Patent Description:
The present invention relates generally to auto-injectors and prefilled syringes and more particularly to auto-injectors that store in a compact state and allow for formation or reconstitution of a therapeutic agent for injection.

It has been recognized that the shelf-life of the medications can be increased dramatically if the drug is stored as a dry medication. In addition, it is often that these medications are deployed in emergency situations where self-administration is preferred. In such emergency situations, the various actuation and mixing steps need to be performed in an intuitive manner such that they can be performed reliably in emergency situations with minimal complexity. For this reason it would be useful to have an easy-to-use auto-injector or a syringe-type device that automates the drug preparation process while also providing a platform which requires minimal user training and opportunity for user failure or dosing inaccuracy.

The invention here describes an interface whereby a single user input, involving removal of the cap, sets off a cascade of mechanical functions that initiates mixing, signals the completion of mixing, and places the device into an injection-ready state.

<CIT> discloses an injector according to the state of the art.

An injector according to an embodiment of the invention is set out in accompanying claim <NUM>.

Some additional features of embodiments of the invention are set out in the dependent claims. The cap can further include two or more interior channels being aligned axially, and wherein the frame further comprises an exterior protrusion corresponding in shape to the interior channel of the cap, wherein the interior channel and exterior protrusion are configured to allow an axial relative translation, but are constrained in a rotational degree of motion.

In various alternative embodiments the one or more engagement lips can be ramped in an axial direction so as to allow travel between the cap and the housing in response to rotation.

In yet additional alternative embodiments the cap can also include a spring being configured to assist in separation of the cap from the housing after actuation.

In yet additional alternative embodiments the lip comprises a plurality of threads on an interior surface, and wherein the protrusion comprises a plurality of corresponding threads on an exterior surface, and wherein rotation of the cap relative to the housing causes the device to move from a stowed state, through an intermediate state, and into a mixed state, whereupon reaching the mixed state the cap is configured to release, and be removed from the housing.

In yet additional alternative embodiments the cap and the housing can be configured to have a corresponding cross-sectional shape. In some such embodiments this cross-sectional shape can be an elliptical cross-sectional shape.

In yet additional alternative embodiments the mixing device can be configured to include a locking mechanism, the locking mechanism being configured to prevent the cap from rotating back into an aligned state indicative of a stowed state after an initial relative rotation between the cap and the housing.

A method of mixing medication in the injector of claim <NUM> is also provided, as set out in accompanying claim <NUM>.

This method can further include releasing energy from a pre-stored energy component disposed when triggering the actuating component.

The method can also include an internal frame disposed within the housing that interacts and rotates with the internal protruding component.

The foregoing and other objects, features, and advantages of the invention will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views.

The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention, wherein:.

It will be appreciated by those having skill in the area of fabrication and storage, and delivery of drugs, that the lifespan and effectiveness of the drug can be increased substantially by keeping the medication in a dry state. Storage in a dry state also decreases the rate of degeneration as well as the degenerative effects of temperature, for example heat exposure. By keeping the drug in a dry state the breadth of environments where the device can be stored is increased while decreasing the frequency of required replacement.

It should be noted that additional description of embodiments including pre-stored energy sources, springs, chambers, fluidic pathways, needles, medicaments, and other components are described in the following applications: <CIT> and <CIT>. <FIG> illustrates an exemplary embodiment of an auto-injector having pre-stored energy sources, mixing components, injection assemblies, and actuation assemblies about which a rotational cap described herein can be integrated therewith.

The present invention illustrates various principles and devices which allow for the storage of a device having two or more components contained therein but which can quickly and reliably reconstitute, dissolve, fluidize, and/or put into a suspension, the components, i.e. mix them, immediately prior to delivery.

However, various issues can arise with drug mixing and delivery devices many of which will be addressed by the present invention as illustrated in the various embodiments. One such issue is that premature mixing of the drugs can also result in associated premature degradation of the drugs. In the present embodiments there are several types of sealing systems which exist between various drugs and/or chambers within the device. These barriers or seals are removed, destroyed, or somehow overcome in the actuation process prior to injection. As such it is desirable to provide indicators or other mechanisms which signal to the user that these barriers or seals remain intact.

In various embodiments the cap is provided at an injection end of the auto-injector. The rotating cap can be configured so as to couple to the auto-injector and provide a seal around an injection assembly and prevent contamination of the injection assembly thus maintaining the injection assembly in a sterile state, regardless of the environment in which it is kept, i.e. a backpack, pocket, purse, glove compartment of a car, etc..

