GB2434754A

GB2434754A - Inhaler with counter

Info

Publication number: GB2434754A
Application number: GB0701946A
Authority: GB
Inventors: Naseem Bari
Original assignee: Trumeter Co Ltd
Current assignee: Trumeter Co Ltd
Priority date: 2006-02-01
Filing date: 2007-02-01
Publication date: 2007-08-08
Anticipated expiration: 2027-02-01
Also published as: WO2007088367A1; GB0602049D0; GB0701946D0; GB2434754B

Abstract

An inhaler canister assembly including a canister (10) with a nozzle (14), the canister (10) being actuatable to deliver a substance from its body by relative displacement of the nozzle (14) and canister body; and an attachment (20) that is permanently attached to the canister body. The attachment (20) has a body (26) for engagement with the nozzle (14) so that, when the canister (10) is actuated, the body (26) moves relative to the canister body. The attachment (20) also has count means which are arranged to register actuations of the canister (10) in response to the actuation of switch means (22) by the movement of the body (26) of the attachment (20) relative to the canister body. The entire attachment (20) may be movable relative to the canister body and the switch means (22) may interact with a portion of the canister body.

Description

1 243475

INHALER

The present invention relates to an inhaler canister assembly, and in particular to a PMDI (pressurised measured-dose inhaler) Inhalers are commonly used to administer medication such as bronchodjiators, cortjcosterojds and anti-allergenics to the pulmonary tracts of humans and other animals, and in particular to treat nasal and bronchial complaints such as asthma.

A typical inhaler includes a canister, having a nozzle, containing the drug or medicine, and a detachable casing for attachment to the canister. In most applications, the canister contains the drug in powder or liquid form, and the dispensing action forces out a regulated dose of the drug in aerosol form.

The aerosol may be created using a propellant e.g. CFC or HFA forced through the drug by the dispensing motion, or more preferably in PMDIs (pressurised measured-does inhaler) by creation of a significant overpressure inside the canister.

In most PMDIs, the dispensing action consists of moving the canister relative to the casing, the action of 4' the casing on the nozzle of the canister causing the predetermined dose to be released when the nozzle has been depressed a set distance. WO 2005/007226, WO 03/103759 and EP 1163922 each disclose such a PMDI.

Existing inhalers therefore include a detachable casing having a seat member that is engaged with the canister nozzle when the canister is removably inserted to the casing. In most existing inhalers the seat member includes a gripping portion for gripping the nozzle, so that the canister is held in the casting, but only held so that the canister can be easily withdrawn from the casing by simply pulling the canister and casing in opposite directions.

The device in WO 03/103759 has an additional attachment attached to an aerosol container with an aperture through which the nozzle of a container can pass so the dispensing action of the container is not impeded by the attachment. The device relies upon a seat in an additional removable external body to activate a nozzle of the container to dispense rnedicament.

The seat member of existing inhaler casings is usually formed to put the nozzle of the canister into fluid communication with a mouthpiece portion of the casing. 4'

Thus, there exists a problem with existing inhalers that the canister is prone to unwanted detachment from the casing, possibly resulting in loss of the casing.

Therefore, a user may find it very difficult, if not impossible, to actuate the canister, to deliver a dose, in a suitable manner to ensure that the drug is delivered e.g. to the user's airway, or other appropriate bodily region. Therefore, there is a need for an inhaler canister that can be relatively easily actuated when it is separated from its casing.

Indeed, typical PMDI canisters for use in PMDIs contain between 60 and 200 doses, and may be administered on a regular (e.g. daily) basis, or only occasionally to relieve particular symptoms. In either case, the patient is unlikely to keep a record of the number of doses administered, so will not be aware when the canister no longer contains any drug. The patient will not necessarily be immediately aware that the drug is no longer being dispensed as the pressure of the canister, or the dispensing motion, may appear unaltered. In an extreme situation, this could result in a patient needing a dose in an emergency but finding that the drug in their inhaler had been exhausted in an earlier use.

Therefore, there is also a need for some form of counting device which can count the number of doses dispensed from a canister and so provide an indication of when the canister is empty. In order to be of use, such a counting device must accurately record each actuation of the canister.

