Patent Description:
Administering an injection is a process which presents a number of risks and challenges for users and healthcare professionals, both mental and physical. Injection devices typically fall into two categories - manual devices and autoinjectors. In a conventional manual device, manual force is required to drive a medicament through a needle. This is typically done by some form of button / plunger that has to be continuously pressed during the injection. There are numerous disadvantages associated with this approach. For example, if the button / plunger is released prematurely, the injection will stop and may not deliver an intended dose. Further, the force required to push the button / plunger may be too high (e.g., if the user is elderly or a child). And, aligning the injection device, administering the injection and keeping the injection device still during the injection may require dexterity which some patients (e.g., elderly patients, children, arthritic patients, etc.) may not have.

Autoinjector devices aim to make self-injection easier for patients. A conventional autoinjector may provide the force for administering the injection by a spring, and trigger button or other mechanism may be used to activate the injection. Autoinjectors may be single-use or reusable devices.

Document <CIT>, which is regarded as useful to understand the invention, discloses a reloadable autoinjector with separate needle injection.

There remains a need for an improved autoinjector.

It is an object of the present invention to provide an improved autoinjector and/or methods.

The invention is defined by independent claims <NUM>, <NUM> and <NUM>.

Preferred embodiments of the invention are defined by the dependent claims.

In the following passages of the description describing exemplary embodiments, the term "embodiment" has to be understood to mean "example", and the wording "present invention" as "present disclosure".

In an exemplary embodiment, an autoinjector according to the present invention comprises a case, a syringe carrier slidably disposed within the case and adapted to hold a syringe including a stopper, a plunger slidably disposed within the syringe carrier and adapted to apply a force on the stopper, and a drive spring disposed within the plunger and biasing the plunger relative to the syringe carrier.

In an exemplary embodiment, the autoinjector further comprises a needle shroud slidably disposed within the case. The needle shroud is telescopically arranged over the syringe carrier. In an exemplary embodiment, the autoinjector further comprises detent mechanism adapted to couple the needle shroud to the syringe carrier and adapted to couple the needle shroud to the case. The detent mechanism comprises a resilient shroud beam on the needle shroud having a shroud boss releasably engaging a carrier opening in the syringe carrier. The case includes a proximal case boss abutting the shroud boss when the needle shroud is in a first extended position.

In an exemplary embodiment, the autoinjector further comprises a plunger release mechanism adapted to releasably couple the plunger to the syringe carrier. The plunger release mechanism comprises a resilient carrier beam on the syringe carrier having a carrier boss releasably engaging a plunger opening in the plunger.

In an exemplary embodiment, the autoinjector further comprises a collar slidably arranged on the syringe carrier, and a control spring applying a biasing force to the collar. The collar includes a resilient collar beam having a collar boss adapted to releasably engage a step on the syringe carrier. The collar abuts the carrier boss when the needle shroud is in the first extended position. The collar, the needle shroud and the syringe carrier are moved proximally relative to the case when the needle shroud is moved from the first extended position to a first retracted position. A proximal end of the syringe carrier abuts a proximal end of the case when the needle shroud is in the first retracted position to provide a feedback. The shroud boss is proximal of the proximal case boss when the needle shroud is in the first retracted position. The syringe carrier is advanced distally when the needle shroud is in a second retracted position proximal of the first retracted position, and the shroud boss disengages the carrier opening. When the shroud boss disengages the carrier opening, the collar pushes the syringe carrier distally until the syringe carrier abuts a front stop in the case and the collar disengages the syringe carrier under the biasing force of the control spring and pushes the needle shroud into a second extended position relative to the case. When the collar disengages the syringe carrier, the carrier boss disengages the plunger opening to release the plunger. The shroud boss abuts a distal case boss when the needle shroud is in the second extended position.

In an exemplary embodiment, the syringe carrier with the integrated drive spring allows for employing a strong drive spring without any impact on the user when triggering the autoinjector or during needle insertion since these actions are achieved or opposed by the control spring which can be specified considerably weaker than the drive spring. This allows for delivering highly viscous medicaments.

In an exemplary embodiment, releasing the drive spring upon the needle reaching an insertion depth avoids a so called wet injection, i.e. medicament leaking out of the needle which is a problem in conventional art autoinjectors, where both needle insertion and injection are achieved by pushing on the stopper.

According to another embodiment, the plunger and the drive spring may be arranged within the syringe prior to use of the autoinjector.

According to another embodiment, the autoinjector may be configured for delivering of highly viscous medicaments.

