EP4683692A1

EP4683692A1 - Breath actuated dry powder inhaler

Info

Publication number: EP4683692A1
Application number: EP24713587.4A
Authority: EP
Inventors: Anne Haaije De Boer; Paul Hagedoorn; Nick VAN BARREVELD; Wouter Sjoerd DIJKSTRA; Marcel HOPPENTOCHT; Floris GRASMEIJER
Original assignee: Pureims BV; Rijksuniversiteit Groningen
Current assignee: Pureims BV; Rijksuniversiteit Groningen
Priority date: 2023-03-20
Filing date: 2024-03-19
Publication date: 2026-01-28
Also published as: WO2024196247A1; CN121079122A; IL323418A; JP2026509561A; NL2034384B1; KR20250162614A

Abstract

A breath actuated dry powder inhaler (301, 401, 501), said inhaler comprising a substantially planar housing built up of a stack of substantially planar elements, said planar elements including a bottom plate (319, 419, 519), an intermediate plate (318, 418, 518) and a top plate (317, 417), said planar elements being parallel to each other, at least one planar element being provided with projections, that in the stack form a substantially disc shaped air circulation chamber (302) for deagglomeration of entrained powdered medicament using the energy of the inspiratory air stream, a plurality of air supply channels (307), an air supply region for a powder flow and a discharge channel (312) of the inhaler, the chamber having a substantially polygonal sidewall (303) extending about a central axis between top and bottom walls of the chamber, the central axis extending transversely to the bottom plate, the height of the chamber being smaller than its diameter. The inhaler has a planar dose compartment (323, 423, 523) that is slidably received between two of the three plates.

Description

Title: Breath actuated dry powder inhaler

The invention relates to a breath actuated dry powder inhaler.

WO20 15/187025 discloses a breath actuated dry powder inhaler with a single air circulation chamber (being basically a classifier) for deagglomeration of entrained powdered medicament using the energy of the inspiratory air stream. The chamber has a substantially polygonal sidewall, a plurality of air supply channels entering the chamber substantially tangentially to its sidewall. A powder channel extends through a powder dose supply region of the inhaler tangentially into the chamber. An air outlet axially extends from a discharge in the chamber and connects to a discharge channel that extends to a mouthpiece. The polygonal sidewall comprises at least six straight line segments, each straight line segment being spaced at the same first distance from an adjacent one forming the plurality of air supply channels. The air supply channels have the same width. The powder channel is defined by two line segments which are spaced from each other at a second distance which is larger than the first distance.

The known dry powder inhaler provides various advantages. By providing the polygonal sidewall with at least six straight sides it appears that the contact surface area between circulating particles and the wall is reduced such that a reduction of adhesion of powder against the wall parts is obtained. In addition, the collision angle, i.e. the angle between the imaginary extension of the sides, has such a value, i.e. 60° or smaller, that the magnitude of the compaction force is also reduced and a higher residual particle velocity after collision is obtained. The many air flows through the air supply channels furthermore create a continuous air barrier for the smaller particles which, in conjunction with the reduced ratio of the centrifugal to drag force, keeps them away from the cylindrical classifier wall and prevents that they contribute to the adhesion and compaction against the classifier sidewall. Instead, it causes them to circulate at a certain distance from the polygonal sidewall and to collide with each other and to disrupt by internal shear in turbulent regions of air flow. Furthermore, since the powder channel is wider than the air supply channels the risk of clogging of the powder channel is reduced, but the symmetry of the air circulation in the chamber is negatively influenced. By providing at least six straight sides the number of air supply channels is large enough so that the air flowing through the air supply channels into the chamber corrects for the asymmetry of the air circulation in the chamber such that de-agglomerated powder can be dispensed from the inhaler correctly.

In the known dry powder inhaler, a sealed dose compartment is applied. The sealed dose compartment is a blister-shaped pocket sealed with a removable cover foil. The blister-shaped pocket is included in a stack with the cover foil extending out of the inhaler as a pull off portion. The resulting unit forms a disposable unit for a single dose.

The powder in the dose compartment, either e.g. as an unprocessed powder, a soft agglomerate formulation or an adhesive mixture, may be the active ingredient or a composition of the active ingredient and one or more excipients, being either a carrier for the drug, a sweeper excipient, a dispersion enhancer, a stabiliser, or any other material suitable for adjusting the specific powder properties to the performance of the circulation chamber.

A single dose of the active ingredient (with or without excipients) may be divided over a plurality of dose compartment pockets for either simultaneous or subsequent inhalation. Each compartment may contain the same component or mixture, or may contain different components or mixtures. The compartments may be loaded from a metering apparatus in the housing, but are preferably pre-filled. US2017/0106154 provides a dry powder inhaler which does not need blister capsules for storing the powder formulation. To that aim, the document proposes a dry powder inhaler wherein during storage of the powder formulation the powder formulation is in direct contact with the housing. Since the powder formulation is in direct contact with the housing of the dry powder inhaler during storage of the dry powder inhaler, i.e. before the dry powder inhaler is used for inhaling a dry powder medicament, and since the dry powder inhaler contains only a single dose of powder formulation, the dry powder inhaler according to this disclosure does not need an extra storing device, e.g. in form of a blister capsule or in form of a foil-faced container for storing the powder formulation before the dry powder inhaler is prepared for usage.

The present invention aims to provide an improved breath actuated dry powder inhaler. In particular, an aim of the invention is to reduce use of materials, thereby benefitting costs and environmental impact (i.e. ‘carbon footprint’). Also, an aim is to provide an inhaler that can deliver a relatively high powder dose.

According to an aspect of the invention, there is provided a breath actuated dry powder inhaler that is defined by the features of claim 1.

An aspect of the invention provides a breath actuated dry powder inhaler, said inhaler comprising a substantially planar housing built up of a stack of substantially planar elements, said planar elements including a bottom plate, an intermediate plate and a top plate, said planar elements being parallel to each other, at least one planar element being provided with projections, that in the stack form a substantially disc shaped air circulation chamber for de-agglomeration of entrained powdered medicament (from the dose compartment) using the energy of the inspiratory air stream, a plurality of air supply channels, an air supply region for a powder flow and a discharge channel of the inhaler, the chamber having a substantially polygonal sidewall extending about a central axis between top and bottom walls of the chamber, the central axis extending transversely to the bottom plate, the height of the chamber being smaller than its diameter, the plurality of air supply channels being disposed about the circumference of the chamber, which channels extend from an air inlet and which channels enter the chamber substantially tangentially to its sidewall, the housing comprising a powder channel extending through a powder dose supply region of the inhaler to the chamber, which powder channel enters the chamber substantially tangentially to its sidewall, the chamber further comprising an air outlet axially extending from a discharge opening and connecting to a discharge channel that extends to a mouthpiece, wherein the discharge channel connects substantially transversely to the air outlet of the chamber, wherein the inhaler comprises a single air circulation chamber and in that the polygonal sidewall comprises at least six straight line segments or sides, each straight line segment being spaced at the same first distance from an adjacent one forming the plurality of air supply channels, the air supply channels having the same width and being regularly disposed about the circumference of the chamber, the powder channel being defined by two straight line segments which are spaced from each other at a second distance which is larger than the first distance, characterized by a planar dose compartment that is slidably received between two of the three plates, for example between the bottom plate and the intermediate plate, for positioning at least one powder dose in the dose supply region.

In this way, improved inhaler operation can be achieved. The resulting inhaler can be made compact, and e.g. structurally rigid, and can provide very effective reliable powder delivery. In particular, the inhaler can be made reusable and (more) durable, and can be less harmful to the environment.

For example, the inhaler can make use of a slidably removable planar dose compartment, providing multi-use operation wherein a plurality of (exchangeable) planar dose compartments can be installed for providing multiple doses for multiple inhaling operations of the inhaler. Alternatively, the inhaler can include two integrated slidable planar dose compartments, that e.g. can be linearly moved (translated) between two (or more) positions for selecting one of the two (or more) dose compartments for discharge during inhaling.

According to a preferred embodiment, the planar dose compartment is removably arranged with respect to the planar housing, wherein the removable dose compartment includes at least one of:

-a sealed dose compartment, having a powder pocket sealed with a removable cover foil; and

- an array of separate dose reservoirs.