Previous attempts to provide such a counting device have had a number of drawbacks. In particular, some solutions have been proposed with a counting device which is mounted on the casing of the inhaler and records each actuation of the canister using, for example, a pressure pad or a lever based switch. These devices suffer from the problem that they either have to be reset manually, or if a canister is removed from the inhaler, the counter automatically resets, so if the same canister is replaced (e.g. after cleaning), the reading will be incorrect.

EP 1163922 discloses a device with a counter. The mechanism of the counter is located in a body that is attached to an aerosol container. A pin connected to an outer removable casing cooperates with switch contacts of the counter mechanism in the body in order to advance the counter on actuation of the device, i.e. the counter is operable in response to movement of the outer removable casing relative to the body. A nozzle of the container is actuatable without the container being located in the outer casing, and thus independently of the count mechanism. Therefore, this device suffers from the problem that, if the aerosol container is removed from the outer casing and the nozzle is actuated, the counter is not progressed, resulting in an inaccurate reading of the number of doses of medicament output from, or remaining in, the container.

The device in WO 03/103759 has a counter triggered by movement of a switch mounted on the aforementioned attachment relative to the external body that is removable from the container and attachment. The nozzle of the container is actuatable without the external body and therefore independently of the counter. Thus, this device too may output an inaccurate count value of the amount of medicament remaining in a container.

WO 01/28887 shows a device with a housing movably attached to an aerosol canister. Movement of the housing relative to the canister actuates the nozzle of the canister to dispense medicament. A counter mechanism is held in the housing, which mechanism is triggered in response to movement of the housing relative to a post of a further external housing that is removable from the canister and housing. In other words, a movement of the attached housing relative to the canister to output a dose of medicament would not be recorded when these components are not located in the external housing.

Moreover, the external housing is movable relative to the housing containing the counter to progress the counter without delivery of a dose of medicamerit. Thus, an output reading from the counter of this device may also be inaccurate.

WO 2005/007226 shows a further inhaler apparatus which has a smooth aerosol canister located in a container holder. In a further outer casing of the apparatus there is both a seat for cooperation with a nozzle of the canister, and a counter adjacent the opposite end of the canister from the nozzle for recording the number of actuations of the canister. The counter is triggered by movement of a sleeve surrounding the non-dispensing end of the canister relative to the outer casing.

Another known device, disclosed in US 2003/0205227, does not include a counter for recording the number of individual actuations of a canister as such, but has count means for measuring how many refill units have been used in a particular refillable device, in the interests of device efficiency and hygiene. The count means are shown as being tab portions detachable from the refill units.

To overcome the above problems, other solutions have proposed a counter mounted on the "top" end of the canister (the opposite end from the dispensing nozzle and normally the part which the user presses to use the inhaler), and includes a pressure-activated switch which increments the counter.

These latter devices do not provide particularly accurate indications of the number of doses dispensed from or remaining in the canister. This is because the pressure required to close the pressure switch is rarely exactly the same as that required to operate the inhaler to dispense the drug. In particular the pressure required to move Lhe riozLle the set disLarice for dispensing the drug may vary considerably, both from canister to canister and indeed during the life of each canister as the pressure inside the canister changes.

Therefore, there is significant potential for either under-or over-counting the doses actually delivered, which can result in patients believing that the inhaler is still dispensing the drug when it has in fact run Out, or in canisters which still contain several doses of the drug being disposed of because they are indicated as being exhausted.

ccordingly, at its broadest, the present invention may provide an inhaler canister assembly including: a canister which has a canister body for containing a substance, for example, a drug or medicine and a suitable propellant, and which canister has a nozzle, by which nozzle the substance may be delivered from the canister body, the canister being actuatable to deliver the substance by displacement of the nozzle relative to the canister body; and, the assembly further including a collar (attachment) having a seat member (body) for engagement with the nozzle, the seat member being movable relative to the canister body to actuate the canister; wherein the collar is permanently attached to the canister body, preferably so that the collar is not re-attachably separable from the canister body, wherein the collar includes count means for registering an actuation of the canister in response to switch means of the count means detecting the actuation, and wherein the switch means is triggerable in response to movement of the seat member relative to the canister body.

Therefore, an inhaler canister according to the present invention permits a user to actuate the inhaler canister reliably without the need for an inhaler casing.

