Patent Description:
Injection devices, such as auto-injectors, are known in the art for dispensing a medicament to the injection site of a patient. Such injection devices typically comprise a body and a cap. A needle syringe is located in the body. The cap is removably attached to the body to shield the needle of the needle syringe. To dispense the medicament, the cap is first removed from the body to expose the needle. The needle is then inserted into the body of the patient at the injection site to dispense the medicament.

It is important that the cap is held onto the body with sufficient force to ensure that the cap is not accidentally removed from the body during transport and storage of the injection device. This ensures that the needle is kept sterile and also prevents the sharp needle from causing injury. However, the force required to hold the cap and body together can make it difficult for the patient to intentionally remove the cap from the body prior to injection, particularly if the patient is elderly or infirm.

<CIT> discloses a one-time use device to deliver preservative-free follicle stimulating hormone (FSH) solution is disclosed. The device includes a needle covered by a sliding needle shield, which covers the needle in all modes of the device. The device can be placed into a ready-to-use position in four or fewer user steps. The device has a knob for setting a desired dose of FSH. The knob includes longitudinally spaced elements respectively corresponding to the lock position and the seven or fewer discrete dosing positions.

It is an object of the present invention to provide an improved injection device.

According to the present invention, there is provided a cap for an injection device having a body for holding a syringe with a needle extending from one end thereof, wherein the cap is removably attachable to the body and comprises: an actuator; a needle shield to cover said needle; and, a coupling between the actuator and the needle shield configured such that when the cap is attached to the body on an injection device axial movement of the actuator away from the body causes rotation of the needle shield relative to the body.

Therefore, the actuator may be linearly pulled away from the body to remove the needle shield from the body. This pulling motion of the actuator may make removal of the needle shield easier for persons who may not have the dexterity required to twist the needle shield, such as the elderly and infirm.

In one embodiment, the coupling is configured such that when the cap is attached to the body of an injection device axial movement of the actuator away from the body by a first distance causes axial movement of the needle shield away from the body by a second distance, which is smaller than the first distance. Therefore, if the actuator is pulled away from the body by a given force then the resultant force acting on the needle shield to urge the needle shield away from the body will be larger than said given force. Therefore, the coupling reduces the amount of force that must be exerted by the patient to remove the needle shield.

The coupling may comprise a connection between the actuator and the needle shield. The connection may be a threaded connection.

The cap may further comprise a holder, wherein the coupling comprises a first connection between the actuator and the needle shield and a second connection between the holder and the needle shield. In one embodiment, the first connection is configured such that when the cap is attached to the body of an injection device axial movement of the actuator away from the body causes rotation of the needle shield relative to the body, and wherein the second connection is configured such that rotation of the needle shield relative to the body causes axial movement of the needle shield away from the body.

The first and second connections may comprise threaded connections. In one embodiment, the pitch of the first connection is different to the pitch of the second connection. Therefore, axial movement of the actuator away from the body by a first distance results in the needle shield moving away from to the body by a second distance. Preferably, the pitch of the first connection is greater than the pitch of the second connection. Therefore, the second distance is smaller than the first distance and thus if a given force is exerted on the actuator to pull the actuator away from the body then the resultant force acting on the needle shield to move the needle shield away from the body will be larger than said given force. Thus, the amount of force that must be exerted by the patient to remove the needle shield is reduced.

In one embodiment, the cap further comprises a lock that releasably couples the holder to the body to prevent rotation of the holder relative to the body. The lock may comprise one or more projections or recesses that are configured to engage with the body when the cap is attached to the body. In one embodiment, the injection device comprises a retractable sleeve and said one or more projections or recesses of the lock are configured to engage with the retractable sleeve.

In one embodiment, the actuator comprises a first stopper and the holder comprises a second stopper, wherein the first and second stoppers are configured such that when the cap is attached to the body the first and second stoppers engage when the actuator is moved away from the body to limit axial movement between the actuator and holder.

The actuator may comprise an end cap. In one such embodiment, the needle shield is disposed in the end cap when the cap is attached to the body. This allows for the injection device to be compact and easy to store.

The actuator may comprise a grip that may be gripped by the patient to move the actuator axially away from the body. The grip may comprise a flanged portion of the actuator.

According to the present invention, there is also provided an injection device comprising a body for holding a syringe having a needle extending from an end thereof and a cap.