In an exemplary embodiment, the autoinjector has a particularly low part count compared to most conventional autoinjectors thus reducing manufacturing costs. The arrangement with separate control spring for advancing the syringe and the needle shroud and a drive spring for fluid injection allows for using one design for different viscosity liquids by just changing the drive spring, and for different volumes just by changing the length of the plunger. This may be an advantage over conventional designs where the drive spring also serves for needle insertion and/or for advancing a shroud.

According to a further aspect, a method of manufacturing an autoinjector may comprise the steps of:.

According to an embodiment, when the medicament container contains a second liquid medicament having a second viscosity different from the first viscosity and/or a second volume different from the first volume, the autoinjector components may be further configured to combine with a second drive spring based on the second viscosity and/or a second plunger based on the second volume into another autoinjector.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the scope of the invention , as defined by the appended clams, will become apparent to those skilled in the art from this detailed description.

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:.

<FIG> is a perspective view of an exemplary embodiment of an autoinjector <NUM> comprising a case <NUM> and a cap <NUM> prior to use. <FIG> and <FIG> are longitudinal sections of the autoinjector <NUM> prior to use.

In an exemplary embodiment, the autoinjector <NUM> comprises a case <NUM> including a distal case <NUM> and a proximal case <NUM> which are coupled during assembly. A cap <NUM> is removably coupled to a distal end of the case <NUM>. The case <NUM> comprises a viewing window <NUM>, which may be a hole or a transparent portion of the case <NUM>.

The case <NUM> is adapted to hold a syringe <NUM> containing a medicament. The syringe <NUM> may be a pre-filled syringe and have a needle <NUM> arranged at a distal end. In another exemplary embodiment, the syringe <NUM> may be a medicament cartridge adapted to removably receive the needle <NUM> (e.g., by snap-fit, friction, threads, etc.). A protective needle sheath <NUM> may be removably attached to the needle <NUM>. A stopper <NUM> is arranged for sealing the syringe <NUM> proximally and for displacing a liquid medicament M contained in the syringe <NUM> through the needle <NUM>.

A needle shroud <NUM> is telescoped within the case <NUM> and movable between an extended position and a retracted position. The needle shroud <NUM> is biased relative to the case <NUM> toward the extended position by a control spring <NUM>.

In an exemplary embodiment, the syringe <NUM> may be held in a syringe carrier <NUM>, which is slidably arranged within the case <NUM>. The syringe carrier <NUM> may include a distal portion adapted to hold the syringe <NUM> and a proximal portion adapted to retain a plunger <NUM>. A drive spring <NUM>, e.g., a compression spring, may be grounded proximally on a proximal end of the syringe carrier <NUM> and distally on a distal end of the plunger <NUM>. In an exemplary embodiment, the plunger <NUM> is telescopically coupled to the proximal portion of the syringe carrier <NUM>, and the drive spring <NUM> is arranged within the plunger <NUM> and biases the plunger <NUM> distally.

In an exemplary embodiment, the drive spring <NUM> is arranged within a proximal part <NUM> of the syringe carrier <NUM>. A plunger <NUM> serves for forwarding the force of the drive spring <NUM> to the stopper <NUM>. In an exemplary embodiment the plunger <NUM> is hollow and telescoped within the proximal part <NUM> of the syringe carrier <NUM> wherein the drive spring <NUM> is arranged within the plunger <NUM> biasing the plunger <NUM> in the distal direction D against the syringe carrier <NUM>.

In an exemplary embodiment, a detent mechanism <NUM> is provided to initiate automated needle insertion. The detent mechanism <NUM> also locks the needle shroud <NUM> after autoinjector <NUM> has been removed from the injection site in an extended position.

In an exemplary embodiment, the detent mechanism <NUM> comprises at least one shroud boss <NUM> adapted to engage in a carrier opening <NUM> within the syringe carrier <NUM> for locking the needle shroud <NUM> to the syringe carrier <NUM>. At least one surface of the shroud boss <NUM> and the carrier opening <NUM> may be ramped to reduce a force necessary to displace the needle shroud <NUM> from the extended position to the retracted position against the biasing force of the control spring <NUM>. When the force on the needle shroud <NUM> overcomes the biasing force of the control spring <NUM>, the shroud boss <NUM> abuts the carrier opening <NUM> and deflects radially via a compliant beam <NUM> coupled to the shroud boss <NUM>, disengaging the needle shroud <NUM> from the syringe carrier <NUM>. When the needle shroud <NUM> is in a first extended position FEP relative to the case <NUM> (as shown in <FIG> and <FIG>), the shroud boss <NUM> radially abuts a radial case boss <NUM>, which prevents the needle shroud <NUM> from disengaging the syringe carrier <NUM> when the needle shroud <NUM> is in the first extended position FEP. An axial case boss <NUM> is adapted to distally abut the shroud boss <NUM> such that the needle shroud <NUM> cannot be moved distally beyond the first extended position FEP prior to use. At least one of the surfaces of the shroud boss <NUM> and the axial case boss <NUM> may be ramped such that if an axial force directed in the distal direction D is applied to the needle shroud <NUM> relative the case <NUM>, the needle shroud <NUM> moves in the distal direction D relative the case <NUM> and the shroud boss <NUM> is radially inwardly deflected via the resilient beam <NUM> around the axial case boss <NUM>. Prior to use, the shroud boss <NUM> is prevented from deflecting radially inward by the presence of the syringe carrier <NUM>. Thus, prior to use the needle shroud <NUM> does not disengage the case <NUM>.

