WO2008110809A2

WO2008110809A2 - Dry powder inhalers

Info

Publication number: WO2008110809A2
Application number: PCT/GB2008/000886
Authority: WO
Inventors: Simon James Smith; Lai Chiu Tang
Original assignee: Cambridge Consultants Limited
Priority date: 2007-03-14
Filing date: 2008-03-13
Publication date: 2008-09-18
Also published as: GB2447560B; GB0704928D0; GB2447560A; GB0804716D0; WO2008110809A3

Abstract

A dry powder inhaler comprises a mouthpiece (12) through which in use a user can inhale a powdered medicament. A mouthpiece obstruction or cover (6, 8) is arranged to prevent a user properly inhaling through the mouthpiece. A plurality of medicament doses are provided in individually sealed compartments (24). The inhaler has means (48, 50) for breaching the seal (25) of one of said compartments (24) to establish a pathway between that compartment and the mouthpiece, wherein the mouthpiece obstruction or cover is mechanically coupled to the seal breaching means so as to operate the latter when the mouthpiece obstruction or cover is opened. The inhaler further comprises one or more piercers (52, 54). The piercers are so shaped and arranged that upon penetration of the sealing member they form a hollow tube therewith for communicating with the interior of the compartment.

Description

Dry Powder Inhalers

This invention relates to dry powder inhalers of the type commonly used to deliver medicaments by inhalation. Such medicaments are not limited to those for treating respiratory conditions, rather it has been recognised that inhalers are an attractive way of being able to deliver medicaments of many different types.

The present invention aims to provide an inhaler which is safe and simple to use. When viewed from a first aspect the invention provides a dry powder inhaler comprising a mouthpiece through which in use a user can inhale a powdered medicament, a mouthpiece obstruction arranged to prevent a user properly inhaling through the mouthpiece, a plurality of medicament doses in individually sealed compartments, and means for breaching the seal of one of said compartments to establish a pathway between that compartment and the mouthpiece, wherein the mouthpiece obstruction is mechanically coupled to the seal breaching means so as to operate the latter when the mouthpiece cover is opened.

Thus in accordance with the invention the action of moving the mouthpiece obstruction away, an action which would be carried out naturally and automatically by a user, causes the inhaler to be primed. This makes it particularly simple to use and also means that the dose is not exposed to moisture and potential contamination from the air as the seal is only broken immediately prior to use.

Many simple mechanical mechanisms for breaching the seal when the cover or other mouthpiece obstruction is opened are possible and the invention is not limited to any particular one. In preferred embodiments the mouthpiece obstruction is linked to a cam arrangement which brings a piercer into contact with a frangible seal.

Preferably the dose compartments are provided on a magazine with means for advancing the magazine to present the next dose also being mechanically coupled to the mouthpiece. This could be arranged also to take place as the mouthpiece obstruction is moved, but preferably is arranged such that the magazine is advanced as the mouthpiece obstruction is returned after use. Although the inhaler would be the most simple to use if the mouthpiece obstruction comprised a mouthpiece cover which could be opened in a single action, e.g. pivoting it away from the mouthpiece, this raises the possibility of accidental priming of the dose (i.e. breaching the seal) e.g. in a pocket or handbag or by absent- minded fiddling. In preferred embodiments therefore means are provided for retaining the mouthpiece obstruction in its inactive position requiring a second action to remove the obstruction. This could be a catch, detent or the like which must be released before the cover can be moved. Preferably there is provided a retaining member which must be moved away before the mouthpiece obstruction can be moved. In particularly convenient embodiments the retaining member also acts at least partially to cover the mouthpiece, i.e. as a conventional mouthpiece cover. For example the retaining member and aforementioned mouthpiece cover could between them cover the mouthpiece. The retaining member might prevent movement of the mouthpiece obstruction by overlapping with it, but there are many other possible mechanisms.

