GB2549769A

GB2549769A - An Inhaler

Info

Publication number: GB2549769A
Application number: GB1607432.0A
Authority: GB
Inventors: James Silcock Alan
Original assignee: Kind Consumer Ltd
Current assignee: Kind Consumer Ltd
Priority date: 2016-04-28
Filing date: 2016-04-28
Publication date: 2017-11-01
Also published as: WO2017187149A1; GB201607432D0

Abstract

An inhaler 100 comprising: a reservoir 64 for an inhalable composition; a composition discharging outlet 56A of diameter d; and a non-metered breath activated valve between the reservoir 64 and the discharging outlet 56A. The breath activated valve itself comprises: a flow path between the reservoir and the discharging outlet 56A; a valve-member 46; and a valve outlet orifice 60 having a maximum dimension h when fully opened and where the value of h/d is in the range 0.01 to 0.1. The breath activated valve may be a pinch valve, where valve member 46 pinches a deformable tube 66. The breath activated valve may comprise an expansion chamber downstream of the valve outlet orifice 60 having a length L and diameter D measured half way long the expansion chamber, where D/d may be in a range 1-10. Also an inhaler comprising a non metered breath activated valve between an inhaler outlet and a reservoir for an inhalable composition. The D/d ratio is disclosed as being important in maintaining a small droplet size exiting the inhaler; and the h/d ratio is described as promoting turbulent flow ensuring a homogenous pattern of bubble dispersion favourable for droplet size reduction and spray formation.

Description

An Inhaler

Technical Field

The present invention relates to an inhaler. In particular, the invention relates to the design of the outlet configuration from a reservoir of pressurised composition.

Background

Administration of medicaments or other compositions via inhalation has been known for some time. By administering the composition via inhalation, the composition is rapidly delivered to the lungs or bloodstream of the user.

In certain applications it may be desirable for the composition to be dispensed from the inhaler as the user inhales air since this allows the majority of the composition to enter the lung rather than the mouth or oesophagus. A number of breath actuated inhalers have been developed to automatically initiate the discharge of a composition from a reservoir in the inhaler when the user inhales.

More recently inhaler devices have been developed in the field of nicotine replacement therapy as an alternative to more traditional therapies for example nicotine patches. Inhalers have advantages in this field since they are able to simulate the act of smoking as well as deliver nicotine in a manner with which a smoker is familiar. WO 2011/015825 discloses an inhaler composed of a non-metered breath activated valve comprising a flow path in the form of a deformable tube extending from a reservoir (containing the formulation) to an outlet end. It discloses a clamping member which pinches the deformable tube when no suction is applied resulting in obstruction of flow. It releases the pinch to form an opening when suction is applied to provide uninterrupted flow from the reservoir to the outlet. However, the disclosure concerns flow control and makes the reference to the particle size generated using this design.

As discussed in WO2014/155091, aerosols are an attractive means of delivering drugs to patients when the site of action is the lungs themselves or for quick delivery of drugs to the brain. The particle size of aerosols is an important parameter to control when delivering an inhaled composition since the depth of penetration into the lungs increases with reducing particle size. It plays a significant role in determining the deposition profile of the aerosol in the respiratory system. It is known that larger particles (>10pm) are deposited in the mouth and upper thoracic region, whilst smaller particles (<10pm) have deposition distributions that are from the upper thoracic through to the alveolar region. Fine droplets (0.1 pm < Dm < 1pm) have good alveolar deposition at between 1~5pm. Ultra-fine droplets (<0.1pm) are optimal for alveolar deposition from where drug molecules can be efficiently absorbed into the circulatory system, but are currently not feasibly produced in a portable device. This deposition distribution can be exploited to allow for effective delivery of pharmaceuticals, proteins, vaccines or, nicotine in the case of a simulated cigarette device. It is known that the D50 (mass-median-diameter, or average particle size by mass) of cigarette smoke is between 0.3- 0.5pm for most main stream cigarettes. To be successful as a cigarette replacement, ideally a simulated cigarette would be able to reproduce this particle size. WO2014/155091 teaches that by providing an inhaler having a particular configuration of the outlet, the inhaler is capable of delivering particles with size distributions that are similar to those found in cigarette smoke.