By "triggerable" it is meant that the switch means is arranged to be triggered, i.e. arranged to detect an actuation of the canister. In other words, the switch means is arranged to detect a movement of the seat member (body) relative to the canister body, e.g. when the movement is sufficiently great. A sufficiently great movement, i.e. the relative movement required to trigger the switch means, may be less than 15mm, or less than 10mm, or less than 5mm, or less than 3mm.

Movement of the seat member relative to the canister body to actuate the canister may be movement of the seat member towards or away from the canister body in the direction of the longitudinal axis of the canister body.

Additionally or alternatively, the relative movement may be rotational movement, e.g. about the longitudinal axis of the canister, to actuate the canister body. The relative movement may have a direction with a component in both the longitudinal and circumferential directions of the canister body.

The seat member may be moveable with the rest of the collar relative to the canister body to actuate the canister, i.e. the whole collar may move relative to the canister body. Alternatively, the seat member may move relative to the rest of the collar and relative to the canister body on actuation of the canister.

A collar according to the present invention may be adapted to include directing means so that the nozzle may be put in fluid communication with the environment outside the space bound by the collar. Thus, the seat member preferably defines a conduit or passage through which the substance delivered from the actuated canister can be passed.

Therefore, a user requiring a dose of the substance is able to direct the delivered dose to the appropriate region of his/her body without the need for the inhaler casing.

It may be that the collar seat member is shaped to cooperate with the exhaust end of the canister nozzle, thereby forming a seal.

Additionally, the seal may be reformably breakable so the seat member and nozzle can be sealably coupled and decoupled.

The collar seat member may include a relay portion shaped to engage with a seat member included in an inhaler casing of the standard type. In effect, the collar seat member may act as an actuating conduit for the passage of the delivered substance from the nozzle to a passageway defined by a seat member of an inhaler casing. In turn the passageway usually guides the delivered substance to a mouthpiece of the inhaler casing.

Therefore, it is preferable that a canister assembly according to the present invention can be inserted to a standard inhaler casing.

Preferably, to accomplish this a collar according to the present invention projects beyond the outermost radial periphery of the canister 5 mm or so, preferably by 1 mm or less, more preferably by 0.5 mm or less, yet more preferably by 0.3 mm or less, or even not at all.

It is also envisaged that the collar may extend along only half, or less, of the length of the canister body; more preferably along only one quarter, or less, of the length of the canister body, or even only one eighth, or less, of the length of the canister body.

A collar according to the present invention is permanently attached to the canister body, and many means and ways to achieve this are envisaged. A preferred permanent attachment means is an adhesive applied between an attachment arm of the collar and a portion of the canister body, the adhesive being of sufficient adhesive strength, so that the collar and canister cannot be separated, preferably, without damage to one or other or both of the component parts of the assembly. When the collar i.s permanently attached to the canister body by an adhesive in this way, the seat member is moveable relative to both the rest of the collar and the canister body to actuate the canister.

By permanently attached, it is meant that the collar and canister body are not readily couplable and decouplable: the assembly is not intended to provide a canister with a detachable collar. Therefore, it is preferred that the means of attaching the collar to the canister body is such that the collar cannot simply be detached from the canister body to be re-attached thereto. In other words, the collar is not detachable from the canister body by a user, at least not without the use of tools such as specially adapted tools for the job. However, by permanently attached it is not intended to mean that parts of the collar are necessarily permanently fixed in position relative to the canister body. The collar may be, for example, permanently attached to the canister body but may be, e.g. slidably, movable relative to the canister body. Preferably, the seat member (with or without the rest of the collar) is moveable towards and away from the canister body in the direction of the longitudinal axis of the canister body.

More preferably this movement is only within predetermined limits. Preferably the switch means is arranged such that it is operable/triggerable by movement in an axis parallel to the axis of movement of the seat member relative to the canister body. The switch means may be triggerable when the seat member (with or without the rest of the collar) moves towards the canister body (i.e. on depression of the nozzle into the canister) or when the seat member (with or without the rest of the collar) moves away from the canister body.

Additionally or alternatively, the seat member (with or without the rest of the collar) may be rotatable relative to the canister, e.g. about the longitudinal axis of the canister, in order to actuate the canister.

Such rotation is preferably only within predetermined limits, e.g. 9Q0, less than 900, less than 450, less than 30 or less than 20 . The switch means may be arranged such that it is operable by movement in a rotational direction, preferably rotational movement about the longitudinal axis of the canister. Such rotational movement of the switch means is preferably in the same rotational direction as the rotational direction of movement of the seat member or the whole collar relative to the canister body on actuation of the canister.

