WO2009102273A1

WO2009102273A1 - Inhaler comprising a plurality of consecutive sealed cavities containing medicaments

Info

Publication number: WO2009102273A1
Application number: PCT/SE2009/050140
Authority: WO
Inventors: William Bakewell; John Briant; Charles Cooke; Chris Groombridge; Nick Harrison; Orest Lastow; Nick Smartt
Original assignee: Astrazeneca Ab
Priority date: 2008-02-12
Filing date: 2009-02-11
Publication date: 2009-08-20

Abstract

The invention relates to an inhaler, comprising a base having a plurality of consecutive sealed cavities containing medicament. A foil is attached to the base for sealing the medicament within the cavities, wherein the width of the foil is defined by a first edge and a second edge of the foil. A plurality of separating elements, one for each cavity, are attached to the foil for separating a foil portion from a respective cavity. Between each pair of neighbouring separating elements, the foil is provided with an indication of fracture at said first edge, wherein when a separating element is moved away from the base, the foil starts to tear at said indication of fracture and continues to tear between the moving separating element and its neighbouring separating element until the foil has torn to said second edge.

Description

Inhaler comprising a plurality of consecutive sealed cavities containing medicaments .

Technical field

The present invention relates to an inhaler, comprising a base having a plurality of consecutive sealed cavities containing medicament, such as in the form of dry powder medicament.

Background of the Invention

There are different types of inhalers on the market. A pressurized Metered Dose Inhaler (pMDI) releases a fixed dose of substance in aerosol form. A powder inhaler generally releases a dose of powdered substance entrained in an air stream. In a powder inhaler the powder may be provided in a bulk container of the inhaler from which doses of powder are metered for dispensing. As an alternative to a bulk container, powder inhalers may comprise a single compartment or a plurality of compartments for containing discrete doses of powdered substance. Such compartments may take the form of sealed blisters in a blister pack, a cavities-containing strip joined to a sealing strip or other suitable forms. There are different solutions to opening compartments containing discrete doses of powder. WO 01/72605 discloses different embodiments of a dose strip for use with a powder inhaler. Various opening mechanisms are disclosed. For instance, in Fig. 4 a lid strip covers spaced apart blisters. Lid tabs are attached to the lid strip over each blister. A peel strip is joined to each lid tab. Pulling of the peel strip opens the blisters. A peel perforation is optionally provided at the leading forward edge of each of the lid tabs. The optional peel perforation provides a location on the lid strip having reduced shear strength, thereby reducing the force required to shear open the blisters. Summary of the Invention

An object of the present invention is to provide an alternative manner of handling sealed compartments or cavities and elements associated thereto inside an inhaler.

This and other objects, which will become apparent in the following disclosure, are accomplished by the invention defined in the accompanied claims.

The present invention is based on the insight separating a sealing material from a cavity which it is covering may be facilitated by initiating the tearing of the sealing material at one of its edges and continuing the tearing to another one of its edges. The present invention is also based on the insight that the material consumption may be reduced in the manufacturing process by providing an inhaler in which the sealing material covering the cavities is to be torn from edge to edge.

According to one aspect of the invention, an inhaler is provided. The inhaler comprises a base having a plurality of consecutive sealed cavities containing medicament, a foil comprising two sides, one side being attached to the base for sealing the medicament within the cavities, wherein the width of the foil is defined by a first edge and a second edge of the foil, a plurality of separating elements, one for each cavity, each separating element being attached to the other side of the foil for separating a foil portion from a respective cavity, wherein, between each pair of neighbouring separating elements, the foil is provided with an indication of fracture at said first edge, wherein when a separating element is moved away from the base, the foil starts to tear at said indication of fracture and continues to tear between the moving separating element and its neighbouring separating element until the foil has torn to said second edge. The extensions of the first edge and the second edge may suitably define a path along which the cavities are located. Thus, the foil portion is torn transversely to such a foil path. Since the foil is torn from one edge to the other, the foil may be readily separated from the cavities segment by segment, without leaving any bonded foil material when all the cavities have been uncovered. The previously mentioned inhaler in WO 01/72605 provides for a relatively more difficult central circular tear in its lid strip, leaving large areas of remaining lid strip material bonded to the base strip. Thus, the prior art inhaler uses a two- dimensional tear of the sealing material, while the present invention enables a one- dimensional tear of the sealing material.