The present invention is aimed at providing a breath activated inhaler which is capable of being used in nicotine replacement therapy.

Summary

Aspects of the invention are defined in the accompanying claims.

In accordance with some embodiments described herein, there is provided an inhaler comprising: a reservoir for an inhalable composition; an inhaler outlet through which the inhalable composition is discharged, wherein the inhaler outlet has a diameter d; a non-metered breath-activated valve between the inhaler outlet and the reservoir, the breath-activated valve comprising a flow path extending from the reservoir to the inhaler outlet, and a valve member, a valve outlet orifice, wherein the valve outlet orifice has a maximum dimension h, measured in the direction of opening when fully opened; wherein 0.01 < h/d < 0.1.

We have found that to deliver particles of inhalable composition having a particle size distribution similar to that of cigarette smoke, the dimensions of the inhaler must be selected to meet the above requirements. In particular wherein the ratio of h to d is 0.01 < h/d < 0.1, wherein d is the inhaler outlet diameter and h is the maximum dimension of the valve outlet orifice, measured in the direction of opening when fully opened. We have found that the dimensions taught by WO2014/15509, and in particular the ratio 0.1 < h/d < 1, are not correct for a device that delivers particles of inhalable composition having a particle size distribution similar to that of cigarette smoke. We have found that the ratio of h to d should be an order of magnitude less than that stated in WO2014/15509.

Description of Drawings

The present teachings will now be described by way of example only with reference to the following figures in which like parts are depicted by like reference numerals:

Figure 1 is a perspective view of an inhaler illustrating the sub-assemblies from which the inhaler is formed;

Figure 2 is a sectional view of the inhaler illustrated in Figure 1;

Figure 3A is a perspective view of a refill valve;

Figure 3B is an exploded view of the refill valve illustrated in Figure 3A;

Figure 4A is a cross section of the valve illustrated in Figures 3A and 3B when the valve is in the closed position;

Figure 4B is a cross section of the valve illustrated in Figures 3A and 3B when the valve is in the open position;

Figure 5A is a schematic axial cross section through the mouthpiece end of the inhaler illustrated in Figures 1 and 2 in which the vane is not shown;

Figure 5B is a perspective view of the mouthpiece end of the inhaler illustrated in Figures 1 and 2 in which the cover, vane and diaphragm are not shown;

Figure 6 is a perspective view of the mouthpiece end of the inhaler illustrated in Figures 1 and 2;

Figure 7 is a plan view of the base of the inhaler illustrated in Figures 1 and 2;

Figure 8 is a cross section of the outlet valve illustrated in Figures 1 and 2 in which dimensions are shown;

Figure 9 shows a cross section of a pinch valve; and

Figure 10 shows the results of the test of the pinch valve of Figure 9.

While the invention is susceptible to various modifications and alternative forms, specific embodiments are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description of the specific embodiments are not intended to limit the invention to the particular forms disclosed. On the contrary, the invention covers all modifications, equivalents and alternatives falling within the scope of the present invention as defined by the appended claims.

Detailed Description

As discussed herein, the inhaler comprises an inhaler outlet through which the inhalable composition is discharged, wherein the inhaler outlet has a diameter d; and a non-metered breath-activated valve between the inhaler outlet and the reservoir, the breath-activated valve comprising a valve outlet orifice, wherein the valve outlet orifice has a maximum dimension h, measured in the direction of opening when fully opened; wherein 0.01 < h/d < 0.1.