However, the switch means may be operable by its rotational movement in the opposite rotational direction.

That is to say in the same rotational direction as the rotational direction of movement of the seat member or the whole collar relative to the canister body from a canister-actuation position to a settled (non-actuation) position.

Alternative means of permanent attachment of the collar to the canister body include ultrasonic welding or heat staking the collar around the canister, shrink fitting the collar to canister or a snap fit around the collar. In other words, there may be an interlock or fit between the collar and the canister. Thus, the combination of the collar and the canister is effectively an integral, unit that allows relative movement between the seat member (or the whole collar) and the canister.

As such, the collar and canister are preferably easily removable from e.g. known inhaler housings without separation of the collar from the canister. *

The assembly includes a collar having count means which is actuated when the nozzle of the inhaler canister has been depressed to the extent necessary to dispense a dose. The count means may be actuated when the nozzle is moved from a rest position to a oepressed position relative to the canister body, or when the nozzle is moved from a depressed position to a rest position.

Therefore, the present invention provides a counting device which maintains an accurate record of the number of doses delivered from a canister, and which is retained with that canister when the canister is removed from the inhaler.

Another aspect of the present invention provides an inhaler canister assembly in which the collar includes: a counter, display means connected to the counter and a switch wherein, in use, the switch triggers the counter when the canister has travelled far enough to dispense a dose of the drug contained in the canister.

The counter may be mechanical, but is preferably electronic, forming part of an electrical circuit with the switch, the display means and/or a battery. The counter may be contained in an integrated circuit.

The collar may radially protrude beyond the side wall of the canister. Preferably, the collar does not protrude more than 5 mm beyond the side wall. Most preferably, it does not radially protrude beyond the side wall of the canister at all. Having a small, or no protrusion, beyond the side wall of the canister means that the attachment of the invention can also be mounted in known inhaler housings, as in known inhaler housing modified to lack a seat member for engagement with the nozzle of the canister.

The collar includes at least one arm for engaging a groove (i.e. ridge or slot) in the side of the canister.

There may be more than one groove in the canister body with which the at least one of the collar is engaged.

The groove(s) may lie in the longitudinal or circumfereritiaj. direction of the canister, or may have a direction with a component in both the longitudinal and circumferential directions. The at least one arm may be moveable relative to the canister body or fixed to the canister body. The arrangement may be such that, when attached to the canister, the at least one arm does not radially protrude more than 1mm beyond the side wall of the canister. Preferably, it does not protrude more than 0.5mm beyond the side wall. Most preferably, it does not radially protrude beyond the side wall of the canister at all.

Preferably, the cross-sectional area of the collar is never more than 1.1 x 13, where 13 is the cross-sectional area of the canister. Preferably, it is never more than 1.025 x 13 Thus, the cross-sectional area of the collar taken normal to the axis of the attachment does not exceed 1.1 x 13 (preferably 1.025 x 13) at any point along the axis.

Preferably, electronic components in the collar are all located in a region having an area less than the cross-sectional area of the canister. Preferably, the electronic components do not radially protrude from the side wall of the canister, (i.e. the region is located directly below the nozzle end of the canister) Preferably, the electronic components are all located in a region of the collar having a longitudinal length of less than 15mm. Preferably, the length is less than 12mm. Most preferably it is less than 10.5mm.

When attached to the canister, the collar preferably extends less than 15mm below the bottom of the canister.

Preferably, it extends less than 12mm. Most preferably it extends less than 10.5mm.

Preferably, the maximum diameter of the collar is no more than 32mm. More preferably, it is no more than 23mm.

Preferably, the maximum longitudinal length of the collar is 50mm. More preferably, it is no more than 30mm. Most preferably, it is no more than 20mm.

The counter may be arranged to count upwards or downwards, and may have respectively a fixed upper limit or a fixed starting number. Alternatively, the attachment may allow the upper limit or the starting number to be set for an appropriate canister.

Preferably the display means provides at least a io warning when a number of doses equal to the upper limit or the starting number have been dispensed. Alternative warning means may also (or alternatively) be used, however.

Particular examples of the display means are a mechanical display, a clock, and/or a liquid crystal display (LCD) (any, or all, of which may display the number of doses dispensed and/or remaining, and may display other information as well, and/or light emitting diodes (LEDs), which may, according to the patterns displayed, indicate one or more states of the canister (e.g. full, in use, nearly empty and/or empty).