Thus preferred embodiments have a mouthpiece cover and a separate member which is must be moved away from the mouthpiece to use the inhaler and which primes the dose. This stems from the applicants recognition that there is a tendency for some users to play with the mouthpiece cover as it is the largest and most accessible part. The preferred embodiments of the invention prevent wastage of doses if such fiddling with the mouthpiece cover were to prime the dose. Instead in such embodiments the cover must be opened to allow the actuation mechanism (mouthpiece obstruction) to be moved

When viewed from a second aspect the invention provides a dry powder inhaler comprising a mouthpiece through which in use a user can inhale a powdered medicament, a mouthpiece cover arranged at least partially for covering said mouthpiece when the inhaler is not in use, a plurality of medicament doses in individually sealed compartments, and means for breaching the seal of one of said compartments to establish a pathway between that compartment and the mouthpiece, wherein the inhaler is arranged so that the seal breaching means is operated during opening of the mouthpiece cover. When viewed from a third aspect the invention provides a dry powder inhaler comprising a mouthpiece through which in use a user can inhale a powdered medicament, a mouthpiece cover arranged at least partially for covering said mouthpiece when the inhaler is not in use, a plurality of medicament doses in individually sealed compartments, and means for breaching the seal of one of said compartments to establish a pathway between that compartment and the mouthpiece, wherein the inhaler is arranged so that the seal breaching means cannot be operated until the mouthpiece cover has been opened.

The preferred features set out in accordance with the first aspect of the invention apply equally to the second and third aspects. It should be understood that operating or removing any catch, retaining member etc. is intended to be included in the definition of "opening of the mouthpiece cover".

The powdered dose is preferably entrained in the inhaled air in the dose compartment. Where, as is preferred, inlet and outlet piercers are used to penetrate a frangible membrane - e.g. foil, covering the dose compartment, the compartment must be big enough to accommodate the piercers whilst leaving enough space for a suitable airflow to entrain the powder. The resulting size and shape of the compartments gives a conveniently pocket-sized device containing 30 doses. However the applicant has devised an arrangement which allows even more doses to be provided in a similar overall size of device.

When viewed from a further aspect the invention provides a dry powder inhaler comprising a plurality of dose compartments covered by frangible sealing means, the inhaler further comprising a pair of piercers projecting from a surface thereof, and so shaped and arranged that upon penetration into a said dose compartment each piercer forms, with a wall of the compartment, a hollow tube.

When viewed from another aspect the invention provides a dry powder inhaler comprising a plurality of dose compartments covered by frangible sealing means, the inhaler further comprising a pair of piercers projecting from a surface thereof, and so shaped and arranged that upon penetration into a said dose compartment, each piercer forms, in conjunction with the frangible sealing means, a hollow tube for communicating with the interior of the dose compartment. Thus in accordance with this arrangement part of the wall of each piercer is omitted to be provided instead by the wall of the dose compartment, either directly or with part or the frangible sealing means, such as a foil flap, trapped therebetween. This then forms a hollow tube for drawing in air to the dose compartment or evacuating the dose of medicament or other formulation in the compartment. In other words the piercer itself is in the form of an open channel. This means that the dose compartment can be narrower and so more can be fitted onto a magazine of given size. In preferred , embodiments for example a pocket-size 60 dose device can be provided. The plurality of dose compartments is preferably provided on a circular magazine to allow a compact advancement arrangement; however this is not essential and other configurations are possible - e.g. a linear strip. Where the magazine is circular the compartments could open axially or radially.

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

Figure Ia is a perspective view of an inhaler in accordance with the invention;

Figure Ib is a series of schematic views showing the opening of the mouthpiece covers; Figure 2 is a view similar to Figure Ia with one of the mouthpiece covers removed;

Figure 3 is a view of the inhaler with both mouthpiece covers removed;

Figure 4 is a view showing a magazine of dose compartments with part of the advance mechanism therefor; Figure 5 is a view similar to Figure 4 but from a different angle and showing the foil cover on top of the dose magazine.

