Dry Powder Medicament Inhaler

Abstract

A dry powder inhaler for delivering medicament from at least one medicament carrier having a plurality of spaced-apart medicament doses. The inhaler includes a housing having regions for accommodating unused and used portions of the medicament carrier, a mouthpiece component extending from the housing and through which a user is able to inhale, a dispensing mechanism arranged in the housing for moving a medicament dose of the medicament carrier to the dispensing position, and a mouthpiece cover being rotatably connected to the housing for sequential movement about a rotation axis from a first position in which the mouthpiece component is completely covered to a second position in which the mouthpiece component is completely covered, and from the second position to a third position in which the mouthpiece component is completely uncovered, the second position being between the first and third positions.

Claims

1. A dry powder inhaler for delivering medicament from at least one medicament carrier having a plurality of spaced-apart medicament doses, the dry powder inhaler comprising: a housing having regions for accommodating unused and used portions of the medicament carrier; a mouthpiece component joined to the housing and through which a user is able to inhale, the mouthpiece component including surfaces for contacting lips of the user; a dispensing mechanism arranged in the housing for moving a next medicament dose of the medicament carrier to a dispensing position; and a mouthpiece cover rotatably connected to the housing for sequential movement about a rotation axis from a first position in which the mouthpiece component is completely covered to a second position, and from the second position to a third position in which the mouthpiece component is completely uncovered, the second position being between the first and third positions, wherein the mouthpiece cover is coupled to the dispensing mechanism such that movement of the mouthpiece cover drives the dispensing mechanism, wherein the coupling is arranged such that movement of the mouthpiece cover from the first position to the second position does not cause the next medicament dose of the medicament carrier to move, and movement of the mouthpiece cover from the second position to the third position does cause the next medicament dose of the medicament carrier to be moved to the dispensing position, with the next medicament dose starting to move to the dispensing position when the mouthpiece cover moves through the second position, wherein movement from the first position to the second position encloses an angle about the rotation axis of at least 5 degrees, and the mouthpiece component is completely covered when the mouthpiece cover is in the second position.

2. The dry powder inhaler according to claim 1, wherein movement of the mouthpiece cover from the first position to the second position encloses an angle about the rotation axis of from 5 to 30 degrees, optionally from 5 to 15 degrees, further optionally from 8 to 15 degrees.

3. The dry powder inhaler according to claim 1, wherein movement of the mouthpiece cover from the second position to a position at which the mouthpiece component starts to be exposed encloses an angle of at least 5 degrees, optionally from 5 to 30 degrees, further optionally from 5 to 15 degrees, further optionally from 8 to 15 degrees.

4. (canceled)

5. The dry powder inhaler according to claim 1, wherein movement of the mouthpiece cover causes movement of at least one resilient drive pawl, and wherein the at least one resilient drive pawl selectively engages a toothed drive gear of the dispensing mechanism for driving the dispensing mechanism to move the next medicament dose of the medicament carrier to the dispensing position.

6. The dry powder inhaler according to claim 5, wherein, on movement of the mouthpiece cover from the first position to the second position, the at least one resilient drive pawl is not engaged with any teeth of the drive gear, and, on movement of the mouthpiece cover from the second position to the third position, the at least one resilient drive pawl is engaged with at least one tooth of the drive gear.

7. The dry powder inhaler according to claim 5, wherein the at least one resilient drive pawl is provided about a first gear wheel which is rotatably driven by the mouthpiece cover, and the drive gear is provided as ratchet teeth about a second gear wheel arranged to rotate coaxially with the first gear wheel, optionally wherein the at least one resilient drive pawl is provided about an outside of the first gear wheel and the drive gear is provided as an internal gear about the second gear wheel.

8. The dry powder inhaler according to claim 7, wherein the first gear wheel is arranged to rotate forwards and backwards when the mouthpiece cover is opened and closed, respectively, and wherein the second gear wheel is arranged to rotate forwards when driven forwards by the first gear wheel and not to rotate backwards, optionally wherein the second gear wheel is provided with a ratchet and pawl arrangement for preventing reverse rotation.

9. The dry powder inhaler according to claim 7, wherein: the first gear wheel is provided with four resilient pawls at 90 degree intervals and the second gear wheel is provided with four teeth at 90 degree intervals, and movement of the mouthpiece cover from the second position to the third position encloses an angle about the rotation axis of 90 degrees; or the first gear wheel is provided with five resilient pawls at 72 degree intervals and the second gear wheel is provided with five teeth at 72 degree intervals, and movement of the mouthpiece cover from the second position to the third position encloses an angle about the rotation axis of 72 degrees.

10. A dry powder inhaler for delivering medicament from at least one medicament carrier having a plurality of spaced-apart medicament doses, the dry powder inhaler comprising: a housing having regions for accommodating unused and used portions of the medicament carrier; a mouthpiece component joined to the housing and through which a user is able to inhale, the mouthpiece component including surfaces for contacting lips of the user; a dispensing mechanism arranged in the housing for moving a next medicament dose of the medicament carrier to a dispensing position; and a mouthpiece cover rotatably connected to the housing for sequential movement about a rotation axis from a first position in which the mouthpiece component is at least partly covered to a second position, and from the second position to a third position in which the mouthpiece component is completely uncovered, the second position being between the first and third positions, wherein the mouthpiece cover is coupled to the dispensing mechanism such that movement of the mouthpiece cover drives the dispensing mechanism, with movement of the mouthpiece cover from the first position to the third position causing the next medicament dose of the medicament carrier to be moved to the dispensing position, wherein the coupling of the mouthpiece cover to the dispensing mechanism is arranged to be non-linear, such that movement of the mouthpiece cover from the first position to the second position causes the next medicament dose to be continuously moved to an intermediate position with a first movement ratio, and movement of the mouthpiece cover from the second position to the third position causes the next medicament dose to be continuously moved from the intermediate position to the dispensing position with a second movement ratio which is different to the first movement ratio.

11. The dry powder inhaler according to claim 10, wherein the mouthpiece component is completely covered when the mouthpiece cover is in the first position, and wherein the mouthpiece component is partly covered when the mouthpiece cover is in the second position.

12-14. (canceled)

15. The dry powder inhaler according to claim 10, wherein movement from the first position to the second position encloses an angle about the rotation axis of from 20 to 160 degrees, optionally from 30 to 90 degrees, and movement from the second position to the third position encloses an angle about the rotation axis of from 20 to 160 degrees, optionally from 30 to 90 degrees.

16. (canceled)

17. The dry powder inhaler according to claim 10, wherein the mouthpiece cover drives a first gear wheel and the dispensing mechanism is driven by a second gear wheel, the first and second gear wheels forming a gear train that is in meshed engagement at least during opening of the mouthpiece cover.

18. The dry powder inhaler of claim 17, and wherein the first and second gear wheels have respective first segments having first pitch circle diameters that define a first gear ratio corresponding to the first movement ratio, and the first and second gear wheels have respective second segments having second pitch circle diameters that define a second gear ratio corresponding to the second movement ratio.

19. The dry powder inhaler according to claim 17, wherein the first and second gear wheels have respective segments with pitch circle diameters that vary, without step changes, such that a gear ratio between the first and second gear wheels varies, without step changes.

20. The dry powder inhaler according to claim 17, wherein the first and second gear wheels form a Geneva drive and the first gear wheel carries a pin of the Geneva drive and the second gear wheel is provided with a plurality of slots of the Geneva drive for engagement by the pin.

21. (canceled)

22. The dry powder inhaler according to claim 10, wherein the mouthpiece cover drives a rotatable cam and the dispensing mechanism is driven by a follower, wherein the cam engages the follower, such that movement of the mouthpiece cover from the first position to the third position causes the next medicament dose to be moved to the dispensing position.