In one aspect 0.01 < h/d < 0.09, such as 0.01 < h/d < 0.08, such as 0.01 < h/d < 0.07, such as 0.01 < h/d < 0.06, such as 0.01 < h/d < 0.05, such as 0.01 < h/d < 0.04, such as 0.01 < h/d < 0.03.

In one aspect 0.02 < h/d < 0.1, such as 0.03 < h/d < 0.1, such as 0.03 < h/d < 0.09, such as 0.03 < h/d < 0.08, such as 0.03 < h/d < 0.07, such as 0.03 < h/d < 0.06, such as 0.03 < h/d < 0.05, such as 0.03 < h/d < 0.04.

In one aspect 0.02 < h/d < 0.09, such as 0.02 < h/d < 0.08, such as 0.02 < h/d < 0.07, such as 0.02 < h/d < 0.06, such as 0.02 < h/d < 0.05, such as 0.02 < h/d < 0.04, such as 0.02 < h/d < 0.03.

It is understood that the ratio h/d is important in promoting turbulent flow. Having an exit orifice, the diameter of which is significantly larger than the valve outlet height is understood to ensure a homogenous pattern of bubbles dispersion which is favourable for droplet size reduction and the formation of a spray instead of a jet.

In one aspect the valve comprises an expansion chamber downstream of the valve outlet orifice. The expansion chamber may be described as having a length L and diameter D, wherein the diameter is D measured half way along the expansion chamber. The diameter D is measured at the mid point of the expansion chamber because typically the expansion chamber tapers from the valve outlet orifice to the exit orifice at an included angle of between 0 and 30°, such as between 9 and 10° or substantially 2°. It is understood that this tapering prevents dead zones from forming in the expansion chamber and promotes a well-mixed system which is useful in maintaining a uniform aerosol.

It is understood that the ratio h/D is important in ensuring that there is sufficient volume for expansion of the formulation as it passes through the valve outlet orifice. If the diameter of the expansion chamber is too large, flow will be laminar thus preventing effective particle break up. In one aspect h/D is from 0.05 to 0.25. In one aspect h/D is from 0.10 to 0.15.

The ratio D/d has an important role in maintaining a small droplet size exiting the device as ensuring that there is still sufficient volume for mixing whilst avoiding significant dead zones. In one aspect D/d is from 1 to 10. In one aspect D/d is from 2 to 7. In one aspect D/d is from 2 to 5. In one aspect D/d is from 3 to 5.

Typically D is from 0.3 to 2 mm, such as from 0.4 to 2 mm, 0.5 to 2 mm, such as from 0.4 to 1 mm, such as from 0.5 to 1 mm, such as from 0.6 to 1 mm, such as from 0.7 to 1 mm, such as from 0.5 to 0.8 mm, such as from 0.3 to 0.6 mm, such as from 0.4 to 0.6 mm, such as from 0.3 to 0.55 mm, such as from 0.4 to 0.55 mm, such as from 0.4 to 0.5 mm.

We have in particular found that when D is less than 0.6 mm the instances of failure of the breath operated valve to reseal are reduced. In particular, at pressures ranging from 6 bar gauge to 9 bar gauge, a clear difference is seen by reducing the internal diameter (D) to less than 0.6. In particular, the internal diameter (D) may be from 0.3 to 0.6 mm, such as from 0.4 to 0.6 mm, such as from 0.3 to 0.55 mm, such as from 0.4 to 0.55 mm, such as from 0.4 to 0.5 mm.

Thus in a further aspect there is provided an inhaler comprising: a reservoir for an inhalable composition; an inhaler outlet through which the inhalable composition is discharged, wherein the inhaler outlet has a diameter d; a non-metered breath-activated valve between the inhaler outlet and the reservoir, the breath-activated valve comprising a flow path extending from the reservoir to the inhaler outlet, and a valve member, a valve outlet orifice, wherein the valve outlet orifice has a maximum dimension h, measured in the direction of opening when fully opened; wherein the valve comprises an expansion chamber downstream of the valve outlet orifice having a length L and diameter D measured half way along the expansion chamber, wherein D is less than 0.6 (such as from 0.3 to 0.6 mm, such as from 0.4 to 0.6 mm, such as from 0.3 to 0.55 mm, such as from 0.4 to 0.55 mm, such as from 0.4 to 0.5 mm).