There are various alternatives for how to arrange the cavities in the base. One alternative is to provide them in a straight line. The covering sealing foil would thus also be linear having two lateral edges, wherein the indications of fracture would be at one of said edges. When a separating element is moved away from the base the foil will follow the separating element and start to tear at the indication of fracture. As the separating element continues to move the tear will progress transversely to the longitudinal extension of the foil until the tear reaches the other lateral edge, whereby a foil portion attached to the moving separating element becomes completely detached from the base. Another alternative is to provide the cavities in a curved path, e.g. in an annular path. In that case, the covering sealing foil would also be annular, having two lateral edges: one inner and one outer edge. This is reflected in at least one example embodiment of the invention, wherein the foil is annular and disk-shaped, wherein the first edge describes an inner perimeter and the second edge describes an outer perimeter of the foil. Thus, in this case the tear would be initiated at the inner perimeter and continue to the outer perimeter of the foil. An alternative would be to tear from the outer perimeter to the inner perimeter.

In both of the above exemplified alternatives, i.e. linear and curved/annular, the tear may be progressed substantially perpendicularly to the direction of extension of the path described by the foil and the series of cavities. Furthermore, in both of the above exemplified alternatives, there is suitably provided only one indication of fracture between each pair of neighbouring separating elements. This means that the tear line initiated from an indication of fracture will be common to both separating elements of such a pair. Thus, once a foil portion has been moved away from its associated cavity and has left a tear line, subsequently when the next separating element is moved away its attached foil portion will already have been torn along said tear line on one side of the separating element and will during this separation only tear on the other side of the separating element, thus requiring less tear force than if the foil portion would be torn simultaneously on both sides of the separating element. Naturally, if desired, there may be arranged two indications of fracture between each pair of neighbouring separating elements, so that each foil portion will be simultaneous torn on both sides when the respective separating element is moved away from the base.

In order to accomplish the tear from the first edge to the second edge of the foil, it is sufficient to provide a stress concentration or force-focusing at the first edge by means of an indication of fracture. The focusing of the force is suitably made to a small an area as possible along a line. When the separating element is moved away from the base the weakest area of the foil portion around the separating element will be at the indication of fracture. Thus, the foil will start to break there and due to the continued motion of the separating element the tear will progress towards the second edge of the foil. A foil may be attached to the base and the separating element by welding, gluing or other suitable method. It should be noted that the terms "foil" and "foil portion" are not limited to a single material layer. On the contrary a foil or foil portion may comprise a plurality of layers. For instance, foil may comprise a metal layer which is coated with lacquer or polymer layer on one or both sides in any suitable combination in order to provide the desired stiffness, attachment capability, tensile strength, etc.

The indication of fracture may be embodied in various ways. According to at least one example embodiment of the invention, the indication of fracture comprises a void at said first edge of the foil. If the foil comprises more than one material layer, such a void would suitably extend through all the layers. The void may be in the form of a perforation or an indentation, such as a notch or a slit, etc. Suitably, if the indication of fracture is in the form of a slit, the slit extends in the desired tearing direction, which is generally a direction defining the shortest distance between the first edge and the second edge of the foil. According to at least one example embodiment of the invention, the indication of fracture comprises a material weakening of the foil at said first edge. If the foil comprises more than one material layer, the weakening may, for instance, be a cut (such as a laser cut) through one or more layers of the foil. A similar result may also be attained by etching with an acid or the like through one or more material layers of the foil. Another alternative for providing a material weakening is to provide a non-planar portion of the foil at said first edge, such as a portion which has been drawn over a raised portion of the base. The drawn portion of the foil will have reduced thickness, thus being easier to tear than thicker portions of the foil. Although not necessary, a tear-guiding feature may be provided for guiding the tear from the first edge to the second edge. There are various alternatives for achieving such a feature. For instance, the tear-guiding feature may be provided in the base or, alternatively, the tear- guiding feature may be provided in the foil.

According to at least one example embodiment of the invention, the tear-guiding feature is an elongated gap, such as a trench, in the base between two neighbouring cavities. Thus, the foil per se is not provided with any tear-guiding feature across its width. It only has the indications of fracture at the first edge.

