WO2024121794A1 - A medicament dispenser - Google Patents

Abstract

A medicament dispenser comprises a housing, a medicament carrier carrying individual medicament doses, a mouthpiece, a dispensing mechanism for dispensing doses to the mouthpiece, and a cover moveably mounted to the housing, the cover moveable from a fully closed position covering the mouthpiece to a fully open position where the mouthpiece is fully uncovered, the cover coupling with the dispensing mechanism such that movement of the cover from closed to fully open actuates the dispensing mechanism through a complete actuation cycle to release a dose and so that movement of the cover from the closed position to a partly open position causes partial actuation of the dispensing mechanism, any subsequent cover movement from the partly open position towards the closed position resulting in no further actuation of the dispensing mechanism, but any subsequent movement of the cover towards the fully open position resulting in continued actuation of the dispensing mechanism.

Description

A MEDICAMENT DISPENSER

TECHNICAL FIELD

This invention relates to a medicament dispenser. More particularly, the present invention relates to a medicament dispenser having a drive mechanism that carries and dispenses multiple distinct medicament dose portions.

BACKGROUND

The use of dry powder inhaler (DPI) devices in the administration of medicaments, for example in bronchodilation therapy, is well known. Devices of this type generally comprise a housing within which a supply of medicament is located. One particular type of inhaler uses a blister strip having multiple blister pockets, where each pocket contains a discrete dose portion of a dry powder medicament. In use, a user activates the device to dispense the dose. The mechanism within the device for dispensing the dose usually comprises either a piercing means for piercing the pocket, or a means to peel a lid sheet away from a base sheet on the strip, to open the pocket. The powdered medicament can then be accessed and inhaled by the patent through a mouthpiece on the device.

With devices of this type, access to each dose is typically enabled by advancing the strip within the device, so as to sequentially bring each discrete dose/blister pocket to an opening part or area within the device. Typically, the device will have a protective cover which encloses the mouthpiece when the device is not in use, and which is coupled to a cover drive mechanism that forms part of a drive mechanism for advancing the strip (e.g. via a gear train).

When the device is actuated (e.g. by a user opening the cover) the cover drive mechanism engages the internal drive mechanism so as to advance the strip, and to pierce or peel the next pocket or blister on the strip, so that the medicament is released from the blister. The patient inhales the released dry powder via the mouthpiece, and then closes the protective cover. This resets the cover drive mechanism.

However, it is not uncommon for a user to only partially open the cover. They may inadvertently misuse the device, or absent-mindedly fiddle with the cover when not using the device, or similar. If the patient does not fully open the cover each time the device is used, this can lead to a blister pocket being partially opened, which then leaves the medicament within the pocket open to the atmosphere, where it can become partly dispersed, or may be rendered unusable due to moisture absorption or similar. Additionally, this may cause the cover drive mechanism to become out-of-sync with the protective cover, so when a user next operates the device, the next blister pocket is not in the correct position to be opened.

W02007/012871 describes and shows a medicament dispenser for use with at least one medicament carrier that carries multiple distinct medicament portions. The medicament dispenser comprises a dispensing mechanism actuable for dispensing the distinct medicament portions carried by said at least one medicament carrier, a mouthpiece, and a cover for said mouthpiece. The cover is movably mounted to the dispenser for sequential movement from a first position, in which said mouthpiece is covered, to a second position, in which said mouthpiece is at least part-uncovered, to a third position in which said mouthpiece is uncovered. The cover is adapted to couple with said dispensing mechanism such that movement of the cover from the second position to the third position, but not the first position to the second position, results in actuation of the dispensing mechanism.

EP3622990 describes and shows an inhaler comprising a housing which contains a blister strip having a plurality of blisters which contain powdered medicament for inhalation, a mouthpiece mounted to the housing through which the medicament is inhaled by a user, an indexing and opening mechanism for indexing the blister strip and for opening the blisters which is operated by an actuator, wherein the blister strip is indexed by forward motion of the actuator from a first position to a second position, such as by opening a cover, and is also indexed in the same direction by reverse motion of the actuator from the second position to the first position, such as by closing the cover.

Conventional DPIs known from the prior art have limitations in their design and operation. One significant issue is the risk of misalignment and exposure of the medicament due to misuse of the mechanism, particularly if the cover is not fully opened during use. This partial opening can result in a partially opened blister strip, exposing the medicament to the atmosphere and potentially leading to decreased efficacy. Additionally, misalignment between the blister strip and the manifold can occur, further compromising the delivery of the medicament. It is possible for a user to misuse a device (either deliberately or inadvertently), and partially open and close their device.

In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a medicament dispenser which goes some way to overcoming the abovementioned disadvantages or which at least provides the public or industry with a useful choice.

Accordingly, in a first aspect the present invention may broadly be said to consist in a medicament dispenser comprising a housing assembly, a medicament carrier located within the housing assembly and configured to carry multiple discrete individual medicament dose portions; a mouthpiece in fluid communication with the housing assembly, the mouthpiece configured so that the medicament dose portions can be dispensed therethrough; a dispensing mechanism located within the housing assembly and configured to dispense the dose portions from the medicament carrier to the mouthpiece; a cover for the mouthpiece, the cover moveably mounted to the housing assembly, the cover and housing assembly mutually configured so that the cover can be moved from a fully closed position in which the mouthpiece is fully covered, to a fully open position in which the mouthpiece is fully uncovered; the cover further adapted to couple with the dispensing mechanism such that movement of the cover from the fully closed position to the fully open position results in actuation of the dispensing mechanism through a complete actuation cycle, such that a dose portion is released from the medicament carrier; the dispensing mechanism configured such that movement of the cover from the closed position to a partly open position between the fully closed and fully open positions causes partial actuation of the dispensing mechanism, and; wherein if a complete actuation cycle has not yet been completed, any subsequent movement of the cover from the partly open position towards the closed position does not result in further actuation of the dispensing mechanism, but any subsequent movement of the cover towards the fully open position results in continued actuation of the dispensing mechanism.