In one embodiment, the injection device comprises a syringe held in the body and having a needle at one end, wherein the needle shield is configured to frictionally engage with the syringe when the cap is attached to the body, and wherein axial movement of the actuator away from the body causes rotation of the needle shield about the syringe. The rotational movement of the needle shield about the syringe may reduce static friction between the needle shield and the syringe to facilitate removal of the needle shield from the syringe. The syringe may contain a medicament.

In one embodiment, the needle shield comprises a spindle, wherein the coupling is between the actuator and the spindle.

In one embodiment, the injection device is an auto-injector.

According to the present invention, there is also provided a method of removing a cap from a body of an injection device, wherein the body holds a syringe having a needle extending from one end thereof and the cap comprises a needle shield to cover said needle, the method comprising: moving an actuator of the cap axially away from the body of the injection device, wherein the actuator is coupled to the needle shield by a coupling configured such that the axial movement of the actuator away from the body causes rotation of the needle shield relative to the body. The injection device may comprise one or more of the features of the injection device described hereinbefore.

A drug delivery device, as described herein, may be configured to inject a medicament into a patient. For example, delivery could be sub-cutaneous, intra-muscular, or intravenous. Such a device could be operated by a patient or care-giver, such as a nurse or physician, and can include various types of safety syringe, pen-injector, or auto-injector. The device can include a cartridge-based system that requires piercing a sealed ampule before use. Volumes of medicament delivered with these various devices can range from about <NUM> to about <NUM>. Yet another device can include a large volume device ("LVD") or patch pump, configured to adhere to a patient's skin for a period of time (e.g., about <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> minutes) to deliver a "large" volume of medicament (typically about <NUM> to about <NUM>).

The delivery devices described herein can also include one or more automated functions. For example, one or more of needle insertion, medicament injection, and needle retraction can be automated. Energy for one or more automation steps can be provided by one or more energy sources. Energy sources can include, for example, mechanical, pneumatic, chemical, or electrical energy. For example, mechanical energy sources can include springs, levers, elastomers, or other mechanical mechanisms to store or release energy. One or more energy sources can be combined into a single device. Devices can further include gears, valves, or other mechanisms to convert energy into movement of one or more components of a device.

The one or more automated functions of an auto-injector may each be activated via an activation mechanism. Such an activation mechanism can include one or more of a button, a lever, a needle sleeve, or other activation component. Activation of an automated function may be a one-step or multi-step process. That is, a user may need to activate one or more activation components in order to cause the automated function. For example, in a one-step process, a user may depress a needle sleeve against their body in order to cause injection of a medicament. Other devices may require a multi-step activation of an automated function. For example, a user may be required to depress a button and retract a needle shield in order to cause injection.

According to some embodiments of the present disclosure, an exemplary drug delivery device <NUM> is shown in <FIG>. Device <NUM>, as described above, is configured to inject a medicament into a patient's body. Device <NUM> includes a housing <NUM> which typically contains a reservoir containing the medicament to be injected (e.g., a syringe) and the components required to facilitate one or more steps of the delivery process. Device <NUM> can also include a cap assembly <NUM> that can be detachably mounted to the housing <NUM>. Typically a user must remove cap <NUM> from housing <NUM> before device <NUM> can be operated.

As shown, housing <NUM> is substantially cylindrical and has a substantially constant diameter along the longitudinal axis A-A. The housing <NUM> has a distal region D and a proximal region P. The term "distal" refers to a location that is relatively closer to a site of injection, and the term "proximal" refers to a location that is relatively further away from the injection site.

Device <NUM> can also include a needle sleeve <NUM> coupled to housing <NUM> to permit movement of sleeve <NUM> relative to housing <NUM>. For example, sleeve <NUM> can move in a longitudinal direction parallel to longitudinal axis A-A. Specifically, movement of sleeve <NUM> in a proximal direction can permit a needle <NUM> to extend from distal region D of housing <NUM>.

Insertion of needle <NUM> can occur via several mechanisms. For example, needle <NUM> may be fixedly located relative to housing <NUM> and initially be located within an extended needle sleeve <NUM>. Proximal movement of sleeve <NUM> by placing a distal end of sleeve <NUM> against a patient's body and moving housing <NUM> in a distal direction will uncover the distal end of needle <NUM>. Such relative movement allows the distal end of needle <NUM> to extend into the patient's body. Such insertion is termed "manual" insertion as needle <NUM> is manually inserted via the patient's manual movement of housing <NUM> relative to sleeve <NUM>.