According to at least one example embodiment, the tear-guiding feature is a material weakening in the foil, such as a perforation line, an elongated laser cut, or an elongated drawn non-planar portion of the foil. These various tear-guiding alternatives may be combined with any suitable indication of fracture that initiates the tear. They may, alternatively, if extending all the way to the first edge of the foil, be the actual indication of fracture.

Although, the tear- guiding feature may be designed in various ways, suitably, the tear- guiding feature is designed to provide a substantially straight tear line from said first edge to said second edge of the foil, i.e. across the width of the foil.

There are various ways to move a separating element away from the base in order to cause the foil to start to tear at the indication of fracture. Suitably, the moving-away of the separating element may be started at the first edge of the foil. Thus, the separation process can be regarded as a progression of a peel line or separation line, which separation line first lies at the first edge and then scans over the contact area between the foil and the base in a direction towards the second edge to finally reach the second edge of the foil, wherein the foil is completely separated from the base. As the separation line is progressed a foil portion is torn away from the rest of the foil.

According to at least one example embodiment of the invention, the inhaler comprises an actuator adapted to affect an actuator-receiving portion of one separating element at a time with a force causing the separating element to move away from the cavity so that the respective foil portion starts to separate from the base at said first edge, the separation continuing to the second edge. This may, for instance, be done by raising the separating element from the base at the first edge of the foil and pivoting the separating element around a pivot point/line near the second edge of the foil. The opening force may come from below and push the actuator-receiving portion upwards. Alternatively, the opening force may be achieved by providing an upper pulling force onto the actuator-receiving portion. Thus, depending on the direction of force and the actuator providing the force, the actuator-receiving portion may be designed in various ways, such as protrusions, dogs, hooks, indentations, overhangs, channels, etc. When the cavity has become uncovered the medicament contained therein is enabled to become entrained in a fluid flow. The fluid flow (typically an airflow) in the inhaler is suitably guided by at least one flow passage. According to at least one example embodiment, the flow passage(s) is (are) provided for guiding an airflow to entrain medicament from the cavities when they have become uncovered, wherein the direction of the flow passage coincides at least partially with the direction from said first edge to said second edge of the foil. Unlike the central tearing in WO 01/72605, the foil portions will be separated across the entire width of the foil, thus generally not leaving any pieces or fringes of foil upstream or downstream of the cavity which could otherwise obstruct the airflow. The risk of leaving foil remains after the separation is reduced by designing the separating element with longer (or equal) extension in the flow path direction than that of the foil. Since the foil portion to be detached extends across the cavity opening in order to seal the cavity, the attached separating element should also extend at least across the cavity opening. When the foil is torn or ruptured between two separating elements any fringes caused by the tearing would be located laterally of the uncovered cavity viewed from a flow direction perspective, and consequently no obstructing fringes would be present upstream or downstream of the cavity.

According to at least one example embodiment of the invention, the contact area between each separating element and the respective attached foil portion is larger than the contact area between that foil portion and the base. The larger contact area with the separating element enables the foil portion to remain attached to the separating element while becoming separated from the base.

According to at least one example embodiment of the invention, when the foil portion has been separated from the base and is still attached to the separating element, the foil portion defines at least partly a flow path for guiding an airflow to entrain medicament from the uncovered cavity. Thus, the separating element and the attached foil portion will have a further functionality in addition to the respective function of separating and sealing.

Those neighbouring separating elements which are not in a removed position, may constitute lateral flow path-defining wall portions. An alternative would be to provide fixed lateral flow path-defining elements, e.g. by providing a partition wall between each pair of neighbouring separating elements, such partition walls extending perpendicularly upwards from the base. When assembled, the partition walls could be mounted onto the foil that covers (or is intended to later cover) the cavities in such way that they cause a weakening in the foil, thereby establishing defined foil portions between the partition walls. The partition walls may thus be used to provide a tear-guiding feature and/or an indication of fracture.

Suitably, the stiffness of the separating elements is substantially larger than the stiffness of the foil, wherein the separating elements enable the respective attached foil portions to perform a rigid body motion, and may thus become snapped off the base rather than peeled off.

