Patent Application
20190298935
The invention relates to a medical injection device for injecting a liquid drug and especially to a pre-filled injection device for apportioning a multiple number of individual settable doses. The invention especially relates to such pen-shaped and pre-filled injection device wherein the same needle cannula is used for multiple injections and wherein the distal tip of the needle cannula is cleaned between subsequent injections.
Different examples of Injection devices for injecting doses of a liquid drug and wherein the distal tip of the needle cannula is cleaned between injections are disclosed in U.S. Pat. Nos. 3,354,881, 4,416,663 and WO 2015/173151.
The injection device disclosed in WO 2015/173151 has a telescopically movable needle shield which covers the distal tip of the needle cannula between injections. This movable needle shield carries a cleaning chamber which contains the same preservative containing liquid drug as present inside the cartridge. Since the liquid drug contains a preservative this preservative keeps the distal tip of needle cannula clean from various bacteria when the distal tip of the needle cannula is located inside the cleaning chamber.
The distal tip of the needle cannula is only moved outside the cleaning chamber during an injection as the telescopically movable needle shield is pushed in the proximal direction when injecting whereby the distal tip of the needle cannula penetrates through the distal septum of the cleaning chamber and into the skin of a user. When the movable needle shield is removed from the skin of the user following an injection a spring urges the shield into its initial position again covering the distal tip of the needle cannula.
The cleaning chamber is in one example filled with preservative containing liquid drug directly from the cartridge by a user operation. However, when filling preservative containing liquid drug into the cleaning chamber an overpressure can be created inside the liquid system. The cleaning chamber is therefore provided with an overflow channel that in one example terminates to the surroundings. Any surplus of liquid can thus escape through this overflow channel such that pressurising of the cleaning chamber is prevented.
However, if the preservative containing drug flows out of from the end of the overflow channel it will potentially form droplets inside the injection device. These droplets could flow to the outer surface of the injection device by flowing through some of the joints between the different parts making up the injection device. In some examples the droplets will end up being visual to the user, which could lead the user to the conclusion that the injection device is broken or have some kind of malfunction.
It is an object of the present invention to provide an injection device having an overflow channel leading to the surroundings but wherein any overflow is kept non-visual to the user at all times.
Accordingly, in a general aspect of the present invention a prefilled injection pen for apportioning multiple set doses of a preservative containing liquid drug comprises:
According to the invention, means are provided for collecting the escaped quantum of the preservative containing liquid drug. These means can be any means which are able to prevent an overflow from flowing further out through the injection device.
Examples of such means could be:
No matter which kind of collecting means are provided, the means are preferably provided in the near proximity of the outlet.
When the cleaning chamber is being filled with preservative containing liquid drug from the cartridge, the air inside the cleaning chamber will escape through the outlet. Depending on the tolerances an amount of the preservative containing liquid drug can also escape through the outlet. By providing means to collect this overflow of liquid drug it can be prevented that the preservative containing liquid drug flows through the various joints in the injection device and becomes visual to the user.
When providing the means as a plurality of capillary tubes these tubes or openings are preferably connected by radial openings allowing air inside the tubes to disappear as the drug is sucked up into the tubes. The capillary tubes can be provided in any position needed but the maximum effect is obtained if the tubes are provided near to the outlet.
In a further example, the outlet terminates into one or more grooves. As described in details in WO2017/050694 the valve mechanism comprises a hollow spacer element holding the two seals or septae in a longitudinal position spaced away from each other. The interior of the spacer element thus forms the cleaning chamber. The spacer element and the two seals or septae are further secured in an outer tube thus supporting the hollow spacer element. The hollow spacer element is in one example welded to an end element. The outer surface of the outer tube guides or least supports the valve ring such that the outer tube together with the spacer element and the valve ring are rotatable in relation to each other. The relative rotation brings the outlet into contact with a sealing material positioned on the valve ring such that the outlet is sealed by the valve ring following such relative rotation.
The outlet is in a preferred example provided in the spacer element preferably in the form of a channel or channel-like structure which extend radially from the spacer element.
This channel or channel-like structure is sealable by the valve ring which further is provided with one or more axial grooves. However, other constructions can be foreseen within the scope of the present claims. These axial grooves thus forms the means for collecting the escaped quantum of the preservative containing liquid drug.