Another form of insertion is "automated," whereby needle <NUM> moves relative to housing <NUM>. Such insertion can be triggered by movement of sleeve <NUM> or by another form of activation, such as, for example, a button <NUM>. As shown in <FIG>, button <NUM> is located at a proximal end of housing <NUM>. However, in other embodiments, button <NUM> could be located on a side of housing <NUM>.

Other manual or automated features can include drug injection or needle retraction, or both. Injection is the process by which a bung or piston <NUM> is moved from a proximal location within a syringe <NUM> to a more distal location within the syringe <NUM> in order to force a medicament from the syringe <NUM> through needle <NUM>. In some embodiments, a drive spring (not shown) is under compression before device <NUM> is activated. A proximal end of the drive spring can be fixed within proximal region P of housing <NUM>, and a distal end of the drive spring can be configured to apply a compressive force to a proximal surface of piston <NUM>. Following activation, at least part of the energy stored in the drive spring can be applied to the proximal surface of piston <NUM>. This compressive force can act on piston <NUM> to move it in a distal direction. Such distal movement acts to compress the liquid medicament within the syringe <NUM>, forcing it out of needle <NUM>.

Following injection, needle <NUM> can be retracted within sleeve <NUM> or housing <NUM>. Retraction can occur when sleeve <NUM> moves distally as a user removes device <NUM> from a patient's body. This can occur as needle <NUM> remains fixedly located relative to housing <NUM>. Once a distal end of sleeve <NUM> has moved past a distal end of needle <NUM>, and needle <NUM> is covered, sleeve <NUM> can be locked. Such locking can include locking any proximal movement of sleeve <NUM> relative to housing <NUM>.

Another form of needle retraction can occur if needle <NUM> is moved relative to housing <NUM>. Such movement can occur if the syringe <NUM> within housing <NUM> is moved in a proximal direction relative to housing <NUM>. This proximal movement can be achieved by using a retraction spring (not shown), located in distal region D. A compressed retraction spring, when activated, can supply sufficient force to the syringe <NUM> to move it in a proximal direction. Following sufficient retraction, any relative movement between needle <NUM> and housing <NUM> can be locked with a locking mechanism. In addition, button <NUM> or other components of device <NUM> can be locked as required. Referring now to <FIG>, part of an injection device <NUM> according to a first embodiment of the invention is shown. The injection device <NUM> is in the form of an auto-injector <NUM> that has similar features to the auto-injector <NUM> described above in relation to <FIG>, with like features retaining the same reference numerals. A difference is that the cap <NUM> of the auto-injector <NUM> described above is omitted and is replaced with an alternative cap <NUM>.

The cap <NUM> of the auto-injector <NUM> of the first embodiment of the invention comprises a needle shield <NUM> and an actuator <NUM>. The needle shield <NUM> comprises a housing <NUM> and an inner sheath <NUM>. The inner sheath <NUM> is fixedly secured in the housing <NUM>. The inner sheath <NUM> comprises a cylindrical recess 25A. The recess 25A is configured to receive an end portion 18A of the syringe <NUM> such that the needle <NUM> is shielded by the inner sheath <NUM>. The friction between the inner sheath <NUM> and the end portion 18A of the syringe <NUM> is sufficient to hold the needle shield <NUM> in place covering the needle <NUM>.

The actuator <NUM> is in the form of an end cap <NUM>. The end cap <NUM> comprises a cylindrical recess 23A at one end and a grip at the other end in the form of a flanged portion 23B at. The flanged portion 23B facilitates gripping of the end cap <NUM> to remove the cap <NUM> from the body <NUM> of the auto-injector <NUM>. The housing <NUM> of the needle shield <NUM> is generally cylindrical and is received within the recess 23A of the end cap <NUM>.

The auto-injector <NUM> further comprises a coupling between the needle shield <NUM> and the end cap <NUM>. The coupling comprises a connection 26A having a screw thread <NUM> and a pair of projections <NUM>.

The screw thread <NUM> is formed into a peripheral surface of the housing <NUM> of the needle shield <NUM> and extends about the central axis A-A of the auto-injector <NUM>. The projections <NUM> protrude from opposing sides of the inner surface of the end cap <NUM> to extend radially into the recess 23A of the end cap <NUM>. Thus, the projections <NUM> engage with the screw thread <NUM> when the needle shield <NUM> is received in the recess 23A of the end cap <NUM>.

