant is ignited by an explosion, and in which the maximum very high pressure is attained almost instantaneously. In the device according to the present invention, after the slow increase, the gas pressure enters a generally constant rate regime, which decays once all the propellant has been burnt. At time t’max, the pressure reaches a maximum P’max, which is kept generally constant during a specified timespan, before it decays as the propellant has been consumed. The maximum pressure is lower than the maximum pressure peak that is generated in known devices, which rely on a primer explosion to ignite the propellant. As shown in dashed lines, different profiles are achievable. The duration of the substantially constant rate regime, and the value of P’max, are among the values that may be impacted by appropriately choosing the propellant, the quantity of propellant and the ignition temperature. These may be specified as a function of the desired jet injection depth, the viscosity of the liquid that is to be delivered, and the volume of liquid among others.

In a jet injector according to the present invention, the proposed actuator 210 is used in conjunction with a triggering device, which is configured to selectively apply a voltage to the contacts 215, The applied voltage results in the circulation of a current through the heating element, which ignites the propellant. By burning, the propellant generates gas at a pressure which acts on a piston head. The plunger end 225 of the piston is further arranged to cooperate with a container chamber. The container chamber comprises the liquid drug that is to be delivered and is sealed by a movable plug. The plunger end 225 directly engages with the movable plug. During operation of the jet injector, the plunger end 225 drives the movable plug at substantially constant speed into the container chamber. Thereby the generally incompressible liquid is driven out of the chamber at a substantially constant rate. It is preferred that the accelerated liquid is then delivered through a delivery nozzle. Figure 6 illustrates an example of a container chamber 150 containing a liquid substance 152, including a movable plug 151 as described. The opening 153 at the opposed end of the container chamber leads into a delivery nozzle 130.

The actuator device according to the present invention allows the provision of a jet injector that enables the delivery of liquid jets at substantially constant rates. The maximum pushing force that is being generated and the duration during which the generated force is applied, both depend on the type of propellant that is used, on the volume of gas that the propellant is capable of generating, and on the ignition temperature of the propellant. These variables can be freely adapted as described in order to generate a jet at the required velocity.

As the generated jet velocity is one of the factors that have an impact on the penetration depth of the liquid jet into the skin tissue, the proposed jet injector enables to tune the parameters of the device to any desired penetration depth, thereby allowing to precisely target delivery sites during drug administration. Intradermal, subcutaneous and intramuscular injections are thereby enabled.

The high velocity liquid jet that is forced out of the container chamber of the jet injector is generally fed into a delivery nozzle, which is used to further increase the velocity of the jet. A nozzle presents an opening for receiving liquid and at least one outlet for releasing liquids. The diameter of the outlet is generally smaller than the diameter of the opening, so that according to the well-known principle of liquid flow rate conservation, the speed of the liquid leaving the nozzle through the outlet is higher than the speed of the liquid entering the nozzle. By carefully choosing the inlet and outlet diameters, the jet speed can be adjusted as required. In general, the ratio between the inlet diameter and the outlet diameter should be greater than one. However, the passage of a liquid stream from a large bore conduit to a small bore conduit generally leads to the generation of flow turbulences in the liquid stream. While the speed of the resulting stream is increased, the resulting stream is also more turbulent and less steady, which hinders the penetration efficiency of the jet into the skin tissue.

In a jet injector device, it is important to generate a high velocity stream that is highly regular and steady, and that presents as little turbulence as possible. A steady and regular jet eases penetration of the jet into the skin tissue and to the targeted delivery depth.

It is therefore a further object of the present invention to propose a delivery nozzle 130 for a jet injector device, as illustrated in Figure 5. The delivery nozzle 130 comprises a body 131 and an inlet 140 leading into at least one conduit 144 having an outlet 142. The inlet 140 has a diameter that corresponds generally to an outlet diameter of a drug containing chamber of the jet injector device, which it is able to receive. In a preferred embodiment the diameter size is of at least 2 mm. Each of the conduits connecting the single inlet 140 to each of the outlets 142 has a length that is suitable for stabilizing the liquid jet that enters it through the inlet at a high velocity. The required length and the outlet diameter of each conduit depend on the velocity of the jet received by the nozzle, as well as on the viscosity of the liquid. The length may therefore be comprised in a range spanning from 1 mm to 20 mm. In another preferred embodiment, the length may correspond to at least 2 mm and an outlet diameter may be comprised in the range between 0.05 mm and 1 mm. Larger outlet diameters are also within the scope of the present invention. The reduction factor between the inlet diameter and the outlet diameter defines the velocity boost factor that is obtained using the nozzle, and it is therefore chosen according to the requirements of each specific application.