In an embodiment, the dispensing mechanism is further configured such that once the complete actuation cycle has been completed, further movement of the cover towards the open position does not cause further actuation of the dispensing mechanism until the cover is returned to the fully closed position.

In an embodiment, the dispensing mechanism comprises a one-way ratchet mechanism.

In an embodiment, the dispensing mechanism comprises a driving plate and primary drive element, the primary drive element coupled to the cover so that movement of the cover drives movement of the primary drive element, the driving plate and primary drive element mutually configured to form the oneway ratchet mechanism.

In an embodiment, the primary drive element and driving plate comprise substantially circular elements arranged in substantially parallel planes with a common axis of rotation, the inner surface of the driving plate comprising a plurality of teeth, the primary drive element configured to engage with at least one of the teeth in use, the teeth configured to only engage with the driving plate when the cover is moving towards an open position.

In an embodiment, the driving plate and housing assembly are mutually configured so that the driving plate can move along the common axis of rotation from a first disengagement plane to a second engagement plane, the housing assembly, primary drive element and driving plate mutually configured so that if the driving plate is initially in the first disengagement plane, rotation of the primary drive element from a fully closed position to a fully open position will cause the driving plate to both rotate and move axially from the first disengagement plane into the second engagement plane and then back to the first disengagement plane, and rotation of the primary drive element from a fully closed position to a partly open position and back causes the driving plate to both rotate and move axially from the first disengagement plane into the second engagement plane and then remain in the second engagement plane, with further rotation of the primary drive element towards the open position then also causing rotation of the driving plate until a complete actuation cycle has been completed, the driving plate retuning to the first disengagement plane on completion of the complete actuation cycle and remaining in the first disengagement plane until the primary drive element has returned to a fully closed position and is moving from the fully closed position towards an open position. In an embodiment, the primary drive element comprises at least one arm comprising a main body and an extended portion extending from the main body, and the driving plate further comprises at least one ski portion or portions extending from the main body of the driving plate, the extended portion(s) and ski portion(s) configured so that if the primary drive element and driving plate are disengaged these will engage if the cover is in the fully closed position and there is movement of the cover towards an open position, and these will disengage when a complete actuation cycle has been completed.

In an embodiment, the at least one arm comprises a plurality of equally spaced apart arms.

In an embodiment, the medicament dispenser comprises three arms.

In an embodiment, the driving plate comprises spaced apart inner and outer rings connected by at least one connecting arm.

In an embodiment, the connecting arm comprises three connecting arms.

In an embodiment, the dispensing mechanism further comprises a primary drive gear, rotation of the primary drive gear driven by the driving plate in use, the primary drive gear and driving plate having a common axis of rotation, the primary drive gear driven at or close to the hub by the inner ring.

In an embodiment, the dispensing mechanism further comprises a primary drive gear, rotation of the primary drive gear driven by the driving plate in use, the primary drive gear and driving plate having a common axis of rotation, the driving plate driven by rotational contact on at least one of the connecting arms.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a side view of a medicament dispenser in accordance with a first embodiment of the invention, the medicament dispenser of this embodiment being a dry powder inhaler that comprises a housing that contains a medicament carrier or blister strip that holds discrete individual doses of a medicament, and a dispensing mechanism that controls movement of the strip so as to control dispensing of the individual doses to a user.

Figure 2 shows a side view from the same angle as figure 1 of the dry powder inhaler shown in figure 1 , with the cover of the housing removed so as to show detail of the dispensing mechanism.

Figure 3 shows a perspective view of part of the dispensing mechanism of the first embodiment of dry inhaler shown in figures 1 and 2, showing detail of a driving plate and primary gear located within the housing, the driving plate comprising skis spaced around the perimeter configured to locate into recesses in the housing.

Figure 4 shows a perspective side view of a rotation control member that forms part of the dispensing mechanism of the first embodiment of dry powder inhaler shown in figures 1 and 2.

Figure 5 shows a close-up perspective side view of part of the driving plate and rotation control member of the dispensing mechanism of the first embodiment of dry powder inhaler shown in figures 1 and 2. Figure 6 shows a close-up perspective top view of part of the driving plate and rotation control member of the dispensing mechanism of the first embodiment of dry powder inhaler shown in figures 1 and 2, the driving plate and rotation control member located within a body that forms part of the inner part of the housing.

Figure 7 shows a perspective side view of part of the dispensing mechanism of the first embodiment of dry powder inhaler shown in figures 1 and 2, the driving plate and rotation control member located within a body that forms part of the inner part of the housing.

Figure 8 shows a close-up perspective view from the side and above of part of the driving plate and rotation control member of the dispensing mechanism of the first embodiment of dry powder inhaler shown in figures 1 and 2, the driving plate and rotation control member located within a body that forms part of the inner part of the housing.

Figure 9 shows a a close-up perspective view from the side and above of part of the driving plate and rotation control member of the dispensing mechanism of the first embodiment of dry powder inhaler shown in figures 1 and 2, the driving plate and rotation control member located within a body that forms part of the inner part of the housing.

Figure 10 shows a a close-up perspective view from the side and above of part of the driving plate and rotation control member of the dispensing mechanism of the first embodiment of dry powder inhaler shown in figures 1 and 2, the driving plate and rotation control member located within a body that forms part of the inner part of the housing.

Figure 11 shows a side view of a medicament dispenser in accordance with a second embodiment of the invention, the medicament dispenser of this embodiment being a dry powder inhaler that comprises a housing that contains a medicament carrier or blister strip that holds discrete individual doses of a medicament, and a dispensing mechanism that controls movement of the strip so as to control dispensing of the individual doses to a user.

