Inhaler and nozzle unit for an inhaler

Abstract

A nozzle unit for an inhaler, the nozzle unit 400 comprising a nozzle for dispensing medicant. A first connector 120 for connecting the nozzle unit 100 to a medicant canister 200 and a second connecto

Description

TECHNOLOGICAL FIELD Examples of the disclosure relate to an inhaler and a nozzle unit for an inhaler. Some relate to a metered dose inhaler for dispensing a medicant to be inhaled by a user. BACKGROUND An inhaler is a medical device used for delivering medicants into the lungs through the work of a user’s breathing. Inhalers may be used to treat a number of medical conditions including asthma and chronic obstructive pulmonary disease. A metered-dose inhaler (MDI) delivers a specific amount of medicant to the lungs, in the form of a short burst of aerosolized medicine. MDI generally comprise: a pressurized canister for storing the medicant and a propellant, a metering valve, and an actuator. The actuator is hand-operated by a user to dispense medicant in aerosol form. The actuator comprises a nozzle for dispensing the medicant and a body. When the canister has been used up the entire inhaler is replaced. This creates a significant amount of waste. BRIEF SUMMARY According to various, but not necessarily all, examples there is provided a nozzle unit for an inhaler. The nozzle unit comprises: a nozzle for dispensing medicant; a first connector for connecting the nozzle unit to a medicant canister; and a second connector for connecting the nozzle unit to a body of the inhaler. The first connector and second connector are configured such that a greater force is required to disconnect the canister and nozzle unit than to disconnect the body and nozzle unit. The first connector and second connector may be configured such that a greater force, in a direction parallel to a stem of the canister, is required to disconnect the canister and nozzle unit than to disconnect the body and nozzle unit. The first connector and second connector may be configured such that a mechanical connection between the nozzle unit and the canister is stronger than a mechanical connection between the nozzle unit and the body. The first connector may comprise a clip. The first connector may form at least part of a snap-fit connector. The first connector may comprise at least one projection configured to be received by at least one recess of the canister. The first connector may be configured to connect to a main body of the canister. The first connector may be configured so that the at least one projection is received by an annular recess of the main body of the canister. The annular recess may be perpendicular to the stem of the canister. The first connector may be configured so that the at least one projection is received substantially in the half of the annular recess closest to the stem. The first connector may be configured to at least partially surround the main body of the canister. The first connector may comprise at least one member configured to extend at least partially around the main body of the canister. The at least one member comprises the at least one projection. The at least one member may comprise at least one arm. The at least one arm may be resiliently deflectable for connection and disconnection of the nozzle unit to the canister. The first connector may comprise at least one slot. The first connector may be configured such that the at least one slot extends at least partially in a direction parallel to the stem when the canister is connected to the nozzle unit. The second connector may be configured to be received by a slot of the inhaler body. The second connector may comprise at least one projection configured to be received by the slot of the inhaler body. The second connector may be configured to mate with the body. The second connector may be configured to be received by the body in a 3 tolerance fit. The nozzle unit may be sized and shaped such that it cannot pass through a mouthpiece opening of the body. According to various, but not necessarily all, examples there is provided an inhaler for dispensing a medicant, the inhaler comprising: the nozzle unit, and the body. The body may define a chamber for receiving the nozzle unit and the canister. The body may comprise a mouthpiece opening. The body may comprise a base which comprises a slot and at least one wall. The base may comprise a cavity for receiving the nozzle. The at least one wall may be sloped. The body may be configured such that when the canister and nozzle unit are received in the chamber, the body at least partially surrounds the canister and nozzle unit such that there is not enough space between the body and first connector for the first connector to resiliently deflect to allow disconnection of the nozzle unit and canister. The body may comprise an opening at the bottom of the base, which allows access to the nozzle unit when the nozzle unit and body are connected. The inhaler may be a metered dose inhaler, and the inhaler may further comprise the canister. According to various, but not necessarily all, examples there is provided an inhaler for dispensing a medicant, the inhaler comprising: a nozzle unit; and a body. The body defines a chamber for receiving the nozzle unit and the canister, and wherein the body comprises the mouthpiece opening. The nozzle unit comprises: a nozzle for dispensing medicant; and a connector for detachably connecting the nozzle unit to a body of the inhaler. The nozzle unit is sized and shaped such that it cannot pass though mouthpiece opening. According to various, but not necessarily all, examples there is provided examples as claimed in the appended claims. While the above examples of the disclosure and optional features are described