Typically L is from 5 to 15mm, such as from 5 to 12 mm, such as from 5 to 10 mm, such as from 6 to 10 mm, such as from 6 to 9 mm, such as from 7 to 9 mm.

It is understood that the ratio of L/D effects the flow regime inside the expansion chamber. Sufficient volume is provided within the claimed range for the formulation to evaporate, recirculate and form sufficiently sized bubbles to provide droplets of a small, uniform size upon exit of the outlet orifice. In one aspect, the ratio L/D is from 6 to 13, such as from 7 to 10.

As discussed herein, the valve outlet orifice has a maximum dimension h, measured in the direction of opening when fully opened.

Typically h is from 0.01 to 0.04 mm, such as from 0.01 to 0.033 mm, such as from 0.015 to 0.035 mm, such as from 0.02 to 0,03 mm, such as from 0.022 to 0.028 mm

As discussed herein, the inhaler outlet through which the inhalable composition is discharged has a diameter d. The length of this orifice may be defined as length I.

Typically d is from 0.1 to 0.5 mm, such as from 0.1 to 0.4 mm, such as from 0.1 to 0.3 mm, such as from 0.15 to 0.25 mm.

Typically I is from 0.2 to 0.8 mm, such as from 0.3 to 0.7 mm, such as from 0.3 to 0.6 mm, such as from 0.4 to 0.5 mm.

It is understood that the ratio l/d is important in the formulation of a turbulent exit aerosol. By optimising its ratio, it is understood that the droplet size can be decreased or increased. In one aspect, l/d is from 1 to 4. In one aspect, l/d is from 2 to 3.

The present invention requires that the inhaler comprises (i) a reservoir for an inhalable composition; (ii) an inhaler outlet through which the inhalable composition is discharged, and (iii) a non-metered breath-activated valve between the inhaler outlet and the reservoir. The breath-activated valve comprises (a) a flow path extending from the reservoir to the inhaler outlet, (b) a valve member, (c) a valve outlet orifice. In one aspect upon application of suction to the inhaler outlet, the breath-activated valve is configured to move into an open position due to the application of an opening force on the valve member. Furthermore upon removal of suction at the outlet, the breath-activated valve is configured to move into a closed position due to the application of a biasing force on the valve member, and wherein the biasing force is configured to retain the breath-activated valve in the closed position when no suction is applied to the outlet. The biasing force is selected based on the configuration of the device. In one aspect the biasing force is from 1 to 3N, such as from 2.7 to 2.9N.

The outlet valve may, for example, be a sliding gate valve member which opens to the required extent. However, preferably, the valve is a pinch valve in which a valve member pinches a deformable tube with the outlet orifice dimension representing the maximum opening height at the pinch point. The deformable tube will typically have a wall thickness of from 0.2 to 0.4 mm such as from 0.2 to 0.3 mm. In this aspect the ratio of the wall thickness (mm) of the deformable tube to the biasing force (N) may be 0.05-0.25:1.

We have in particular found that when the deformable tube has a wall thickness of greater than 0.25mm the instances of failure of the breath operated valve to reseal are reduced. In particular, at pressures ranging from 6 bar gauge to 9 bar gauge, a clear difference is seen by increasing the wall thickness of the deformable tube to at least 0.25mm. In particular, the wall thickness of the deformable tube may be from 0.25 to 0.6 mm, such as from 0.3 to 0.6 mm, such as from 0.3 to 0.5 mm, such as from 0.3 to 0.4 mm.