Figure 12 shows a side view of a driving plate that forms part of the dispensing mechanism of the inhaler, the driving plate located in the housing.

Figure 13 shows a side view from the same angle as figure 11 of the second embodiment of dry powder inhaler shown in figure 11 , with the cover of the housing removed so as to show detail of the dispensing mechanism.

Figure 14 shows a close-up perspective side view of part of the dispensing mechanism of the second embodiment of dry inhaler shown in figure 11 , showing detail of a driving plate located within the housing, the driving plate comprising skis spaced around the perimeter configured to locate into recesses in the housing, and a primary drive gear that engages with the driving plate in use.

Figure 15a shows a side view of a primary drive gear that forms part of the dispensing mechanism of the second embodiment shown in figures 11 to 14. Figure 15b shows a top or plan view of the primary drive gear of figure 15a

Figure 16a shows a perspective side view of the driving plate of figure 14.

Figure 16b shows a top or plan view of the driving plate of figure 14.

Figure 16c shows a side view of the driving plate of figure 14.

Figure 17 shows a perspective side view of the driving plate of figures 14, 16a, and 16b located in the housing of the inhaler of the second embodiment.

Figures 18a to 18c show side views of the medicament dispenser of the first embodiment of the invention, the cover of the medicament dispenser shown opening sequentially from a full closed position in figure 18a, to a fully open position in figure 18d, via two partly open positions in figures 18b and 18c.

Figure 19 shows a cutaway side view of a medicament dispenser, the medicament dispenser being a variant of the medicament dispenser of the first embodiment and suitable for use with the dispensing mechanism of the second embodiment.

DETAILED DESCRIPTION

Embodiments of the invention will now be described in detail with reference to the figures.

It should be noted that directional terms as used in this specification - e.g. ‘vertical wall’, ‘horizontal portion’, ‘clockwise’, anticlockwise’, etc are not to be considered as literal or absolute, and are intended to be understood within the overall context of the specification - for example as applying to an inhaler lying on a horizontal surface on one of its side faces.

First Embodiment - Structure

A dry powder inhaler 100 according to a first embodiment of the invention is shown in figures 1 and 18.

The dry powder inhaler 100 comprises an outer shell or body 130, which encloses and contains an inner housing 102. The outer shell or body 130 and inner housing 102 form a housing assembly for this embodiment. The inner housing 102 is configured to contain a medicament carrier - in this embodiment a blister strip 170 (shown in figure 19), the blisters of the strip each containing a discrete dose of a supply of medicament. It should be noted that the blister strip in figure 19 is shown only on one side of the device (the right-hand side), but in normal use there would be separate mirrored blister stips on each side of the device.

A manifold 106a is located at the top of the housing 102, extending from the top of the housing 102. The manifold 106a enables released doses of the dry powder medicament to be inhaled into the lungs of a user of the inhaler 100 through a mouthpiece 106b connected to the manifold (the mouthpiece not shown in Figure 1). The release of the doses from the blister strip is controlled by a dispensing mechanism as outlined below.

Dispensing Mechanism

Figure 19 shows the internal elements of the dispensing mechanism directly associated with the blister strip, and the blister strip on one side of the dispenser. It should be noted that the variation shown in figure 19 comprises dual take-up spools 44b at the lower end of the housing, whereas the variation shown in figure 2 (and figure 13, for the second embodiment) only has a single take up spool 144b (first embodiment) or 244b (second embodiment). However, the structure and operation of all of the variations and embodiments is substantially similar. The elements shown in figure 19 sit ‘behind’ the mechanism shown in figures 1 , 2 and 13 (i.e. ‘behind’ when viewed from the angle shown in these figures).

A pair of strip spindles 104 are located in the housing 102, at opposite sides of the housing 102 towards the top of the housing 102. A take-up spool 144b is located in the lower part of the housing. In use, the blister strip peels apart to release the contents of the blisters. Blister strips are commonly formed with a plastic strip of blisters closed by a backing strip such as a peelable foil strip. In use, as the strip passes through the dispensing mechanism, the ‘foil’ or backing part of the blister strip winds around the strip spindles 104. The ‘blisters’ part winds around the single take up spool 144b in the variation of figure 2, or the dual spools 44b in the variation of figure 19.

A driving plate 110 is located in the body 102 of the dry powder inhaler 100. The driving plate comprises a body having a substantially circular perimeter in side view. The housing 130 has a circular opening sized to receive the driving plate 110. The main function of the driving plate 110 is to drive a mechanism for releasing doses from the blister strip in a stepwise fashion.

A primary rotation control member 120 is located adjacent to the driving plate 110. The primary rotation control member 120 is located on the outside of the driving plate 110 (that is, closer to the side wall of the housing or closer to the exterior of the inhaler).

The driving plate 110 is connected to and rotatable about a central spindle 146, which protrudes upwardly from the housing 102.

The dry powder inhaler 100 further comprises a cover 160 that is connected to the primary rotation control member 120 to drive rotation of the primary rotation control member 120. With reference to the side view of figure 1 , the cover 160 can be moved in use from a first fully closed (i.e. rest) position in which it is located at the top of the inhaler 100 and covers the manifold 106a and mouthpiece 106b, to a second fully open (i.e. actuated) position, by rotating the cover 160 clockwise through 120° around the inhaler 100 (i.e. from the twelve o’clock position to the four o’clock position on figure 1). In the open position, the mouthpiece 106bis fully uncovered - the cover 160 does not cover the mouthpiece 106b.

In the closed position, the cover 160 prevents dirt from entering the manifold 106a when the dry powder inhaler 100 is not in use. Reciprocal movement of the cover 160 through 120° from the first (fully closed) position to the second (fully open) position, and then subsequently from the second (fully open) position back to the first (fully closed) position causes rotation of the primary rotation control member 120 anticlockwise and clockwise respectively through 120° (as viewed from the side - the view shown in figures 1 and 2).