Although the above exemplified embodiments have discussed one cavity having one associated separating element, an alternative would be to have two cavities having one common associated separating element. For instance, if two incompatible drug components are to be inhaled essentially simultaneously, they may suitably be provided in two separate cavities. Thus, when the separating element is moved away from the base, it will bring along a foil portion, uncovering both cavities from which the drug components can be entrained in an inhalation flow. The cavities could either be located in series in the base, i.e. one cavity being downstream of the other one, or they could be located in parallel, i.e. the inhalation flow reaches the cavities essentially simultaneously.

The inhaler may contain various drugs and/or bioactive agents to be inhaled. The bioactive agent may be selected from any therapeutic or diagnostic agent. For example it may be from the group of antiallergic s, bronchodilators, bronchoconsitrictors, pulmonary lung surfactants, analgesics, antibiotics, leukotrine inhibitors or antagonists, anticholinergics, mast cell inhibitors, antihistamines, antiinflammatories, antineoplastics, anaesthetics, anti-tuberculars, imaging agents, cardiovascular agents, enzymes, steroids, genetic material, viral vectors, antisense agents, proteins, peptides and combinations thereof. Examples of specific drugs which can be incorporated in the inhalation device according to the invention include mometasone, ipratropium bromide, tiotropium and salts thereof, salemeterol, fluticasone propionate, beclomethasone dipropionate, reproterol, clenbuterol, rofleponide and salts, nedocromil, sodium cromoglycate, flunisolide, budesonide, formoterol fumarate dihydrate, Symbicort™ (budesonide and formoterol), terbutaline, terbutaline sulphate, salbutamol base and sulphate, fenoterol, 3-[2-(4-Hydroxy- 2-oxo-3H-l,3-benzothiazol-7-yl)ethylamino]-N-[2-[2-(4- methylphenyl)ethoxy]ethyl]propanesulphonamide, hydrochloride. All of the above compounds can be in free base form or as pharmaceutically acceptable salts as known in the art.

Combinations of drugs may also be employed, for example formoterol/budesonide; formoterol/fluticasone; formoterol/mometasone; salmeterol/fluticasone; formoterol/tiotropium salts; zafirlukast/formoterol, zafirlukast/budesonide; montelukast/formoterol; montelukast/budesonide; loratadine/montelukast and loratadine/zafirlukast.

Further combinations include tiotropium and fluticasone, tiotropium and budesonide, tiotropium and mometasone, mometasone and salmeterol, formoterol and rofleponide, salmeterol and budesonide, salmeterol and rofleponide, and tiotropium and rofleponide.

Brief description of the drawings

Fig. 1 is an exploded view illustrating some of the components of an inhaler according to at least one example embodiment of the invention. Fig. 2 illustrates a detail of the inhaler illustrated in Fig. 1.

Fig. 3 is a cross-sectional view of a portion of Fig. 2.

Fig. 4 illustrates a detail of the inhaler according to a second example embodiment.

Fig. 5 is a cross-sectional view of a portion of Fig. 4.

Fig. 6 illustrates a detail of the inhaler according to a third example embodiment. Fig. 7 is a cross-sectional view of a portion of Fig. 6.

Fig. 8 illustrates a detail of the inhaler according to a fourth example embodiment.

Detailed description of the drawings

Fig. 1 is an exploded view illustrating some of the components of an inhaler 2 according to at least one example embodiment of the invention. The inhaler 2, which has a generally circular shape, comprises a housing having a lower part 4 shaped like a tray and an upper closure part 6. The housing is provided with a mouthpiece 8 through which a user may inhale in order to draw medicament from the inhaler 2. Inside the housing, there is provided a generally ring-shaped base 10 provided with a plurality of consecutive cavities 12 which contain medicament, such as in dry powder form. The cavities 12 are sealed by a generally ring-shaped and planar foil 14 which is attached to the base 10. The foil has a first edge 14a defining an inner perimeter of the foil, and a second edge 14b defining an outer perimeter of the foil. The foil 14 comprises a plurality of foil portions 16, one for each cavity 12. Although the foil portions 16 do not need to be defined in any other way than being located above a respective associated cavity 12, they may, as illustrated in Fig. 1, be defined by perforations 18 or other type of material weakenings. A plurality of separating elements 20 is provided, each separating element 20 being attached to a respective associated foil portion 16.