separately, it is to be understood that their provision in all possible combinations and permutations is contained within the disclosure. It is to be understood that various examples of the disclosure can comprise any or all of the features described in respect of other examples of the disclosure, and vice versa. Also, it is to be appreciated that any one or more or all of the features, in any combination, may be implemented by / comprised in / performable by an apparatus, a method, and / or computer program instructions as desired, and as appropriate. BRIEF DESCRIPTION Some examples will now be described with reference to the accompanying drawings in which: FIG. 1 shows a first example of a nozzle unit; FIG. 2 shows a first example of a medicant canister; FIG. 3 shows a first example of a body of an inhaler; FIG. 4 shows a second example of a nozzle unit; FIG. 5 shows a cross-sectional view of the second example of a nozzle unit connected to the first example of a canister; FIGs 6a shows the second example of a nozzle unit being connected to the first example of the inhaler body; FIG. 6b shows a first example of an inhaler; FIG. 7 illustrates a cross-sectional view of the first example of an inhaler; FIG. 8 illustrates the first example of an inhaler; FIG. 9 shows a second example of a canister and a third example of a nozzle unit; FIG. 10 shows the second example of a canister and the third example of a nozzle unit; and FIG. 11 shows a second example of an inhaler. The figures are not necessarily to scale. Certain features and views of the figures can be shown schematically or exaggerated in scale in the interest of clarity and conciseness. For example, the dimensions of some elements in the figures can be exaggerated relative to other elements to aid explication. Similar reference numerals are used in the figures to designate similar features. For clarity, all reference numerals are not necessarily displayed in all figures. DETAILED DESCRIPTION FIG. 1 shows a first example of a nozzle unit 100 according to embodiments of the disclosure. The nozzle unit 100 is for an inhaler and comprises a nozzle 110, a first connector 120 and a second connector 130. The nozzle 110 is for dispensing medicant and comprises a hole 112 for emitting I spraying the medicant in aerosol form. The first connector 120 is for connecting the nozzle unit 100 to a medicant canister. The second connector 130 is for detachably connecting the nozzle unit 100 to a body of the inhaler. The first connector 120 and second connector 130 are configured such that a greater force is required to disconnect the canister and nozzle unit 100 than to disconnect the body and nozzle unit 100. During use a nozzle unit 100 will lose efficiency over time due to the build-up of medicant. Additionally, the nozzle unit 100 may become contaminated. A nozzle unit 100 which is attachable and detachable to an inhaler body means that the nozzle unit 100 can be replaced without replacing the inhaler body. This allows the body to be reused a number of times, for example 5-10 times. This significantly reduces waste and so reduces the environmental impact. FIG. 2 shows a first example of a medicant canister 200 according to embodiments of the disclosure. The canister 200 comprises a main body 210, a chamber 220, a valve stem 230 and a metering valve. The metering valve is inside the canister 200 and so is not visible. The chamber 220 is for storing the medicant and a propellent under pressure. The chamber 220 is within the main body 210. The medicant may be any suitable medicant, such as salbutamol or beclomethasone. The propellant provides the force to generate an aerosol spray cloud and is also the medium in which the medicant is suspended or dissolved. The propellant may be a hydrofluorocarbon. The metering valve allows a metered quantity of the propellant and medicant to be dispensed with each actuation. The propellant and medicant pass from the chamber 220, through the metering valve to the stem 230. The stem 230 is a hollow tube. The propellant and medicant pass through the stem 230 to a nozzle unit 100 / actuator from which a spray of the propellant and medicant is emitted. The illustrated canister 200 is substantially cylindrical and comprises a substantially circumferential wall 222. The at least one wall 222 at least partially defines the main body 210 of the canister 200. The at least one wall 222 may comprise at least one recess 224, 226. The illustrated wall 222 comprises a first annular recess I groove / ring 224, and a second annular recess I groove I ring 226. The first annular recess 224 is further from the stem 230 than the second annular recess 226. The canister 200 may be formed of any suitable material, for example a metal such as aluminium or stainless steel. The illustrated canister 200 is substantially symmetrical. The illustrated second annular recess 226 has a plurality of ridges. In other examples, the second annular recess 226 is substantially smooth. The canister 200 has a height, width, and depth. For the illustrated canister 200, the width is similar to the depth and the height is larger than the width and depth. Coordinate axes 50 are illustrated in FIG. 2 that include an x axis, a y axis and a z axis. The x dimension is aligned with the width of the canister 200, the y dimension is aligned with the depth of the canister 200, and the z dimension is aligned with the height of the canister 200. The x, y, and z dimensions are orthogonal to each other. The illustrated main body 210, chamber 220, and stem 230 are each elongate in the z dimension. The stem 230 extends downwardly from the main body 210 in the negative z dimension. The first annular recess 224 and the second annular recess 226 are both located in planes defined