The appropriately chosen conduit length allows to stabilize the stream flowing through the conduits 144 and to significantly lessen the turbulences of the jet.

The body 131 has preferably a generally cylindrical shape. The inlet 140 is defined by a hollowed out section delimited by an abutment surface 133, which comprises the respective inlets of the conduits 144 that pierce the body and lead to the outlets 142. The conduits may be provided coaxially with the axis of the cylinder, or at an angle therewith, as shown in the example of Figure 5. The nozzle may comprise a single conduit, or a plurality of conduits, depending on the requirements of the targeted application. In the case of a plurality of conduits, the conduits are preferably arranged symmetrically around the axis of the body’s cylinder, as illustrated in Figure 5.

The body 131 may be made of any metal or plastic material. It may for example be moulded from a plastic material, such as polypropylene (PP). Alternatively, the material may be a metal or ceramic. Any other pressure resilient plastic materials may equally be used and will be known to the skilled person. As the nozzle head is used for drug delivery, it is important to maintain high standards when manufacturing the device.

In one embodiment according to the present invention, the conduit may be drilled into the body using appropriate tools. Drilling of bores having a diameter smaller than 0.5 mm and a length of more than 10 mm is an inherently difficult task. The resulting nozzle head needs to be certified for drug delivery use, as the drug will have to pass through the drilled conduit tunnels. This problem is resolved by a preferred embodiment according to the present invention, in which each conduit 144 is formed by a hollow metal tube 146, or needle, which is already certified for use in drug administration. The tubes are inserted into the body 131 during production and may be provided at any desired length and/or diameter, as required by the specific application.

In a preferred embodiment of the present invention, the manufacturing process of the delivery nozzle 130 therefore comprises several steps. In a first step, hollow metal tubes 146 are provided. The tubes may preferably have an inner diameter in the range of 0.05 mm to 1 mm. Hypodermic needles having similar bore diameters are known in the art and are certified for use in drug administration to human or animal bodies. It is advantageous to provide such needles during the first step. The needles may be shortened to the required length using appropriate tools.

The needles are positioned in an appropriated mould for moulding the nozzle body 131, at positions corresponding to the positions of the conduits 144 in the final product. In a further step, the body 131 is injection moulded and the certified needles 146 are overmoulded, for example with a plastic resin, such as PP.

Once the plastic resin has set, the body 131 is unmoulded and comprises the hollow metal tubes 146. Each tube 146 defines a conduit leading from the nozzle inlet 140 to one of the nozzle outlets 142.

It will be clear to the skilled person that the body may alternatively be cast using any other material, for example using metal. As long as an appropriate mould is provided and as long as the manufacturing step allows to firmly enclose the certified tubes 146 in the body, these methods are considered to be equivalent in the context of this invention.

During operation of the delivery nozzle for a jet injector, the inlet 140 receives a corresponding outlet 153 of a drug containing container chamber 150. Figure 6 illustrates an example of a container chamber 150 containing a liquid substance 152, including a movable plug 151. The opening 153 of the container chamber leads into the delivery nozzle 130. The diameter of the opening 140 is larger than the diameter of the opening 153 of the container 150.

The opening 153 of the container abuts the surface 133 of the delivery nozzle. While the depicted surface 133 is flat, it may also define a bowl shaped form preferably surrounded by an annular shoulder. The inlets of the conduits 144 are preferably arranged centrally on the surface 133, so that they are contained in the central region that is enclosed by the opening 153 of the container chamber 150. Preferably the inlets of the conduits or needles extend from the surface 133. This allows establishing liquid communication between the interior of the container chamber and the outlets 142 of the delivery nozzle. The surface 133 of the delivery nozzle body further advantageously comprises a seat for receiving a seal, such as an O-ring 134. This enables a liquid tight fit between the container chamber and the nozzle body.