In Figures 2 and 3 the dry powder inhaler 100 is shown with both the primary rotation control member 120 and housing 130 removed to show the driving plate 110 and the associated underlying gear mechanism. A primary gear or primary drive gear 140 is arranged on the underside of the driving plate 110, and is also connected to and rotatable about the central spindle 146. The primary gear 140 aligns with and is driven by the driving plate 110. The primary gear 140 connects to an idler gear 141 , which in turn is connected to gears 143a and 144a. Gear 143a connects to gear 143b and similarly gear 144a connects to gear 144b. Together, gears 143a, 143b, 144a and 144b control motion of the strip spindles 104, which in turn controls movement of the blister strip and therefore the release of dry powder medicament in a stepwise fashion from the blister strip and the spooling of waste blisters/used strip. Rotation of the driving plate 110 is driven by the primary rotation control member 120.

The driving plate 110 comprises an inner circumferential ring 111 which is attached to an outer circumferential ring 112 by three equally spaced apart curved arms 114. A series of ratchet teeth 116 run in a continuous loop around the circumference of an upper side of the outer circumferential ring 112. Three equally spaced apart skis 118 extend radially outward from the outer circumferential ring 112. As can be seen in Figure 3, each ski 118 comprises an extended ratchet tooth 116a that extends beyond the outer circumferential ring 112, and a recess 118a located behind the portion of the extended ratchet tooth 116a extending past the outer circumferential ring 112.

The driving plate 110 is secured on the central spindle 146. A spring 148 (shown in Figure 3) is arranged between the spindle 146 and the driving plate 110 to act as a ratchet due to the spring 148 binding to the central spindle 146 on clockwise (i.e. reverse) rotation. Due to the binding action of the spring 148, the primary rotation control member 120 can be rotated backwards clockwise without causing any rotation of the driving plate 110.

As shown in Figure 4, the primary rotation control member 120 comprises a cylindrical core 121 having a central aperture for receiving the central spindle 146. Three equally spaced apart curved flexible arms 124 extend radially outward from the cylindrical core 121 and are angled downwardly below the plane of the cylindrical core 121 . The end of each of the flexible arms 124 defines an engagement face 126 for engaging with the ratchet teeth 116 of the driving plate 110. Each engagement face 126 is asymmetric in profile having a horizontal portion 126a and a radially outward vertical portion 126b.

Figures 5 and 6 show perspective views of the assembly of the driving plate 110, primary rotation control member 120 and housing 130 as shown in the first embodiment of Figure 1 . In Figure 5 and 6 the driving plate 110 is in the first (disengagement) plane. The driving plate 110 is positioned within the circular opening of housing 130, with the primary rotation control member 120 situated above the driving plate 110 with respect to the housing 102. As can be seen from Figure 6, a gap 150 runs circumferentially around the driving plate 110, between the driving plate 110 and the opening of the housing 130.

In Figures 5 and 6, the vertical portions 126b of the engagement faces 126 at the end of each of the flexible arms 124 of the primary rotation control member 120 are shown located in the recesses 118a of the skis 118, abutting the extended ratchet teeth 116a of the skis 118. In this configuration, the horizontal portions 126a of the engagement faces 126 lie above the plane of the driving plate 110.

In Figure 6, the primary rotation control member 120 is depicted as transparent, for illustrative purposes, to show the structure of the driving plate 110. As can be seen from Figure 6, the housing 130 comprises three slots 132 spaced apart at equal distances at the edge of the circular opening of the housing 130. The slots 132 are sized to accommodate the skis 118 of the driving plate 110. As the slots 132 are equally spaced apart, if one ski 118 is accommodated in a slot 132, the other two skis 118 will also be accommodated in the two other slots 132. In this way, all three skis 118 are always accommodated in all three slots 132 at the same time. When the skis 118 are accommodated in the slots 132, the skis 118 are in the in the first (disengagement) plane. Each slot 132 has a ramp 134 in the forward circumferential direction of rotation of the driving plate 110 and vertical wall 135 in the rear direction. In this embodiment, the forward circumferential direction of rotation of the driving plate 110 is anticlockwise as viewed from above with respect to the housing 102.

As can be seen, the spindles 104, driving plate 110, gears 140, 141 , 143a, 144a, spindle 146, and primary rotation control member 120 form a dispensing mechanism for the inhaler. It can also be seen that the driving plate 110 and the primary rotation control member 120 are arranged in substantially parallel planes.

First Embodiment - Operation - Normal Use

Figures 6 to 8 show sequential movement of the driving plate 110, where the cover 160 is initially in the first (fully closed) position in which it covers the manifold 106a and mouthpiece 106b (not shown in Figures 6 to 8). When the cover 160 is in this first (fully closed) position, the driving plate 110 is in the first (disengagement) plane as shown in Figure 6, with the skis 118 accommodated in the slots 132 of the housing 130. Actuation of the cover 160 through a 120° movement from the first (fully closed) position in which it covers the manifold 106a to the second (fully open) position in which it does not cover the manifold 106a and mouthpiece 106b, rotates the primary rotation control member 120 anticlockwise through 120°.

During this full dose movement, as shown in Figure 7, as the primary rotation control member 120 starts to rotate anticlockwise, the vertical portions 126b of the engagement faces 126 at the end of each of the flexible arms 124 of the primary rotation control member 120 push the extended ratchet teeth 116a of the skis 118, thereby causing the driving plate 110 to rotate anticlockwise. As a result, the skis 118 are pushed up and over the ramps 134 in the slots 132 such that the skis 118 slide over a surface 131 at the top of the housing 130 which runs around the circumference of the circular opening in the housing 130. This pushes the driving plate 110 from the first (disengagement) plane to the second (engagement) plane.