In any case, two of the three plates can provide (i.e. act as) guiding means for guiding the planar dose compartment between respective operating positions. The third plate can serve for air conduction over the classifier discharge hole and improves structural integrity of the inhaler, counteracting deformation of the other plates, improving reliability of sliding movement of the planer dose compartment.

In each case, it is preferred that one of the plates of the housing (e.g. the bottom plate) includes an aperture (opening) for receiving part of the planar dose compartment. More particularly, after assembly, a bottom of the planar dose compartment can protrude below e.g. the bottom plate of the plate stack, so that the dose compartment can provide additional volume for holding a dose of dry powder.

Further advantageous embodiments are described in the dependent claims. In the following, non-limiting examples of the invention will be described with reference to the drawings. Therein shows:

Fig. 1 an exploded view of a first embodiment of a breath actuated dry powder inhaler having a single circulation chamber;

Fig. 2 a top plan view of the bottom plate of a second embodiment of an inhaler; Fig. 3 an exploded view, similar to Fig. 1, of an embodiment of the present invention;

Fig. 4A a top view of part of the embodiment of Fig. 3, during installing of a slidable planar dose compartment;

Fig. 4B a top view similar to Fig, 4A, with the planar dose compartment in assembled state;

Fig. 4C a top view of the embodiment of Fig. 3 after assembly;

Fig. 5A a back view of the embodiment of Fig. 3, with the plate stack shown in cross-section, before assembly of the planar dose compartment;

Fig. 5B a back view of the embodiment of Fig. 3, with the plate stack shown in cross-section, after assembly of the planar dose compartment;

Fig. 6A an exploded view, similar to Fig. 1, of another embodiment of the present invention;

Fig. 6B a bottom view of a planar dose compartment of the embodiment of Fig. 6A;

Fig. 7 A a top view of the embodiment of Fig. 6A;

Fig. 7B an opened top view of the embodiment of Fig. 6A, with the dose compartment in a respective operating position;

Fig. 7C a top view of the bottom plate of the embodiment of Fig. 6A;

Fig. 7D a top view of the planar dose compartment of the embodiment of Fig. 6A;

Fig. 7E a back view of the housing of the embodiment of Fig. 6A;

Fig. 8A an opened top view, similar to Fig. 7B, of a further embodiment of the inhaler, with the planar dose compartment in a first position; Fig. 8B an opened top view, similar to Fig. 7B, of the further embodiment of the inhaler, with the planar dose compartment in a second position;

Fig. 8C a top view of the bottom plate of the embodiment of Fig. 8 A;

Fig. 8D a top view of the planar dose compartment of the embodiment of Fig. 8A

Fig. 9 a top view of an example of an array of dose compartments;

Figure 10 schematically an opened top view of an embodiment of a breath actuated dry powder inhaler and part of the array of dose compartments shown in Fig .9;

Fig. 11A an opened top view of the inhaler example shown in Fig. 10;

Fig. 11B a longitudinal cross-section of a bottom plate of the inhaler example of Fig. 11 A;

Figure 12A a back view of a stopper element of the inhaler example of Fig. 11 A; and

Figure 12B a side view of the stopper element of the embodiment of Fig. 11A.

The drawings show schematically representations of exemplary embodiments, which are given as non-limiting examples of the invention. In the drawings, for the various embodiments, identical or corresponding parts are denoted with the same or corresponding reference numerals.

Figure 1 shows a breath actuated dry powder inhaler 1, comprising a single, substantially disc shaped air circulation chamber 2 for de-agglomeration of entrained powdered medicament using the energy of the inspiratory air stream. The chamber 2 has a polygonal sidewall 3 extending about a central axis 4 between a substantially parallel top wall (formed by a substantially planar intermediate plate 18) and bottom wall (formed by a substantially planar bottom plate 19) of the chamber 2 so that the height of the chamber is smaller than its diameter. In the embodiment shown in Figure 1 the diameter of the single chamber 2 is about 25 mm, but it can in other embodiments have another value between 20 mm and 30 mm. In the embodiment shown in Figure 1 the polygonal sidewall 3 has seven straight line segments or sides 5a - 5g, being formed by a surface of a respective projection 20. The projections 20a-20b, 20b-20c, 20c-20d, 20d-20e, 20e-20f and 20f-20g are spaced at the same distance (also called first distance) from each other so as to form a plurality of air supply channels 7 (in the embodiment shown in Figure 1 six) which have the same width and which are regularly disposed about the circumference of the chamber 2, which channels 7 extend from separate air inlets and which channels enter the chamber 2 substantially tangentially to its sidewall 3. Said distance, i.e. the width of the air supply channels, is in the embodiment shown in Figure 1 about 1.5 mm, but can in other embodiments be between 1 and 2 mm.

Also, the width of each of the air supply channels 7 can be constant but that is not required (e.g. the channels 7 can be wider at their inlet sides compared to a width at their outlet sides). The projections 20a and 20g, however, are spaced at a larger distance from each other forming a powder channel 7a. In the shown embodiment this larger, second distance (i.e. the width of the powder channel) is about three to four, preferably 3.5 times the first distance, i.e. about 5 mm, but can in other embodiments be at least twice the first distance, i.e. at least 3 mm. In yet another embodiment, this larger, second distance (i.e. the width of the powder channel) is about two to five, preferably four times the first distance (preferably at least 2 mm).

The powder channel 7a extends from a joint air supply inlet to the powder dose region 8 of the inhaler 1. The chamber 2 further comprises an air outlet 9 axially extending from a (preferably circular) discharge opening 10 in the centre of the top wall of the chamber 2 and that connects to a discharge channel 12. The discharge channel 12 extends to a mouthpiece 13. Please note that in Figure 1 an embodiment is disclosed with seven sides, but that the invention is not limited to this number and any number of sides can be provided as long as there are more than six sides.

The discharge channel 12 connects substantially transversely to the air outlet 9 of the chamber. The axis MP of the mouthpiece 13 is orientated transversely to the central axis 4 of the classifying chamber 2.

By means of an assembling element 14a which can be inserted in respective openings 14b of the parts of the inhaler 1 the inhaler 1 can be assembled such that it comprises a substantially planar housing having the shape and size of a thick credit card, being constructed as e.g. a disposable unit. Please note, that the invention is not limited to the manner in which the parts are connected to each other and that e.g. a construction with which the parts are clicked together with flexible bps or tapered pins falling in corresponding holes is also possible (see e.g. Figure 3). The chamber 2 is disposed in the housing such that the central axis 4 of the chamber 2 extends transversely to the bottom plate 19. The discharge channel 12 is disposed in the housing such that it extends in a plane parallel to the bottom plate. The mouthpiece 13 is provided on a peripheral edge 15 of the housing. The discharge channel 12 and the circulation chamber 2 extend in substantially parallel planes. During inhalation, the mouthpiece 13 discharges an aerosol cloud of de-agglomerated powder particles entrained from the air recirculation chamber 2 in a direction parallel to the longitudinal axis of the inhaler housing which coincides with the axis MP, while the axis of the classifying chamber 2 is perpendicular to the longitudinal axis of the inhaler housing 14.

The housing is thus built up of a stack of substantially planar elements 16. These elements 16 include the bottom plate 19, the intermediate plate 18 and a top plate 17. During operation (i.e inhaling, by a user), the inhaler 1 is positioned such that top plate 18 is located above the bottom plate 19. In this example, the planar bottom plate 19 is provided with projections 20, that in the stack form the chamber 2, the air supply channels 7, the air supply region for the powder flow 8 and the discharge channel 12 of the inhaler 1. The top surface of the bottom plate 19 e.g. forms the bottom wall of the chamber 2, and carries the projections 20 that form the sides 5a- 5g. The free edges of the sides can be rounded off pointing towards the centre of the chamber 2 and are substantially positioned on an imaginary circle. The chamber 2 is closed off by the bottom surface of the intermediate plate 18, forming the top wall of the chamber 2. The intermediate plate 18 forms a division between a bottom plane in which the chamber 2 extends and a parallel top plane in which the discharge channel 12 extends. A (e.g. circular) discharge opening 10 in the intermediate plate 18 forms a passage for air and entrained, de-agglomerated medicine particles exiting the chamber through air outlet 9 extending co-axially with axis 4.