Figure 7 illustrates a particularly preferred embodiment according to the present invention. An actuating device 310 having contacts 315 for triggering the electrical ignition means is provided. When triggered, the ignition means ignite a gas propellânt which burns in a controlled manner, a steady rate during a prolonged timespan. Thereby the propellant releases gas at a generally steady and constant rate during a prolonged timespan. The generated gas pressure acts upon a piston head 322 and drives the plunger 324 of the piston 320 away from the body of the actuating means 310. The end of the plunger 325 engages with a movable plug 351, which seals a container chamber 350. At the opposite end of the chamber, an outlet 353 engages with the delivery nozzle 330 as described above. The container chamber is therefore in liquid communication with at least one outlet 342 of the delivery nozzle. The container chamber, which may for example be a known ampule for storing liquid drugs, is surrounded by a cartridge 370, in which it tightly fits. The walls of the cartridge 370 reinforce the walls of the container chamber 350, rendering the latter more resilient to internal pressure.

As the piston 320 is driven by the generated gas, the movable plug 351 is pushed at a steady and constant speed into the container chamber 350 during a prolonged timespan. The chamber stores a substance or drug that is generally in the form of a substantially uncompressible liquid 350. The substance is forced out of the chamber and into the delivery nozzle 330 at a steady and constant rate. Inside the delivery nozzle, the liquid jet is further accelerated and stabilized for producing a stable high velocity jet at the outlet 342. The resulting jet is capable of piercing skin tissue. The penetration depth of the jet is a function of, among other parameters, the jet velocity. It may therefore be adapted by appropriately designing the elements of the device as described.

The embodiment shown in Figure 8 is similar to the embodiment of Figure 7, however Figure 8 further illustrates a triggering device 460 to which the actuating device 410 is coupled. The triggering device comprises a trigger button 461 and a power source, such as a battery, which is not depicted. A visual indicator, such as a display or a Light Emitting Diode (LED) 462 may be provided on the surface of the housing of the triggering device, in order to visually indicate that the device is functional and ready to use. The trigger device may further comprise a plug for recharging the power source by connecting it to a power outlet. The trigger may therefore be constructed for single use or for multiple uses. The trigger button 461 is electrically connected to the power source and to contacts that are coupled with the contacts 451 of the actuating device 410. By activating the trigger button 461, the corresponding electrical circuit is closed, and the actuating device operates as described. The shape of the trigger device 460 is arbitrary and may be adapted for ergonomic use to the shape of a stick, pen or pistol. The triggering device may be repeatedly used and present coupling means for releasably engaging with a corresponding structure on the actuating device.

The present invention allows for the provision of a jet injector device which is capable of delivering generally constant velocity jets that are highly stabilized and exhibit few turbulences. This facilitates the penetration of the jets into skin tissue, and allows for precisely targeting delivery sites and tissue depths. As the proposed delivery nozzle may be produced from elements that already have certification for drug administration, the production cost overhead is greatly reduced. Similarly, the actuating device according to the present invention relies on material and gas generating compounds that do generally not require any certification for use in the jet injector device. As the actuating device according to the present invention does no submit the container chambers, such as cartridges or ampules, to very high pressures, standard ampules or cartridges can readily be used in conjunction with the corresponding jet injector device.

It should be understood that the detailed description of specific preferred embodiments is given by way of illustration only, since various changes and modifications within the scope of the invention will be apparent to the skilled person. The scope of protection is defined by the following set of claims.

Claims (19)