Figure 6 is a perspective view of the lower part of the dose magazine advancing mechanism;

Figure 7 is a view showing the dose magazine attached to the flange member in the primed position immediately before inhalation;

Figure 8 is a sectional view through the inhaler and its storage configuration; Figure 9 is a section through the mouthpiece, upper flange and dose magazine showing a dose primed for inhalation;

Figure 10 is a partial perspective view of a mouthpiece and piercer arrangement in accordance with a second embodiment of the invention; Figure 11 is a view similar to Figure 10 from behind;

Figure 12 is a sectional view through a dose compartment for use with the mouthpiece arrangement shown in Figures 10 and 11 ;

Figure 13 is a sectional view showing the piercers penetrating the dose compartment of Figure 12; and Figure 14 is a sectional view in a horizontal plane showing the two piercers received in the dose compartment.

Figure Ia shows a dry powder inhaler in accordance with an embodiment of the invention. It will be seen that the inhaler has a generally torroidal shape with a main body section made up of upper and lower shell portions 2, 4 and a pair of mouthpiece cover sections 6, 8. The two mouthpiece cover portions 6, 8 can be rotated around the torros away from each other as is shown in Figure Ib. An arcuate grove is provided on the upper surface of the upper shell portion 2 to guide the arcuate movement of the right base mouthpiece cover member 8 by means of a guide pin (not shown). Fig. Ib shows a sequence in which the two cover sections 6, 8 are opened and closed again.

The arcuate movement of the other mouthpiece cover member 6 will be described with reference to Figures 3 and 4 herein below.

Figure 2 is similar to Figure 1 a except that the rightmost mouthpiece cover section 8 has been omitted for illustration. This reveals a mouthpiece 12 having a generally oval front face and having a large central bore 14 and two side bores 16. The side bores 16 simply extend through the mouthpiece member 12 to provide bypass air during inhalation. The mouthpiece member 12 is integrally moulded with the upper body shell piece 2. Figure 3 is similar to Figure 2 but with the other mouthpiece cover section 6 removed. From here it may be seen this mouthpiece cover section 6 is supported on a fin-like horizontal flange 18 which projects radially from between the upper and lower body shell sections 2, 4 with a suitable slit being provided between them to allow for its arcuate movement.

With reference now to Figures 4, 5 and 6 it will be seen that the fin-like projecting flange 18 is in fact part of a lower magazine advancing member 20 which is shown in Figure 6. As may be seen in Figures 4 and 5, an annular dose magazine 22 is received in the advancing member 20. The dose magazine 22 comprises a circumferentially spaced array of thirty dose compartments 24 each of which has an approximately oval opening. As shown in Fig. 5 but omitted from Fig. 4, the dose compartments 24 are sealed by a foil layer 25. It will be seen that the radially outer edge of the magazine member 22 is serrated to form part of a ratchet mechanism. The pawl 26 of the ratchet mechanism is formed on a resilient arm 28 which is moulded integrally with and projects from the dose magazine advancing member 20. It will be seen that the serrations are shaped so that clockwise movement (as viewed from Figure 4) of the magazine support member 20 causes the pawl 26 to slip over one of the teeth 30 without moving the magazine 22 but that the return anti-clockwise movement bears against the tangential flat surface of the teeth 30 and therefore moves the dose magazine 22 together with it in an anti-clockwise direction.

In Figure 6, it may be seen that the magazine advancing member has a central hub portion comprising three arcuate upstands 32 which pass through the middle of the annular dose magazine. Each of these comprises an upwardly inclined cam groove 34.

Referring now to Figure 7, a flange member 36 can be seen. This comprises an approximately annular horizontal upper flange 38 and a downwardly depending hub portion 40. A circumferentially spaced series of clips 42 are provided to clip the flange member 36 onto the upper flange of the dose magazine 22. Since the clips 42 engage a continuous inner rim of the dose magazine flange, relative rotational movement between the magazine 22 and the flange member 36 is permitted.