Upon removal of the cap using one of the aforementioned embodiments, the injection assembly, which can involve the use of a bump switch, can be exposed, the needle can be extended, inserted into the patient, and the drug appropriately delivered.

Another issue addressed by the present invention is that the needle or injection assembly should not be exposed until the device is ready to inject. As discussed briefly above, auto-injectors are often used in emergency situations, such as to treat anaphylactic shock by mixing and delivering a dose of epinephrine. Or, using glucagon for treating hypoglycemia, sumatriptan for migraine headaches, diazepam for seizure medication, clotting factors for hemophelia, and so on. As such the atmosphere can be hectic and in order to reduce instances of premature activation of the injection assembly, loss of sterility by not properly cleaning a drug vial before manually drawing up a dose, or accidental unintentional sticks by the injection needle, the injection assembly, and associated needle, with an associated injection mechanism can be covered or shielded until the device is ready for injection, i.e. the drug has been completely mixed. In the present embodiment, the cap is configured to interact with actuation assemblies carried by the housing such that twisting and removal of the cap signal that the device is ready for injection.

Yet another issue which is addressed by the various embodiments discussed herein involves the reduction of mandatory steps that need to be performed by the user. As discussed above, such high-intensity situations can result in an inability to remember numerous steps and as such removal of as any necessary steps and streamlining the activation process will be of great advantage in ensuring proper drug delivery. The devices of the present invention, and as illustrated in <FIG>, illustrate various aspects of the present invention which involves providing an auto-injector <NUM> wherein <FIG> illustrates a stowed state. The injector <NUM> can include a housing <NUM> and a cap <NUM>. Rotation of the cap <NUM> with respect to the housing <NUM> causes an actuation of an internal mixing assembly (not shown here) which activates the mixing of the various drugs contained within the housing. <FIG> illustrates a partial or intermediate relative rotation between the cap <NUM> and the housing <NUM>. <FIG> illustrates a full rotation wherein the cap <NUM> is released from the housing <NUM> thus signalling that the mixing step has begun, and readying the device for injecting the mixed medicament components. Other indicators can be provided that indicate a fully-mixed state, provide visibility on the mixed drug, and then allow exposure of an injection assembly <NUM> and switch <NUM> to be triggered. At this point the device can be pressed against an injection site, i.e. the skin of the patient, the switch <NUM> will be pressed upward into the housing <NUM> and the injection assembly <NUM> can extend a needle (not shown here) and eject the now mixed drugs contained therein.

As shown in <FIG>, and <FIG>, the cap <NUM> can include one or more channels <NUM> which can be axially aligned, and are configured to correspond in shape with, as well as interact with, one or more axially aligned protrusions <NUM> provided on the frame <NUM>. The channels <NUM> and the protrusions <NUM> act as an internal cam system to rotate the frame <NUM> with respect to the housing <NUM> as the cap <NUM> is rotated, which in turn operates to open a valve or otherwise allow for mixing of various drugs contained within the housing. For example, a valve can be opened and a displacement mechanism released which allows a wet solvent to flow into and dissolve a dry drug contained in a secondary dry chamber. It will be appreciated that by aligning the channels and the protrusions in an axial manner, the cap will be capable of sliding axially with respect to the frame, which will be necessary for removal of the cap upon completion of the necessary rotation for actuation.

In some embodiments, and as seen in <FIG>, <FIG>, <FIG>, the cap <NUM> can further include one or more protrusions <NUM>, and wherein the housing <NUM> can further comprises a corresponding lip <NUM> about a distal or injection end, wherein the one or more protrusions <NUM> of the cap <NUM> can be configured to
engage the corresponding lip <NUM> in a stowed and intermediate state, as shown in <FIG> respectively, and wherein the protrusions <NUM> disengage from the corresponding lipl02 at a mixed state, as shown in <FIG>.

It will be appreciated that in order to facilitate release upon completion of the mixing, the corresponding lip <NUM> can be provided with a release channel or cutout <NUM> which at a relative radial rotation allows for the cap <NUM>, and protrusions <NUM>, to disengage from the housing <NUM> and corresponding lip <NUM> so as to expose the injection assembly <NUM> and injection trigger <NUM>.