In a further example the one or more grooves are open either at a distal end, at a proximal end or at both ends. When the one or more grooves guides the escapable quantum to the absorptive material, the absorptive material are preferably provided at the open end or ends of the one or more channels, or at least in the near proximity of the open end or ends.
In a specific example, the one or more grooves are sealed by a sealing ring such that the one or more channels which thus form a physical collection chamber can be sealed to thereby confine and encapsulate the escaped preservative containing liquid drug in order to prevent dripping from the injection device.
In order to seal the one or more channels, a sealing ring is provided which sealing ring in a relaxed state allows air and liquid to pass but which sealing ring can be compressed to thereby seal off the one or more channels.
The compression of the sealing ring is in one example done by applying an axial pressure onto the sealing ring. In one preferred example, the axial pressure is applied by moving a part of the injection device in an axial direction. The part moved is in a preferred example the valve ring or the outer tube. The sealing ring could e.g. be provided between the outer tube and the valve ring such that a relative axial movement between these two parts squeezes the sealing ring. In order to move the outer tube and the valve ring relatively to each other one of the parts can be provided with a guiding track and the other part with a protrusion engaging the guiding track. The guiding track is then further provided with a curve-shape or a raised portion such that the protrusion and the other part is moved axially when the protrusion during rotation encounters this curve or raised portion.
An “injection pen” is typically an injection apparatus having an oblong or elongated shape somewhat like a pen for writing. Although such pens usually have a tubular cross-section, they could easily have a different cross-section such as triangular, rectangular or square or any variation around these geometries.
The term “Needle Cannula” is used to describe the actual conduit performing the penetration of the skin during injection. A needle cannula is usually made from a metallic material such as e.g. stainless steel and preferably connected to a needle hub to form a complete injection needle, all though the needle cannula could also be connected directly to the housing structure without a needle hub. A needle cannula could however also be made from a polymeric material or a glass material.
As used herein, the term “drug” is meant to encompass any drug-containing flowable medicine capable of being passed through a delivery means such as a hollow needle in a controlled manner, such as a liquid, solution, gel or fine suspension. Representative drugs includes pharmaceuticals such as peptides, proteins (e.g. insulin, insulin analogues and C-peptide), and hormones, biologically derived or active agents, hormonal and gene based agents, nutritional formulas and other substances in both solid (dispensed) or liquid form.
“Cartridge” is the term used to describe the container actually containing the drug. Cartridges are usually made from glass but could also be moulded from any suitable polymer. A cartridge or ampoule is preferably sealed at one end by a pierceable membrane referred to as the “septum” which can be pierced e.g. by the non-patient end of a needle cannula. Such septum is usually self-sealing which means that the opening created during penetration seals automatically by the inherent resiliency once the needle cannula is removed from the septum. The opposite end is typically closed by a plunger or piston made from rubber or a suitable polymer. The plunger or piston can be slidable moved inside the cartridge. The space between the pierceable membrane and the movable plunger holds the drug which is pressed out as the plunger decreased the volume of the space holding the drug. However, any kind of container—rigid or flexible—can be used to contain the drug.
Since a cartridge usually has a narrower distal neck portion into which the plunger cannot be moved not all of the liquid drug contained inside the cartridge can actually be expelled. The term “initial quantum” or “substantially used” therefore refers to the injectable content contained in the cartridge and thus not necessarily to the entire content.
“Cleaning chamber” is in the present description broadly meant to be any kind of reservoir containing a cleaning solvent to clean at least the distal tip of the needle cannula between subsequent injections. Such cleaning chamber is preferably both distally and proximally sealed by a pierceable septum. However, the proximal septum could be replaced by any kind of sealing which would seal against the outer surface of the needle cannula. The distal septum and the proximal septum or seal of the cleaning chamber defines a confinement containing the cleaning solvent which cleaning solvent in a preferred embodiment is identical to the preservatives contained in the liquid drug used in the specific injection device. In a most preferred solution, the same preservative containing liquid drug is present in both the cleaning chamber and in the cartridge of the injection device thereby avoiding contamination of the preservative containing drug inside the cartridge.