An actuator arrangement 22 comprises a projecting actuator arm 24 which is adapted to affect one separating element 20 at a time by engaging the separating element 20 and moving it upwardly in order to separate the associated foil portion 16 from the base 10 and cavity 12 below the separating element 20. The actuator arrangement 22 may be manually operated by pushing, pressing, rotating, etc. a button, lever or the like (not shown) on the inhaler housing, or may be triggered by a user's inhalation in which case it would be latched by an air- flow sensitive release mechanism (not shown).

Before, during or after inhalation the base 10 is rotated (indexed) to bring the next cavity 12 into alignment with the mouthpiece 8. This may be implemented in various ways, such as using a standard lever on the housing. Another alternative could be to use a connection between the base 10 and a mouthpiece cover, wherein removal (or replacement) of the mouthpiece cover would cause the base 10 to index one step to the next cavity 12. Yet another alternative could be to use a breath-triggering mechanism to cause the base 10 to index one step. The inhaler 2 may suitably comprise a structure that provides moisture protection, such as e.g. a moisture absorbent sink as described in WO 2006/000758, or any other appropriate alternative for including desiccant material. Most components of the inhaler 2, such as the base 10, the separating elements 20 and the actuator arrangement 22 are suitably made of a plastic material, such as a polymer, however, other materials, such as metal or ceramic, are conceivable alternatives.

Fig. 2 illustrates a detail of the inhaler illustrated in Fig. 1. Although not illustrated in Fig. 2 for sake of clarity, each cavity 12 in the base 10 is covered by the foil 14. The foil portion 14 is attached by any suitable type of bonding, welding, gluing, etc to an area of the base 10 which surrounds the cavity opening. Likewise, above each foil portion 16 an associated separating element 20 is attached by any suitable type of bonding, welding, gluing, etc, however for illustrative purposes only some separating elements 20 are shown. As can be seen from Fig. 2, each cavity 12 contains medicament 26 and is surrounded by a respective ridge 28. Although not necessary for the general idea of the present invention, the base 10 may suitably be provided with geometrically distinguishable features as will be explained in the following.

Towards the inner radius of the base 10, i.e. towards the centre of the inhaler, each ridge 28 is provided with a geometrically distinguishable feature in the form of a plurality of teeth 30. Although Fig. 2 illustrates ridges 28 around the cavities 12, an alternative would be to have a plane base without ridges. For a plane base, if desired, it would be conceivable to provide recesses in the base 10 towards its inner radius (rather than the teeth 30 of the ridge 28) in order to form geometrically distinguishable features. Each foil portion 16 is attached to the base 10 to seal a respective cavity 12. More particularly, the foil portion 16 is attached to the ridge 28 surrounding the cavity 12. The contact area between the foil portion 16 and the base 10 thus corresponds to the upper surface area of the ridge 28, extending from a first end 32 (where the teeth 30 are) to a second end 34 (nearer the outer radius of the base). However, the foil portion 16 per se, may suitably extend past the first end 32 of the contact area (i.e. past the teeth 30). Each separating element 20 suitably covers its entire associated foil portion 16, thus suitably also extending past the teeth 30. In the extension of the flow path direction, the separating element 20 covers the entire foil portion 16, the flow path direction being from the inner radius of the base 10 towards the outer radius of the base 10, i.e. from the first edge 14a to the second edge 14b of the foil 14 (see Fig. 1). Thus, the contact area between the separating element 20 and the foil portion 16 is larger than the contact area between the foil portion 16 and the base 10, enabling the achievement of a larger attachment force between the separating element 20 and the foil portion 16 compared to the attachment force between the foil portion 16 and the base 10.

The separating element 20 comprises a lower portion 36 and an upper portion 38, which may be produced in one piece or as two separate pieces joined together. There is an actuator-receiving portion in the form of a space 40 between the lower portion 36 and the upper portion 38. The space 40 is formed like a bay which opens towards the centre of the inhaler, i.e. towards the actuator arrangement 22 (see Fig. 1). As the actuator arm 24 (see Fig. 1) is inserted into the space 40 it will at first engage the upper portion 38 of the separating element 20 at a point near the centrally facing opening of the space 40, and when pivoted upwards it will affect the separating element 20 with a lifting force. This causes the separating element 20 together with the attached seal or foil portion 16 to be raised in a pivoting motion around a pivot point at the second end 34 of the foil/base interface (contact area) downstream of the cavity 12.