23. The dry powder inhaler according to claim 10, wherein the mouthpiece cover includes an eccentrically mounted pin, and dispensing mechanism is driven by a gear wheel having a radially-extending slot for receiving the pin, and wherein, during opening of the mouthpiece cover, the pin is arranged to engage the slot to thereby rotate the gear wheel, such that movement of the mouthpiece cover from the first position to the third position causes the next medicament dose to be moved to the dispensing position.

24. The dry powder inhaler according to claim 17, wherein the dispensing mechanism is driven by a gear wheel, a hub associated with the gear wheel being rotationally driven by the opening of the mouthpiece cover, and wherein the hub and the gear wheel resiliently coupled, such that movement of the mouthpiece cover from the first position to the second position causes torsional deformation of the resilient coupling along with movement of the next medicament dose with the first movement ratio, and movement of the mouthpiece cover from the second position to the third position causes a lesser amount of torsional deformation of the resilient coupling along with movement of the next medicament dose with the second movement ratio.

25. The dry powder inhaler according to claim 24, wherein, during movement of the mouthpiece cover from the second position to the third position, the hub directly engages the gear wheel so that there is no further torsional deformation of the resilient coupling.

26. The dry powder inhaler according to claim 19, wherein movement of the mouthpiece cover from the first position to the third position causes the dispensing mechanism to be driven with a gear ratio that varies, without any step changes in the gear ratio.

27. (canceled)

28. The dry powder inhaler according to claim 17, wherein the dispensing mechanism comprises an anti-reverse rotation mechanism, such that opening movement of the mouthpiece cover from the first position to the third position causes the next medicament dose to be moved, and closing movement of the mouthpiece cover from the third position to the first position does not causes the next medicament dose to be moved, optionally wherein the anti-reverse rotation mechanism comprises a ratchet and pawl arrangement.

29. The dry powder inhaler according to claim 1, further comprising a manifold arranged in the housing, the manifold defining at least part of an air flow path extending from an air inlet to the mouthpiece component, the manifold also defining the dispensing position for the next medicament dose of the medicament carrier, wherein the dispensing mechanism is also arranged for placing the next medicament dose at the dispensing position in fluid communication with the air flow path, ready for inhalation by the user, optionally by selectively peeling or piercing a portion of the medicament carrier.

30. (canceled)

31. The dry powder inhaler according to claim 1, wherein the medicament carrier comprises an elongate blister strip having a base layer defining spaced-apart blister openings containing medicament doses, and a cover layer adhesively bonded to the base layer to close the blisters, and wherein the cover layer is arranged to be peeled from the base layer.

32. The dry powder inhaler according to claim 31, wherein the dispensing mechanism comprises: an indexing mechanism for moving a blister of the elongate blister strip containing the next medicament dose to the dispensing position; and a peeling mechanism for peeling the cover layer from the blister for placing the medicament dose in fluid communication with an air flow path ready for inhalation by the user.

33. The dry powder inhaler according to claim 1, further comprising the medicament carrier, optionally wherein the dry powder inhaler comprises a single medicament carrier, and further optionally wherein the medicament carrier is arranged in a replaceable cartridge received by the housing and wherein each of the spaced-apart medicament doses comprises budesonide, formoterol, beclomethasone, fluticasone, salmeterol, albuterol, salbutamol, indacaterol, tiotropium, ipratropium, glycorpyrronium or umeclidinium, vilanterol, or any combination thereof.

34. (canceled)

35. The dry powder inhaler according to claim 32, wherein the indexing mechanism is arranged to move at least two blisters of the elongate blister strip containing the next medicament doses to the dispensing position, and the peeling mechanism is arranged to peel the cover layer from the at least two blisters for placing at least two medicament doses in fluid communication with the air flow path ready for inhalation by the user, such that the dry powder inhaler can be used for simultaneous inhalation of different medicaments from different blisters.

36. (canceled)

37. The dry powder inhaler according to claim 35, wherein the different medicaments for simultaneous inhalation comprise: LABA or SABA in a first blister and an ICS in a second blister; or LABA or SABA in a first blister and LAMA or SAMA in a second blister; or LABA or SABA and LAMA or SAMA in a first blister and ICS in a second blister, or budesonide in a first blister and formoterol in a second blister; or beclomethasone in a first blister and formoterol in a second blister; or fluticasone in a first blister and salmeterol in a second blister, or fluticasone in a first blister and albuterol in a second blister, or fluticasone in a first blister and vilanterol in a second blister, or umeclidinium in a first blister and vilanterol in a second blister, or two selected from umeclidinium, fluticasone and vilanterol in a first blister, the remaining medicament from umeclidinium, fluticasone and vilanterol in a second blister, or fluticasone furoate in a first blister and vilanterol trifenatate in a second blister, or umeclidinium bromide in a first blister and vilanterol trifenatate in a second blister, or two selected from umeclidinium bromide, fluticasone furoate and vilanterol trifenatate in a first blister and the remaining medicament from umeclidinium bromide, fluticasone furoate and vilanterol trifenatate in a second blister.

38. (canceled)

39. The dry powder inhaler according to claim 1, for delivering medicament from a plurality of medicament carriers each having a plurality of spaced-apart medicament doses, wherein the dry powder inhaler optionally comprises exactly two medicament carriers, and further optionally wherein the medicament carriers are arranged in at least one replaceable cartridge received by the housing.

40. The dry powder inhaler according to claim 39, wherein each of the medicament carriers comprises an elongate blister strip having a base layer defining spaced-apart blister openings containing medicament doses, and a cover layer adhesively bonded to the base layer to close the blisters, and wherein the cover layer is arranged to be peeled from the base layer.

41. The dry powder inhaler according to claim 40, wherein the dispensing mechanism comprises: an indexing mechanism for moving a blister of each of the elongate blister strips containing the next medicament to the dispensing position; and a peeling mechanism for peeling the cover layer from each of the blister strips for placing the medicament doses in fluid communication with an air flow path ready for simultaneous inhalation by the user.

42-45. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Embodiments of the invention will now be described in more detail and by way of non-limiting examples with reference to the accompanying drawings, in which:

[0067] FIG. 1 is a perspective view of a dry powder inhaler according to a first embodiment of the invention;

[0068] FIG. 2 is a perspective view of a medicament carrier for use in the dry powder inhaler shown in FIG. 1;

[0069] FIG. 3 is a view of the inhaler shown in FIG. 1 with certain components removed and including a pair of the medicament carriers shown in FIG. 2 installed;

[0070] FIG. 4 is an exploded perspective view of the inhaler shown in FIG. 1 with certain components removed, from the opposite direction;

[0071] FIGS. 5a and 5b are schematic views showing the inhaler and a part of its dispensing mechanism in a first position of the mouthpiece cover;

[0072] FIGS. 6a and 6b are schematic views showing the inhaler and a part of its dispensing mechanism in a second position of the mouthpiece cover;

[0073] FIGS. 7a and 7b are schematic views showing the inhaler and a part of its dispensing mechanism in a third position of the mouthpiece cover;

[0074] FIG. 8 is a graphical representation of operation of the dispensing mechanism of the dry powder inhaler shown in FIG. 1;

[0075] FIGS. 9a to 9c are schematic views showing an inhaler according to a second embodiment of the invention with its mouthpiece cover in first, second and third positions;

[0076] FIGS. 10a to 10c are schematic views showing a non-linear transmission means of the inhaler when the mouthpiece cover is in the first, second and third positions;