In one embodiment, before the counter reaches a first predetermined level, a first LED is lit permanently or flashes in a first predetermined pattern, and when the counter reaches the first predetermined level, that first LED flashes in a second predetermined pattern. Then, when the counter reaches a second predetermined level, a second LED is lit or flashes in a predetermined pattern.

The display means may include a green LED as the first LED and a red LED as the second LED. Thus, in normal use, the green LED may be lit permanently. When the number of doses remaining in the canister reaches a first level (for example 10 doses remaining) , the green LED may flash continuously. When there are no more doses remaining in the canister, the green LED is no longer lit and the red LED may be lit permanently. In this way, the user can be given some warning that the canister is about to run out, and so be able to obtain a replacement canister assembly before it becomes necessary.

In a different embodiment, the display means may include at least two and preferably three LEDs.

Preferably, the display means includes control means for operating one or more of the LEDs for a predetermined time interval, at a predetermined point in the operation of the device. For example, the LED(s) may activate for a predetermined time, e.g. 10, 15 or 20 seconds, immediately after the canister has been activated or a dose has been dispensed. In one example, a green LED would flash when the canister was operating normally, an amber LD would instead operate or flash when a set level is reached (e.g. the canister is becoming nearly empty) and a red LED would operate or flash when the canister is empty. The operation of the bEDs for a suitable time after a dose is dispensed from the canister has the advantages of conserving battery life and also serving as an indication that a dose has been dispensed.

Preferably, all of the components of the counter, switch and display means are sealed within a body of the collar, and preferably that body is waterproof. This allows the canister assembly to be removed from an inhaler casing (if provided) and cleaned without any risk of damaging the components with water or damp. In one embodiment, the body of the collar is made from silicone rubber.

When electronic components are used, various orientations and locations of the circuitry within the body of the collar are envisaged. Preferably some of the electronics are mounted on a printed circuit board, and more preferably that circuit board is made from a flexible substrate which allows that circuit board to be fitted into the best location in the collar.

In an alternative embodiment, the electronic components (including an integrated circuit containing the counter) are mounted on one or more metal frames.

These frames may also form part of the switch, such as one of the contacts of the switch. The or each frame may connect one or more of the electronic components to each other, or to the power source (e.g. a battery) The switch may be mounted on the collar so that when the collar has been displaced relative to the canister sufficiently for the canister to be actuated by the collar seat member, the switch is triggered thereby indicating a dose is delivered from the canister.

Alternatively, if the collar is fixed relative to the canister body (e.g. with adhesive) with the seat member moveable relative to the canister body and the rest of the collar, the switch may be mounted on the seat member or on the rest of the collar so that it is triggerable on displacement of the seat member relative to the rest of the collar, this latter displacement being equivalent to displacement of the seat member relative to the canister body.

The switch may interact with a portion of the canister main body, for example the end face of the canister from which the canister nozzle projects. Thus, the switch may be configured so that when the collar seat member is engaged with the canister nozzle and the collar seat member is positioned relative to the canister body so that the canister is actuated, the switch is triggered, indicating an actuation of the canister.

The switch may be mounted on one or other of the seat member or the rest of the collar (the collar casing or attachment casing) such that it may interact with the io other of the scat member or the collar casing. Thus, the switch may be configured such that, when the collar casing is fixed to the canister body leaving the seat member free to move relative to the canister body, relative movement of the seat member to the collar casing is equivalent to relative movement of the seat member to the canister body, and such relative movement triggers the switch.

It is preferable that the switch is moulded at the same time as the body is formed. In a preferred embodiment of this, the switch includes two electrical contacts and a substantially circu1.r button with a head portion, the button being connected to the body of the collar by a skirt, wherein both the head portion and the skirt are made from resilient material, and the button has a projection extending radially inwards from the head portion, wherein the face of the projection opposite the head portion is made from, or has on it, conducting material, such that when the button is subjected to a longitudinal force on the head portion, the button deforms urging the conducting face of the projection into contact with both of the contacts, thereby completing an electrical circuit.

Further aspects of the present invention provide a canister assembly according to this invention, together with an inhaler incorporating such a canister assembly.

The canister and casing may be any of the usual types used in these devices.