The bottom plate 19 comprises peripheral ridges 21, defining an aperture in which intermediate plate 18 is placed. Top plate 17 is stacked on top intermediate plate 18 and bottom plate 19. The assembly of the plates 16-18 is such that the housing is substantially airtight (except for the air inlet openings).

The powder dose supply area 8 is, in the embodiment shown in Figure 1, formed by a sealed dose compartment 23 containing a premeasured dose of powdered medicament. Please note that for clarity of drawing the sealed dose compartment is shown upside down with regard to the use position, in Figure 1. The dose compartment 23 is included in the powder channel 7a and is blocking air passage through the channel 7a until removal of the seal 24 of the dose compartment 23. The sealed dose compartment 23 is shown as a powder pocket sealed with a removable cover foil 24 . The pocket 23 is included in the stack with the cover foil 24 extending out of the inhaler 1 as a pull off portion. As shown in Figure 1, the housing forms a disposable unit for a single dose. Please note, that the invention is not limited to the use of powder pockets as compartments for the powdered medicament.

An air inlet 27 is provided on the rear 25 of the inhaler, generally opposite to the mouth piece 13. The thickness of the top plate 17 is reduced locally, so that during inhalation through the mouth piece 13, air may enter between the top plate 17 and the intermediate plate 18 to entrain powder from supply region 8 and carry it into the powder channel 7a. Please note, that other embodiments for creating an air inlet are also possible.

The flow of air entrains the powder and carries it through the wide channel 7a formed between the bottom 19 plate and intermediate plate 18 to the classifying chamber 2. In the embodiment shown in Figure 1, the flow of air passes via aperture 11 in the intermediate plate 18 and trough the supply region 8 formed by the opened powder pocket. The air passes through aperture 11 into the opened powder pocket for entrainment of the powder and the powder flow is guided over the downstream wall of the powder cup through a channel profiled in the centre plate. This channel with inclining and declining depth starts at approximately s the length of the powder pocket and ends with its declining section over the declining part of the powder channel towards the classifier and has its maximal depth at 50% of its length.

An air flow without powder flows from the central inlet 27 at the rear 25 of the housing through a joint channel 7b to the supply channels 7 formed between the projections 20 and bottom plate 19 and the intermediate plate 18 to the chamber 2. In the shown embodiment the joint channel 7b runs parallel to the powder channel 7a which latter is situated opposite the joint channel when seen from the longitudinal axis MP of the inhaler.

Powder particles are thus introduced into the chamber 2 by entrainment with air entering tangentially into the chambers 2 through the powder supply channel 7a. Additional air is supplied to the chambers 2 through supply channels 7, which also enter tangentially into the chambers. This way, a circular air flow is created in the chamber 2 during inhalation and as a result of the relatively large diameter of the chamber 2 the circulation is sufficient for higher doses of medication. By distributing the relatively large number of supply channels 7 evenly about the circumference of the chamber, the circulation of the flow in the chambers 2 is further enhanced.

In addition, as a result of the seven line segments or sides 5a-5g the contact surface area between circulating particles and the wall is - compared to the prior art - reduced which attributes to a reduction of compaction of powder against the wall parts. A further reduction of compaction is obtained in that the collision angle, more detailed explained with regard to Figure 2, is maximally 30° to 45° (depending on the number of channels). The high number of air channels results in an improved symmetry of the flow within the classifier chamber in which the smaller particles circulate at a certain distance from the polygonal sidewall. This prevents that they do collide with the sidewall, thereby preventing adhesion and compaction against this wall. Flow symmetry can be further influenced by lengthening the wall 20g’ of the projection 20g forming one of the walls of the powder channel 7a. Due to the relatively wide powder channel 7a, which is at least twice as wide as the air flow channels 7 and preferably three times as wide, clogging of the powder channel 7a is strongly reduced c.q. can be prevented.

Due to the polygonal shape of the chamber 2, the at least six sides 5, and the relatively large diameter of the chamber the powder particles break up correctly, i.e. they are correctly dispersed while retention is strongly reduced, so as to improve the suitability of the inhaler for cohesive, hygroscopic and compacting powders. Furthermore, finer particles are effectively entrained with the air flow exiting the chamber 2 axially through the air outlet 9 under the action of dominant drag forces. Larger particles, including sweeper crystals used to clean deposited particles from the walls of the chamber 2, remain in the chamber 2 under the action of dominant centrifugal forces unless they break up. A further advantage of the inventive inhaler is that even in case the dry powder does not contain sweeper crystals the sides 5 of the chamber can remain clean.

The air flow exiting the chamber axially though the air outlet flows into the discharge channel leading to the mouth piece 13.

As the discharge channel 12 has a central axis MP that extends perpendicularly to the central axis 4 of the chamber 2, the discharge 12 channel connects transversely to the central axis of the air outlet 9 of the chamber 2, which coincides with the central axis 4 of the chamber 2, it is achieved that the flow from the air outlet 9 to the discharge channel changes direction from coaxial to the chamber axis to transverse to the chamber axis before exiting the mouthpiece 13. This way, the tangential component in the flow is decreased, so that mouth deposition is reduced without the need to provide a sheath flow. This increases the efficiency of the actual deh very of medicine to the lungs.

The powder in the dose compartment 23, either e.g. as an unprocessed powder, a soft agglomerate formulation or an adhesive mixture, may be the active ingredient or a composition of the active ingredient and one or more excipients, being either a carrier for the drug, a sweeper excipient, a dispersion enhancer, a stabiliser, or any other material suitable for adjusting the specific powder properties to the performance of the circulation chamber. The powder in the dose compartment 23 may be the active ingredient or a formulation with the active ingredient being e.g. an unprocessed powder, a spherical pellet formulation, an adhesive mixture or a physical mixture, and/or a carrier excipient respectively a sweeper excipient, whereby the properties of the powder (formulation) may be adjusted to the specific properties of the classifier. A single dose of the active ingredient (with or without excipients) may be divided over a plurality of dose compartments pocket 23 for either simultaneous or subsequent inhalation. Each compartment may contain the same component or mixture, or may contain different components or mixtures. The compartments may be loaded from a metering apparatus in the housing, but are preferably prefilled.

In Figure 2 another embodiment of a breath actuated dry powder inhaler 201 is shown, in which the polygonal sidewall has eleven straight line segments or sides 205a - 205k (only the sides 205a and 205k are shown for convenience of drawing), which are formed by a surface of a respective projection 220. The projections 220a-220b, 220b-220c, 220c-220d, 220d-220e, 220e-220f; 220f-220g; 220g-220h; 220h-220i; 220i-220j and 220j-220k are spaced at the same distance from each other so as to form a plurality of air supply channels 207 (in the embodiment shown in Figures 2 and 3 ten) which have the same width and which are regularly disposed about the circumference of the chamber. The projections 220a and 220k are again spaced at a larger distance from each other forming a powder channel 207a. As a result of the eleven side sides 205a-205k the contact surface area between circulating particles and the wall is even further reduced which attributes to a reduction of compaction of powder against the wall parts. With regard to the embodiment of Figure 1 a further reduction of compaction is also obtained in that the collision angle ca - i.e. the angle between the imaginary extension of the sides, is approximately 30° (for example 33°). This high number of air channels results in even better flow symmetry in the classifier chamber in which smaller particles circulate at a certain distance from the polygonal sidewall to prevent that they do collide with the sidewall thereby preventing that they contribute to adhesion and compaction. Again, the free edges of the projections are all positioned on an imaginary circle (indicated by broken lines). Please note that in order to avoid unnecessary repetition of the description of components reference is made to Figure 1 in which the other analogous components of the inhaler are described.