1. A delivery nozzle (130; 330; 430) for a jet injector, comprising a body (131 ) and an inlet (140) leading into at least one conduit (144) having an outlet (142), wherein each conduit is defined by a hollow tube (146).
2. The device according to claim 1, wherein the ratio between the diameter of the inlet (140) and the diameter of an outlet (142) is greater than one.
3. The device according to any of claims 1 or 2, wherein each tube (146) has a length of at least 2 mm and an outlet diameter comprised between 0.05 and 1 mm.
4. The device according to any of claims 1 to 3, wherein each conduit (144) has a constant cross section.
5. The device according to any of claims 1 or 4, wherein each conduit (144) is a straight conduit.
6. The device according to any of claims 1 to 5, wherein the delivery nozzle body (130) comprises an abutment surface (133) comprising the opening of each conduit.
7. The device according to any of claims 1 to 6, wherein said at least one hollow tube (146) is a needle that is certified for use in drug administration.
8. The device according to any of claims 1 to 7, wherein said hollow tube (146) is made of metal, ceramic or a plastic material.
9. The device according to any of claims 1 to 8, wherein the delivery nozzle body (131) has generally the shape of a cylinder.
10. The device according to claim 9, wherein each conduit (146) is arranged at an angle with respect to the axis of the cylinder.
1 The device according to any of the preceding claims, wherein the body (131) is moulded from a metal, ceramic or plastic material.
12. A jet injector device for injecting a liquid substance into a tissue, wherein the device comprises a trigger for triggering actuating means, which are arranged for cooperating with a first end of a container chamber, and a delivery nozzle which is attached to a second end of said container chamber, and wherein said delivery nozzle conforms to the device of any of claims 1 to 11.
13. A method for producing a delivery nozzle (130) for a jet injector, the method comprising the steps of: - providing at least one hollow tube (146); - inserting said at least one hollow tube into a mould that is adapted for injection moulding a delivery nozzle body (131): - overmoulding said at least one hollow tube using a material, thereby creating at least one conduit (144), which leads from the nozzle inlet (140) to an outlet (142).
14. The method according to claim 13, wherein the material is a metal or a plastic material.
15. The method according to any of claim 13 or 14 wherein the at least one hollow tube (146) has a length of at least 2 mm and a diameter comprised between 0.05 mm and 1 mm.
16. The method according to any of claims 13 to 15, wherein the at least one hollow tube (146) is a needle that is certified for use in drug administration
17. The method according to any of claims 13 to 16, wherein the at least one hollow tube (146) is made of metal, ceramic or a plastic material.
18. The method according to any of claims 13 to 17, wherein the at least one hollow tube (146) has a constant cross section.
19. The method according to any of claims 13 to 18, wherein the at least one hollow tube (146) is a straight hollow tube.
LU92112A 2012-12-12 2012-12-12 Delivery nozzle for a jet injector and method of production LU92112A1 (en)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2667874A (en) * 1951-07-09 1954-02-02 Becton Dickinson Co Medicament cartridge assembly
EP0295917A2 (en) * 1987-06-19 1988-12-21 Bioject, Inc. Non-invasive hypodermic injection device
US5569190A (en) * 1987-06-08 1996-10-29 D'antonio; Nicholas F. Hypodermic fluid dispenser
CH694483A5 (en) * 2000-08-17 2005-02-15 Cilag Ag Cartridge of an injection medium for an injection unit without needle comprises a cartridge body with an injection nozzle formed by an injection element attached to the cartridge body
US20080071211A1 (en) * 2006-09-19 2008-03-20 Bioject Inc. Needle-free injector and process for providing serial injections
AU2008203046A1 (en) * 2007-07-13 2009-01-29 Cobbett Technologies Pty Ltd Needleless Injector Head
DE202010005982U1 (en) * 2010-04-22 2010-07-15 Lts Lohmann Therapie-Systeme Ag Cylinder-piston unit with a tubular outlet element

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2667874A (en) * 1951-07-09 1954-02-02 Becton Dickinson Co Medicament cartridge assembly
US5569190A (en) * 1987-06-08 1996-10-29 D'antonio; Nicholas F. Hypodermic fluid dispenser
EP0295917A2 (en) * 1987-06-19 1988-12-21 Bioject, Inc. Non-invasive hypodermic injection device
CH694483A5 (en) * 2000-08-17 2005-02-15 Cilag Ag Cartridge of an injection medium for an injection unit without needle comprises a cartridge body with an injection nozzle formed by an injection element attached to the cartridge body
US20080071211A1 (en) * 2006-09-19 2008-03-20 Bioject Inc. Needle-free injector and process for providing serial injections
AU2008203046A1 (en) * 2007-07-13 2009-01-29 Cobbett Technologies Pty Ltd Needleless Injector Head
DE202010005982U1 (en) * 2010-04-22 2010-07-15 Lts Lohmann Therapie-Systeme Ag Cylinder-piston unit with a tubular outlet element

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