[0077] FIG. 11 is a graphical representation of operation of the non-linear transmission means shown in FIGS. 10a to 10c;

[0078] FIGS. 12a to 12c are schematic views showing a non-linear transmission means of a first alternative embodiment when the mouthpiece cover is in the first, second and third positions;

[0079] FIG. 13 is a graphical representation of operation of the non-linear transmission means shown in FIGS. 12a to 12c;

[0080] FIGS. 14a to 14c are schematic views showing a non-linear transmission means of a second alternative embodiment when the mouthpiece cover is in the first, second and third positions;

[0081] FIG. 15 is a graphical representation of operation of the non-linear transmission means shown in FIGS. 14a to 14c;

[0082] FIGS. 16a to 16c are schematic views showing a non-linear transmission means of a third alternative embodiment when the mouthpiece cover is in the first, second and third positions;

[0083] FIG. 17 is a graphical representation of operation of the non-linear transmission means shown in FIGS. 16a to 16c;

[0084] FIGS. 18a to 18c are schematic views showing another non-linear transmission means that may be used in the inhaler according to the first or second embodiment;

[0085] FIG. 19 is an exemplary graphical representation of operation of the non-linear transmission means shown in FIGS. 18a to 18c;

[0086] FIGS. 20a to 20c are schematic views showing yet another non-linear transmission means that may be used in the inhaler according to the first or second embodiment;

[0087] FIG. 21 is an exemplary graphical representation of operation of the non-linear transmission means shown in FIGS. 20a to 20c; and

[0088] FIG. 22 is a schematic view showing a transmission means that may be used in the inhaler according to the first embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0089] It should be understood that the detailed description, while indicating exemplary embodiments of the inventive dry powder inhaler, are intended for the purposes of illustration only and are not intended to limit the scope of the invention. Features, aspects, and advantages of the inhaler will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

[0090] The first aspect of the invention provides a dry powder inhaler for delivering medicament from at least one medicament carrier having a plurality of spaced-apart medicament doses. The inhaler comprises: a housing having regions for accommodating unused and used portions of the medicament carrier; a mouthpiece component joined to the housing and through which a user is able to inhale; a manifold arranged in the housing and defining at least part of an air flow path extending from an air inlet to the mouthpiece, the manifold further defining a dispensing position for the medicament carrier; a dispensing mechanism arranged in the housing for moving a next medicament dose of the medicament carrier to the dispensing position and for placing the medicament dose in fluid communication with the air flow path ready for inhalation by the user; and a mouthpiece cover being rotatably connected to the housing for sequential movement about a rotation axis from a first position in which the mouthpiece component is completely covered to a second position in which the mouthpiece component is also completely covered, and from the second position to a third position in which the mouthpiece component is completely uncovered (the second position being between the first and third positions).

[0091] The mouthpiece cover is coupled to the dispensing mechanism such that movement of the mouthpiece cover drives the dispensing mechanism. In particular, movement of the mouthpiece cover from the first position to the second position does not causes the next medicament dose to be moved, and movement of the mouthpiece cover from the second position to the third position does cause the next medicament dose to be moved to the dispensing position, with the next medicament dose starting to move to the dispensing position when the mouthpiece cover moves through the second position.

[0092] FIGS. 1, 3 and 4 show a dry powder inhaler 1 according to a non-limiting embodiment of the first aspect of the invention. FIG. 2 shows a medicament carrier 201 for use with the inhaler 1. A dry powder inhaler using the same type of medicament carrier is described in WO 2007/012871 A1, the entire contents of which is incorporated herein by reference.

[0093] As shown in FIG. 1, the inhaler 1 is a hand-held device having a substantially flat or planar shape with a rounded outer profile. The outer profile of the inhaler is mainly defined by its housing 3 which encloses its internal components and receives at least one medicament carrier 201 (not shown in FIG. 1 but shown in FIGS. 2 and 3). Extending from the housing 3 is a mouthpiece component 5 having a central opening through which the user inhales the powder medicament (the terms “mouthpiece component” and “mouthpiece” are used interchangeably herein to mean a mouthpiece component). The mouthpiece component 5 is assembled or joined to the housing 3.

[0094] The inhaler also comprises the mouthpiece cover 7, which is rotatably connected to the housing 3 for sequential movement about a rotation axis from a first position in which the mouthpiece 5 is completely covered to a second position in which the mouthpiece 5 is also completely covered, and from the second position to a third position in which the mouthpiece 5 is completely uncovered. FIG. 1 shows the mouthpiece cover 7 in its third position.

[0095] Also visible in FIG. 1 is an air inlet 9 and a dose counter display 11. The air inlet 9, which can be covered by the mouthpiece cover 7, defines the start of an air flow path that extends from the air inlet 9 to the central opening of the mouthpiece 5. The dose counter display 11 is coupled to a dispensing mechanism of the inhaler 1, to be described subsequently, so as to provide an indication of the number of medicament doses used or remaining in the inhaler 1.

[0096] FIG. 2 shows a medicament carrier 201 for use with the inhaler 1 shown in FIG. 1. The medicament carrier 201 is in the form of an elongate blister strip. The blister strip comprises a semi-rigid base layer 203 which is formed with spaced-apart blister openings 205 and more flexible cover layer 207 which covers the blister openings 205 to define spaced-apart blisters 209. The blisters 209 each contain a sealed dose of powder medicament.

[0097] The cover layer 207 of the medicament carrier 201 is adhesively bonded to the base layer 203 such that the layers 203, 207 can be peeled apart to open the blisters 209 and liberate the powder medicament without any risk of either layer 203, 207 breaking. The base layer 203 and the cover layer 207 typically comprise plastics/aluminium laminates and are adhesively bonded by a heat seal lacquer. A suitable medicament carrier is described in more detail in WO 2007/012871 A1.

[0098] The inhaler 1 shown in FIG. 1 is designed for use with a pair (i.e. two) of the medicament carriers 201 shown in FIG. 2, as will now be described with reference to FIG. 3. It is to be noted, however, that embodiments according to the invention may be used with, or comprise, any number of the medicament carriers 201, including just one.

[0099] FIG. 3 is a view of the inhaler 1 shown in FIG. 1 with certain components removed and including a pair of the medicament carriers 201a, 201b installed. In particular, the mouthpiece 5, mouthpiece cover 7, and part of the housing 3 have been removed to reveal a remaining part of the housing 3 and the medicament carriers 201a, 201b, as well as parts of the dispensing mechanism. As shown in the drawing, the housing 3 provides regions 13a, 13b for accommodating unused portions of the medicament carriers 201a, 201b, which are loosely-coiled. Regions are also provided for accommodating used portions of the medicament carriers 201a, 201b, as will be described below. It is noted that the internal arrangement of the inhaler 1 is generally symmetrical, with one medicament carrier 201a being accommodated on one side (left side in the drawing) and the other medicament carrier 201b being accommodated on the other side (right side in the drawing).

[0100] The dispensing mechanism, which is only partly shown in FIG. 3, comprises an indexing wheel 15a, 15b and a peeling spool 17a, 17b for each of the medicament carriers 201a, 201b. Each medicament carrier 201a, 201b is fed around its respective indexing wheel 15a, 15b with the base layer 203a, 203b having the blisters facing the indexing wheel 15a, 15b. The indexing wheels 15a, 15b are provided with a plurality of recesses about their circumference which are sized and positioned to receive the blisters of the medicament carrier 201a, 201b. When the index wheels 15a, 15b are rotatably driven by the dispensing mechanism, they engage the medicament carriers 201a, 201b, in particular their semi-rigid blisters, so that the next medicament-containing blister of each medicament carrier 201a, 201b can be advanced to a dispensing position 19 of the inhaler 1 (at which the medicament is to be presented for inhalation).