Figures 3-8 show exemplary embodiments 301, 401 of improved inhalers. As follows from Figure 3, analogue the example of Figure 1, the improved inhaler 301 has a substantially planar housing built up of a stack of substantially planar elements 317, 318, 319, said planar elements including a bottom plate 319, an intermediate plate 318 and a top plate 317, said planar elements are parallel to each other. At least one planar element 319 (in this case the bottom plate) is provided with the projections 320, that in the stack form a substantially disc shaped air circulation chamber 302 for de-agglomeration of entrained powdered medicament using the energy of the inspiratory air stream. The inhaler 301 includes a plurality of air supply channels 307, an air supply region for a powder flow and a discharge channel 312. The chamber 302 has a substantially polygonal sidewall 303 extending about a central axis between top and bottom walls of the chamber 302, the central axis extending transversely to the bottom plate 319, the height of the chamber 302 being smaller than its diameter. The plurality of air supply channels 307 are disposed about the circumference of the chamber 302, which channels 307 extend from an air inlet and which channels 307 enter the chamber 302 substantially tangentially to its sidewall 303. The housing of the inhaler 301 comprises a powder channel 307a extending through a powder dose supply region 308 of the inhaler 301 to the chamber 302, which powder channel 307a enters the chamber 302 substantially tangentially to its sidewall 303. The chamber 302 further comprises an air outlet 309 axially extending from a discharge opening and connecting to said discharge channel 312 (that extends to a mouthpiece 313). For example, the latter discharge opening can be a circular discharge opening, located centrally/concentrically with respect to a central axis of the chamber 302, the discharge opening being provided in a top of the chamber 302, the discharge opening preferably having a diameter that is significantly smaller than the diameter of the chamber 302.

The discharge channel 312 connects substantially transversely to the air outlet 309 of the chamber 302. The inhaler 301 comprises a single air circulation chamber 302. As in the above example 1, the polygonal sidewall 303 comprises at least six straight line segments or sides, each straight line segment being spaced at the same first distance from an adjacent one forming the plurality of air supply channels 307. The air supply channels 307 have the same width and are regularly disposed about the circumference of the chamber 302. The powder channel 307a can be defined by two straight line segments which are spaced from each other at a second distance which is larger than the first distance. An aperture 311 can be provided in the intermediate plate 318 allowing passage of air (from an air supply area 311a between the top plate and intermediate plate, see Fig. 5) through the powder supply region 308 during inhaler operation.

The exemplary inhaler embodiments 301, 401 differ from the inhaler 1 depicted in Figures 1, 2 in that a planar dose compartment 323 is slidably received between two of the three plates, for example between the bottom plate 319 and the intermediate plate 318 (see the drawings), for positioning at least one powder dose in the dose supply region 308.

For example, the planar dose compartment 323 can be removably arranged with respect to the planar housing (see Figures 3-5). Figures 4A and 5A show a first position of the planar dose compartment 323, wherein it is located externally with respect to (i.e. removed from) the inhaler housing. Figures 4B, 4C and 5B show a second position, i.e. a mounted (assembled) position, of the planar dose compartment 323, wherein it has been joined with the housing of the inhaler to position a powder dose in the dose supply region 308. For example, the planar dose compartment 323 can be movable (i.e. between the removed position and the inserted operating position) in longitudinal direction with respect to a longitudinal axis MP of the inhaler 301.

The planar dose compartment 323 preferably has a substantially rectangular shape (viewed in a top view). Preferably, the planar dose compartment 323 includes a (flat) slide plate 323a having a (single) dose reservoir 323b that is preferably covered by a removable foil 324 (see Figure 4A). In particular, the removable foil 324 can cover substantially an entire upper surface 323f of the slide plate 323a, or at least a part of the surface that surrounds the reservoir 323b. For example, the dose reservoir 323b can extend in parallel with the planar elements 317, 318, 319 of the housing, at least after assembly (when the dose compartment 323 has been brought to its operating position between the housing plates 318, 319). According to an embodiment, the planar dose compartment 323 includes a recessed and/or (slightly) oblique upper side for accommodating the removable foil 324. For example, a receptive recessed section of the upper side of the planar dose compartment 323 can have a depth in the range of about 0.2-0.4 mm for receiving the foil 324. Similarly, the inhaler housing is preferably dimensioned to allow removal of the foil 324 once the planar dose compartment 323 has been positioned into the housing.

The substantially planar housing of the inhaler 301 and the planar dose compartment 323 preferably include cooperating guide structures for guiding movement of the dose compartment 323 with respect of the housing. Such guide structures can include opposite side walls and/or external surfaces of the respective components 323, 318, 319, as will be appreciated by the skilled person.

For example, the planar element 319 that is provided with the projections 320, that in the stack form a substantially disc shaped air circulation chamber 302, can also include guide projections 319b for guiding the slidable planar dose compartment 323. For example, the (preferably flat) upper side 323f of the slide plate 323a can extend in parallel with respect to an opposite surface of the intermediate plate 318 of the housing, after mounting. Similarly, a lower side 323g of the slide plate 323a (that is faced away from the respective upper side 323f, see Fig. 5A) preferably extends in parallel with respect to an opposite surface of the lower plate 319 of the housing, after mounting. It is preferred that the upper side 323f and lower side 323g of the slide plate snuggly fit between opposite parts of the respective housing plates 318, 319 after mounting, allowing precise dose compartment positioning.

Also, for example, the bottom plate 319 of the housing can include opposite longitudinal guide walls 319b, that preferably sealingly engage the intermediate wall 318, and that guidingly engage lateral sides of the slide plate 323a during sliding movement of the slide plate 323a with respect to (into or out of) the inhaler housing. In addition or alternatively, the bottom plate 319 of the housing can include two opposite longitudinal support walls 319g, for supporting the slide plate 323a during sliding movement of the slide plate 323a with respect to (into or out of) the inhaler housing. For example, these support walls 319g can enclose a cup receiving aperture 319a of the housing there-between, and can e.g. be located above a vertical level of a bottom side of the respective bottom plate 319 (see Figures 5A, 5B).

Further, the bottom plate 319 of the housing can include a lateral end stop wall 319c (extending laterally with respect to said longitudinal axis MP), for engaging a front side of the slide plate 323a when that plate 323a has been guided (along said longitudinal axis MP) to its operating position in the inhaler housing. The end stop wall 319c can e.g. extend between distal parts of the longitudinal guide walls 319b, and can e.g. include an opening 319d (see Fig. 4A) for passage of powder and air (during inhaler operation) from the dose supply region 308 towards the downstream powder channel 307a. The end stop wall 319c of the housing can e.g. include curved (rounded) corners for snuggly contacting curved (rounded) distal edges of the slide plate 323a when the plate 323a is positioned in the housing, allowing improved positioning.

The dose reservoir 323b can be defined by a cup shaped section of the slide plate 323a, having a cup bottom 323c (see Fig. 5A), two opposite longitudinal cup sides 323d (extending in longitudinal direction) and two lateral opposite cup sides 323e (extending laterally with respect to the longitudinal sides 323d). The cup bottom 323c is preferably located at a vertical level below a lower side of the slide plate 323a (after mounting), for providing increase of dose cup volume. In particular, the bottom plate 319 of the inhaler’s housing can include an aperture 319a (see Fig. 4A) for receiving the cup shaped section (i.e. respective downwardly protruding cup sides 323d, 323e and cup bottom wall 323c) of the planar dose compartment 323 (see Fig. 5B), when the dose compartment 323 is in an operating position. The opposite cup sides 323e can have various shapes, e.g. flat, curved and/or slanted. In an example, a front cup side 323e can be slanted and the opposite cup side 323e can be curved (see Fig. 3, showing a slanted cup side 323e).

Also, it is preferred that at least part of the dose reservoir 323 has a bottom side extending at an angle, for example slanting, upwardly, e.g. an angle in the range of 15-45 degrees, with respect to an upper side 323f of the slide plate (and with respect to a center plane of the inhaler housing after assembly). As follows from the drawings, for example, the cup shaped section of the slide plate 323a can include an oblique front side wall 323e that reaches towards the powder channel 307a of the housing after mounting, which front side wall 323e extends at the above-mentioned angle (from a bottom surface of the bottom 323c of the cup to a top surface of the respective slide plate 323f). In this way, improved powder discharge from the dose reservoir 323 towards the downstream powder channel 30a can be achieved (when the dose reservoir is in its operation position).