The continued rotation of the cover 160 through 120° results in the similar rotation of the driving plate 110 through 120° until the skis 118 pass over the vertical walls 135 of the next slots along (slots 132) such that they drop into these next slots along as shown in Figure 8. As the skis 118 drop into the next slots along, the driving plate 110 moves back from the second (engagement) plane back to the first (disengagement) plane. Rotation of the driving plate through 1207a full dose movement also rotates the primary gear 140, which in turn rotates the idler gear 141 and the number of other gears 143a, 143b, 144a, 144b through 120°, causing the strip to move on the strip spindles 104, and to peel open to release a dose of dry powder medicament from a position located directly below the manifold 106a in the housing 102. The user can then inhale the released dose of dry powder medicament through the manifold 106a and the connected mouthpiece 106b.

Once in the second (fully open) position, the cover 160 cannot be physically moved any further open due to the geometry of the dry powder inhaler 100 - the configuration of the external casing blocks further movement of the cover 160. Therefore, the user can now only return the cover back to towards the first (fully closed) position in which it covers the manifold 106a. This rotates the primary rotation control member 120 back through 120° and thus the vertical portions 126b of the engagement faces 126 at the end of each of the flexible arms 124 of the primary rotation control member 120 now rotate backwards over the housing 130 until the flexible arms 124 are returned to the reset position.

The flexibility of the flexible arms 124 allows them to slide over the extended ratchet teeth 116a of the rearward skis 118, such that they return to the position shown in Figure 6, in which the vertical portions 126b of the engagement faces 126 at the end of each of the flexible arms 124 of the primary rotation control member 120 are shown located in the recess 118a and abutting the extended ratchet teeth 116a of the skis 118. Thus, the cover 160 can then be returned from the second (fully open) position back to the first (fully closed) position without causing any further rotation of the driving plate 110. Movement of the cover 160 by a user through 120° from the first (fully closed) position in which it covers the manifold 106a and mouthpiece 106b, back to the second (fully open) position in which it does not cover the manifold 106a and mouthpiece then causes the process above to repeat, to release a further dose of dry powder medicament from the blister strip.

First Embodiment - Operation - Misuse

In a misuse scenario when the user moves the cover 160 anticlockwise from the first (fully closed) position by only a part of the 120° towards the second (fully open) position - for example by only 60° towards the second (fully open) position - and then returns the cover 160 clockwise back to the first (fully closed) position, this will not cause the release of a full dose of dry powder medicament(i.e. the dry powder inhaler 100 would not be actuated). A full dose movement has not been completed.

During rotation of the cover 160 anticlockwise from the first (fully closed) position to a partly open position (e.g. rotation through 60° as outlined above), rotation of the primary rotation control member 120 anticlockwise causes the vertical portions 126b of the engagement faces 126 at the end of each of the flexible arms 124 of the primary rotation control member 120 to push the extended ratchet teeth 116a of the skis 118, thereby causing the skis 118 to move upwards from the first (disengagement) plane to the second (engagement) plane and rotate anticlockwise by 60° (that is, angular movement of the cover 160 corresponds to angular movement of the skis, so if the cover 160 is moved by 60° then the skis will also move by 60°). As the cover 160 is returned clockwise from this partly open position back towards the first (fully closed) position, the vertical portions 126b of the engagement faces 126 at the end of each of the flexible arms 124 of the primary rotation control member 120 rotate clockwise through 60° flexing and clicking over the ratchet teeth 116 of the driving plate 110, and not engaging with the teeth, so the driving plate 110 remains stationary, prevented from rotating by the spindle and spring 148.

When the cover 160 is back in the first (fully closed) position, the driving plate 110 will therefore remain in the same position where it has been partly rotated to - that is, moved by only 60° anticlockwise with the skis 118 still in the second (engagement) plane. As the primary gear 140 has only been rotated anticlockwise by 60°, this in turn means the idler gear 141 and the other gears 143a, 143b, 144a, 144b, have also only rotated anticlockwise through a part of a full actuation movement (i.e. 50% in this case, where the primary gear has been rotated by 60°), and therefore a full dose of dry powder medicament will not be released (i.e. the dry powder inhaler 100 has not yet been actuated).

However, when the user again moves the cover 160 anticlockwise from the first (fully closed) position back towards the second (fully open) position, the horizontal portions 126a of the engagement faces 126 at the end of each of the flexible arms 124 of the primary rotation control member 120 now engage the nearest ratchet tooth 116, thereby causing the driving plate 110 to continue rotating anticlockwise to complete the full dose movement. As the cover 160 is moved anticlockwise through the first 60°, the driving plate 110 also rotates anticlockwise through a further 60° until the skis 118 pass over the vertical walls 135 of the next slots along (slots 132) such that they drop into the next slots along, having completed the full dose movement. As the skis 118 drop into the next slots along, the driving plate 110 moves back from the second (engagement) plane back to the first (disengagement) plane.

At this point the driving plate 110 has now rotated anticlockwise a full 120°, which means that the primary gear 140 has also rotated anticlockwise a full 120°, which in turn has rotated the idler gear 141 and the number of other gears 143a, 143b, 144a, 144b a full 120°, thereby releasing a full dose of dry powder medicament. Because the skis 118 have moved downwards back to the first (disengagement) plane, further anticlockwise rotation of the cover 160 to the second (fully open) position (i.e. by a further 60°) simply rotates the vertical portions 126b of the engagement faces 126 at the end of each of the flexible arms 124 of the primary rotation control member 120 forward by 60° such that they run over the housing 130 until they return to the position shown in Figure 6. Due to this “lost motion” of the driving plate 110, the cover can be moved to the second (fully open) position without releasing a further dose of dry powder medicament.