Because the first end 32 of the contact area between the foil portion 16 and the base 10 is very small, in this case corresponding to the edges of the teeth 30, the initial separation of the foil portion 16 is facilitated compared to if the contact area at the first end 32 would have been the same as the contact area between the separating element 20 and the foil portion 16. The teeth 30 are widened in a direction towards the second end 34. Thus, starting from the first end 32, the contact area between the foil portion 16 and the base 10 (ridge 28) increases, at least initially, in a direction towards the second end 34. Thus, on the one hand it is acknowledged that a certain width is desired for the contact area between the foil portions 16 and the base 10 in order to provide an adequate sealing of the cavities 12, and on the other hand it is realised that by reducing the area at least at the location where the separation is initiated an effective separation is achievable. The relatively small initial contact area between the foil portion 16 and the base 10 makes the detachment easier than if it would have been a larger contact area. As the peel or separation line progresses from the initial separation point or points towards the circumference of the base 10 (i.e. from the inner first edge 14a towards the outer second edge 14b of the foil), the contact area of the foil portion 16 with the base 10 goes from small to relatively large. After the separating element 20 has been raised, the foil portion 16 remains attached thereto. The underside of the separating element 20 and the foil portion 16 will thus form a flow path-defining wall portion which will guide a fluid flow that entrains the medicament 26 from the cavity 12. The separating element 20 and the attached foil portion 16 may after the inhalation be returned to cover the cavity 12, in order to reduce the risk of any remaining medicament 28 being entrained in a subsequent inhalation effort by a user, thereby reducing the risk of dose variability.

As has been illustrated in Fig. 1, the foil portions 16 are provided as part of an integral circular foil 14. In order to enable each foil portion 16 to readily remain attached to its associated separating element 20 when the separating element is moved away from the base 10 by the actuator arm 24, an indication of fracture, herein illustrated as a notch 50 (Fig. 2) is provided at the first edge 14a of the foil 14 (Fig. 1). As the separating element 20 is moved away from the base 10, the foil portion 16 will start to tear away from the rest of the foil 14 at said notch 50. Once the tearing has been initiated at the notch 50, the foil portion will continue to be torn in a direction towards the outer perimeter of the foil 14, i.e. the second edge 14b (Fig. 1).

It may be quite sufficient to have an indication of fracture for initiating the tearing- away of the foil portion and the tearing can continue to the second edge 14b, without need for any further guiding of the tear line. Nevertheless, in the case of a base 10 having the illustrated ridges 28, elongated gaps or trenches 52 between neighbouring cavity- surrounding ridges 28 may be sufficient for guiding the tear line. Since the foil 14 is not bonded to the base 10 along these trenches 52 between the ridges 28, the foil will tear along the trenches (gap lines). For a plane base without the ridges 28, it would be conceivable to provide elongated recesses between neighbouring cavities 12 to achieve the corresponding effect as achieved by the trenches 52.

There may be various alternatives for facilitating the tearing. Fig. 2 illustrates a perforation line 54 from extending from the notch 50 towards the second end 34 of the contact area between the foil portion 16 and the ridge 28. The perforation line 54 further contributes to guiding the tearing of the foil portions 16 from the rest of the foil 14.

Fig. 3 is a cross-sectional view of a portion of Fig. 2, further illustrating the trench 52 between neighbouring cavities 12 and the perforation line 54 between neighbouring foil portions 16. It is to be understood that trenches 52 and the perforation lines 54 may be provided in combination as illustrated in Fig. 2 and Fig. 3, or they may be provided independently without the other.

Fig. 4 and Fig. 5 illustrate an alternative indication of fraction. In the illustrated example embodiment, instead of a notch, the foil 14 has at its inner radius an indication of fracture in the form of a reduced material thickness 56a. This indication of fracture is the start of a continuous line 56 of reduced material thickness between each pair of neighbouring foil portions 16 for guiding the tear. To obtain the indication of fracture 56a and the continued line 56, the foil 14 may suitable be cut by laser. For instance, the foil 14 may be a laminated foil which comprises a metal layer, such as a aluminium, and an upper polymer layer. The polymer layer provides the desired tensile strength of the foil 14, while the metal layer provides the desired moisture protection for the medication in the cavities 12. A laser could thus be used to cut the indication of fracture 56a and the continued line 56 through the polymer layer without cutting through the metal layer, thereby providing the desired tearing capabilities of the foil portions, while maintaining the moisture protection. An alternative to laser-cutting could be etching with an acid or the like.