Preferably, releasable locking means are provided for releasably locking the planar dose compartment 323 to the housing when it is in a powder delivery position (i.e. the afore-mentioned second position, see Fig. 4B). A resulting locked condition of the planar dose compartment 323 is preferably such that it immobilizes the dose reservoir 323 with respect to the stack of plates 317, 318, 319 (wherein the immobilization can be abolished by unlocking the locking means), allowing reliable powder discharge, and benefitting removal of the foil 324 if that is still in place on the slide plate 323a.

For example, the slide plate 323a can include an integral resilient locking finger 323h, cooperating with a locking structure/relief (e.g. retaining wall 319e) of the housing for releasably holding the slide plate 323a in its operating position. Such a locking structure 319e can be located e.g. at or near a proximal side of the housing (as in the drawings), and/or internally in the housing.

After mounting, the resilient locking finger 323h preferably protrudes out of the housing of the inhaler 302, to be operated by a user. For example, the resilient locking finger 323h can be moved from a locking position (shown in Figure 4B) to a release position, preferably against an inherent spring force of the locking finger, wherein the slide plate 323a can be removed from the inhaler housing when the locking finger is in its release position. Further, during placement of the slide plate 323a into the housing, the resilient locking finger 323h can automatically snap into its locking position, once the slide plate 323a has reached its operation position (such placement is indicated by arrow Q in Figure 4A).

Optionally, external sides of the planar dose compartment 323, including the integral locking finger, can be configured to be held in a force closed manner by opposite plates 318, 319 of the housing, when the planar dose compartment 323 is in its second position. For example, the resilient locking finger 323h can be spring biased against an opposite surface or wall (e.g. against a said longitudinal guide wall 319b) of the housing when the slide plate 323a is its operating position, allowing stable positioning of the planar dose compartment 323.

Alternatively, external sides of the planar dose compartment 323, including the integral locking finger, can be arranged/shaped to be held in a form closed manner by opposite plates 318, 319 of the housing, when the planar dose compartment 323 is in its second position.

In an alternative embodiment (not shown), the housing of the inhaler 301 can include a resilient locking finger, for releasably locking the planar dose compartment in its second position.

It is preferred that the dose reservoir 323b of the planar dose compartment 323 is located in line with, i.e. longitudinally opposite, the powder channel 307a of the inhaler housing when the dose compartment 323 is in its second (i.e. operating) position (see Figure 4B). Also, the thus positioned dose reservoir 323b is preferably located below/opposite the air passage (aperture) 311 of the intermediate plate 318. Good results can be achieved in case the air passage 311 of the intermediate plate 318 is dimensioned such that it has a significantly smaller cross-section than (e.g. a cross-section of at most 50% or at most 30% of) an open upper section of the cup shaped section of the slide plate 323a (which open upper section is defined between upper edges of the two longitudinal sides 323d and lateral sides 323e of the cup). Preferably, the air passage 311 of the intermediate plate 318 is located above a proximal section of the open upper section of the cup shaped section of the slide plate 323a (i.e. near a proximal side of the housing of the inhaler). Also, preferably, a rear side (edge) of the air passage 311 is located above a rear side (edge) of the dose reservoir 323b when the dose compartment 323 is in its second position. It is preferred that the intermediate plate 318 includes an upstanding bridge section 318b, extending opposite each of the powder channel 307a and the open upper section of the cup shaped section of the slide plate 323a, for defining an air/powder passage there-below. A central section of the upstanding bridge section 318b can be located e.g. opposite the end stop wall opening 319d. It is preferred that a bottom side of the upstanding bridge section 318b has a generally concave shape, e.g. having both a slanted proximal section and a slanted distal section (viewed along a flow direction), with a straight section between the two slanted sections. For example, according to a preferred embodiment, the upstanding bridge section 318b is configured/arranged such that a respective slanting bottom side has about the same slope percentage as a slope of an aforementioned slanted lateral cup side 323e (if present). According to a preferred embodiment, the upstanding bridge section 318b is configured/arranged such that it defines a bridge channel with opposite surfaces of a positioned slide plate 232a and the bottom plate 319, the bridge channel having a substantially constant cross-section viewed along a respective powder flow direction along the bridge section 318b. In this way, powder blockage in the bridge powder channel can be prevented.

Also, preferably, the slide plate 323a of the dose compartment 323 has a thickness W (measured normally with respect to the main surfaces of the housing plates 317, 318, 319, as indicated in Fig. 5B) that is the same as or a smaller than a height of the air circulation chamber 302 of the housing. The slide plate 323a can be dimensioned such that part of the plate protrudes externally of the inhaler housing when it is in its second position (see Figure 4B, 4C). The protruding slide plate part can include part the optional locking finger, and can provide a user operating member for manual handling of the slide plate 323a.

Further, an entry section of the inhaler housing can include slanted or curved proximal entry edges 319f, e.g. leading to said longitudinal support wall sections 319g of the bottom plate 319, allowing ease of slide plate insertion. Similarly, an opposite edge of the intermediate plate 318 can be slanted or curved, for the same purpose.

Moreover, the top plate 317 and the bottom plate 319 of the housing are preferably interconnected via a plurality of integrated connectors 314a, for example click connectors and/or clamping studs 314a. It is preferred that a plurality spaced-apart connectors 314a (for example five or six connectors) are arranged along a contour of the housing. The connectors can e.g. be made in one piece with the bottom plate 319 to be fixed to connector receivers (not shown) of the top plate 317, or alternatively with the top plate 317 to be fixed to connector receivers of the bottom plate, or a combination thereof. The intermediate plate 318 can include connector passages or grooves 318a for passing the integrated connectors 314a between the top and bottom plates 317, 319, and for positioning the intermediate plate 318 with respect to the other plates of the stack.

Operation of the embodiment of Figures 3-5 is basically the same as that of the inhaler shown in Figures 1, 2. Before initial use, in case the planar dose compartment 323 has not yet been introduced in the inhaler housing, it can be mounted and locked in place from its first position into its section position. Subsequently, the optional foil 324 can be removed from the slide plate 323a, after which powder present on the slide plate (i.e. in the cup shaped section thereof) can be inhaled by a user inhaling via the mouthpiece 313. After use, the emptied planar dose compartment 323 can be removed from the inhaler 301 (unlocking optional locking means if present), to be replaced by another planar dose compartment 323 that provides a new powder dose.

Due to the present configuration, optimal use of the inhaler 301 can be achieved, in an economical, compact, reliable and user-friendly manner. Different dose compartments can be provided having the same or different powder(s) to be inhaled via the inhaler 323. For example, two subsequent doses to be administered can provide a multi-dose of the same powder.

Figures 6-7 depict another example of an improved powder inhaler 401, including a top plate 417, intermediate plate 418, and bottom plate 419, and the respective substantially disc shaped air circulation chamber 402 (see above). The present example differs from the example shown in Figures 4-5 in that the slidable planar dose compartment 423 is not removable from the housing of the inhaler 401. Besides, the dose compartment 423 includes more than one (in this case two) dose reservoirs 423c containing separate doses DI, D2. However, in yet another embodiment (not shown), a slidable planar dose compartment 423 having several separate dose reservoirs can be provided wherein the planar dose compartment is removable from the housing (in that case, the housing preferably includes an entry and/or exit port for installing and/or removing the dose compartment 423). In the latter case, a dry powder inhaler having an exchangeable planar dose compartment, the dose compartment having at least two separate dose reservoirs, is provided.

After assembly, the planar dose compartment 423 is preferably movable within the housing, between two of the plates (the bottom plate 419 and the intermediate plate 418) between a first operating position (see Fig. 7B) for positioning a first dose DI in a dose supply region and a second operating position (not shown) for positioning a second dose D2 in the dose supply region. The planar dose compartment 423 can e.g. be movable in transversal direction with respect to a longitudinal axis MP of the inhaler 401.

After assembly, the respective dose supply region can e.g. be located centrally in the housing, e.g. in line with the mouthpiece 413. The same holds for the powder channel 407a (see Fig. 7B), which can e.g. be defined by one straight line segment and one (slightly) curved or angled line segment, the two line segments being spaced from each other at a second distance which is larger than the above-mentioned first distance (concerning the air supply channels of the air circulation chamber 402). For example, said second distance can be a varying distance (or distance range), e.g. a distance that reduces viewed along a powder flow direction. The aperture 411 in the intermediate plate 318 (allowing passage of air from an air supply area between the top plate and intermediate plate through the powder supply region during inhaler operation) can also be located centrally in the housing, e.g. in line with the mouthpiece 413.