The connection 26A is configured such that axial movement of the end cap <NUM> away from the body <NUM> causes the projections <NUM> to engage with the screw thread <NUM> such that the needle shield <NUM> rotates relative to the body <NUM> about the central axis A-A (in the direction of arrow 'B' shown in <FIG>). Axial movement of the end cap <NUM> away from the body <NUM> also causes the needle shield <NUM> to move axially away from the body <NUM> (in the direction of arrow 'F' in <FIG>).

The cap <NUM> is initially attached to the body <NUM> such that the end portion 18A of the syringe <NUM> is completely received in the recess 25A of the inner sheath <NUM> (as shown in <FIG>). Thus, the needle <NUM> is covered by the needle shield <NUM> to keep the needle <NUM> sterile and to prevent the needle <NUM> from causing injury to the patient.

To inject a medicament, the cap <NUM> must first be removed from the body <NUM> to expose the needle <NUM>. Removal of the cap <NUM> from the body <NUM> is achieved by the patient holding the body <NUM> in one hand and exerting a force on the end cap <NUM> with the other hand (in the direction of arrow 'F' shown in <FIG> and <FIG>) to pull the end cap <NUM> away from the body <NUM>. This causes the projections <NUM> to be urged relative to the needle shield <NUM> (in the direction of arrow 'F') such that the projections <NUM> exert a force on the screw thread <NUM> which results in the needle shield <NUM> rotating about the central axis A-A relative to the body <NUM> and end cap <NUM>. The needle shield <NUM> also moves axially away from the body <NUM> as the end cap <NUM> is pulled away from the body <NUM>.

The needle <NUM> is fixed relative to the body <NUM>. Therefore, as the end cap <NUM> is pulled away from the body <NUM>, the needle shield <NUM> moves axially away from the needle <NUM> such that it first becomes partially removed from the end portion 18A of the syringe <NUM> (as shown in <FIG>) and then becomes fully removed from the end portion 18A of the syringe <NUM> such that the end portion 18A is no longer received in the recess 25A of the inner sheath <NUM> (as shown in <FIG>). Once the end portion 18A of the syringe <NUM> has been fully removed from the recess 25A in the inner sheath <NUM>, the friction between the cap <NUM> and the body <NUM> is reduced such that the cap <NUM> can easily be removed from the body <NUM>.

The rotational movement of the needle shield <NUM> relative to the end portion 18A of the syringe <NUM> when the end cap <NUM> is moved axially away from the body <NUM> overcomes the static friction between the inner sheath <NUM> and the end portion 18A, making it easier to remove the cap <NUM> from the body <NUM>. The linear pulling motion (in the direction of arrow 'F') of the end cap <NUM> relative to the body <NUM> makes removal of the cap <NUM> easier for the elderly and infirm, who may not have the dexterity required to manually twist the cap <NUM> relative to the body <NUM>.

Although in the above described embodiment the housing <NUM> of the needle shield <NUM> comprises the screw thread <NUM> and the end cap <NUM> comprises the pair of projections <NUM>, in an alternative embodiment (not shown) the needle shield comprises the pair of projections and the end cap comprises the screw thread. In another alternative embodiment, the first pair of projections are omitted and are replaced by a second screw thread that is configured to engage with the first screw thread.

In the above described embodiment the end cap <NUM> comprises a flanged portion 23B which facilitates gripping of the end cap <NUM> to remove the cap <NUM> from the body <NUM> of the auto-injector <NUM>. However, in alternative embodiments (not shown) the flanged portion 23B is omitted. In one such alternative embodiment, the end cap comprises a loop of material that may be gripped by the user to pull the end cap away from the body. The end cap may comprise a cylindrical portion for receiving the needle shield and the loop of material may be secured to the cylindrical portion. In another embodiment (not shown), the end cap comprises a hook or handle that may be gripped by the user to pull the end cap away from the body.

Referring now to <FIG>, an injection device <NUM> according to a second embodiment of the invention is shown. The injection device <NUM> is in the form of an auto-injector <NUM> that has similar features to the auto-injector <NUM> described above in relation to <FIG>, with like features retaining the same reference numerals. A difference is that the cap <NUM> of the auto-injector <NUM> described above is omitted and is replaced with an alternative cap <NUM>.