Fig. 6 and Fig. 7 illustrate an alternative indication of fraction. In the illustrated example embodiment, instead of a notch, the foil 14 has at its inner edge 14a (Fig. 1) an indication of fracture in the form of a weakening 60a over a raised strip 60. The foil 14 is weakened by being e.g. "deep-drawn" over the raised strip 60, which defines foil portions 16 on both sides thereof. Due to the reduced thickness 60a at the inner radius of the foil, the stress concentration of the foil will there initiate the tear as the separating elements are moved away from the base, and the continued elongated weakening over the raised strip 60 will guide the tear after it has been initiated.

Fig. 8 illustrates an alternative to notches 50 in the foil 14 as illustrated in Fig. 1. Rather, Fig. 8 illustrates a perforation line 70 between foil portions 16, wherein the perforation line extends all the way to from the inner edge of the foil 14. Thus, the indication of fracture and initial tear is accomplished by the start 70a (inner end) of the perforation line 70, whereas the continued guiding of the tear is accomplished by the rest of the perforation line 70.

In the drawings, the cavities 12 have been illustrated as having a generally rectangular shape. While this allows for small foil portions on the base with relatively little excess foil material between the cavities, it is to be understood that other cavity shapes are also conceivable.

Claims

1. An inhaler, comprising a base having a plurality of consecutive sealed cavities containing medicament, a foil comprising two sides, one side being attached to the base for sealing the medicament within the cavities, wherein the width of the foil is defined by a first edge and a second edge of the foil, a plurality of separating elements, one for each cavity, each separating element being attached to the other side of the foil for separating a foil portion from a respective cavity, wherein, between each pair of neighbouring separating elements, the foil is provided with an indication of fracture at said first edge, wherein when a separating element is moved away from the base, the foil starts to tear at said indication of fracture and continues to tear between the moving separating element and its neighbouring separating element until the foil has torn to said second edge.

2. The inhaler as claimed in claim 1, wherein the foil is annular and disk-shaped, wherein the first edge describes an inner perimeter and the second edge describes an outer perimeter of the foil.

3. The inhaler as claimed in claim 1 or 2, wherein said indication of fracture comprises a void at said first edge of the foil.

4. The inhaler as claimed in claim 3, wherein said void is a notch, a slit or a perforation.

5. The inhaler as claimed in claim 1 or 2, wherein said indication of fracture comprises a material weakening of the foil at said first edge.

6. The inhaler as claimed in claim 5, wherein said material weakening is provided by a cut, such as a laser cut, through one or more layers of the foil.

7. The inhaler as claimed in claim 5, wherein said material weakening is provided by a non-planar portion of the foil at said first edge, such as a portion which has been drawn over a raised portion of the base.

8. The inhaler as claimed in any one of claims 1-7, comprising a tear-guiding feature for guiding the tear from the first edge to the second edge.

9. The inhaler as claimed in claim 8, wherein the tear-guiding feature is an elongated gap in the base between two neighbouring cavities.

10. The inhaler as claimed in claim 8, wherein the tear-guiding feature is a material weakening in the foil, such as a perforation line, an elongated laser cut, or an elongated drawn non-planar portion of the foil.

11. The inhaler as claimed in claim 8, wherein the tear-guiding feature provides a substantially straight tear line from said first edge to said second edge of the foil.

12. The inhaler as claimed in any one of claims 1-11, comprising an actuator adapted to affect an actuator-receiving portion of one separating element at a time with a force causing the separating element to move away from the cavity so that the respective foil portion starts to separate from the base at said first edge, the separation continuing to the second edge.

13. The inhaler as claimed in any one of claims 1-12, comprising at least one flow passage for guiding an airflow to entrain medicament from the cavities when they have become uncovered, wherein the direction of the flow passage coincides at least partially with the direction from said first edge to said second edge of the foil.

14. The inhaler as claimed in any one of claims 1-13, wherein the contact area between each separating element and the respective attached foil portion is larger than the contact area between that foil portion and the base.

15. The inhaler as claimed in any one of claims 1-14, wherein, when the foil portion has been separated from the base and is still attached to the separating element, the foil portion defines at least partly a flow path for guiding an airflow to entrain medicament from the uncovered cavity.