It will be appreciated that in certain instances the user will desire some sort of an indication that the device is responding to user input and is performing the requisite internal functions, and that mere removal of the cap may, in some instances be insufficient indication of such functionality. As such, in some embodiments, and as shown in <FIG> and <FIG>, the one or more engagement lips <NUM> B-D can be provided in an axially ramped configuration being engaged with internal protrusions <NUM> B-D extending from the cap <NUM> wherein relative rotation between the cap <NUM> and the housing <NUM> results in an axial translation or travel between the cap <NUM> and the housing <NUM>. This axial translation results in a manual separation between the cap and the housing which provides a gap <NUM> which provides some measure of tactile or even visual indication to the user that the rotational input provided between the housing and the cap is providing the desired internal functionality, i.e. that mixing is actually occurring. In some embodiments, the gap <NUM> which is generated between the cap <NUM> and the housing <NUM> can be provided with additional visual or tactile indicia which provide confirmation of internal operations. In some embodiments an underlying color band can be provided on the housing <NUM> as
the cap translates respective to the housing, wherein the color band is initially hidden by the cap in the stowed state, wherein the gap <NUM> provides visibility of the color band, which increases throughout relative rotation therebetween.

It will be appreciated that <FIG> illustrate how the cap and the frame can have the axial protrusions and channels reversed wherein the channels <NUM> are provided on the frame <NUM> with corresponding internal protrusions <NUM> provided in the cap <NUM>. <FIG> also illustrates how the retention mechanisms can be reversed wherein tabs 102A can be provided on the housing <NUM> which engage a corresponding lip 202A provided on the cap <NUM>.

In yet additional embodiments, and as shown in <FIG>, the cap <NUM> can be provided with a spring <NUM> which is configured to aid or otherwise assist in separation of the cap <NUM> from the housing <NUM> upon completion of the requisite relative rotation between the cap <NUM> and the housing <NUM> so as to signal completion of the actuation of the mixing by the mixing assembly, <NUM> (as shown in <FIG>), wherein the spring provides a separation force and causes the cap <NUM> to separate from the housing <NUM> upon completion of the required relative rotation absent a pulling or tensile force input by the user. This is achieved because the spring cannot overcome the tensile strength of the protrusions and corresponding lip discussed above until the protrusions <NUM> are aligned with the separation channel <NUM> (see <FIG>) at a desired relative rotational position between the cap <NUM> and the housing <NUM>.

In some alternative embodiments, and as shown in <FIG>, the engagement components of the cap <NUM> and the housing <NUM>, can be reversed, with respect to the embodiments discussed above. In this embodiment the cap <NUM> can instead include one or more engagement lips <NUM> A on an interior surface, and the housing <NUM> can instead include one or more corresponding protrusions 102A about a distal end. In this embodiment the one or more protrusions 102A of the housing <NUM> engage the one or more engagement lips <NUM> A in a stowed and intermediate state, and wherein the one or more protrusions 102A disengage from the one or more engagement lips <NUM> A at a mixed state, wherein rotation of the cap <NUM> relative to the housing causes the device to move from the stowed state, through the intermediate state, and into the mixed state, whereupon reaching the mixed state the cap is configured to release, and be removed from the housing.

In yet additional embodiments, and as shown in <FIG> the cap <NUM> can be provided with a plurality of threads 102D on an interior surface, and wherein the housing <NUM> is provided with a plurality of corresponding threads 102D on an exterior surface, and wherein rotation of the cap relative to the housing causes the device to move from a stowed state, through an intermediate state, and into a mixed state, whereupon reaching the mixed state the cap the relative threads are configured to release, and the cap <NUM> release so as to be removed from the housing <NUM>.

<FIG> illustrate how the housing <NUM> and the cap <NUM> can have varying cross-sectional shapes, wherein the cross-sectional shape of the housing <NUM> and the cap <NUM> correspond to one another. It will be further appreciated that the corresponding nature of the relative shapes can be properly aligned and flush in the stowed state. However, the variation of the cross-sectional shape renders any relative rotation between the cap <NUM> and the housing <NUM> particularly obvious, as any rotation would result in readily apparent misalignment, both in a tactile and visual sense. <FIG> help illustrate this visual and tactile misalignment between cap and housing.

Additionally, an elliptical cross-sectional shape allows for easier assembly when initially preparing the device as the space between the major and minor radii allows for access, depression of, and engagement of various assembly tools, locking mechanisms, etc..

As discussed briefly above, it will be appreciated, that any rotation out of the stowed and aligned state may result in a partial removal or overcoming of barriers or seals in place to keep the various drug components separated, wherein any mixing thereof would likely accelerate the degradation process and thus render the drugs inert or contaminated. As such a locking mechanism can be provided to the device which prevents any backward rotation after an initial rotation between the cap and the housing. One such embodiment of a locking mechanism is illustrated in <FIG> and <FIG>. The locking mechanism <NUM> can be provided as a series of ratcheting protrusions <NUM> which engage a corresponding protrusion <NUM>, as seen in <FIG>, in the frame <NUM> or housing <NUM>. In this manner, as the frame <NUM> rotates with respect to the housing <NUM>, and stationary plunger and protrusion <NUM>, in response to a torsional force between the cap <NUM> and the housing <NUM>, the ratchet engages and allows movement is one relative rotational direction, but not backwards into a realigned state. In this manner once the cap <NUM> is rotated out of the stowed state, it cannot be returned to the stowed position by the user, thus signalling that the drugs contained therein may have been compromised, and the device needs to be replaced.