by the y and x dimensions. The first annular recess 224 is higher than the second annular recess 226. It will be appreciated that medicant canisters 200 come in a wide variety of forms which may be different to the illustrated example. For example, some canisters 200 may have different projections I recesses, and some canisters 200 may be substantially cuboid. The nozzle unit 100 as described herein may connect is to a wide variety of canisters 200. FIG. 3 shows a first example of a body 300 of an inhaler according to embodiments of the disclosure. The body 300 may be considered a mouthpiece body 300 or an inhaler body 300. Together the body 300 and nozzle unit 100 may be considered to form an actuator. The inhaler body 300 comprises a main body 310, a chamber 320 for receiving the nozzle unit 100 and the canister 200, a base I connector 330 for connecting to the nozzle unit 100, and a mouthpiece opening 340. The main body 310 may define the chamber 320. The mouthpiece body 300 may be comprised of any suitable material. For example, a plastic such as high density polyethylene. In some examples, as seen in FIGs 8, the body 300 is substantially transparent. The inhaler body 300 has a height, width, and depth. For the illustrated body 300, the height is larger than the width. Coordinate axes 50 are illustrated in FIG. 3 that include an x axis, and a z axis. The y axis would point out of the page. The x dimension is aligned with the width of the body 300, the y dimension is aligned with the depth of the body 300, and the z dimension is aligned with the height of the body 300. The x, y, and z dimensions are orthogonal to each other. The illustrated main body 310, chamber 320 and base 330 extend substantially parallel to the z dimension, but at a small angle with the z dimension. In this example the main body 310 comprises at least one ridge 312. The at least one ridge 312 is positioned on the inside of the main body 310 and run along the main body 310 in the direction it extends. The illustrated inhaler body 300 is substantially symmetrical. The mouthpiece opening 340 is for emitting the aerosolized medicant to the user, and in use it is placed next to a mouth of the user. The illustrated mouthpiece body 300 comprises a cap 350 for covering the mouthpiece opening 340. The illustrated mouthpiece opening 340 is open in the x direction, and the mouthpiece opening 340 is configured to emit the aerosolized medicant substantially in the positive x direction. The base 330 comprises a slot 332, at least one wall 334, and a cavity 336 for receiving at least part of the nozzle unit 100, such as the nozzle 110. The illustrated slot 332 and at least one wall 334 of the base 330 are substantially aligned with the chamber 320 of the mouthpiece body 300. The body 300 comprises an opening 314 at the bottom of the base 330. This allows access to the nozzle unit 100 when the nozzle unit 100 and body 300 are connected. FIG. 4 shows a second example of a nozzle unit 400 of an inhaler according to embodiments of the disclosure. The second example of a nozzle unit 400 may comprise some or all of the features of the first example of a nozzle unit 100. The second example of a nozzle unit 400 is configured to be used with the first example of a canister 200 and the first example of a mouthpiece body 300, as is shown in FIGs 5, 6a, 6b, 7 and 8. The nozzle unit 400 has a height, width, and depth. Coordinate axes 50 are illustrated in FIG. 4 that include an x axis, a y axis and a z axis. The x dimension is aligned with the width of the nozzle unit 400, the y dimension is aligned with the depth of the nozzle unit 400, and the z dimension is aligned with the height of the nozzle unit 400. The x, y, and z dimensions are orthogonal to each other. The illustrated nozzle unit 400 is substantially symmetrical. The nozzle unit 400 comprises a nozzle 110, a first connector 120 and a second connector 130. The nozzle 110 comprises a hole 112 for emission of medicant, a recess 416 for receiving the stem 230, an expansion chamber 414 for the medicant, and bottom alcove(s) 415. In the illustrated example, the nozzle 110 comprises two bottom alcoves 415. However, in other examples the the nozzle 110 may comprise only one bottom alcove 415. The first connector 120 is for connecting the nozzle unit 400 to the medicant canister 200. In this example the first connector 120 comprises at least one clip for clipping on to the canister 200; and the first connector 120 forms at least part of a snap-fit connector 120. The first connector 120 may form part of a cantilever snap-fit connection. In some examples the connection of the nozzle unit 400 and canister 200 is a permanent connection, In others the connection is a detachable connection. The illustrated first connector 120 is configured to connect the nozzle unit 400 to a main body 210 of the canister 200. In some examples, the first connector 120 is configured to at least partially surround the main body 210 of the canister 200. In some examples, the first connector 120 comprises a cavity 421 for receiving the main body 210 of the canister 200. The illustrated first connector 120 comprises a platform 422 and at least one wall 423, which at least partially define the cavity 421. The illustrated platform 422 extends substantially horizontally, in the x and y dimensions. The illustrated wall 423 extends substantially vertically, in the z dimension. The illustrated first connector 120 comprises at least one member 424 configured to extend at least partially around the main body 210. In this example, the at least one member 424 comprises at least one arm 424 , which may be resiliently deflectable for connection and disconnection of the nozzle unit 400 to the canister 200. The first connector 120 