Thus in a further aspect there is provided an inhaler comprising: a reservoir for an inhalable composition; an inhaler outlet through which the inhalable composition is discharged, wherein the inhaler outlet has a diameter d; a non-metered breath-activated valve between the inhaler outlet and the reservoir, the breath-activated valve comprising a flow path extending from the reservoir to the inhaler outlet, and a valve member, a valve outlet orifice, wherein the valve outlet orifice has a maximum dimension h, measured in the direction of opening when fully opened, wherein the valve is a pinch valve in which a valve member pinches a deformable tube having a wall thickness of at least 0.25mm (such as from 0.25 to 0.6 mm, such as from 0.3 to 0.6 mm, such as from 0.3 to 0.5 mm, such as from 0.3 to 0.4 mm).

The inhaler of the present invention may deliver any suitable inhalable composition. In one aspect, the inhaler is suitable for the delivery of nicotine. In one aspect, the reservoir contains a composition comprising nicotine.

Figure 1 illustrates a sectional view of an inhaler 100. The inhaler 100 is designed to simulate a cigarette and therefore has a substantially cylindrical shape and is approximately the same size as a cigarette. The inhaler 100 has a first refill end 20 and a second mouthpiece end 40 opposite the refill end 20. The inhaler 100 is formed of four sub-assemblies namely a mouthpiece 42, a composition chamber 62, a refill valve 22 and a label 90. The composition chamber 62 is provided between the mouthpiece 42 and the refill valve 22. The label 90 is wrapped around the assembled mouthpiece 42, composition chamber 62 and refill valve 22. Each of the sub-assemblies and their operation are described in detail below.

As illustrated in Figure 2 the inhaler device 100 is formed of a housing 1 in the form of a main body 2 and a closure member 3. The closure member 3 is held in place on the housing 1 by the label 90.

Composition Chamber

The composition chamber 62 is provided as a reservoir 64 containing an inhalable composition within the housing.

The reservoir 64 is provided in the central portion of the inhaler 100 and occupies the majority of the internal space of the inhaler 100. The reservoir 64 includes a portion adjacent to the refill valve 22 which substantially fills the cross section of the inhaler 100 and a portion adjacent to the mouthpiece 42 which fills approximately half off the cross section of the inhaler 100. The portion of the reservoir 64 adjacent to the mouthpiece 42 has a smaller cross sectional area since the mouthpiece end 40 of the inhaler 100 also contains the valve mechanism for discharging the composition from the reservoir 64.

Located in the reservoir 64 is a flexible tube 66. The tube 66 has an outlet in fluid communication with the mouthpiece subassembly 42 and an inlet in fluid communication with the refill valve sub assembly 22. The inlet of the tube 66 is supported by a funnel-shaped support 68 in order to locate the tube inlet substantially in the centre of the circular cross section of the device. The outer diameter of the support 68 corresponds to the inner diameter of the reservoir 64. Openings are provided in the support 68 to permit the composition in the reservoir 64 to pass through the support 68 into the inlet of the tube 66.

Refill Valve

Figures 3A and 3B illustrate the refill valve 22 in further detail. The refill valve 22 is located adjacent the composition chamber 62 and includes a spring 24, a spring cage 25, a valve member 26, an annular member 29 and an end cap 30. The spring cage 25 abuts against the support 68 for the tube 66 located in the composition chamber 62 at the end closest to the refill valve 22. The spring cage 25 surrounds the spring 24 and the valve member 26 thereby retaining the spring 25 and the valve member 26 within the cage 25. The cage 25 includes a plurality of laterally arranged apertures 25A in fluid communication with the composition chamber 62 such that the space within the cage 25 forms part of the reservoir 64.

The spring 24 contained within the cage 25 is received by a surface of the valve member 26 and biases the valve member 26 into a closed position as shown in Figure 4A. The valve member 26 includes a circular base 27 and a spigot 28 projecting from the centre thereof. The spigot 28 projects from a surface of the base 27 opposite to the surface which receives the spring 24. The spigot 28 has a plurality of axially extending grooves or channels 28A extending from the proximal end of the spigot 28 near the base 27 of the valve member 26 to the distal end of the spigot 28.