The cap <NUM> of the auto-injector <NUM> of the second embodiment of the invention comprises a needle shield <NUM> and an actuator <NUM>. The needle shield <NUM> comprises a housing <NUM> and an inner sheath <NUM>. The housing <NUM> is generally cylindrical. The inner sheath <NUM> is fixedly secured in the housing <NUM>. The inner sheath <NUM> comprises a cylindrical recess 35A. The recess 35A is configured to receive end portion 18A of the syringe <NUM> such that the needle <NUM> is shielded by the inner sheath <NUM>. The friction between the inner sheath <NUM> and the end portion 18A of the syringe <NUM> is sufficient to hold the needle shield <NUM> in place covering the needle <NUM>.

The actuator <NUM> is in the form of an end cap <NUM>. The end cap <NUM> comprises a cylindrical recess 33A.

The cap <NUM> further comprises a support member <NUM>, a spindle <NUM> and a holder <NUM>. The support member <NUM> is tubular and extends into the recess 33A of the end cap <NUM> from the end of the end cap <NUM>. The support member <NUM> defines a recess 36A that is configured to receive the spindle <NUM>. The support member <NUM> is co-axial with the end cap <NUM> and is integrally formed therewith.

The spindle <NUM> is generally cylindrical and extends from an end of the housing <NUM> of the needle shield <NUM>. The spindle <NUM> is part of the needle shield <NUM> and is co-axial and integrally formed with the housing <NUM>.

The holder <NUM> is a hollow tube. An end of the holder <NUM> is configured to receive the support member <NUM> such that part of the holder <NUM> towards said end is located between the support member <NUM> and a peripheral wall of the end cap <NUM>. The needle shield <NUM> is received within the holder <NUM> such that the spindle <NUM> is located in the recess 36A of the support member <NUM> when the inner sheath <NUM> is received on the end portion 18A of the syringe <NUM> (as shown in <FIG>).

The auto-injector <NUM> further comprises a coupling between the needle shield <NUM> and the end cap <NUM>. The coupling comprises first and second connections 39A, 39B.

The first connection 39A comprises a first screw thread <NUM> and a first pair of projections <NUM>. The first screw thread <NUM> is formed into a peripheral surface of the spindle <NUM> and extends about the central axis A-A of the auto-injector <NUM>. The first pair of projections <NUM> protrude from opposing sides of an end of the support member <NUM> to extend radially towards the central axis A-A of the auto-injector <NUM>. Thus, the first pair of projections <NUM> engage with the first screw thread <NUM> when the spindle <NUM> is received in the recess 36A in the support member <NUM>.

The first connection 39A is configured such that axial movement of the end cap <NUM> away from the body <NUM> causes the first pair of projections <NUM> to engage with the first screw thread <NUM> such that the spindle <NUM> rotates relative to the body <NUM>, end cap <NUM>, and holder <NUM> about the central axis A-A (in the direction of arrow 'C' shown in <FIG>). Axial movement of the end cap <NUM> away from the body <NUM> also causes the end cap <NUM> to move axially away from the spindle <NUM> (in the direction of arrow 'F' in <FIG>) as the spindle <NUM> rotates relative to the end cap <NUM>.

The second connection 39B comprises a second screw thread <NUM> and a second pair of projections <NUM>. The second screw thread <NUM> is formed into a peripheral surface of the housing <NUM> of the needle shield <NUM> and extends about the central axis A-A of the auto-injector <NUM>. The second pair of projections <NUM> protrude from opposing sides of an inner surface of the holder <NUM> to extend towards the central axis A-A of the auto-injector <NUM>. Thus, the second pair of projections <NUM> engage with the second screw thread <NUM> when the needle shield <NUM> is received in the holder <NUM>.

The second connection 39B is configured such that rotation of the needle shield <NUM> relative to the holder <NUM> causes the second pair of projections <NUM> to engage with the second screw thread <NUM> such that the needle shield <NUM> moves axially relative to the body <NUM> and holder <NUM> in a direction away from the body <NUM> (in the direction of arrow 'F' shown in <FIG>).

The cap <NUM> is initially attached to the body <NUM> such that the end portion 18A of the syringe <NUM> is completely received in the recess 35A of the inner sheath <NUM> (as shown in <FIG>). Thus, the needle <NUM> is covered by the needle shield <NUM> to keep the needle <NUM> sterile and to prevent the needle <NUM> from causing injury to the patient.