[0101] Simultaneously, a leading end of the cover layer 207a, 207b of each medicament carrier 201a, 201b is separated from its base layer 203a, 203b and fed around a peeling edge 21a, 21b, which is positioned between used portions of the cover layer 207a, 207b and the base layer 203a, 203b. For this purpose, the leading end of the cover layer 207a, 207b of each medicament carrier 201a, 201b is attached to a respective peeling spool 17a, 17b. The peeling spools 17a, 17b are rotatably driven at the same time as the indexing wheels 15a, 15b, and this causes each cover layer 207a, 207b to be gradually peeled away from its base layer 203a, 203b at the peeling edge 21a, 21b, so that the medicament-containing blister 209a, 209b is opened for inhalation by the user.

[0102] As medicament doses are dispensed from the inhaler 1, used portions of the cover layers 207a, 207b are wound onto the peeling spools 17a, 17b. Used portions of the base layers 203a, 203b are accommodated in a separate region of the housing where they are coiled up by rotatably-driven coiling spools 23a, 23b. By way of example, the medicament carriers 201a, 201b may each comprise 60 doses of a powder medicament, with a dose from each carrier being dispensed simultaneously.

[0103] The remaining parts of the dispensing mechanism of the inhaler 1 will now be described with reference to FIG. 4, which is an exploded perspective view of the inhaler shown in FIG. 1 with certain components removed. It is noted that FIG. 4 shows an opposite side of the inhaler to that shown in FIG. 3, i.e. FIG. 4 shows the back side of the inhaler 1. In FIG. 4, the mouthpiece cover 7, and part of the housing 3 have been removed to reveal a remaining part of the housing 3 and remaining parts of the dispensing mechanism. FIG. 4 also shows the mouthpiece 5 and a manifold 25.

[0104] The manifold 25 is a moulded plastics component arranged in the housing 3 and which defines an air flow passage extending from the air inlet 9 (FIG. 1) to the central opening of the mouthpiece 5. When a user inhales through the mouthpiece 5, air is drawn in to the air inlet 9, through the air flow passage, and out through the mouthpiece 5. The manifold 25 is arranged in such a way that the air flow passage is provided with at least one opening adjacent to the dispensing position 19 of the inhaler, so that the medicament doses of opened blisters are placed in fluid communication with the air flow path. In this way, when the user inhales through the mouthpiece 5, the powder medicament can be drawn out of the blisters by the turbulent airflow and inhaled.

[0105] FIG. 4 shows the back sides of the indexing wheels 15a, 15b, peeling spools 17a, 17b and coiling spools 23a, 23b, each of which is rotatably mounted in the housing and provided with a gear wheel for driven rotation. The gear wheels form part of a gear train which is driven by opening the mouthpiece cover 7 (FIG. 1).

[0106] For this purpose, the mouthpiece cover 7 (not shown in FIG. 4) is coupled to a first gear wheel 27, which is arranged to rotate with the mouthpiece cover 7 about its rotation axis. In particular, the first gear wheel 27 is arranged to rotate forwards and backwards when the mouthpiece cover 7 is opened and closed.

[0107] The first gear wheel 27 is arranged to selectively drive a second gear wheel 29 which is mounted coaxially with the first gear wheel 27 on a stub shaft 3a. The second gear wheel 29 is a drive gear of the dispensing mechanism and directly or indirectly drives the indexing wheels 15a, 15b, peeling spools 17a, 17b and coiling spools 23a, 23b when the mouthpiece cover 7 is opened. The coiling spools 23a, 23b are also driven via idler gear wheels 31, 33. The first and second gear wheels 27, 29 will now be described in greater detail.

[0108] The first gear wheel 27 is directly coupled to a hub of the mouthpiece cover 7, which is covered by the housing 3 in FIG. 1. For this purpose, a front face of the first gear wheel 27 is provided with a raised rib 27a, which is received into a corresponding slot of the hub. When the mouthpiece cover 7 is opened and closed, the slot engages the rib 27a to transmit torque, so that the first gear wheel 27 rotates with the mouthpiece cover 7.

[0109] The outer circumference of the first gear wheel 27 is provided with a plurality, in this embodiment five, resilient drive pawls 27b which are equally spaced-apart at an angle of 72 degrees. It should be noted that other embodiments may comprise a different number of resilient drive pawls 27b. For example, another preferred embodiment comprises four resilient drive pawls which are equally spaced-apart at an angle of 90 degrees.

[0110] The resilient drive pawls 27b of the first gear wheel 27 are arranged to selectively engage corresponding ratchet teeth 29a formed as an internal gear on the second gear wheel 29. In particular, when the first gear 27 is rotated forwards upon opening of the mouthpiece cover 7, the resilient drive pawls 27b come into contact with and engage the ratchet teeth 29a of the second gear wheel 29 so as to drive it forwards. However, when the first gear 27 is rotated backwards upon closing of the mouthpiece cover 7, the resilient drive pawls 27b slide over the ratchet teeth 29a of the second gear wheel 29 so that it is not driven.

[0111] The second gear wheel 29 is provided about its outer circumference with a second plurality of ratchet teeth 29b which function, together with a fixed pawl attached to the housing (not shown), as a means for preventing reverse rotation of the second gear wheel 29.

[0112] The second gear wheel 29 is also provided about its outer circumference, in a different axial plane, with a set of ordinary gear teeth 29c which engage and drive a first one of the indexing wheels 15b. This indexing wheel 15b drives the other indexing wheel 15a and a first one of the peeling spools 17b. The other indexing wheel 15a drives the other peeling spool 17a. It will be understood that the gear train is sequenced so as to ensure that each of the driven elements rotates in the appropriate direction for dispensing the powder medicament from the blisters of the medicament carriers 201a, 201b.

[0113] Further detail relating to the structure and design of a suitable dispensing mechanism can be found for example in WO 2007/012871 A1.

[0114] Operation of the inhaler and, in particular of the mouthpiece cover 7 and dispensing mechanism, will now be described with reference to FIGS. 5a to 7b. FIGS. 5a and 5b are schematic views showing the inhaler 1 and a part of its dispensing mechanism in a first position of the mouthpiece cover 7. FIGS. 6a and 6b are schematic views showing the inhaler 1 and a part of its dispensing mechanism in a second position of the mouthpiece cover 7. FIGS. 7a and 7b are schematic views showing the inhaler 1 and a part of its dispensing mechanism in a third position of the mouthpiece cover 7. It is noted that FIGS. 5b, 6b and 7b show an opposite (back) side of the inhaler to that shown in FIGS. 5a, 6a and 7a (which is a front side).

[0115] Referring now to FIG. 5a, the inhaler 1 is shown with the mouthpiece cover 7 in its first position, which is its normal (completely closed) position when the inhaler 1 is not in use. In this position, the mouthpiece 5 is completely covered by the mouthpiece cover 7 and the mouthpiece cover 7 is rotated to the maximum extent possible in the counter-clockwise direction (also referred to herein as the backwards direction). In this position, the mouthpiece 5 is completely protected from contamination. Such contamination can be unhygienic and can potentially affect the medicament delivery performance of the inhaler 1.

[0116] FIG. 5b is a view showing the first gear wheel 27 and second gear wheel 29 when the mouthpiece cover 7 is in the first position shown in FIG. 5a. In this position, the resilient drive pawls 27b of the first gear wheel 27 are spaced away from, and are not therefore engaged with, the corresponding ratchet teeth 29a formed as an internal gear on the second gear wheel 29.