An annular member in the form of a washer 29 is located on the valve element 26 such that the spigot 28 extends through the centre of the washer 29. An end cap 30 is provided at the end of the inhaler 100 and seals with the annular member 29 thereby closing the cylindrically shaped housing at the refill end 20 of the inhaler 100. The spigot 28 extends through a central opening 30A in the end cap 29.

Figure 4A illustrates the closed position of the refill valve 22. In this position the valve member 26 is biased by the spring 24 against the annular element 29 thereby sealing the annular element 29 against the end cap 30.

In order to fill or refill the reservoir 64 of the inhaler 100, the refill end 20 of the inhaler 100 is pressed onto an outlet 32 of a refill container 34. The container outlet 32 passes through the central opening 30A of the end cap 30 and engages with the spigot 28. The force of the container outlet 32 on the spigot 28 overcomes the biasing force of the spring 24 and causes the valve member 26 and the annular member 29 located thereon to move away from the end cap 30 thus providing a flow path from the container outlet 32, through the grooves 28A of the spigot 28, between the annular member 29 and the end cap 30, around the valve member 26 through the apertures 25A in the cage 25 to the reservoir 64. Figure 4B illustrates this open position of the refill valve 22. In this manner the reservoir 64 can be filled or refilled via the refill valve 22.

Mouthpiece

The mouthpiece 42 of the inhaler 100 can be seen in Figure 2. Figures 5A-5B and Figures 6-7 illustrate further details of the mouthpiece 42 of the inhaler 100. The mouthpiece subassembly 42 is located adjacent the composition chamber 62 at the opposite end of the composition chamber 62 to the refill valve 22. The mouthpiece 42 includes a resilient tube 44, a valve member 46, a spring 48, a diaphragm 50, a vane 52 and an end cap 54. The end cap 54 is located over the end of the housing thereby closing the housing at the mouthpiece end 40 of the inhaler 100.

The resilient tube 44 is provided in fluid communication with the outlet of the flexible tube 66 in the reservoir 64. The resilient tube 44 extends from the outlet of the flexible tube 66 to an opening 45 in the end cap 54 of the mouthpiece 42. The resilient tube 44 is pinched closed by a valve member 46 that is biased against the resilient tube 44 by a spring 48. The valve member 46 is in the form of a substantially triangularly shaped tooth configured to press down on the resilient tube 44 and pinch it closed. Figure 2 illustrates the valve member 46 in the closed position in which no composition can pass through the resilient tube 44 to the opening 45 in the end cap 54.

The vane 52 extends along substantially all of the length of the mouthpiece 42 and is pivotally mounted at one end of the vane 52 to the housing near the end cap 54 of the mouthpiece 42. The vane 52 is surrounded by a diaphragm or membrane 50 which extends over the lower surface of the vane 52 and is sealed to the housing. The diaphragm 50 thereby forms a chamber in which the vane 52 is sealed. In this manner the mouthpiece 42 is divided into two regions. A first region or chamber containing the vane 52 is located above the resilient tube 44 between the cover 3 of the housing and the diaphragm 50. A second region or chamber is provided below the first chamber between the diaphragm 50 and the main body 2 of the housing. The valve member 46 is integrally formed with the vane 52 and an aperture 50A is provided in the diaphragm 50 through which the valve member 46 extends. The valve member 46, vane 52 and diaphragm 50 together form a breath-activated valve such that when a user sucks on the end cap 54 the breath-activated valve opens to allow the inhalable composition in the reservoir 64 to be inhaled.