As the cover 160 is returned clockwise through 120° from the second (fully open) position back to the first (fully closed) position, the vertical portions 126b of the engagement faces 126 at the end of each of the flexible arms 124 of the primary rotation control member 120 now rotate clockwise over the housing 130 until they are returned to the reset position shown in Figure 6.

Thus, in the misuse scenario, the user may move the cover 160 anticlockwise from the first (fully closed) position by only a part of the 120° towards the second (fully open) position to a part open position, and then can move the cover 160 clockwise to any position between the part open position and the first (fully closed) position without releasing a full dose of medicament (i.e. without actuating the dry powder inhaler 100). However, any further anticlockwise movement of the cover forward from the part open position towards the second (fully open) re-engages the primary rotation control member 120 with the driving plate 110, such that a dose of medicament is released once the driving plate 110 has been rotated through a full 120° movement.

It is also possible for there to be a misuse scenario where the cover 160 is moved to the fully open position, and then moved only partly back towards the closed position. In this scenario, the skis 118 will have already dropped into ‘the next slots along’, as outlined above (i.e. a full clockwise rotation of the cover has taken place), and the driving plate 110 will have therefore moved back from the second (engagement) plane to the first (disengagement) plane.

In this scenario, the cover is then moved back towards the first (fully closed) position, but not all the way to the fully closed position. This rotates the primary rotation control member 120 back, with the vertical portions 126b of the engagement faces 126 at the end of each of the flexible arms 124 of the primary rotation control member 120 rotating backwards over the housing 130. However, as the cover is not rotated fully back to the closed position, the flexible arms 124 never reach the reset position, and the engagement faces 126 remain in contact with the housing 130. The vertical portion 126b will not reach and drop into a recess 118a, and therefore will not engage with the extended ratchet teeth 116a on the skis 118. Therefore, the skis will not be rotated, to move/rotate the driving plate 110 out of the disengagement plane and into the engagement plane. A user can therefore repeatedly move the cover between a fully or partly open position, and a partly closed position, without this advancing the driving mechanism and dispensing a dose.

Second Embodiment - Structure

Similar numbering will be used to describe the second embodiment as used for the first embodiment above - e.g. housing 102, 202, strip spindles 104, 204, primary rotation control member 120, 220, etc.

A dry powder inhaler 200 according to a second embodiment of the invention is shown in figure 11 .

The external structure of the inhaler 200 is substantially the same as for the first embodiment (and as shown in figure 18), comprising an outer shell or body 230 which encloses and contains an inner housing 202, with a mouthpiece 206a is located at the top of the housing 202, connected to a manifold 206a extending from the top of the housing 202. The outer shell or body 230 and inner housing 202 form a housing assembly for this embodiment, with a blister strip contained within the housing, the blisters of the strip each containing a discrete dose of a supply of medicament in the form of a dry powder.

The mouthpiece 206a enables released doses of the dry powder medicament to be inhaled into the lungs of a user of the inhaler 200. The release of the doses from the blister strip is controlled by a dispensing mechanism as outlined below. Dispensing Mechanism

A pair of strip spindles 204 are located in the housing 202, at opposite sides of the housing 202 towards the top of the housing 202. The strip spindles 204 form part of the dispensing mechanism contained within the housing 202 that is configured to in use enable the release of the contents of the blisters in a stepwise manner.

Figure 19 shows the internal elements of the dispensing mechanism directly associated with the blister strip. As for the first embodiment, it should be noted that the variation shown in figure 19 comprises dual take-up spools at the lower end of the housing, whereas the variation shown in figure 13 for the second embodiment only has a single take up spool 244b. However, the structure and operation of all of the variations and embodiments is substantially similar.

In use, the blister strip peels apart to release the contents of the blisters. As the strip passes through the dispensing mechanism, the ‘foil’ or backing part of the blister strip winds around the strip spindles 204. The ‘blisters’ part of the strip winds around the take up spool 244b in the variation of figure 13, or the dual spools 44b in the variation of figure 19.

The dry powder inhaler 200 comprises an interface 208, which sits within a circular opening in the body 230, which is arranged over a side face of the housing 202. The interface 208 sits above and is engaged with a primary rotation control member 220. Opening and closing a cover (not shown in figure 11 ) drives rotation of the interface 208, which then drives rotation of the primary rotation control member 220. The primary rotation control member 220 sits above and is engaged with a driving plate 210, which drives a gear mechanism configured for releasing dry powder medicament from the dose portions of the blister strip in a stepwise fashion.

The dry powder inhaler 200 further comprises a cover 260, attached to the interface 208, which is moveable through 120° from a first fully closed (i.e. rest) position in which it covers the mouthpiece 206 to a second fully open (i.e. actuated) position in which it does not cover the mouthpiece 206. The cover in the closed position prevents dirt from entering the mouthpiece 206 when the dry powder inhaler 200 is not in use. Reciprocal 120° movement of the cover from the first (fully closed) position to the second (fully open) position and from the second (fully open) position back to the first (fully closed) position rotates the interface 208 and primary rotation control member 220 anticlockwise and clockwise respectively through 120°.

Figure 12 shows a close-up view of the dry powder inhaler 200 of Figure 11 , in which the interface 208 and primary rotation control member 220 have been removed or are not shown in order to show the underlying driving plate 210. The driving plate 210 comprises an inner circumferential ring 211 which is attached to an outer circumferential ring 212 by three equally spaced apart arms 214. A series of ratchet teeth 216 run in a continuous loop around the circumference of an upper side of the outer circumferential ring 212. Three equally spaced apart skis 218 extend radially outward from the outer circumferential ring 212. Each ski 218 comprises an extended ratchet tooth 216a that extends beyond the outer circumferential ring 212, and a recess 218a located behind the portion of the extended ratchet tooth 216a extending past the outer circumferential ring 212.