[0117] FIG. 6a shows the inhaler 1 after the mouthpiece cover 7 has been moved from the first position to the second position. In this position, the mouthpiece cover 7 has rotated clockwise (or forwards) but the mouthpiece 5 is still completely covered by the mouthpiece cover 7. Movement of the mouthpiece cover 7 from the first position to the second position may enclose an angle of at least 5 degrees and, in the illustrated embodiment, encloses an angle of 10 degrees.

[0118] FIG. 6b is a view showing the first gear wheel 27 and second gear wheel 29 when the mouthpiece cover 7 is in the second position shown in FIG. 6a. In this position, the first gear wheel 27 has rotated forwards (counter-clockwise in this view) to bring the resilient drive pawls 27b just into contact with the corresponding ratchet teeth 29a of the second gear wheel 29. The second gear wheel 29 has not, however, moved, and so the dispensing mechanism of the inhaler 1 has not yet been driven.

[0119] FIG. 7a shows the inhaler 1 after the mouthpiece cover 7 has been moved from the second position to the third position. In this position, the mouthpiece cover 7 has rotated further clockwise (or forwards) to completely uncover the mouthpiece 5 ready for the user to inhale dispensed doses of the powder medicament. In this position, the mouthpiece cover 7 is rotated to the maximum extent possible in the clockwise direction. For reasons that will become apparent from the following description, movement of the mouthpiece cover 7 from the second position to the third position encloses an angle of exactly 72 degrees. This implies that, in the illustrated embodiment, movement of the mouthpiece cover 7 from the first position to the third position encloses a total angle of 82 degrees (i.e. 10 degrees plus 72 degrees).

[0120] FIG. 7b is a view showing the first gear wheel 27 and second gear wheel 29 when the mouthpiece cover 7 is in the third position shown in FIG. 7a. In this position, the first gear wheel 27 has rotated further forwards (counter-clockwise in this view) and in this case the resilient drive pawls 27b have engaged the corresponding ratchet teeth 29a of the second gear wheel 29 to drive the second gear wheel 29 forwards. This driving of the second gear wheel 29 functions to drive the dispensing mechanism so that the next medicament-containing blister of each medicament carrier 201a, 201b is moved to the dispensing position 19 of the inhaler 1 and so that the cover layers 207a, 207b are peeled away to place the medicament doses in fluid communication with the air flow passage of the manifold 25, ready for inhalation by the user.

[0121] The mouthpiece cover 7 is configured so that movement from the second position to the third position encloses an angle of exactly 72 degrees because this results in the five resilient drive pawls 27b of the first gear wheel 27 and the corresponding five ratchet teeth 29a of the second gear wheel 29 rotating through 72 degrees so that they start and end with the same angular positions, as can be seen by comparing FIGS. 6b and 7b, which facilitates resetting the device when the mouthpiece cover 7 is subsequently closed.

[0122] In particular, when the mouthpiece cover 7 is closed after use of the inhaler 1, by rotating the mouthpiece cover 7 counter-clockwise from the third position shown in FIG. 7a to the first position shown in FIG. 5a, the second gear wheel 29 is prevented from rotating backwards (clockwise in the views of FIGS. 5b, 6b and 7b) owing to the means for preventing reverse rotation 29b and therefore remains in the same angular position. The first gear wheel 27 rotates backwards (clockwise in the views of FIGS. 5b, 6b and 7b) as the mouthpiece cover 7 is closed, with the resilient drive pawls 27b sliding back over the ratchet teeth 29a of the second gear wheel 29 to the position shown in FIG. 6b and then back to the position shown in FIG. 5b.

[0123] With the mouthpiece cover 7 closed, the five resilient drive pawls 27a of the first gear wheel 27 and the corresponding five ratchet teeth 29a of the second gear wheel 29 have the positions shown in FIG. 5b, ready for the next use.

[0124] The inhaler 1 described above comprises a first gear wheel 27 having five resilient drive pawls 27b. It should be noted that the first gear wheel may instead comprise a different number of resilient drive pawls. For example, the first gear wheel may be provided with four resilient drive pawls equally spaced-apart at 90 degree intervals (and correspondingly the second gear wheel may be provided with four ratchet teeth equally spaced-apart at 90 degree intervals), in which case movement of the mouthpiece cover from the second position to the third position would encloses an angle of exactly 90 degrees (360 degrees divided by four).

[0125] The inhaler 1 described above provides an arrangement in which movement of the mouthpiece cover 7 from the first position shown in FIG. 5a to the second position shown in FIG. 6a does not result in any actuation of the dispensing mechanism and does not uncover the mouthpiece 5, even partly. As such, actuation caused by unintentional or accidental movement of the mouthpiece cover when the inhaler is not in use can be avoided. Further, such unintentional or accidental movement of the mouthpiece cover does not risk of contamination of the mouthpiece, since the mouthpiece remains completely covered.

[0126] FIG. 8 provides a graphical representation of this operation of the dispensing mechanism. In particular, FIG. 8 illustrates how rotation of the mouthpiece cover is translated into actuation (driving) of the dispensing mechanism. It can be seen that initial opening of the mouthpiece cover from the first position to the second position 51 does not actuate the dispensing mechanism. Further rotation of the mouthpiece cover from the second position 51 to the third position 53 causes full actuation of the dispensing mechanism.

[0127] The second aspect of the invention will now be described in detail. The second aspect of the invention provides a dry powder inhaler for delivering medicament from at least one medicament carrier having a plurality of spaced-apart medicament doses, the dry powder inhaler comprising: a housing having regions for accommodating unused and used portions of the medicament carrier; a mouthpiece component joined to the housing and through which a user is able to inhale; a manifold arranged in the housing and defining at least part of an air flow path extending from an air inlet to the mouthpiece, the manifold further defining a dispensing position for the medicament carrier; a dispensing mechanism arranged in the housing for moving a next medicament dose of the medicament carrier to the dispensing position and for placing the medicament dose in fluid communication with the air flow path ready for inhalation by the user; and a mouthpiece cover being rotatably connected to the housing for sequential movement about a rotation axis from a first position in which the mouthpiece component is at least partly covered to a second position, and from the second position to a third position in which the mouthpiece component is completely uncovered, the second position being between the first and third positions.

[0128] The mouthpiece cover is coupled to the dispensing mechanism such that movement of the mouthpiece cover drives the dispensing mechanism. In particular, movement of the mouthpiece cover from the first position to the third position causes the next medicament dose of the medicament carrier to be moved to the dispensing position.

[0129] According to the second aspect, the coupling of the mouthpiece cover to the dispensing mechanism is arranged to be non-linear, such that movement of the mouthpiece cover from the first position to the second position causes the next medicament dose to be continuously moved to an intermediate position with a first movement ratio, and movement of the mouthpiece cover from the second position to the third position causes the next medicament dose to be continuously moved from the intermediate position to the dispensing position with a second movement ratio which is different to the first movement ratio.

[0130] As noted hereinabove, the term “movement ratio” refers to the ratio between movement of the medicament dose and movement of the mouthpiece cover, for example the ratio between linear movement (displacement) of the medicament dose as the medicament carrier is fed through the dispensing mechanism and angular movement of the mouthpiece cover. The first movement ratio is calculated as an average over the angle defined between the first and second positions of the mouthpiece cover. The second movement ratio is calculated as an average over the angle defined between the second and third positions of the mouthpiece cover. These average movement ratios may be calculated as a ratio of the displacements (linear or angular displacement of the medicament dose and angular displacement of the mouthpiece cover).