In use the breath-actuated valve is opened against the action of the spring 48 upon inhalation by the user. In order to achieve this actuation first and second air flow paths 56, 58 are provided. These air flow paths are illustrated in detail in Figures 5A-5B. The first air flow path 56 is located in the chamber containing the vane 48 that is sealed by the diaphragm 50. An outlet 56A to this chamber is provided in the end cap 54.

The second air flow path 58 is located in the second region below the first chamber between the diaphragm 50 and the main body 2 of the housing. In the illustrated example the second air flow path 58 is formed of two separate paths extending from inlet apertures 58A in the housing, through the second chamber to outlet apertures 58B in the end cap 54. The outlet apertures 58B are smaller than the inlet apertures 58A. In some examples baffles 59 are provided along the second flow path 58.

Figure 6 is a perspective view of the mouthpiece end 40 of the inhaler 100. As illustrated, the mouthpiece end cap 54 includes four apertures, two outlet apertures 58B in fluid communication with the second air flow path 58, one outlet aperture 56A in fluid communication with the first air flow path 56 and an opening 45 in fluid communication with the resilient tube 44 from which the inhalable composition is dispensed to the user. Figure 7 illustrates the inlet apertures 58A of the second air flow path 58 in the base of the inhaler device 100.

In use, a user inhales on the device 100 thereby providing suction at the mouthpiece end 40 of the inhaler 100. Upon the application of suction, air is drawn out of the first and second flow paths 56, 58. Since the first flow path 56 contains no means for air to be introduced to this flow path 56, the pressure in the first flow path 56 is reduced upon the application of suction to the device 100. However as the second flow path 58 includes inlet apertures 58A, air is drawn into the second flow path 58 at the same time as air is sucked out of the second flow path 58. The pressure in this flow path 58 therefore remains substantially the same. The combination of the reduced pressure in the first air flow path 56 and the prevention of a pressure reduction in the second air flow path 58 overcomes the biasing force of the spring 48 and causes the vane 52 to move against the action of the spring 48 thereby raising the valve member 46 away from the resilient tube 44 and thus enabling composition to flow from the reservoir 64 through the resilient tube 44 to the composition opening 45 in the end cap 54.

When a user stops sucking on the mouthpiece end 40 of the inhaler 100 the pressure in the two flow paths 56, 58 equalises and the bias of the spring 48 causes the valve member 46 to return to the closed position in which the valve member 46 pinches closed the resilient tube 44.

Figure 8 shows a pinched pinch tube in which the outlet orifice is applied. The pinch tube 66 has an exit orifice 56A at its downstream end and is pinched closed by jaw 46 in a region in the vicinity of the opposite end. The point where it is pinched closed represents the valve outlet orifice 60 which has a maximum height h measured in the direction of opening when the valve is fully open. To the right of this pinch point is the reservoir 64 containing the inhalable composition. Part of the reservoir is made up by the right-hand portion of the pinch tube 66, and the remainder is made up by the device housing as described above. Between the valve outlet orifice 60 and the exit orifice 56A is expansion chamber 61. This has an axial length L and an internal diameter D which is measured halfway along the expansion chamber. The exit orifice 56Ahas a length I and a diameter d.

Figure 9 shows a cross section of pinch valve of inhaler. Figure 9A has a wall thickness of 0.2mm and D=0.71mm. Figure 9B has a wall thickness of 0.3mm and D=0.51mm. Tests were completed on 30 valves of each thickness using compressed air at 6 bar gauge up to 9 bar gauge in 1 bar increments. The results of these tests can be seen Figure 10. A “standard device" performance was included for comparison purposes. The results show that the 0.2mm wall devices (D=0.71) have an improved performance than the standard devices. We also showed a clear difference between the performance of the 0.2mm wall devices and the 0.3mm wall devices (D=0.51), with 0% of 0.3mm wall devices showing reseal failures at 9 bar gauge. The 0.2mm wall devices on the other hand have 80% failure at 8 bar gauge, and although there is an unexpected result at 9 bar gauge, the overall result shows that the 0.3mm wall is much less likely to have reseal failures at a given pressure.