A primary drive gear 240 sits within the within the outer circumferential ring 212 of the driving plate 210 and has three equally spaced apart ribs 241 which engage with corresponding slots 213 in the outer circumferential ring 212. The driving plate 210 drives rotation of the primary 240 and is able to move inwards and outwards with respect to the primary drive gear 240 by sliding along the ribs 241 of the primary drive gear 240. The primary drive gear 240 also has a circular groove 242 in which the inner circumferential ring 212 of the driving plate 210 sits. The primary drive gear 240 and plate 210 are attached to a spindle 246, which protrudes upwardly from the housing 202. The primary drive gear 240 and driving plate 210 are rotatable about the spindle 246.

Figure 13 shows a view of the dry powder inhaler 200 of Figure 11 , in which the interface 208, primary rotation control member 220 and body 230 have all been removed or are not shown, in order to show the underlying gear mechanism. The primary drive gear 240 connects to an idler gear (not shown), which in turn is connected to a number of other gears 243a, 243b, 244a, 244b, which connect to the strip spindles 204 to control the release of dry powder medicament in a stepwise fashion from the portions of the blister strip and spooling of waste blisters.

The driving plate 210 is secured on the spindle 246. A spring 248 arranged between the spindle 246 and the primary drive gear 240 acts as a ratchet due to the spring 248 binding to the spindle 246 on clockwise (i.e. reverse) rotation. Due to the binding action of the spring 248, the primary rotation control member 220 can be rotated backwards clockwise without causing any rotation of the driving plate 210 and primary drive gear 240.

Referring to Figures 15a and 15b, the primary drive gear 240 has a central core 244 having a central aperture for receiving the spindle 246. As outlined above, the primary drive gear 240 has three equally spaced apart ribs 241 for engaging with the slots 213 in the outer circumferential ring 212 of the driving plate 210 and circular groove 242 for receiving the inner circumferential ring 212 of the driving plate 210. Figures 16a to 16c show various views of the driving plate 210.

It can be seen that the driving plate 210 and the primary drive gear 240 are arranged in substantially parallel planes.

Second Embodiment - Operation - Normal Use

Referring to Figure 17, as the primary rotation control member 220 (not shown in Figure 17) starts to rotate anticlockwise, the primary rotation control member 220 pushes on the extended ratchet teeth 216a of the skis 218, thereby causing the driving plate 210 to rotate. As a result, the skis 218 are pushed up and over ramps in slots of the body 230 (not shown in Figure 17). This pushes the skis 218 upwards, causing the driving plate 210 to slide upwards along the ribs 241 of the primary drive gear 240 from the first (disengagement) plane to the second (engagement) plane as indicated by the vertical movement arrows 290.

As the cover is moved through 120°, the driving plate 210 also rotates through 120° until the skis 218 pass over vertical walls of the next slots along such that they drop into the next slots along. Rotational movement of the driving plate 210 is transferred to the primary drive gear 240 through the ribs 241 of the primary drive gear 240.

As a result, the primary drive gear 240 also rotates through 120° as indicated by the rotational arrows 292. As the skis 218 drop into the next slots along, the driving plate 210 moves back from the second (engagement) plane back to the first (disengagement) plane as indicated by the vertical movement arrows 290. Rotation of the primary drive gear 240 through 120° also causes rotation of the idler gear (not shown) and the other gears 243a, 243b, 244a, 244b through 120°, thereby releasing a full dose of dry powder. The user can then inhale the released dose of dry powder medicament through the mouthpiece 206. A full dose movement is completed in a similar manner to that outlined above for the first embodiment.

It can be seen that in this embodiment, the primary rotation control member 220 is generally equivalent to and operates in the same manner as the primary rotation control member 120 of the first embodiment. These items are generally referred to collectively as ‘primary drive elements’ in this specification.

It should be noted that in this second embodiment, the potential for rotation between the inner ring and toothed outer ring of the driving plate 210 in use is reduced. In this second embodiment, the inner ring of the driving plate 210 acts primarily as a biasing member/spring to return the toothed outer ring to the correct working plane during operation (that is, it assists with ensuring the correct position of the toothed outer ring ‘into and out of the page’, if viewing the device in the orientation shown in figure 11 ). The driving plate 210 in the second embodiment drives the primary drive gear 240 over a larger length of the diameter or greater contact length of the diameter, which helps to provide a better control of position and tolerances, and helps to ensure that there is greater accuracy and control in the overall operation of the inhaler.

In contrast, and as described above, in the first embodiment the driving plate 110 comprises an inner circumferential ring 111 which is attached to an outer circumferential ring 112 by three equally spaced apart curved arms 114. The inner ring delivers rotation driving force to the primary gear 140 via the spring arms 114. Due to the length and planar arrangement of the arms 114 there is inevitably a certain amount of flexing or movement of the arms during operation, which can result in mechanical play or mechanical lost motion during normal operation, resulting in less accuracy and control.

Second Embodiment - Operation - Misuse

The misuse scenario described above for the first embodiment of the invention (dry powder inhaler 100) also applies to the second embodiment of dry powder inhaler 200. A user may move the cover anticlockwise from the first (fully closed) position by only a part or portion of the 120° required to move to a second (fully open) position, and may then move the cover clockwise or anticlockwise to any position between the part open position and the first (fully closed) position. The mechanism described above for the second embodiment ensures that this partial opening and closing operation will not release a dose of medicament from a portion of the blister strip. However, any further anticlockwise movement of the cover, forward from the part open position towards the second (fully open) position reengages the primary rotation control member 220 with the driving plate 210, such that a full dose movement is completed, and a dose of medicament is released once the driving plate 210 has been rotated through a full 120° movement.