In an exemplary embodiment, a plunger release mechanism <NUM> is arranged for preventing release of the plunger <NUM> prior to the needle <NUM> reaching an insertion depth and for releasing the plunger <NUM> once the needle <NUM> reaches its insertion depth. In an exemplary embodiment, the plunger release mechanism <NUM> comprises: one or more compliant beams <NUM> with a respective first boss <NUM> arranged on the syringe carrier <NUM>, a respective first opening <NUM> laterally arranged in the plunger <NUM> for engaging the first boss <NUM>, a collar <NUM> slidably arranged within the case <NUM> and over the syringe carrier <NUM>. When the needle shroud <NUM> is in the first extended position FEP, the collar <NUM> abuts the first boss <NUM>, preventing it from disengaging the first opening <NUM>. As described further below, as the needle <NUM> reaches its insertion depth, the collar <NUM> moves axially away from the first boss <NUM>, so that the first boss <NUM> may deflect via the beam <NUM> and disengage from the first opening <NUM>. The syringe carrier <NUM> is then disengaged from the plunger <NUM>. At least surface of the first boss <NUM> and the first opening <NUM> may be ramped to reduce a force necessary to disengage the first boss <NUM> from the first opening <NUM>.

In an exemplary embodiment, a control mechanism <NUM> (shown in <FIG>) is arranged for selectively coupling the control spring <NUM> to the syringe carrier <NUM> or to the needle shroud <NUM> for advancing either in the distal direction D or opposing movement thereof in the proximal direction P. In an exemplary embodiment, the collar <NUM> may be a component of the control mechanism <NUM>. The control spring <NUM> is proximally grounded in the case <NUM> and distally bears against the collar <NUM> which is movable axially with respect to the case <NUM> and arranged over the syringe carrier <NUM>. The collar <NUM> comprises at least one collar boss <NUM> adapted to be engaged to a step <NUM> in the carrier <NUM>. At least one of the mating surfaces of the carrier boss <NUM> and the step <NUM> may be ramped to reduce a force necessary to deflect the collar boss <NUM> radially via a compliant collar beam <NUM> when it abuts the step <NUM>. Once assembled, the collar boss <NUM> is prevented from deflecting radially by a narrow section <NUM> in the case <NUM>. A wide section <NUM> is arranged distally from the narrow section <NUM>. Upon axial movement of the syringe carrier <NUM> and the collar <NUM> in the distal direction D, the carrier boss <NUM> can deflect radially when the collar <NUM> enters the wide section <NUM> and disengage the collar <NUM> from the syringe carrier <NUM> under force from the control spring <NUM>.

In an exemplary embodiment, prior to use the control spring <NUM> is compressed between the case <NUM> and the collar <NUM>. The control mechanism <NUM> couples the collar <NUM> to the syringe carrier <NUM> which is in turn coupled to the case <NUM> by the detent mechanism <NUM>.

A exemplary embodiment of a sequence of operation of the autoinjector <NUM> is as follows:
Prior to use, the autoinjector <NUM> is in the state as illustrated in <FIG>. If applicable, the user removes the autoinjector <NUM> from a packaging. The medicament M may be viewed through the viewing window <NUM>. The cap <NUM> is removed from the case <NUM> by pulling the cap <NUM> in the distal direction D. The cap <NUM> is coupled to the protective needle sheath <NUM>, and thus removing the cap <NUM> also removes the protective needle sheath <NUM>. Prior to use, the needle shroud <NUM> is in the first extended position FEP protruding from the case <NUM> in the distal direction D. The first extended position FEP is defined by the detent mechanism <NUM>, i.e. by the engagement of the shroud boss <NUM> in the carrier opening <NUM> of the syringe carrier <NUM> and abutment of the shroud boss <NUM> against the axial case boss <NUM> to prevent it from disengaging the carrier opening <NUM>.