To inject medicament, the cap <NUM> must first be removed from the body <NUM> to expose the needle <NUM>. Removal of the cap <NUM> from the body <NUM> is achieved by the patient holding the body <NUM> in one hand and exerting a force on the end cap <NUM> with the other hand (in the direction of arrow 'F' shown in <FIG> and <FIG>) to pull the end cap <NUM> away from the body <NUM>. This causes the first pair of projections <NUM> to be urged relative to the spindle <NUM> (in the direction of arrow 'F') such that the first pair of projections <NUM> exert a force on the first screw thread <NUM> which results in the spindle <NUM> rotating about the central axis A-A relative to the body <NUM>, holder <NUM>, and end cap <NUM>. The end cap <NUM> also moves axially away from the spindle <NUM> as the first pair of projections <NUM> move relative to the first screw thread <NUM>.

The spindle <NUM> is integrally formed with the housing <NUM> of the needle shield <NUM> such that rotation of the spindle <NUM> causes rotation of the housing <NUM> and needle sheath <NUM>. Thus, when the spindle <NUM> rotates due to the patient pulling on the end cap <NUM>, the second screw thread <NUM> engages with the second pair of projections <NUM> to urge the needle shield <NUM> axially relative to the holder <NUM> (in the direction of arrow 'F' in <FIG> and <FIG>). The holder <NUM> is fixed axially and rotationally relative to the body <NUM> by a lock <NUM>. The lock <NUM> comprises a plurality of recesses <NUM> in the holder <NUM> and a plurality of protuberances <NUM> on the retractable sleeve <NUM> that engage with the plurality of recesses <NUM>. Therefore, when the needle shield <NUM> rotates and moves axially relative to the holder <NUM>, the needle shield <NUM> rotates and moves axially away from the body <NUM> (in the direction of arrow 'F' in <FIG> and <FIG>).

The needle <NUM> is fixed relative to the body <NUM>. Therefore, when the end cap <NUM> is pulled away from the body <NUM> by the patient, the needle shield <NUM> rotates and moves axially away from the needle <NUM> such that it first becomes partially removed from the end portion 18A of the syringe <NUM> (as shown in <FIG>) and then becomes fully removed from the end portion 18A such that the end portion 18A is no longer received in the recess 35A of the inner sheath <NUM> (as shown in <FIG>).

Once the end portion 18A of the syringe <NUM> has been fully removed from the recess 35A in the inner sheath <NUM>, the friction between the cap <NUM> and the body <NUM> is reduced such that the cap <NUM> can easily be removed from the body <NUM>. This is achieved by pulling the end cap <NUM> away from the body <NUM> such that the holder <NUM> is urged away from the body <NUM>, which results in the protuberances <NUM> disengaging with the recesses <NUM> such that the holder <NUM> is separated from the retractable sleeve <NUM>. The support member <NUM> has a first stopper <NUM> that engages with a second stopper <NUM> of the holder <NUM>. The first stopper <NUM> is in the form of an annular lip that extends radially outwardly and the second stopper <NUM> is in the form on an annular lip that extends radially inwardly. The first and second stoppers <NUM>, <NUM> are configured to limit the range of axial movement between the end cap <NUM> and holder <NUM> such that pulling on the end cap <NUM> exerts an axial force on the holder <NUM> that urges the holder <NUM> away from the body <NUM>.

The first screw thread <NUM> has a higher pitch than the second screw thread <NUM> such that axial movement of the end cap <NUM> relative to the needle shield <NUM> by a first distance, due to the end cap <NUM> being pulled away from the body <NUM> (in the direction of arrow 'F'), results in the needle shield <NUM> moving axially relative to the body <NUM> and holder <NUM> by a second distance that is smaller than the first distance. This configuration of the first and second screw threads <NUM>, <NUM> means that if the end cap <NUM> is pulled away from the body <NUM> by a given force then the resultant force acting on the needle shield <NUM> to urge the needle shield <NUM> away from the end portion 18A of the syringe <NUM> will be larger than said given force. Therefore, the coupling reduces the amount of force that must be exerted by the patient to remove the cap <NUM> from the body <NUM>.

Although in the second embodiment the first connection 39A comprises the first screw thread <NUM> on the spindle <NUM> and a first pair of projections <NUM> on the support member <NUM>, in an alternative embodiment (not shown) the first pair of projections are provided on the spindle and the support member comprises the first screw thread. Similarly, in another alternative embodiment (not shown) the second pair of projections are provided on the housing of the needle shield and the holder comprises the second screw thread. In yet another embodiment, the first and/or second pairs of projections are omitted and are replaced by corresponding third and/or fourth screw threads that are configured to engage with the first/and or second screw threads respectively. In another alternative embodiment (not shown) the first and second screw threads are omitted and are each replaced by a corresponding pair of tracks that receive the projections. The pairs of tracks are angled with respect to the central axis of the auto injector such that movement of the projections in the direction of the central axis relative to the tracks results in rotation of the tracks relative to the projections about the central axis.