It will also be observed that at one point around the flange member 36, an arch-shaped portion is cut out of the upper flange 38 to accommodate the piercer member 44. It should be noted that the piercer member 44 is not attached to the flange member 36. It will also be observed that on the inwardly facing wall of the hub portion 40 of the flange member is a series of three projecting bosses 46 (two of which can be seen) which interface with the cam grooves 34 of the dose magazine advancing member 20. It can therefore be appreciated that as the magazine advancing member 20 is rotated clockwise relative to the upper flange member 36, the flange member 36 and therefore the dose magazine 22 will be forced upwardly by the inclined cam surfaces 34 which causes the piercer members (not shown in Figure 7) to penetrate through the foil membrane on top of the boot compartments and therefore penetrate into one of the dose compartments. This is the situation shown in Figure 7 and may be seen more clearly in cross-section in Figure 9 (where some of the components have been omitted for clarity.

The cross-section of Figure 8 shows the storage state of the inhaler with the relative rotational positions of the upper flange member 36 and the lower magazine advancing member 20 are such that the pins 46 of the upper member are at the lower portions of the cam grooves 34 in the lower member so that the dose magazine 22 is below the piercers 48, 50 which can be seen in Figure 8. When the user wishes to inhale a dose, he or she first slides round the rightmost mouthpiece cover portion 8 which, in storage, overlaps the edge of the leftmost cover portion 6 so preventing it from being opened. Once the rightmost cover portion 8 has been opened, the leftmost portion 6 can be opened in the opposite direction. This is shown in Figure Ib. Since the leftmost cover portion is fixed to the fin-like projection 18 of the magazine advancing member 20, the latter is moved clockwise (from the perspective of the Figures) which means that the pawl 26 of the ratchet mechanism slips over the tooth 30 so that the magazine 22 does not rotate but the movement of the bosses 46 on the flange member 36 in the cam grooves 34 causes the flange member 36 and therefore the dose magazine 22 to be lifted up. This causes the piercers 48, 50 to pierce the aluminium foil 25 covering the dose compartment 24 beneath them. This is shown in Figure 9. It will be seen therefore that simply by opening the mouthpiece cover portion 6, 8 the user has primed the device ready for inhalation. The user may then inhale through the mouthpiece 12 which draws in air through the inlet piercer 50 and entrains the powdered dose in the dose compartment 24 and the entrained powder passes through the outlet piercer 48 and then into the main bore 14 of the mouthpiece. The side bores 16 provide bypass air so that the user's full breath is not drawn through the dose compartment 24 which would give too high a flow rate for most efficient entrainment.

Once the dose has been inhaled, the user need only close the mouthpiece cover portions 6, 8 again (see Fig. Ib). The closing action of the cover portion 6 will move the dose magazine 22 around relative to the flange member 36 as the pawl 26 engages against the tooth 30 of the dose magazine. As the dose magazine advances round, the relative movement between the flange and magazine advancing members 36, 20 moves the flange member 36 and therefore the dose magazine 22 downwardly away from the piercers 48, 50 so that the next dose compartment remains sealed. Once the mouthpiece covers 6,8 are closed, the inhaler is ready for another use, but the next compartment will remain sealed until just before it is needed which avoids the ingress of contamination or moisture. If there is any powder left in the compartment 24 after the user has inhaled, the flange 38 of the flange member 36 prevents this from escaping from the device. Once all thirty doses have been used, the whole device can be discarded.

Figures 10 to 14 show another embodiment of the piercer mechanism and compartment. Figure 10 shows part of the piercer member where it may be seen that two piercers 52, 54 are provided as in the earlier embodiment but it will be noted that rather than forming a complete tube they form open channels. Figure 11 shows a view of the piercer member portion from above which shows that the inlet piercer 54 communicates with an air inlet 56 and that the outlet piercer 52 communicates with a mouthpiece tube 58.

Figure 12 shows a section through the corresponding dose compartment. It will be appreciated from this that the compartment is significantly narrower than that shown in the previous embodiment which allows more of them to be put onto a dose magazine without increasing the size. For example in accordance with a preferred embodiment sixty dose compartments can be fitted into a magazine for use in a pocket sized inhaler of similar dimensions to that shown in the first embodiment. It will also be seen from here that the vertical sectional profile of the compartment is different from that of the first embodiment, namely that it has a rounded wall 62 and a substantially flat wall 64. As may be seen in Figure 13 and 14, the piercers 52, 54 engage snugly into the dose compartment 60 so that foil flap (not shown), formed when the foil is pierced, is pressed against the flat wall of the compartment 64, effectively forming the missing wall of the piercer tubes 52, 54. This enables them to have the same function as in the previous embodiment but with a narrower compartment which allows for more efficient packing on the magazine.