Also, similarly to the first embodiment, it is also possible for there to be a misuse scenario where the cover 260 is moved to the fully open position, and then moved only partly back towards the closed position. In this scenario, the skis 218 will have already dropped into ‘the next slots along’, as outlined above (i.e. a full clockwise rotation of the cover has taken place), and the driving plate 210 will have therefore moved back from the second (engagement) plane to the first (disengagement) plane. The extended ratchet teeth 216a of the skis 218 will not engage with the primary rotation control member 220 until these are in a position to drop down and engage, which requires a user to move the cover 260 to a fully closed position. A user can therefore repeatedly move the cover between a fully or partly open position, and a partly closed position, without this advancing the driving mechanism and dispensing a dose.

Claims

1 . A medicament dispenser (100) comprising: a housing assembly (102, 130); a medicament carrier (170) located within the housing assembly and configured to carry multiple discrete individual medicament dose portions; a mouthpiece (106b) in fluid communication with the housing assembly (102, 130), the mouthpiece configured so that the medicament dose portions can be dispensed therethrough; a dispensing mechanism (104, 110, 120, 140, 141 , 143a, 144a, 146) located within the housing assembly (102, 130) and configured to dispense the dose portions from the medicament carrier (170) to the mouthpiece; a cover (160) for the mouthpiece (106b), the cover moveably mounted to the housing assembly (102, 130), the cover and housing assembly mutually configured so that the cover can be moved from a fully closed position in which the mouthpiece (106b) is fully covered, to a fully open position in which the mouthpiece (106b) is fully uncovered; the cover further adapted to couple with the dispensing mechanism (104, 110, 120, 140, 141 , 143a, 144a, 146) such that movement of the cover from the fully closed position to the fully open position results in actuation of the dispensing mechanism through a complete actuation cycle, such that a dose portion is released from the medicament carrier; characterised in that the dispensing mechanism is configured such that movement of the cover from the closed position to a partly open position between the fully closed and fully open positions causes partial actuation of the dispensing mechanism, and; wherein if a complete actuation cycle has not yet been completed, any subsequent movement of the cover from the partly open position towards the closed position does not result in further actuation of the dispensing mechanism, but any subsequent movement of the cover towards the fully open position results in continued actuation of the dispensing mechanism.

2. A medicament dispenser as claimed in claim 1 wherein the dispensing mechanism is further configured such that once the complete actuation cycle has been completed, further movement of the cover towards the open position does not cause further actuation of the dispensing mechanism until the cover is returned to the fully closed position.

3. A medicament dispenser as claimed in claim 1 or claim 2 wherein the dispensing mechanism comprises a one-way ratchet mechanism.

4. A medicament dispenser as claimed in any one of claims 1 to 3 wherein the dispensing mechanism comprises a driving plate (110, 210) and primary drive element (120, 220), the primary drive element coupled to the cover so that movement of the cover drives movement of the primary drive element, the driving plate and primary drive element mutually configured to form the one-way ratchet mechanism.

5. A medicament dispenser as claimed in claim 4 wherein the primary drive element and driving plate comprise substantially circular elements arranged in substantially parallel planes with a common axis of rotation, the inner surface of the driving plate comprising a plurality of teeth, the primary drive element configured to engage with at least one of the teeth in use, the teeth configured to only engage with the driving plate when the cover is moving towards an open position.

6. A medicament dispenser as claimed in claim 5 wherein the driving plate and housing assembly are mutually configured so that the driving plate can move along the common axis of rotation from a first disengagement plane to a second engagement plane, the housing assembly, primary drive element and driving plate mutually configured so that if the driving plate is initially in the first disengagement plane, rotation of the primary drive element from a fully closed position to a fully open position will cause the driving plate to both rotate and move axially from the first disengagement plane into the second engagement plane and then back to the first disengagement plane, and rotation of the primary drive element from a fully closed position to a partly open position and back causes the driving plate to both rotate and move axially from the first disengagement plane into the second engagement plane and then remain in the second engagement plane, with further rotation of the primary drive element towards the open position then also causing rotation of the driving plate until a complete actuation cycle has been completed, the driving plate retuning to the first disengagement plane on completion of the complete actuation cycle and remaining in the first disengagement plane until the primary drive element has returned to a fully closed position and is moving from the fully closed position towards an open position.

7. A medicament dispenser as claimed in claim 5 or claim 6 wherein the primary drive element comprises at least one arm comprising a main body and an extended portion extending from the main body, and the driving plate further comprises at least one ski portion or portions extending from the main body of the driving plate, the extended portion(s) and ski portion(s) configured so that if the primary drive element and driving plate are disengaged these will engage if the cover is in the fully closed position and there is movement of the cover towards an open position, and these will disengage when a complete actuation cycle has been completed.

8. A medicament dispenser as claimed in claim 7 wherein the at least one arm comprises a plurality of equally spaced apart arms.

9. A medicament dispenser as claimed in claim 8 comprising three arms.

10. A medicament dispenser as claimed in any one of claims 5 to 9 wherein the driving plate comprises spaced apart inner and outer rings connected by at least one connecting arm.

11 . A medicament dispenser as claimed in claim 10 wherein the connecting arm comprises three connecting arms.

12. A medicament dispenser as claimed in claim 9 or claim 10 wherein the dispensing mechanism further comprises a primary drive gear, rotation of the primary drive gear driven by the driving plate in use, the primary drive gear and driving plate having a common axis of rotation, the primary drive gear driven at or close to the hub by the inner ring.

13. A medicament dispenser as claimed in claim 9 or claim 10 wherein the dispensing mechanism further comprises a primary drive gear, rotation of the primary drive gear driven by the driving plate in use, the primary drive gear and driving plate having a common axis of rotation, the driving plate driven by rotational contact on at least one of the connecting arms.