Another embodiment of a locking mechanism is illustrated in <FIG> wherein the cap itself is provided with a resilient ramped lock <NUM>, which ramped lock can be disengaged during initial assembly, but upon initial rotation out of the stowed state engages a corresponding tab <NUM> or other protrusion on the frame or housing can be provided which prevents backward rotation back into the stowed state.

In yet additional embodiments, and as shown in <FIG>, the locking mechanism <NUM> can be alternatively provided as a series of ratcheting protrusions <NUM> provided on the frame <NUM> can be interior facing and engage with a rotationally fixed plunger <NUM> device of the mixing assembly.

It will be appreciated that various cap shapes can be utilized, either circular or non-circular. Some advantage has been realized through the use of non-circular geometric shapes, and in particular ellipsoid cap. Ellipsoid shapes provide additional interior space between the major and minor diameters into which the tabs and corresponding locking grooves can be formed. In addition to providing additional interior space, the relative rotation between the cap <NUM> and the frame of the drug mixing system results in a visible change in relative position, as the edges will change respective position with respect to one another continuously through the rotational distance as the cap is twisted.

It will also be appreciated that a rotational distance, i.e. a distance the cam is required to move in order to fully activate or open the valve, can be adjusted to be virtually any fixed value. However, it has been recognized, particularly with respect to ellipsoid shapes that a relative rotational distance from <NUM>-<NUM> relative degrees is preferred because at <NUM> degrees the two ellipsoid shapes will be the furthest out of phase which can signify a complete opening before the two shapes begin to move back into phase and can give the mental impression that the valve is moving back to closed.

It will also be appreciated that the cross-sectional area of the frame <NUM> can be provided as circular, wherein the circular cross-section of the frame <NUM> rides or engages a series of interior rails <NUM> of the housing <NUM> which rails <NUM> provide an effectively circular interior profile to the housing <NUM> and allow for free rotation, upon actuation, between the frame <NUM> and the housing <NUM>.

Claim 1:
An injector comprising:
a housing (<NUM>);
a frame (<NUM>) being rotatably disposed within the housing (<NUM>);
a mixing assembly (<NUM>) being disposed within the frame (<NUM>), the mixing assembly (<NUM>) being configured to actuate in response to rotation of the frame (<NUM>) with respect to the housing (<NUM>);
a trigger assembly; and
a cap (<NUM>) being disposed at a distal end of the housing (<NUM>) over the trigger assembly, the cap (<NUM>) being operatively connected to the housing (<NUM>) on an interior portion, wherein rotation of the cap (<NUM>) with respect to the housing (<NUM>) imparts a relative rotation between the frame (<NUM>) and the housing (<NUM>), thus actuating the mixing assembly (<NUM>),
characterised in that
the cap (<NUM>) further comprises an interior channel (<NUM>) being aligned axially, and wherein the frame (<NUM>) further comprises an exterior protrusion (<NUM>) corresponding in shape to the interior channel (<NUM>) of the cap (<NUM>), wherein the interior channel (<NUM>) and exterior protrusion (<NUM>) are configured to allow an axial relative translation, but are constrained in a rotational degree of motion, and
wherein the cap (<NUM>) further comprises one or more protrusions (<NUM>), and wherein the housing (<NUM>) further comprises a corresponding lip (<NUM>) about a distal end, wherein the one or more protrusions (<NUM>) of the cap (<NUM>) engage the lip (<NUM>) in a stowed and intermediate state, and wherein the protrusions (<NUM>) disengage from the lip (<NUM>) at a mixed state, wherein rotation of the cap (<NUM>) relative to the housing (<NUM>) causes the device to move from the stowed state, through the intermediate state, and into the mixed state, whereupon the cap (<NUM>) is configured to release, and be removed from the housing (<NUM>), and
wherein the rotation of the cap (<NUM>) is limited between <NUM> to <NUM> degrees with respect to the housing (<NUM>) and whereupon the cap (<NUM>) is configured to be released from the housing (<NUM>) after a rotation of <NUM> to <NUM> degrees.