By the term “Pre-filled” injection device is meant an injection device in which the cartridge containing the liquid drug is permanently embedded in the injection device such that it cannot be removed without permanent destruction of the injection device. Once the pre-filled amount of liquid drug in the cartridge is used, the user normally discards the entire injection device. This is in opposition to a “Durable” injection device in which the user can himself change the cartridge containing the liquid drug whenever it is empty. Pre-filled injection devices are usually sold in packages containing more than one injection device whereas durable injection devices are usually sold one at a time. When using pre-filled injection devices an average user might require as many as 50 to 100 injection devices per year whereas when using durable injection devices one single injection device could last for several years, however, the average user would require 50 to 100 new cartridges per year.
Using the term “Automatic” in conjunction with injection device means that, the injection device is able to perform the injection without the user of the injection device delivering the force needed to expel the drug during dosing. The force is typically delivered—automatically—by an electric motor or by a spring drive. The spring for the spring drive is usually strained by the user during dose setting, however, such springs are usually prestrained in order to avoid problems of delivering very small doses. Alternatively, the spring can be fully preloaded by the manufacturer with a preload sufficient to empty the entire drug cartridge though a number of doses. Typically, the user activates a latch mechanism e.g. in the form of a button on, e.g. on the proximal end, of the injection device to release—fully or partially—the force accumulated in the spring when carrying out the injection.
The term “Permanently connected” as used in this description is intended to mean that the parts, which in this application is embodied as a cartridge and a housing assembly, requires the use of tools in order to be separated and should the parts be separated it would permanently damage at least one of the parts.
All references, including publications, patent applications, and patents, cited herein are incorporated by reference in their entirety and to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
All headings and sub-headings are used herein for convenience only and should not be constructed as limiting the invention in any way.
The use of any and all examples, or exemplary language (e.g. such as) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. The citation and incorporation of patent documents herein is done for convenience only and does not reflect any view of the validity, patentability, and/or enforceability of such patent documents.
This invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law.
The invention will be explained more fully below in connection with a preferred embodiment and with reference to the drawings in which:
The figures are schematic and simplified for clarity, and they just show details, which are essential to the understanding of the invention, while other details are left out. Throughout, the same reference numerals are used for identical or corresponding parts.
When in the following terms as “upper” and “lower”, “right” and “left”, “horizontal” and “vertical”, “clockwise” and “counter clockwise” or similar relative expressions are used, these only refer to the appended figures and not to an actual situation of use. The shown figures are schematic representations for which reason the configuration of the different structures as well as there relative dimensions are intended to serve illustrative purposes only.
In that context it may be convenient to define that the term “distal end” in the appended figures is meant to refer to the end of the injection device which usually carries the injection needle whereas the term “proximal end” is meant to refer to the opposite end pointing away from the injection needle and usually carrying the dose dial button.
Distal and proximal are meant to be along an axial orientation extending along the longitudinal axis “X” of the injection device as further indicated in
The housing structure 1 secures a cartridge 10 which contains a suitable volume of a preservative containing liquid drug. As the injection device in scope is prefilled it contains only one single cartridge 10 which is permanently embedded in the housing structure 1 and which cartridge 10 is both non-refillable and non-exchangeable.
The preservative containing liquid drug contained inside the cartridge 10 is injectable through a needle cannula 20 having a distal part 21 and a proximal part 23 which proximal part 23, at least during injection, is connected to the cartridge 10, e.g. by being inserted into the cartridge 10 as disclosed in
Between injections an axially movable needle shield 30 surrounds the needle cannula 20. This axially movable needle shield 30 is moved in the proximal direction during injection to thereby expose at least the distal part 22 of the needle cannula 20. Following an injection a not-shown spring urges the axially movable needle shield 30 back to its initial position.
The axially movable needle shield 30 further carries a cleaning assembly 15 for cleaning the distal tip 21 of the needle cannula 20 between injections. This cleaning assembly 15 which is depicted in close-up in
The spacer element 45 together with the two seals 41, 42 defines a cleaning chamber 40 for cleaning the distal part 22 of the needle cannula 20 between injections as will be explained. The seals 41, 42 can be any kind of seals but are preferably two pierceable septae 41, 42 through which the needle cannula 20 is able to penetrate and which pierceable septae 41, 42 are self-sealing as it is known from a traditional septum 11 used in a cartridge 10.