[0131] A non-limiting embodiment of the second aspect of the invention will now be described with reference to the drawings. The inhaler 1 of the second aspect has a structure that is identical to that shown in FIGS. 1 to 3, and the following description will therefore focus on those parts of the inhaler 1 that are different, in particular with reference to FIGS. 4 and 9a to 11.

[0132] Thus, in brief summary, the inhaler 1 of the second aspect comprises the housing 3, with the mouthpiece component 5 and the mouthpiece cover 7 shown in FIG. 1. The inhaler 1 is configured for use with a pair of the medicament carriers 201 shown in FIG. 2, and these are received by the inhaler 1 in the manner shown in FIG. 3. The inhaler 1 has the dispensing mechanism comprising pairs of indexing wheels 15a, 15b, peeling spools 17a, 17b and coiling spools 23a, 23b, as illustrated in FIG. 3. For further detail, reference is made to the description of FIGS. 1 to 3 set out above in relation to the inhaler of the first aspect, all of which is applicable to the inhaler of the second aspect.

[0133] The remaining parts of the dispensing mechanism of the inhaler 1 of the second aspect will now be described with reference to FIGS. 4 and 9a to 11.

[0134] The dispensing mechanism of the inhaler 1 of the second aspect is substantially the same as is shown in FIG. 4. Thus, the inhaler has the mouthpiece 5 and the manifold 25, as shown and described hereinabove. Further, the indexing wheels 15a, 15b, peeling spools 17a, 17b and coiling spools 23a, 23b of the dispensing mechanism are each rotatably mounted in the housing and provided with a gear wheel for driven rotation, in the manner shown in FIG. 4. These gear wheels form part of a gear train which is driven by opening the mouthpiece cover 7 (FIG. 1).

[0135] For this purpose, the mouthpiece cover 7 (not shown in FIG. 4) is arranged to drive the first gear wheel 27, and the first gear wheel 27 is arranged to selectively drive a second gear wheel 29, which functions as the drive gear of the dispensing mechanism. It is the particular manner in which the mouthpiece cover 7 is coupled to the first gear wheel 27, and the particular design of the first and second gear wheels 27, 29, that distinguishes the inhaler 1 of the second aspect from what is shown in FIG. 4.

[0136] In the inhaler 1 of the second aspect, the mouthpiece cover 7 is reversibly coupled to the first gear wheel 27 so that opening of the mouthpiece cover 7 causes the first gear wheel 27 to rotate in one direction, and so that closing of the mouthpiece cover 7 causes the first gear wheel 27 to rotate in the other direction. The coupling takes the form of a non-linear transmission means, to be described below.

[0137] The first and second gear wheels 27, 29 of the inhaler 1 of this aspect are similar to those shown in FIG. 4, but are configured to function as a simple one-way clutch, such that all rotation of the first gear wheel 27 when the mouthpiece cover 7 is opened is transmitted to the second gear wheel 29, and any rotation of the first gear wheel 27 when the mouthpiece cover 7 is closed is not transmitted to the second gear wheel 29. By way of example, this could be achieved by increasing the number of ratchet teeth 29a formed inside the second gear wheel 29, so that the resilient pawls 27b of the first gear wheel 27 engage with the ratchet teeth 29a essentially immediately upon opening of the mouthpiece cover 7. Other forms of one-way clutch will be readily apparent to those of ordinary skill in the art.

[0138] Consequently, the dispensing mechanism of the inhaler 1 is driven via the first and second gear wheels 27, 29 when the mouthpiece cover 7 is opened, but not when the mouthpiece cover 7 is closed.

[0139] As mentioned hereinabove, the mouthpiece cover 7 of the second aspect of the invention is coupled to the first gear wheel 27 via a non-linear transmission means, and this non-linear transmission means will now be described with reference to FIGS. 9a to 11.

[0140] FIGS. 9a to 9c are schematic views showing the inhaler 1 with its mouthpiece cover 7 in first, second and third positions. FIGS. 10a to 10c are schematic views showing the non-linear transmission means of the inhaler 1 when the mouthpiece cover 7 is in the first, second and third positions. It is noted that FIGS. 10a to 10c show an opposite (back) side of the inhaler and/or its components to that shown in FIGS. 9a to 9c (the front side).

[0141] Referring first to FIGS. 9a and 10a, these drawings show the inhaler 1 and the non-linear transmission means that couples the mouthpiece cover 7 to the first gear wheel 27 when the mouthpiece cover 7 is in its first position, which is the normal position when the inhaler 1 is not in use. In this position, the mouthpiece 5 is completely covered by the mouthpiece cover 7 and the mouthpiece cover 7 is rotated to the maximum extent possible in the counter-clockwise direction (FIG. 9a).

[0142] With reference to FIG. 10a, it will be noted that the mouthpiece cover 7, in particular the hub 7a of the mouthpiece cover 7, is directly connected to an input gear wheel 301 such that the input gear wheel 301 rotates with the mouthpiece cover 7. The first gear wheel 27 is directly connected to an output gear wheel 303 so that the first gear wheel 27 rotates with the output gear wheel 303. The input and output gear wheels 301, 303 are in meshed engagement.

[0143] The input and output gear wheels 301, 303 have respective first segments 301a, 303a having first pitch circle diameters that define a first, relatively low gear ratio. The input and output gear wheels 301, 303 also have respective second segments 301b, 303b having second pitch circle diameters that define a second, relatively higher gear ratio. When the mouthpiece cover 7 is in the first position, the first segments 301a, 303a are in meshed engagement. It is noted that herein the term “gear ratio” is used to mean a ratio between the pitch circle diameters of gear wheels, so that this term does not have the same meaning as the term “movement ratio” also used herein.

[0144] FIGS. 9b and 10b show the inhaler 1 and the non-linear transmission means after the mouthpiece cover 7 has been moved from the first position to the second position. It is noted that the hub 7a of the mouthpiece cover has been omitted from FIG. 10b (and FIG. 10c) for clarity reasons. In this position, the mouthpiece cover 7 has been rotated clockwise (or forwards) to part-uncover the mouthpiece 5, as shown in FIG. 9b. Movement from the first position to the second position may enclose an angle of from 20 to 160 degrees, and preferably from 30 to 90 degrees. In the embodiment illustrated, the angle enclosed is approximately 45 degrees.

[0145] With reference to FIG. 10b, it can be seen that movement of the mouthpiece cover 7 has been transmitted to the first gear wheel 27 through engagement of the first segments 301a, 303a of the input and output gear wheels 301, 303, with the first, relatively low gear ratio. In particular, rotation of the input gear wheel 301 through angle 301c has caused rotation of the output gear wheel 303 through angle 303c, which is smaller than angle 301c. This opening rotation of the output gear wheel 303 is transmitted to the first gear wheel 27, which in turn is transmitted to the second gear wheel 29 for driving the dispensing mechanism.

[0146] In summary, therefore, movement of the mouthpiece cover 7 from the first position to the second position has driven the dispensing mechanism of the inhaler 1 such that the next medicament-containing blisters of the medicament carriers 201a, 201b have been moved part way towards the dispensing position 19 of the inhaler 1 with a first, relatively low movement ratio.

[0147] FIGS. 9c and 10c show the inhaler 1 and the non-linear transmission means after the mouthpiece cover 7 has been moved from the second position to the third position. In this position, the mouthpiece cover 7 has been rotated further clockwise (or forwards) to fully uncover the mouthpiece 5, as shown in FIG. 9c. Movement from the second position to the third position may enclose an angle of from 20 to 160 degrees, and preferably from 30 to 90 degrees. In the embodiment illustrated, the angle enclosed is approximately 45 degrees.