Also, it is preferred that the intermediate plate 418 includes an upstanding bridge section 418b, extending opposite each of the powder channel 407a and an open upper section of a cup shaped section of the slide plate 423a (for defining an air/powder passage there-below) when that plate is in one of its two operating positions.

The bottom plate 419 of the housing can include a (in this case rectangular) aperture 419a for receiving part of the planar dose compartment 423. Also, as is shown in Fig. 7B by arrow AF indicating an air flow, this aperture 419a can provide an air passage towards the projections 420 of the substantially disc shaped air circulation chamber 402, in each of the two positions of the planar dose compartment 423. For example, to that aim, the housing can include two air channels 407b to the supply channels formed between the projections 420 and bottom plate 419 and the intermediate plate 418 to the chamber 402, for receiving the air AF from the aperture 419a, the two air channels 407b being associated with the two operating positions of the dose compartment 423. As follows from the drawing, the powder channel 407a can be located between the two air channels 407b.

The planar dose compartment 423 preferably has a substantially rectangular shape (viewed in a top view). Preferably, the planar dose compartment 423 includes a (flat) slide plate 423a having two dose reservoirs 423b that may e.g. be covered by one or two respective removable foils (not shown). In this example, the two dose reservoirs 423b extend in parallel.

For example, each dose reservoir 423b can extend in parallel with the planar elements 417, 418, 419 of the housing, after assembly of the inhaler.

The substantially planar housing of the inhaler 401 and the duodose planar dose compartment 423 preferably includes cooperating guide structures for guiding lateral movement of the dose compartment 423 with respect of the housing. Such guide structures can include opposite side walls and/or external surfaces of the respective components 423, 418, 419, as will be appreciated by the skilled person.

For example, the planar element 419 that is provided with the projections 420, that in the stack form a substantially disc shaped air circulation chamber 402, can also include guide projections 419b, 419c for guiding the slidable planar dose compartment 423.

For example, a (preferably flat) upper side 423f of the slide plate 423a can extend in parallel with respect to an opposite surface of the intermediate plate 418 of the housing, after mounting. Similarly, a lower side 423g of the slide plate 423a (that is faced away from the respective upper side 4231) preferably extends in parallel with respect to an opposite surface of the lower plate 419 of the housing, after mounting. It is preferred that the upper side 423f and lower side 423g of the slide plate snuggly fit between opposite parts of the respective housing plates 418, 419 after mounting, allowing precise dose compartment positioning.

Also, for example, the bottom plate 419 of the housing can include opposite longitudinal guide walls 419b, that may optionally provide end stops engaging respective lateral sides of the slide plate 423a when that plate is in one of its two operation positions.

Further, the bottom plate 419 of the housing can include a lateral guide wall sections 419c, for engaging and guiding a front side and back side of the slide plate 423a when that plate 423a is guided (transversally) one of its operating positions in the inhaler housing. The internal guide wall(s) 419c can e.g. include an opening 419d for passage of powder and air (during inhaler operation) from the respective dose supply region towards the downstream powder channel 407a.

Preferably, the guide walls 419c of the housing include curved (rounded) corners for snuggly contacting curved (rounded) distal edges of the slide plate 423a when the plate 423a is positioned in one of its two operating positions.

For example, each of the two dose reservoirs 423b can be defined by a cup shaped section of the slide plate 423a, having a cup bottom 423c, two opposite longitudinal cup sides and two lateral opposite cup sides. Each cup bottom 423c is preferably located at a vertical level below a lower side of the slide plate 423a, for providing increase of dose cup volume. In particular, the bottom plate 419 of the inhaler’s housing can include the aforementioned aperture 419a for receiving the two cup shaped sections (i.e. respective downwardly protruding cup sides and cup bottom walls) of the planar dose compartment 423.

Also, it is preferred that at least part of the dose reservoir 423 has a bottom side extending at an angle, for example slanting, upwardly, e.g. an angle in the range of 15-45 degrees, with respect to an upper side 423f of the slide plate (and with respect to a center plane of the inhaler housing after assembly). As follows from the drawings, for example, each of the two cupshaped sections of the slide plate 423a can include an oblique front side wall 423e that reaches towards the powder channel 407a of the housing when the respective cup has been positioned in an operating (i.e. powder discharge) position.

Preferably, releasable locking means are provided for releasably locking the planar dose compartment 423 to the housing when it is in one of its two powder delivery positions. For example, the slide plate 423a can include an integral resilient locking finger 423h, cooperating with a locking structure/relief (e.g. retaining wall 419e) of the housing for releasably holding the slide plate 423a in each operating position. Such a locking structure 419e can be located e.g. at or near a proximal side of the housing (as in the drawings), and/or internally in the housing.

After mounting, the resilient locking finger 423h preferably protrudes out of the housing of the inhaler 402, to be operated by a user. For example, the resilient locking finger 423h can be moved upwardly from a locking position (shown in Figure 7B) to a release position, preferably against an inherent spring force of the locking finger, after which the slide plate 423a can moved transversally to its second operating position. Once the slide plate 423a has reached its second operating position, the resilient locking finger 423h can automatically snap back into a locking position.

The duo-dose slide plate 423a, and particular its integral locking finger 423h, can be dimensioned such that it protrudes externally of the inhaler housing, to be operated by a user. A rear end of the inhaler housing (faced away from the mouthpiece 413) can include an opening or slit, e.g. defined between the bottom plate 419 and intermediate plate 418), allowing passage and transversal movement of the locking finger 423h. The respective slit can extend along the afore-mentioned retaining wall 419e, that e.g. can be located centrally, and that may optionally include slanted lateral sides for ease of locking finger operation.

As in the earlier embodiment, the top plate 417 and the bottom plate 419 of the housing are preferably interconnected via a plurality of integrated connectors 414a, for example click connectors and/or clamping studs 414a. The connectors 414a can be are arranged along a contour of the housing. The intermediate plate 418 can include connector passages or grooves 418a for passing the integrated connectors 414a between the top and bottom plates 417, 419, and for positioning the intermediate plate 418 with respect to the other plates of the stack. In this example, two of these connectors 414a are located at the rear side of the housing, in partial near opposite ends of the rear slit. Preferably a second pair of these connectors 414a is located relatively centrally or near the center of the housing (viewed in a longitudinal housing direction). Also, preferably a pair of the connectors 414a is located at or near a front side of the housing (near the mouth piece 413). In this way, a sturdy plate stack can be provided, allowing improved repositioning of the duo-dose compartment 423.

Operation of the embodiment of Figures 6,7 is basically the same as that of the inhaler shown in Figures 3-5, with the difference that the dose-compartment can not be removed from the housing, but is positioned (and releasably locked by the locking finger 423h) into one of its two operation positions for discharge of a respective powder dose DI, D2. After a respective one of the two doses DI, D2 has been discharged, a user can transversally slide the slide plate 423a to its other operating position (upon handling the locking finger 423h), for discharging the other of the two doses DI, D2. Once both doses have been used, the inhaler 401 can be discarded, and is preferably recycled.

Figures 8A-8D depict a further example of an inhaler 501, that differs from the example of Figures 6, 7 in that the housing (only part being shown) includes a limited number of integrated connectors 514a, for example only four such connectors, that can be made e.g. in one piece with the bottom plate 519 of the housing (or alternatively the top plate of the housing). In this case, the housing does not have connectors located at the rear side of the housing. As a result, relatively compact inhaler assembly can be achieved. In particular, the inhaler can provide a relatively reduced rigidity at a back side of the housing, thereby improving sliding operation of the dose compartment 523. Operation of this example is shown in Figures 8A, 8B and is basically the same as operation of the embodiment of Figures 6, 7. As follows from Figure 8 A, when the dose compartment 523 is in a first position, a first dose DI can be discharged, wherein air AF can enter the housing via the opening 519a extending below (and next to) the slide plate 523a, to be fed to one of the two downstream air channels 507b.