Preferably, a casing according to the present invention includes a casing body portion, and that casing body portion is adapted so as to allow the display means, included in some embodiments according to the present invention, to be visible at least some of the time. Particular embodiments of the present invention will now be described

in relation to the attached dra:ings, in which: Figure 1 shows an inhaler canister and an attachment according to the present invention; Figure 2 shows the inhaler canister and attachment according to the present invention mounted in an inhaler casing; Figure 3 is an exploded view of the attachment of Figure 1; Figures 4 to 6 show an alternative embodiment in which the attachment includes a mouthpiece; Figures 7 to 9 show a further embodiment in which the mouthpiece section is removable from the attachment; Figures 10 to 11 show a further embodiment with a different attachment.

In Figure 1, an attachment (collar) 20 is shown about to be attached to an inhaler canister 10. The attachment includes a body (seat member) 26, from which arms 24 extend. Ihe arms 24 will engage with the ridges 16 on the body of the inhaler canister. The attachment has an aperture 32 through which the nozzle 14 of the canister 10 can pass, so the dispensing action of the canister is not impeded by the attachment. On the inside of body 26, a switch 22 is mounted. The attachment and canister assembly may then he located inside the casing 12, which includes mouthpiece 14.

When the canister 10 is forced into body 26, nozzle 14 is forced into the canister. When nozzle 14 has been depressed by a predetermined amount, a dose of the drug contained in canister 10 is dispensed in aerosol form. The body of casing 12 may include a mouthpiece to facilitate administration of the drug concerned. Various designs of mouthpiece can be used since its function is simply to act as a passage for delivery of the drug to the exterior of the assembly. The part of the assembly which cooperates with the nozzle 14 of the canister 10, and which thus inherently has design restrictions, is body 26.

Switch 22 is located such that when canister 10 has travelled far enough to dispense a dose, as detailed above, it is engaged by the canister 10. This causes switch 22 to be depressed, which motion causes the counter to either increment (in the case of a counter initially set to zero which is counting the number of doses dispensed from the inhaler canister) or decrement (in the case of a counter initially set to the number of doses in the canister and recording the number remalning at any time) The casing 12 of the inhaler shown in Figure 1 also has viewing means (see Figure 2), e.g. a window 56, which may be cut out from the body, or be an integral part of the body which is translucent. This allows display 30 (in this case a counter, but it could be other means e.g. one or more LEDs)to be visible to the patient through the body of the inhaler. It will be appreciated that many other ways of mounting the display are possible, and this is purely an example.

Figure 3 shows a cut-away view of the inside of a first embodiment of attachment 20, showing the switch 22 io and hole 32 through which the nozzle 14 passes when the attachment is attached to a canister. iso inside the attachment are the circuit board 28 on which the circuitry for the electronic counter is mounted, powered by a power source 36. Mounted in the body 26 of the attachment is the display (in this case LEDs)which displays the current status of the counter.

Figures 4-6 show an alternative embodiment wherein the attachment 70 includes a mouthpiece 80, removing the need for any casing. In this example, in Figure 6 display 30 is shown as an LCD.

Using LEDs to display the state of the canister rather than an LCD connected to the counter is much cheaper in terms of components. The second embodiment of the attachment also shows that when using LEDs as the display means, the attachment can be made much smaller, since there is no need to incorporate the display.

In a further alternative embodiment, the attachment may have both LEDs and an LCD. Ear example, the LEDs may be visible to the patient/user when the canister is in the inhaler body, and give general indication as to the state of the canister, whilst removing the canister from the inhaler body allows the LCD to be viewed which gives more detailed information, for example about the exact number of doses used from or remaining in the canister.

Whatever form the display means takes, in order to minimise the size of the attachment, some or all of the electrical components may be mounted on a printed circuit board made from flexible substrate, which allows the circuit board to be fitted into a smaller space.

Figures 7-9 show a further embodiment similar to Figures 4-6, but in which the mouthpiece section 85 is removable from the attachment 90.

Figures 10-11 show a further embodiment, similar to Figures 7-9, but which includes additional arms 24, which substantially surround canister 10, to provide a more secure connection.

It is to be understood that variants of the above described examples of the invention in its various aspects, such as would be readily apparent to the skilled person, may be made without departing from the scope of the invention in any of its aspects.