[0148] With reference to FIG. 10c, it can be seen that movement of the mouthpiece cover 7 has been transmitted to the first gear wheel 27 through engagement of the second segments 301b, 303b of the input and output gear wheels 301, 303, with the second, relatively higher gear ratio. In particular, rotation of the input gear wheel 301 through angle 301d has caused rotation of the output gear wheel 303 through angle 303d, which is greater than angle 301d. This further opening rotation of the output gear wheel 303 is transmitted to the first gear wheel 27, which in turn is transmitted to the second gear wheel 29 for further driving of the dispensing mechanism.

[0149] To further summarise, therefore, movement of the mouthpiece cover 7 from the second position to the third position has driven the dispensing mechanism such that the next medicament-containing blisters of the medicament carriers 201a, 201b have been further moved all the way to the dispensing position 19 of the inhaler 1, with a second, relatively higher movement ratio.

[0150] It is noted that, in the inhaler 1 of this aspect, the non-linear transmission means adds an additional gear wheel to the overall gear train, as compared to the inhaler 1 of the first aspect. This has the effect of changing the rotation direction of the first and second gear wheels 27, 29, so that suitable further alterations have to be made to ensure that the indexing wheels 15a, 15b, peeling spools 17a, 17b and coiling spools 23a, 23b rotate in the correct direction. This can be achieved by introducing an additional idler gear wheel (not shown) between the second gear wheel 29 and the rest of the dispensing mechanism to cause a further change in direction, or by reconfiguring the sequential order of the gear train.

[0151] FIG. 11 is a graphical representation of operation of the non-linear transmission means shown in FIGS. 10a to 10c. It can be seen that the dispensing mechanism is actuated in a non-linear manner, initially with a first, lower movement ratio 305, and then with a second, higher movement ratio 307.

[0152] The inhaler 1 of the second aspect provides an arrangement which allows for improved operation of the inhaler by providing a more adaptable dispensing mechanism. In particular, when the mouthpiece cover 7 is opened, the user does not experience a sudden resistance when the dispensing mechanism is engaged, but rather the increase in resistance is more gradual or progressive. This helps to protect the mouthpiece cover 7 and components of the dispensing mechanism from damage by avoiding excessive stress, and the resulting smoother operation helps to avoid vibration-induced movement of the powder medicament, which could otherwise result in poor dosing consistency and contamination of the internal components of the inhaler 1.

[0153] A further advantage of the inhaler 1 described above is that by initially driving the dispensing mechanism at a lower rate (i.e. movement ratio), it is more likely that any actuation caused by unintentional or accidental movement of the mouthpiece cover 7 between the first and second positions will be reversible. In particular, it is more likely that the unintentional or accidental movement will not have caused the next medicament-containing blisters to be peeled open.

[0154] A number of modifications to the inhaler 1 of the second aspect are possible. FIGS. 12a to 12c are schematic views showing a non-linear transmission means of a first alternative embodiment of the inhaler 1 when the mouthpiece cover is in the first, second and third positions (as shown in FIGS. 9a to 9c). FIG. 13 is a graphical representation of operation of the non-linear transmission means shown in FIGS. 12a to 12c.

[0155] The inhaler 1 of the first alternative embodiment is the same as that described above, except that the input gear wheel 301 and the output gear wheel 303 define a varying gear ratio that gradually increases, without any step changes, as the mouthpiece cover 7 is opened.

[0156] With reference to FIG. 12b, it can be seen that movement of the mouthpiece cover 7 has been transmitted to the first gear wheel 27 through engagement of the input and output gear wheels 301, 303, with a relatively low, but increasing, gear ratio. In particular, rotation of the input gear wheel 301 through angle 301c has caused rotation of the output gear wheel 303 through angle 303c, which is smaller than angle 301c.

[0157] With reference to FIG. 12c, it can be seen that further movement of the mouthpiece cover 7 has been transmitted to the first gear wheel 27 through engagement of the input and output gear wheels 301, 303, with a relatively higher, and still increasing gear ratio. In particular, rotation of the input gear wheel 301 through angle 301d has caused rotation of the output gear wheel 303 through angle 303d, which is greater than angle 301d.

[0158] With reference to FIG. 13, it can be seen that the dispensing mechanism according to this alternative embodiment is actuated in a non-linear manner, initially with a first, lower movement ratio 305, and then with a second, higher movement ratio 307.

[0159] FIGS. 14a to 14c are schematic views showing a non-linear transmission means of a second alternative embodiment of the inhaler 1 when the mouthpiece cover is in the first, second and third positions (as shown in FIGS. 9a to 9c). FIG. 15 is a graphical representation of operation of the non-linear transmission means shown in FIGS. 14a to 14c.

[0160] The inhaler 1 of the second alternative embodiment is the same as that described above, except that the input gear wheel 301 is replaced with a pin 401 eccentrically mounted to the mouthpiece cover 7 (shown in highly schematic form in FIGS. 14a to 14c) and the output gear wheel 303 is replaced with a gear wheel 403 (also shown in highly schematic form in FIGS. 14a to 14c) having a radially extending slot 403a for receiving the pin 401. During opening of the mouthpiece cover 7, the pin 401 is arranged to engage the slot 403a to thereby rotate the gear wheel 403. The interaction between the pin 401 and gear wheel 403 defines a gear ratio that varies, without any step changes, as the mouthpiece cover 7 is opened.

[0161] With reference to FIG. 14b, it can be seen that movement of the mouthpiece cover 7 has been transmitted to the first gear wheel 27 through engagement of the pin 401 and slot 403a, with a relatively low, gear ratio and in a direction that reverses (see also FIG. 15). In particular, rotation of the pin 401 (and mouthpiece cover 7) through angle 401c has caused back-and-forth rotation of the gear wheel 403 through angle 403c.

[0162] With reference to FIG. 14c, it can be seen that further movement of the mouthpiece cover 7 has been transmitted to the first gear wheel 27 through engagement of the pin 401 and slot 403a, with a higher gear ratio. In particular, rotation of the pin 401 through angle 401d has caused rotation of the gear wheel 403 through angle 403d.

[0163] With reference to FIG. 15, it can be seen that the dispensing mechanism according to this alternative embodiment is actuated in a non-linear manner, initially with a first, lower movement ratio 405, and then with a second, higher movement ratio 407.

[0164] FIGS. 16a to 16c are schematic views showing a non-linear transmission means of a third alternative embodiment of the inhaler 1 when the mouthpiece cover is in the first, second and third positions (as shown in FIGS. 9a to 9c). FIG. 17 is a graphical representation of operation of the non-linear transmission means shown in FIGS. 16a to 16c.

[0165] The inhaler 1 of the third alternative embodiment is the same as that described above, except that the input gear wheel 301 is replaced with a hub 501 mounted to the mouthpiece cover 7 and the output gear wheel 303 is replaced with an annular gear wheel 503. The hub 501 and the gear wheel 503 are resiliently coupled by spring elements 505a, 505b, such that movement of the mouthpiece cover 7 from the first position to the second position causes torsional deformation of the resilient coupling 505a, 505b along with some transmission of rotation from the hub 501 to the gear wheel 503 (see arrow 503c). Further movement of the mouthpiece cover 7 from the second position to the third position causes no further torsional deformation of the resilient coupling 505a, 505b owing to direct engagement between the hub 501 and a pair of internal teeth 503a, 503b of the gear wheel 503. This movement of the mouthpiece cover 7 instead results in a greater transmission of rotation from the hub 501 to the gear wheel 503 (see arrow 503d).

[0166] With reference to FIG. 17, it can be seen that the dispensing mechanism according to this alternative embodiment is actuated in a non-linear manner, initially with a first, lower movement ratio 507, and then with a second, higher movement ratio 509.