Label A label 90 is provided on the outer surface of the device 100 to hold the closure member 3 in place on the main body 2 of the housing. The label 90 includes apertures (not shown) in a location corresponding to the location of the inlet apertures 58A such that the label 90 does not block the inlet apertures 58A and air can flow into the device 100.

The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and/or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc, other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.

Claims

1. An inhaler comprising: a reservoir for an inhalable composition; an inhaler outlet through which the inhalable composition is discharged, wherein the inhaler outlet has a diameter d; a non-metered breath-activated valve between the inhaler outlet and the reservoir, the breath-activated valve comprising a flow path extending from the reservoir to the inhaler outlet, and a valve member, a valve outlet orifice, wherein the valve outlet orifice has a maximum dimension h, measured in the direction of opening when fully opened; wherein 0.01 < h/d < 0.1.

2. An inhaler according to claim 1, wherein 0.01 < h/d < 0.07.

3. An inhaler according to claim 1 or 2, wherein 0.01 < h/d < 0.05.

4. An inhaler according to claim 1,2 or 3, wherein 0.02 < h/d < 0.04.

5. An inhaler according to any one of claims 1 to 4, wherein the valve comprises an expansion chamber downstream of the valve outlet orifice having a length L and diameter D measured halfway along the expansion chamber.

6. An inhaler according to claim 5, wherein D/d is from 1 to 10.

7. An inhaler according to claim 5 or 6, wherein D/d is from 2 to 5.

8. An inhaler according to any one of claims 5 to 7 wherein D is from 0.5 to 2 mm.

9. An inhaler according to any one of claims 5 to 8 wherein D is from 0.7 to 1 mm.

10. An inhaler according to any one of claims 5 to 9 wherein L is from 7 to 9 mm.

11 An inhaler according to any one of claims 5 to 10 wherein D is from 0.5 to 0.8 mm.

12 An inhaler according to any one of claims 1 to 11 wherein upon application of suction to the inhaler outlet, the breath-activated valve is configured to move into an open position due to the application of an opening force on the valve member, wherein upon removal of suction at the outlet, the breath-activated valve is configured to move into a closed position due to the application of a biasing force on the valve member, and wherein the biasing force is configured to retain the breath-activated valve in the closed position when no suction is applied to the outlet.

13. An inhaler according to claim 12 wherein the biasing force is from 1 to 3N.

14. An inhaler according to claim 12 wherein the biasing force is from 2.7 to 2.9N.

15. An inhaler according to any one of claims 1 to 14 wherein the breath-activated valve is a pinch valve in which the valve member pinches a deformable tube, wherein the outlet orifice dimension h represents the maximum opening height at the pinch point.

16. An inhaler according to claim 15 wherein the deformable tube has a wall thickness of from 0.2 to 0.3 mm.

17. An inhaler according to claim 12 and claim 15 wherein the ratio of the wall thickness (mm) of the deformable tube to the biasing force (N) is 0.05-0.25:1

18. An inhaler according to any of claims 1 to 17 wherein the reservoir contains a composition comprising nicotine.

19. An inhaler comprising: a reservoir for an inhalable composition; an inhaler outlet through which the inhalable composition is discharged, wherein the inhaler outlet has a diameter d; a non-metered breath-activated valve between the inhaler outlet and the reservoir, the breath-activated valve comprising a flow path extending from the reservoir to the inhaler outlet, and a valve member, a valve outlet orifice, wherein the valve outlet orifice has a maximum dimension h, measured in the direction of opening when fully opened; wherein the valve comprises an expansion chamber downstream of the valve outlet orifice having a length L and diameter D measured half way along the expansion chamber, wherein D is less than 0.6.

20. An inhaler according to claim 19 characterised by the features of any one of claims 1 to 18.

21. An inhaler substantially as hereinbefore described with reference to the accompanying Figures.