As is shown in Figure 8B, when the dose compartment 523 is in its second position, a second dose D2 can be discharged, wherein air AF can also enter the housing via the opening 519a extending below (and next to) the slide plate 523a, to be fed to the other of the two downstream air channels 507b.

Figures 9-12 schematically depict a further example of an inhaler 601, that differs from the above-described examples in that the planar dose compartment is provided by an array S (e.g. more than two) of separate dose reservoirs 623 (e.g. an elongated carrier strip having the dose reservoirs 623), the reservoirs 623 e.g. extending in-line with each other. The inhaler housing is configured such that the array S can be fed into and out of the housing of the inhaler, for example via opposite (left and right) sides of the housing, for subsequently bringing respective powder doses D into the dose region of the inhaler. Then, after depletion (use) of one of the dose reservoirs, the array S can slide with respect to the housing for removing the depleted reservoir out of the housing, and for positioning a subsequent dose reservoir or array (filled with powder D) into the dose region. Feeding of the array S into the housing is indicated by arrow F in Figure 10, whereas arrow G indicates removal of a used dose reservoir 623. In this example, a feeding direction F is perpendicular to the longitudinal axis of the inhaler housing.

As follows from Fig. 9, for example, a strip (array S) of interconnected dose reservoirs 623 can be provided, to be fed into the inhaler housing. Preferably, the dose reservoirs 623 of the array S are releasably connected to each other, e.g. via releasable connection structures 670, for example via intermediate weakening lines, tear-offlines, perforation lines and/or the like as will be clear to the skilled person. Each of the dose reservoirs 623 can have a rectangular shape (viewed in a top view). Preferably, each planar dose compartment 623 includes a (flat) slide plate 623a having a (single) dose reservoir 623b (containing a dose D), wherein the or each reservoir 623b is preferably covered by a removable foil 624.

As in the above examples, the housing of the inhaler 601 of the present embodiment comprises a powder channel 607a extending through a powder dose supply region 608 of the inhaler 301 to the chamber 602, which powder channel 607a enters the chamber 302 substantially tangentially to its sidewall. The respective air circulation chamber (which is only schematically shown) has the same configuration as described above.

The bottom plate 619 of the housing of the inhaler 601 can include a guide structure, in particular a depression providing opposite guide walls 619b (extending in parallel, perpendicular to the longitudinal axis of the inhaler housing), for receiving the array S of dose reservoirs and feeding a first one of the reservoirs to the dose region. A first lateral side of the housing can e.g. include an entry opening EO for entry of the array S of reservoirs 623, wherein a second lateral side that faces away from the first side can include a discharge opening XO for discharging used dose reservoirs 623.

Referring to the drawings, preferably, the inhaler 601 has releasable locking means 680 for releasably locking each planar dose compartment 623 of the array S to the housing when the dose compartment 623 is in a powder delivery position. For example, the slide plate 623a of each of the dose compartments 623 can include an integral locking structure/relief, for cooperation with a stopper element (e.g. retaining element) 680 of the housing for releasably holding the slide plate 623a in its operating position. After mounting, an operating part 680a of the stopper element 680 (e.g. a knob) preferably protrudes out of the housing of the inhaler 6302, to be operated by a user. For example, the locking element 680 can be a resilient element 680 (e.g. a flexible beam, having a snapping relief for cooperating with the locking structures of the dose compartments 623) that can be moved from a locking position (shown in Figures 10, 11A) to a release position, preferably against an inherent spring force of the element 680, wherein the slide plate 623a can be removed from the inhaler housing when the locking element 680 is in a respective release position. Further, during placement of the strip S and respective slide plate 623a into the housing, the resilient locking element 680 can automatically snap into its depicted locking position, once the slide plate has reached its operation position.

According to an embodiment, the resilient locking element 680 can be connected or coupled to e.g. the bottom plate 619 or intermediate plate of the inhaler housing via respective mounting means, for example one or more pins 680b that connect to pin receiving openings of the housing. In this example, these mounting means are located near the array entry opening EO of the housing.

While this disclosure includes specific example embodiments, it will be apparent to one of ordinary skill in the art that various changes in form and details may be made in these example embodiments without departing from the scope of the claims. The example embodiments described herein are to be considered in a descriptive sense only, and not for purposes of limitation.

For example, in case of an exchangeable dose compartment, the inhaler housing can be configured to receive the dose compartment via a back side of the housing (as in Figures 3-4) or via a different side, e.g. via a lateral side of the housing. The inhaler can be configured in various ways for circulating air in or through the housing, in different air circulating directions (e.g. clockwise or counter clockwise).

Also, a location of the housing’s powder channel is not limited to the locations shown in the exemplary drawings. For example, the powder channel can be located at a left or right side or e.g. in or near a middle of the housing of the inhaler (when viewed in a top view).

Similarly, the powder channel can have various shapes and various dimensions, as will be appreciated by the skilled person. The powder channel can be a straight channel, a curved channel, or a combination of such or other shapes.

A said planar dose compartment, e.g. a respective slide plate, can include a single dose reservoir for holding a single powder dose, two separate dose reservoirs for holding two respective powder doses, or more than two (e.g. three) dose reservoirs.

As follows from the above, according to an embodiment, the planar dose compartment can include an array (e.g. more than two) of separate dose reservoirs (e.g. a carrier strip having the dose reservoirs), wherein the inhaler housing is configured such that the array can be fed into and out of the housing of the inhaler, for example via opposite (left and right) sides of the housing, for subsequently bringing respective powder doses into the dose region of the inhaler. Then, after depletion (use) of one of the dose reservoirs, the array can slide with respect to the housing for removing the depleted reservoir out of the housing, and for positioning a subsequent dose reservoir or array (filled with powder) into the dose region.

Also, a dose reservoir of a dose compartment can have various orientations and shapes. For example, in case of a substantially rectangular dose reservoir (when viewed in a top view), the dose reservoir can extend substantially parallel with respect to a longitudinal axis MP of the inhaler, but that is not required. In another embodiment, the dose reservoir extends at an angle (larger than 0 degrees) with respect to the longitudinal axis MP of the inhaler, e.g. an angle in the range of 10 - 45 degrees.

In embodiments, the planar dose compartment is slidably received between the bottom plate and the intermediate plate, but that is not required. For example, in an alternative example, the planar dose compartment can be slidably received between the top plate and the intermediate plate.

In an embodiment, part of the dose compartment can protrude through the bottom plate of the inhaler housing (see Figure 5B, as an example). In an alternative embodiment, the dose compartment can be positioned in an upside-down orientation, and/or e.g. part of the dose compartment protrudes through a dedicated opening that can be provided in the intermediate plate of the inhaler housing.

Also, for example, the slidable planar dose compartment can be substantially or entirely embedded in the housing of the inhaler.

The slidable planar dose compartment can include a user operating member, e.g. a handle, knob, integral platelet section or the-like for manual manipulation of the planar dose compartment with respect to the inhaler’s housing. Such an operating member can e.g. protrude from the housing after assembly, in various directions, e.g. backwards (see Figures 3-8), downwards, or differently.

The inhaler (e.g. the housing) can be made of various materials, e.g. plastic(s), as will be appreciated by the skilled person. According to an advantageous embodiment, the inhaler is substantially or entirely made of biodegradable or bio-based material (e.g. biodegradable or bio-based plastic material).