Claims

CLAIMS: 1. An inhaler canister assembly including: a canister having a

canister body for containing a substance, and a nozzle by which the substance may be delivered from the canister body, the canister being actuatable to deliver the substance by relative displacement between the nozzle and canister body; and the assembly includes an attachment having a body for engagement with the nozzle, the body being movable relative to the canister body o actuate the canister; wherein the attachment is permanently attached to the canister body through engagement of at least one arm of the attachment with a ridge on the canister body; wherein the attachment includes count means for registering an actuation of the canister in response to switch means of the count means detecting the actuation; and wherein the switch means is triggerable in response to movement of the body relative to the canister body.

2. An inhaler canister assembly according to Claim 1 wherein the switch means is triggerable in response to linear movement of the body relative to the canister body.

3. An inhaler canister assembly according to Claim 2 wherein the linear movement is movement along the longitudinal axis of the canister body.

11. An inhaler canister assembly according to Claim 2 or Claim 3 wherein the linear movement is movement of the body towards the canister body.

5. An inhaler canister assembly according to any one of is the preceding claims wherein the switch means is arranged to interact with a portion of the canister body.

6. An inhaler canister assembly according to any one of the preceding claims wherein the switch means is operable by movement in an axis parallel to the axis of movement of the body relative to the canister body.

7. An inhaler canister assembly according to any one of the preceding claims wherein the attachment is moveable relative to the canister body.

8. An inhaler canister assembly according to any one of the preceding claims wherein the switch means is triggerable in response to a predetermined displacement of the body relative to the canister body.

9. An inhaler canister assembly according to Claim 8 wherein the predetermined displacement of the body relative to the canister body corresponds to a displacement of the nozzle relative to the canister body needed to actuate the canister.

10. An inhaler canister assembly according to any one of the preceding claims, wherein the count means includes a counter for storing count information derivable from the number of detected actuations of the canister; and wherein the counter registers an actuation of the canister in response to the switch means detecting an actuation.

11. An inhaler canister assembly according to Claim 10, wherein the attachment further includes display means connected to the counter, for displaying information derived from the count information.

12. An inhaler canister assembly according to Claim 10 or Claim 11, wherein the attachment further includes an electronic circuit, the switch means being connected to the electronic circuit, and the counter being an electronic counter connected to the electronic circuit.

13. An inhaler canister assembly according to Claim 12, wherein the electronic circuit is an integrated circuit including a printed circuit board to which one or more electronic components are connected.

14. An inhaler canister assembly according to Claim 13, wherein the printed circuit board includes a flexible substrate.

15. An inhaler canister assembly according to any one of the preceding claims, wherein the attachment extends along less than half the length of the canister body.

16. An inhaler canister assembly according to Claim 15, wherein the attachment extends along less then one quarter of the length of the canister body.

s 17. An inhaler canister assembly according to any one of the preceding claims, wherein the attachment does not extend more than 5mm along the length of the canister body.

18. An inhaler canister assembly according to Claim 17, wherein the attachment does not extend more than 3mm along the length of the canister body.

19. An inhaler canister assembly according to any one of the preceding claims, wherein when assembled, the attachment does not radially protrude more than 0.5mm beyond the side wall of the canister.

20. An inhaler canister assembly according to any one of the preceding claims, wherein, when assembled, the attachment does not radially protrude beyond the side wall of the canister.

21. An inhaler canister assembly according to any one of the preceding claims, wherein, when assembled, the at least one arm does not radially protrude more than 0.5mm beyond the side wall of the canister.

22. An inhaler canister assembly according to any one of the preceding claims, wherein the attachment includes a waterproof body which encloses the components of the attachment.

23. An inhaler canister assembly according to Claim 22, wherein the waterproof body is formed from moulded silicone rubber.

24. An inhaler canister assembly according to Claim 22 or Claim 23, wherein the switch means is moulded as part of the waterproof body.

25. An inhaler canister assembly according to any one of Claims 11 to 24, wherein the display means includes a light emitting diode.

26. An inhaler canister assembly according to any one of the Claims 11 to 25, wherein the display means includes a liquid crystal display.

27. An inhaler canister assembly substantially as described herein with reference to, and as illustrated in, the accompanying drawings.

28. An attachment for attachment to an inhaler canister to form an assembly substantially as described herein with reference to, and as illustrated in, the accompanying drawings.