<FIG> are perspective views of the autoinjector <NUM> being pressed against an injection site. When the autoinjector <NUM> is pressed against the injection site, the needle shroud <NUM> moves from the first extended position FEP toward a first retracted position FRP relative to the case <NUM>. Because the needle shroud <NUM> is coupled to the syringe carrier <NUM> by the detent mechanism <NUM> (by the shroud boss <NUM> engagement with the carrier opening <NUM>), the syringe carrier <NUM> (and the syringe <NUM> therein) are retracted relative to the case <NUM> such that the needle <NUM> is not exposed. Because the collar <NUM> is coupled to the syringe carrier <NUM> (by the collar boss <NUM> abutting the step <NUM>), the collar <NUM> is moved with the syringe carrier <NUM> in the proximal direction P against the force of the control spring <NUM>.

When the needle shroud <NUM> has reached the first retracted position FRP, the proximal end <NUM> of the syringe carrier <NUM> may contact (or nearly contact) a proximal end <NUM> of the case <NUM>. The contact between the syringe carrier <NUM> and the case <NUM> (and/or the increased resistance provided by the control spring <NUM>) may provide a tactile feedback that further depression of the needle shroud <NUM> will activate the autoinjector <NUM>. In the first retracted position FRP, the shroud boss <NUM> is proximal of the case boss <NUM> such that the shroud boss <NUM> no longer abuts the case boss <NUM>. However, in an exemplary embodiment, the biasing force of the control spring <NUM> is less than the force required to deflect the shroud boss <NUM> out of the carrier opening <NUM>. Thus, if the needle shroud <NUM> is not further depressed and the autoinjector <NUM> is removed from the injection site (or axial force is no longer applied to the autoinjector <NUM>), the needle shroud <NUM> will re-extend into the first extended position FEP and the autoinjector <NUM> will return to its initial state.

<FIG> are perspective views of the autoinjector <NUM> being pressed against an injection site. As the user continues to depress the needle shroud <NUM> into a second retracted position SRP, an increase in resistance is experienced as the case <NUM> advances the syringe carrier <NUM> in the distal direction D relative to the needle shroud <NUM> through contact of the proximal ends <NUM>, <NUM> of the case <NUM> and the syringe carrier <NUM>. As the shroud boss <NUM> is no longer radially supported by the case boss <NUM>, as the case <NUM> is advanced in the distal direction D, the shroud boss <NUM> is deflected radially when it abuts the carrier opening <NUM>, causing the syringe carrier <NUM> to disengage from the needle shroud <NUM>.

<FIG> are perspective views of the autoinjector <NUM> being pressed against an injection site. When the shroud boss <NUM> disengages the carrier opening <NUM>, the syringe carrier <NUM> is decoupled from the needle shroud <NUM>. The control spring <NUM> applies the biasing force to the collar <NUM>, and the collar boss <NUM> pushes the step <NUM> on the syringe carrier <NUM> to drive the syringe carrier <NUM> (and the syringe <NUM>) in the distal direction D. When the syringe carrier <NUM> abuts a front stop <NUM> in the case <NUM>, the needle <NUM> protrudes beyond the distal end of the case <NUM> and is inserted into the injection site. The collar <NUM> has been advanced in the distal direction D to such an extent, that the collar boss <NUM> is no longer supported by the narrow section <NUM> but has reached the wide section <NUM> of the case <NUM>. The control spring <NUM> continues advancing the collar <NUM> and due to the syringe carrier <NUM> having abutted the front stop <NUM>, the collar boss <NUM> is deflected radially, disengaging the collar <NUM> from the syringe carrier <NUM>. The collar <NUM> advances further under the force of the control spring <NUM> until it abuts the needle shroud <NUM>.

As the collar <NUM> advances, it is distal of the first boss <NUM> on the syringe carrier <NUM> so as to allow radially deflection of the first boss <NUM> due to its ramped engagement to the first opening <NUM> under load from the drive spring <NUM>. The plunger <NUM> is thus released and advanced by the drive spring <NUM> displacing the stopper <NUM> within the syringe <NUM> and ejecting the medicament M through the needle <NUM>. The release of the plunger release mechanism <NUM> may provide an audible and/or tactile feedback to the user. The progress of the delivery of the medicament M can be observed through the viewing window <NUM> by examining the movement of the plunger <NUM>. The plunger <NUM> (which may be a contrasting color to the case <NUM>) is visible in the viewing window <NUM>, providing visual feedback about whether or not the autoinjector <NUM> has been used.