Claims

1. A breath actuated dry powder inhaler, said inhaler (301; 401; 501; 601) comprising a substantially planar housing built up of a stack of substantially planar elements (317, 318, 319; 417, 418, 418; 519; 619), said planar elements including a bottom plate (319; 419; 519; 619), an intermediate plate (318; 418) and a top plate (317; 417), said planar elements being parallel to each other, at least one planar element (319; 419; 519; 619) being provided with projections, that in the stack form a substantially disc shaped air circulation chamber (302; 402; 602) for deagglomeration of entrained powdered medicament using the energy of the inspiratory air stream, a plurality of air supply channels (307), an air supply region for a powder flow and a discharge channel (312) of the inhaler, the chamber having a substantially polygonal sidewall (303) extending about a central axis between top and bottom walls of the chamber (302; 402; 602), the central axis extending transversely to the bottom plate (319; 419; 519; 619), the height of the chamber (302; 402; 602) being smaller than its diameter, the plurality of air supply channels (307) being disposed about the circumference of the chamber (302; 402; 602), which channels (307) extend from an air inlet and which channels (307) enter the chamber substantially tangentially to its sidewall, the housing comprising a powder channel (307a; 407a; 607a) extending through a powder dose supply region (308) of the inhaler (301; 401; 501; 601) to the chamber (302; 402; 602), which powder channel (307a; 407a; 607a) enters the chamber (302; 402; 602) substantially tangentially to its sidewall (303), the chamber (302; 402; 602) further comprising an air outlet (309) axially extending from a discharge opening and connecting to a discharge channel (312) that extends to a mouthpiece (313; 413), wherein the discharge channel (312) connects substantially transversely to the air outlet (309) of the chamber (302; 402; 602), wherein the inhaler (301; 401; 501; 601) comprises a single air circulation chamber and in that the polygonal sidewall (303) comprises at least six straight line segments or sides, each straight line segment being spaced at the same first distance from an adjacent one forming the plurality of air supply channels (307), the air supply channels (307)having the same width and being regularly disposed about the circumference of the chamber (302; 402; 602), the powder channel (307a; 407a; 607a) being defined by two line segments which are spaced from each other at a second distance which is larger than the first distance, characterized by a planar dose compartment (323; 423; 523; 623) that is slidably received between two of the three plates, for example between the bottom plate and the intermediate plate, for positioning at least one powder dose in the dose supply region (308).

2. The breath actuated dry powder inhaler according to claim 1, wherein the planar dose compartment (323; 623) is removably arranged with respect to the planar housing, wherein preferably releasable locking means are provided for releasably locking the planar dose compartment to the housing when it is in a powder delivery position.

3. The breath actuated dry powder inhaler according to any of the preceding claims, wherein the planar dose compartment (423; 52; 6233)is movable between a first position for positioning a first dose in the dose supply region and a second position for positioning a second dose in the dose supply region.

4. The planar breath actuated dry powder inhaler according to any of the preceding claims, wherein one of the plates (319; 419; 519; 619) of the housing includes an aperture (319a; 419a; 519a) for receiving part of the planar dose compartment (323; 423; 523; 623).

5. The planar breath actuated dry powder inhaler according to any of the preceding claims, wherein the substantially planar housing and the planar dose compartment (323; 423; 523; 623) include cooperating guide structures for guiding movement of the dose compartment with respect of the housing.

6. The planar breath actuated dry powder inhaler according to any of the preceding claims, wherein the planar dose compartment (323) is movable in longitudinal direction with respect to a longitudinal axis (MP) of the inhaler

7. The planar breath actuated dry powder inhaler according to any of the preceding claims 1-5, wherein the planar dose compartment (423; 523; 623) is movable in transversal direction with respect to a longitudinal axis (MP) of the inhaler

8. The planar breath actuated dry powder inhaler according to any of the preceding claims, wherein the planar dose compartment (323; 423; 523; 623) includes a slide plate having a dose reservoir that is preferably covered by a removable foil.

9. The planar breath actuated dry powder inhaler according to claim 8, wherein the dose reservoir extends in parallel with the planar elements of the housing.

10. The planar breath actuated dry powder inhaler according to claim 8 or 9, wherein at least part (323e) of the dose reservoir extends at an angle, e.g. an angle in the range of 15-45 degrees, with respect to an upper side (3231) of the dose compartment and/or with respect to a center plane of the housing.

11. The planar breath actuated dry powder inhaler according to any of the preceding claims, wherein the planar element (319 ;419; 519; 619) that is provided with projections (320), that in the stack form a substantially disc shaped air circulation chamber (302), includes guide projections for guiding the slidable planar dose compartment.

12. The planar breath actuated dry powder inhaler according to any of the preceding claims, wherein the planar dose compartment (323; 423; 523; 623) has a substantially rectangular shape.

13 The planar breath actuated dry powder inhaler according to any of the preceding claims, wherein the planar dose compartment (323; 423; 523; 623) includes a slide plate (323a; 423a; 523a), the slide plate preferably having a thickness that is the same as or a smaller than a height of the air circulation chamber (302; 402; 602).

14. The planar breath actuated dry powder inhaler according to any of the preceding claims, wherein the top plate and the bottom plate are interconnected via a plurality of integrated connectors (314a), for example click connectors and/or clamping studs.

15. The breath actuated dry powder inhaler according to any of the preceding claims, wherein:

-the polygonal sidewall comprises seven to eleven straight line segments; and/or

-wherein the second distance is at least twice, preferably about three times or four times the first distance; and/or

-wherein the first distance is between 1 and 2 mm, preferably about 1.5 mm; and/or

-wherein a surface of each of the projections forms a respective straight line segment, each surface having a free edge, the free edges of the surfaces of the respective projections being rounded off and situated on a circle around the central axis; and/or

-wherein the diameter of the single chamber is between about 20 mm to about 30 mm, preferably about 25 mm.

16. The breath actuated dry powder inhaler according to any of the preceding claims, the planar dose compartment includes an array of separate dose reservoirs, wherein the inhaler housing is configured such that the array of separate dose reservoirs can be fed into and out of the housing of the inhaler, for example via opposite sides of the housing, for subsequently bringing respective powder doses into the dose region of the inhaler.

17. The breath actuated dry powder inhaler according to claim 16, wherein the array of separate dose reservoirs is a carrier strip having the dose reservoirs.

18. The breath actuated dry powder inhaler according to any of the preceding claims, wherein the dose compartment is a sealed dose compartment, having a powder pocket sealed with a removable cover foil (324).

19. A breath actuated dry powder inhaler, said inhaler (301; 401; 501; 601) comprising a substantially planar housing built up of a stack of substantially planar elements (317, 318, 319; 417, 418, 418; 519; 619), said planar elements including a bottom plate (319; 419; 519), an intermediate plate (318; 418) and a top plate (317; 417), said planar elements being parallel to each other, at least one planar element (319; 419; 519) being provided with projections, that in the stack form a substantially disc shaped air circulation chamber (302; 402; 602) for de-agglomeration of entrained powdered medicament using the energy of the inspiratory air stream, a plurality of air supply channels (307), an air supply region for a powder flow and a discharge channel (312) of the inhaler, the chamber having a substantially polygonal sidewall (303) extending about a central axis between top and bottom walls of the chamber (302; 402; 602), the central axis extending transversely to the bottom plate (319; 419; 519; 619), the height of the chamber (302; 402; 602) being smaller than its diameter, the plurality of air supply channels (307) being disposed about the circumference of the chamber (302; 402; 602), which channels (307) extend from an air inlet and which channels (307) enter the chamber substantially tangentially to its sidewall, the housing comprising a powder channel (307a; 407a; 607a) extending through a powder dose supply region (308) of the inhaler (301; 401; 501; 601) to the chamber (302; 40; 6022), which powder channel (307a; 407a; 607a) enters the chamber (302; 402; 602) substantially tangentially to its sidewall (303), the chamber (302; 402; 602) further comprising an air outlet (309) axially extending from a discharge opening and connecting to a discharge channel (312) that extends to a mouthpiece (313; 413), wherein the discharge channel (312) connects substantially transversely to the air outlet (309) of the chamber (302; 402; 602), wherein the inhaler (301; 401; 501; 601) comprises a single air circulation chamber and in that the polygonal sidewall (303) comprises at least six straight line segments or sides, each straight line segment being spaced at the same first distance from an adjacent one forming the plurality of air supply channels (307), the air supply channels (307)having the same width and being regularly disposed about the circumference of the chamber (302; 402; 602), the powder channel (307a; 407a; 607a) being defined by two line segments which are spaced from each other at a second distance which is larger than the first distance, characterized by a planar dose compartment (323; 423; 523; 623) that is slidably received between two of the three plates, for example between the bottom plate and the intermediate plate, for positioning at least one powder dose in the dose supply region (308), wherein the planar dose compartment (323; 623) is removably arranged with respect to the planar housing, wherein the removable dose compartment (323; 623):

-is a sealed dose compartment, having a powder pocket sealed with a removable cover foil (324; 624); and/or

- includes an array (S) of separate dose reservoirs (623.