Claims

Claims:

1. A dry powder inhaler comprising a mouthpiece through which in use a user can inhale a powdered medicament, a mouthpiece obstruction arranged to prevent a user properly inhaling through the mouthpiece, a plurality of medicament doses in individually sealed compartments, and means for breaching the seal of one of said compartments to establish a pathway between that compartment and the mouthpiece, wherein the mouthpiece obstruction is mechanically coupled to the seal breaching means so as to operate the latter when the mouthpiece obstruction is opened.

2. An inhaler as claimed in claim 1 wherein said mouthpiece obstruction is linked to a cam arrangement which brings a piercer into contact with a frangible seal.

3. An inhaler as claimed in claim 1 or 2 wherein the dose compartments are provided on a magazine with means for advancing the magazine to present the next dose also being mechanically coupled to the mouthpiece obstruction.

4. An inhaler as claimed in claim 3 arranged such that the magazine is advanced as the mouthpiece obstruction is returned after use.

5. An inhaler as claimed in any preceding claim comprising means for retaining the mouthpiece obstruction in its inactive position.

6. An inhaler as claimed in any preceding claim comprising a retaining member which must be moved away before the mouthpiece obstruction can be moved.

7. An inhaler as claimed in claim 6 wherein the retaining member also acts at least partially to cover the mouthpiece.

8. A dry powder inhaler comprising a mouthpiece through which in use a user can inhale a powdered medicament, a mouthpiece cover arranged at least partially for covering said mouthpiece when the inhaler is not in use, a plurality of medicament doses in individually sealed compartments, and means for breaching the seal of one of said compartments to establish a pathway between that compartment and the mouthpiece, wherein the inhaler is arranged so that the seal breaching means is operated during opening of the mouthpiece cover.

9. A dry powder inhaler comprising a mouthpiece through which in use a user can inhale a powdered medicament, a mouthpiece cover arranged at least partially for covering said mouthpiece when the inhaler is not in use, a plurality of medicament doses in individually sealed compartments, and means for breaching the seal of one of said compartments to establish a pathway between that compartment and the mouthpiece, wherein the inhaler is arranged so that the seal breaching means cannot be operated until the mouthpiece cover has been opened.

10. An inhaler as claimed in claim 8 or 9 wherein the powdered dose is entrained in the inhaled air in the dose compartment.

11 An inhaler as claimed in claim 8, 9 or 10 wherein said mouthpiece cover is linked to a cam arrangement which brings a piercer into contact with the seal.

12. An inhaler as claimed in any of claims 8 to 11 wherein the dose compartments are provided on a magazine with means for advancing the magazine to present the next dose also being mechanically coupled to the mouthpiece cover.

13. An inhaler as claimed in claim 12 arranged such that the magazine is advanced as the mouthpiece cover is returned after use.

14. An inhaler as claimed in any of claims 8 to 13 comprising means for retaining the mouthpiece cover in its inactive position.

15. An inhaler as claimed in any preceding claim comprising a retaining member which must be moved away before the mouthpiece cover can be moved.

16. An inhaler as claimed in claim 15 wherein the retaining member also acts at least partially to cover the mouthpiece.

17. A dry powder inhaler comprising a plurality of dose compartments covered by frangible sealing means, the inhaler further comprising a pair of piercers projecting from a surface thereof, and so shaped and arranged that upon penetration into a said dose compartment, each piercer forms, with a wall of the compartment, a hollow tube.

18. A dry powder inhaler comprising a plurality of dose compartments covered by frangible sealing means, the inhaler further comprising a pair of piercers projecting from a surface thereof, and so shaped and arranged that upon penetration into a said dose compartment, each piercer forms, in conjunction with the frangible sealing means, a hollow tube for communicating with the interior of the dose compartment.