If the user removes the autoinjector <NUM> from the injection site at any time after the needle <NUM> having reached insertion depth, the needle shroud <NUM> moves in the distal direction D, because it is abutted by the collar <NUM> which is driven by the control spring <NUM>.

<FIG> are perspective views of the autoinjector <NUM> after it is removed from the injection site. As the needle shroud <NUM> advances in the distal direction D under the force of the control spring <NUM>, the shroud boss <NUM> is deflected radially by the axial case boss <NUM> since the syringe carrier <NUM> has been moved in the distal direction D during needle insertion and does not abut the shroud boss <NUM>. The shroud boss <NUM> hence deflects around the case boss <NUM>, and then returns to a non-deflected position when it is distal of the case boss <NUM>. The shroud boss <NUM> abuts a ramped stop <NUM> on the syringe carrier <NUM> which resolves the remaining axial force of the control spring <NUM> and arrests the needle shroud's <NUM> extension. The needle shroud <NUM> is now in a second extended position SEP extending further from the case <NUM> than in the first extended position FEP and the extended needle <NUM> is hidden from view and finger access within the needle shroud <NUM>.

Any attempt to displace the needle shroud <NUM> in the proximal direction P relative to the case <NUM> from the second extended position SEP is prevented, because the shroud boss <NUM> abuts a distal end of the case boss <NUM>.

In another exemplary embodiment, an opening may be arranged in the proximal end <NUM> of the case <NUM> allowing the proximal part <NUM> of the syringe carrier <NUM> to protrude proximally from the case <NUM> and serve as a trigger button (not shown). In this exemplary embodiment, the detent mechanism <NUM> prevents release of the trigger button prior to depression of the needle shroud <NUM> into the retracted position RP. The needle shroud <NUM> may be fully depressed into the second retracted position SRP thereby extending the proximal part <NUM> of the syringe carrier <NUM> from the case <NUM> which may then be depressed to start an injection. If the trigger button is not depressed at this point, the needle shroud <NUM> can re-extend into the first extended position FEP and the autoinjector <NUM> can return to its initial state. If the trigger button is depressed, it may be locked to the case in the depressed position to provide a visual indication that the autoinjector <NUM> has been used.

After full depression of the needle shroud <NUM> into the second retracted position SRP, the shroud boss <NUM> is no longer supported by the case boss <NUM>. The trigger button, e.g., the proximal end <NUM> of the syringe carrier <NUM> protruding proximally from the case <NUM> can now be depressed thereby radially outwardly deflecting the shroud boss <NUM> out of engagement with the carrier opening <NUM> due to their ramped engagement. The syringe carrier <NUM> is thus decoupled from the needle shroud <NUM> and the control spring <NUM>, coupled to the syringe carrier <NUM> through the control mechanism <NUM>, advances the syringe carrier <NUM> in the distal direction D extending the needle <NUM> from the case <NUM> in the distal direction D. The length of the syringe carrier <NUM> and the case <NUM> may be such that the proximal end <NUM> of the syringe carrier <NUM> is flush with the proximal end <NUM> of the case <NUM> once the needle <NUM> reaches its insertion depth.

Hormones are for example hypophysis hormones or hypothalamus hormones or regulatory active peptides and their antagonists as listed in Rote Liste, ed. <NUM>, Chapter <NUM>, such as Gonadotropine (Follitropin, Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin), Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin, Buserelin, Nafarelin, Goserelin.

Antibodies are globular plasma proteins (~<NUM> kDa) that are also known as immunoglobulins which share a basic structure. As they have sugar chains added to amino acid residues, they are glycoproteins. The basic functional unit of each antibody is an immunoglobulin (Ig) monomer (containing only one Ig unit); secreted antibodies can also be dimeric with two Ig units as with IgA, tetrameric with four Ig units like teleost fish IgM, or pentameric with five Ig units, like mammalian IgM.

Claim 1:
An autoinjector (<NUM>) comprising:
a case (<NUM>),
a syringe carrier (<NUM>) slidably disposed within the case (<NUM>), the syringe carrier (<NUM>) adapted to hold a syringe (<NUM>) including a stopper (<NUM>);
a plunger (<NUM>) slidably disposed within the syringe carrier (<NUM>), the plunger (<NUM>) adapted to apply a force on the stopper (<NUM>);
a drive spring (<NUM>) disposed within the plunger (<NUM>) and biasing the plunger (<NUM>) relative to the syringe carrier (<NUM>);
a needle shroud (<NUM>) slidably disposed within the case (<NUM>), the needle shroud (<NUM>) telescopically arranged over the syringe carrier (<NUM>), and
a control spring (<NUM>) biasing the needle shroud (<NUM>) to an extended position.