[0167] FIGS. 18a to 18c are schematic views showing another non-linear transmission means that may be used in the inhaler 1 of the first or second aspect of the invention, and FIG. 19 is an exemplary graphical representation of its operation.

[0168] The non-linear transmission means shown in FIGS. 18a to 18c comprises a cam 601 which rotates with the mouthpiece cover 7 and a resiliently-biased follower 603 which is arranged for reciprocating movement in the direction of arrows 603a, 603b. The follower carriers a pawl 603b which engages a gear wheel for driving the dispensing mechanism.

[0169] FIG. 19 is an exemplary graphical representation of the non-linear transmission's operation. It can be seen that the dispensing mechanism is actuated in a non-linear manner, initially with a first, lower movement ratio 605, and then with a second, higher movement ratio 607, in line with the principles of the second aspect of the invention. However, it will be appreciated that the profile of the cam 601 could be modified to change the transmission properties. This includes modifying the cam profile to include a segment having a constant diameter so that movement of the mouthpiece cover 7 from the first position to the second position does not result in any movement of the medicament dose, in line with the principles of the first aspect of the invention.

[0170] FIGS. 20a to 20c are schematic views showing another non-linear transmission means that may be used in the inhaler 1 according to the first or second embodiment, and FIG. 21 is an exemplary graphical representation of its operation.

[0171] The non-linear transmission means shown in FIGS. 20a to 20c is a Geneva drive. The Geneva drive comprises a first gear wheel 701 carrying an eccentrically-mounted pin 701a, which is driven by the mouthpiece cover 7, and a second gear wheel 703 provided with a plurality of slots 703a, which drives the dispensing mechanism. The coupling between the mouthpiece cover 7 and the first gear wheel 701 is typically via a one-way clutch (not shown), so that the first gear wheel 701 is only driven by opening of the mouthpiece cover 7, not by closing it. When the mouthpiece cover 7 is opened, the pin 701a of the first gear wheel 701 engages a slot 703 of the second gear wheel 703 to thereby transmit the rotational motion.

[0172] Further information on the Geneva drive can be found in, for example, Theory of Machines and Mechanisms, Shigley et al., second edition, 1995, McGraw-Hill, Inc. (pages 373 to 376).

[0173] FIG. 21 is an exemplary graphical representation of the non-linear transmission's operation. It can be seen that the dispensing mechanism is actuated in a non-linear manner, in line with the principles of the second aspect of the invention. It can also be seen that movement of the mouthpiece cover 7 from the first position to the second position does not result in any movement of the medicament dose, in line with the principles of the first aspect of the invention.

[0174] FIG. 22 is a schematic view showing another transmission means that may be used in the inhaler 1 according to the first embodiment. The transmission means comprises a gear train in which the gear teeth are designed to exhibit a large amount of backlash. This can be achieved, for example, by spacing the gear teeth further apart than normal and configuring the gear wheels to have relatively large diameters (so as to reduce curvature and maintain suitable engagement). The effect of these adaptations is to delay the transmission of rotational movement so that the dispensing mechanism is not driven when the mouthpiece cover 7 is moved from its first position to its second position, in line with the principles of the first aspect of the invention.

[0175] In any of the embodiments described above, the medicament carriers 201a, 201b may be provided in a removable cartridge received by the housing 3 of the inhaler 1. The medicament carriers may comprise respective different medicaments for simultaneous inhalation by the user. For example, the different medicaments for simultaneous inhalation may comprise: LABA or SABA in a first medicament carrier and an ICS in a second medicament carrier; or LABA or SABA in a first medicament carrier and LAMA or SAMA in a second medicament carrier; or LABA or SABA and LAMA or SAMA in a first medicament carrier and ICS in a second medicament carrier, or budesonide in a first medicament carrier and formoterol in a second medicament carrier; or beclomethasone in a first medicament carrier and formoterol in a second medicament carrier; or fluticasone in a first medicament carrier and salmeterol in a second medicament carrier, or fluticasone in a first medicament carrier and albuterol in a second medicament carrier, or fluticasone in a first medicament carrier and vilanterol in a second medicament carrier, or umeclidinium in a first medicament carrier and vilanterol in a second medicament carrier, or two selected from umeclidinium, fluticasone and vilanterol in a first medicament carrier, the remaining medicament from umeclidinium, fluticasone and vilanterol in a second medicament carrier.

[0176] In particular, the different medicaments for simultaneous inhalation may comprise: fluticasone furoate in a first medicament carrier and vilanterol trifenatate in a second medicament carrier, or umeclidinium bromide in a first medicament carrier and vilanterol trifenatate in a second medicament carrier, or two selected from umeclidinium bromide, fluticasone furoate and vilanterol trifenatate in a first medicament carrier and the remaining medicament from umeclidinium bromide, fluticasone furoate and vilanterol trifenatate in a second medicament carrier.

[0177] Other medicaments that may be used include for example any one of long acting beta antagonists (LABA), short acting beta antagonists (SABA), corticosteroids (ICS), long acting muscarinic antagonists (LAMA), short acting muscarinic antagonists (SAMA), or any other drug that can be administered via inhalation including combination thereof. Examples for such drugs include but are not limited to budesonide, formoterol, beclomethasone, fluticasone, salmeterol, albuterol, salbutamol, indacaterol, Tiotropium, ipratropium, glycorpyrronium, umeclidinium and combination thereof.

[0178] Although the inhalers 1 described above comprise two medicament carriers 201a, 201b, alternative embodiments of the invention may comprise a single medicament carrier, in which case only one half of the dispensing mechanism would be need to be provided. In this case, each of the spaced-apart medicament doses comprises budesonide, formoterol, beclomethasone, fluticasone, salmeterol, albuterol or umeclidinium.

[0179] Alternatively, the single medicament carrier containing embodiment of the invention may be configured for simultaneous inhalation of different medicaments by configuring the dispensing mechanism to open two blisters at a time, and providing different blisters of the medicament carrier with different medicaments. For example, the different medicaments for simultaneous inhalation may comprise: budesonide in a first blister and formoterol in a second blister; or beclomethasone in a first blister and formoterol in a second blister; or fluticasone in a first blister and salmeterol in a second blister, or fluticasone in a first blister and albuterol in a second blister, or fluticasone in a first blister and vilanterol in a second blister, or umeclidinium in a first blister and vilanterol in a second blister, or two selected from umeclidinium, fluticasone and vilanterol in a first blister, the remaining medicament from umeclidinium, fluticasone and vilanterol in a second blister.

[0180] In particular, the different medicaments for simultaneous inhalation comprise: fluticasone furoate in a first blister and vilanterol trifenatate in a second blister, or umeclidinium bromide in a first blister and vilanterol trifenatate in a second blister, or two selected from umeclidinium bromide, fluticasone furoate and vilanterol trifenatate in a first blister and the remaining medicament from umeclidinium bromide, fluticasone furoate and vilanterol trifenatate in a second blister.

[0181] Several non-limiting embodiments of the invention have been described hereinabove with reference to the accompanying drawings. Various changes may be made to these embodiments without departing from the scope of the invention, which is defined by the claims.

[0182] For example, the inhalers described hereinabove are for use with medicament carriers in the form of blister packs that are peeled open. However, the inhalers may be for use with blister packs that are opened by piercing or bursting, or with completely different types of medicament carrier, provided they have spaced-apart doses of medicament. The medicament carriers described above are in the form of elongate strips. In other embodiments, the medicament carriers may be in the form of discs having the medicament doses arranged about the circumference.