As best seen in the close-up in
The cleaning chamber 40 is filled with preservative containing liquid drug directly from the cartridge 10 in a user initiated process. In order to make sure the cleaning chamber 40 is properly filled a radial outlet 46 is provided through which outlet 46 air and any surplus of preservative containing liquid drug filled into the cleaning chamber 40 can escape. The radial outlet 46 is preferably shaped as a channel radially terminating in an orifice.
On the outside of the outer tube 50, a valve ring 60 is provided. This valve ring 60 has one or more axial grooves 61 through which any surplus of preservative containing liquid drug can flow. The valve ring 60 which is disclosed in details in WO 2017/050694 by Novo Nordisk A/S further has a sealing material provided on the inner surface such that when the spacer element 45 and the valve ring 60 are rotated relative to each other this sealing material is brought into a position covering the radial outlet 46 thereby preventing further flow from the cleaning chamber 40.
Further, the outer tube 50 is provided with a number of longitudinal openings 54 through which the radial channel-shaped outlet 46 extend and contacts the valve ring 60. In
However, during filling of the cleaning chamber 40 from the cartridge 10, both the radial outlet 46 and the axial grooves 61 are open to the surroundings such that any air contained in the liquid system can escape. Due to the tolerances of the parts of the injection device it is possible that not only air but also preservative containing liquid drug will escape through both the outlet 46 and the axial grooves 61. In case the preservative containing liquid drug flows out at the open ends of the axial grooves 61 it can in some cases be seen by a user using the injection device. The user could henceforth in some cases see drops appearing on a surface of the injection device. This is highly unwanted as it could lead the user to conclude that the injection device has a defect.
To prevent this surplus of preservative containing liquid drug from becoming visual to the user an absorbing material 65a, 65b is provided at the open end of the axial grooves 61.
However, the axial channel 61 can in one example be open at both the distal end and the proximal end. As disclosed in
In one embodiment, the hub 25 is provided with a series of capillaries channels, holes or tubes 27 into which any surplus of the preservative containing liquid drug can be drawn by the capillary effect. These capillary tubes 27 are preferably connected to each other by radial openings 28 allowing air to flow out of the capillary tubes.
In the disclosed example these capillary tubes 27 are provided in a bottom surface of the hub 25 but the capillary tubes 27 can in principle be provided in any suitable position. Further, the capillary tubes 27 can be combined with the absorptive material 65a, 65b of the previous embodiment or they can be provided as the only liquid collecting means.
In this embodiment, the distal septum 141 and the proximal septum 142 are kept apart by the spacer element 145 as in the cleaning assembly in the first embodiment. The two septae 141, 142 together with the spacer element 145 are provided inside an outer tube 150 which is welded to an end element 155 to form a sealed cleaning chamber 140.
On the outside surface of the outer tube 150, a rotatable valve ring 160 is provided. This valve ring 160 is on its inner surface provided with a sealing material which can be brought into a position wherein this sealing material seals the radial outlet 146 thereby preventing further liquid to escape from the cleaning chamber 140.
The radial outlet 146 extends through longitudinal openings 154 provided in the outer tube 150. When the radial outlet 146 is not sealed it leads to one or more axial grooves 161 through which air and any surplus of preservative containing liquid drug can escape form the cleaning chamber 140.
In the axial direction the distal end surface 162 of the valve ring 160 is located and held in a position proximally to the outer tube 150 such that an air-gap (indicated by “a” in
In this air-gap, a sealing ring 170 is provided. The sealing ring 170 is only loosely fitted between the outer tube 150 and the valve ring 160 thereby allowing air and any surplus of preservative containing liquid drug to escape through the air-gap.
As further seen from
When the valve ring 160 and the outer tube 150 rotates in relation to each other, the outwardly pointing protrusion 163 travels along the sidewall 152 of the outer tube 150. This is indicated by the arrow “R” in
As a result whenever the user rotates the valve ring 160 and the outer tube 150 relatively to seal off the radial outlet 146, the valve ring 170 is automatically moved axially in the distal direction thus at the same time sealing of the air-gap “a” and the axial channel 161.
Some preferred embodiments have been shown in the foregoing, but it should be stressed that the invention is not limited to these, but may be embodied in other ways within the subject matter defined in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 16201915.2 | Dec 2016 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/079839 | 11/21/2017 | WO | 00 |