Although in the above described embodiments the actuator <NUM>, <NUM> comprises an end cap <NUM>, <NUM>, in alternative embodiments (not shown) the actuator comprises a different type of component, for example, an outer ring that circumscribes the needle shield and is slid in the axial direction to relative to the needle shield to urge the needle shield to rotate relative to the body.

Although in the above described embodiments the injection device <NUM>, <NUM> is in the form of an auto-injector <NUM>, <NUM>, in alternative embodiments (not shown) the injection device <NUM>, <NUM> comprises a different type of drug delivery device.

Although in the above described embodiments the needle shield <NUM>, <NUM> comprises a housing <NUM>, <NUM> and a separate inner sheath <NUM>, <NUM> that is received in the housing <NUM>, <NUM>, in an alternative embodiments (not shown) the housing is omitted or is integrally formed with the inner sheath.

It should be noted that in <FIG> the screw threads <NUM>, <NUM>, <NUM> are shown schematically and therefore appear to have a relatively low pitch. However, it should be recognised that in certain arrangements the screw threads may require a higher pitch than is shown to ensure that axial movement of the actuator away from the body results in rotation of the needle shield relative to the body.

Exemplary insulin derivatives are, for example, B29-N-myristoyl-des(B30) human insulin; B29-N-palmitoyl-des(B30) human insulin; B29-N-myristoyl human insulin; B29-N-palmitoyl human insulin; B28-N-myristoyl LysB28ProB29 human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin; B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N-palmitoyl- ThrB29LysB30 human insulin; B29-N-(N-palmitoyl-gamma-glutamyl)-des(B30) human insulin; B29-N-(N-lithocholyl-gamma-glutamyl)-des(B30) human insulin; B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(ω-carboxyhepta¬decanoyl) human insulin. Exemplary GLP-<NUM>, GLP-<NUM> analogues and GLP-<NUM> receptor agonists are, for example: Lixisenatide / AVE0010 / ZP10 / Lyxumia, Exenatide / Exendin-<NUM> / Byetta / Bydureon / ITCA <NUM> / AC-<NUM> (a <NUM> amino acid peptide which is produced by the salivary glands of the Gila monster), Liraglutide / Victoza, Semaglutide, Taspoglutide, Syncria / Albiglutide, Dulaglutide, rExendin-<NUM>, CJC-<NUM>-PC, PB-<NUM>, TTP-<NUM>, Langlenatide / HM-11260C, CM-<NUM>, GLP-<NUM> Eligen, ORMD-<NUM>, NN-<NUM>, NN-<NUM>, NN-<NUM>, Nodexen, Viador-GLP-<NUM>, CVX-<NUM>, ZYOG-<NUM>, ZYD-<NUM>, GSK-<NUM>, DA-<NUM>, MAR-<NUM>, MAR709, ZP-<NUM>, ZP-<NUM>, TT-<NUM>, BHM-<NUM>. MOD-<NUM>, CAM-<NUM>, DA-<NUM>, ARI-<NUM>, ARI-<NUM>, Exenatide-XTEN and Glucagon-Xten.

Claim 1:
A cap (<NUM>, <NUM>) for an injection device (<NUM>, <NUM>) having a body (<NUM>) for holding a syringe (<NUM>) with a needle (<NUM>) extending from one end thereof, wherein the cap (<NUM>, <NUM>) is removably attachable to the body (<NUM>) and comprises:
an actuator (<NUM>, <NUM>);
a needle shield (<NUM>, <NUM>) to cover said needle (<NUM>); and,
a coupling between the actuator (<NUM>, <NUM>) and the needle shield (<NUM>, <NUM>) configured such that when the cap (<NUM>, <NUM>) is attached to the body (<NUM>) of the injection device (<NUM>, <NUM>) axial movement of the actuator (<NUM>, <NUM>) away from the body (<NUM>) along a longitudinal axis of the body (<NUM>) causes rotation of the needle shield (<NUM>, <NUM>) relative to the body (<NUM>) and an axial displacement of the needle shield (<NUM>, <NUM>) relative to the needle (<NUM>).