comprises at least one slot 425 which is substantially aligned with the z dimension. The first connector 120 is configured such that the at least one slot 425 extends at least partially in a direction parallel to the stem 230 when the canister 200 is connected to the nozzle unit 400. This illustrated first connector 120 comprises four arms 424 and slots 425 are positioned between the arms 424. In other examples different numbers of arms 424 are present, such as six arms 424, or eight arms 424. The illustrated arms 424 each comprises a hole / cut out 427 which increases flexibility and decreases weight. The arms 424 extend substantially upward, in the positive z dimension. In some examples, the arms 424 at least partially define the wall 423. The arms 424 may be considered to be clips 424. In some examples, the first connector 120 comprises at least one projection 426 configured to be received by at least one recess 224, 226 of the canister 200. The at least one member 424 comprises the at least one projection 426. In the illustrated example a projection 426 is positioned at or towards the end of each arm 424. The illustrated projections 426 have a substantially trapezoidal prism shape. In other examples the projections 426 may be different shapes, such as a triangular prism, cuboid, or hemi-spherical. The second connector 130 is configured to connect the nozzle unit 400 to the body 300 of the inhaler. In this example the second connector 130 is configured to be received by a slot 332 of the inhaler body 300, and the second connector 130 comprises at least one projection 432 configured to be received by the slot 332 of the inhaler body 300. The illustrated nozzle unit 400 is integrally formed and is a one-piece member. In other example the nozzle unit 400 may comprise a number of separate pieces. The nozzle unit 400 is comprised of any suitable material. For example, a plastic such as high density polyethylene. In some examples, the nozzle unit 400 and / or inhaler body 300 may comprise a plastic with an anti-microbial additive. For example, isothiazolinone, zinc pyrithione, thiabendazole, or silver. FIG. 5 shows a cross-sectional view of the second example of a nozzle unit 400 connected to the first example of a canister 200. Only part of the canister 200 is shown. In this example, to connect the canister 200 and nozzle unit 400: the canister 200 and nozzle unit 400 are pushed together so that the main body 210 of the canister 200 is received by the cavity 421 of the nozzle unit 400, and so that the stem 230 is received by the recess 416 of the nozzle unit 400. As the canister 200 and nozzle unit 400 are pushed together, the at least one arm 424 resiliently deflects and the at least one projection 426 is received by a recess 224, 226 of the main body 210 of the canister 200, securing the canister 200 and nozzle unit 400 together. The at least one arm 424 resiliently deflects in a direction substantially perpendicular to the stem 230 when connected. The stem 230 may be received in the recess 416 of the nozzle unit 400 in a friction fit or a clearance fit. In this example, the at least one projection 426 is received by the lower annular recess 226 of the main body 210 of the canister 200. In other examples the at least one projection 426 is received by the higher annular recess 224 of the main body 210 of the canister 200, or a different recess. In some examples, multiple projections 426 may be received by multiple recesses 224, 226. In some examples, the main body 210 of the canister 200 may comprise at least one projection which is received by at least one a recess of the first connector 120 of the nozzle unit 400. After the canister 200 is received by the nozzle unit 400, they may be pressed together by a user to actuate the inhaler and so to cause the nozzle unit 400 to emit medicant. When the canister 200 is received by the nozzle unit 400, there is a gap 521 between the main body 210 of the canister 200 and the floor I platform 422 of the nozzle unit 400. The gap 521 provides space for the canister 200 to move into when the inhaler is actuated. After actuation the canister 200 will move back to its previous position. In FIG.5 these movements would be parallel to the z dimension. In the example of FIG. 5, the at least one projection 426 is received substantially towards the bottom of the recess 226, in the half of the annular recess 226 closest to the stem 230. This allows for easier actuation of the inhaler, as when the canister 200 and nozzle unit 400 are pressed together, the at least one projection 426 can move upward without the at least one arm 424 needing to be deflected, thus reducing the force needed. This also reduces wear on the at least one arm 424. FIGs 6a and 6b show the second example of a nozzle unit 400 being connected to the first example of the inhaler body 300 to form a first example of an inhaler 600. FIG. 6a shows the inhaler 600 part way through assembly. FIG. 6b shows the assembled inhaler 600. The illustrated inhaler 600 is a metered dose inhaler 600 which comprises the canister 200, the nozzle unit 400 and the body 300. FIGs 6a and 6b illustrate views where portions of the inhaler body 300 have been removed for clarity. In these examples the cap 350 is not present. In the illustrated example, to connect the nozzle unit 400 and inhaler body 300; the nozzle unit 400 and inhaler body 300 are pushed together. This causes the second connector 130 of the nozzle unit 400, and the base I connector 330 of the inhaler body 300 to connect. In FIG. 6a the nozzle unit 400 and inhaler body 300 are pushed together. However they are currently misaligned, such that the slot 332 and projection 432 are not aligned. The projection 432 contacts the at least one wall 334 of the base 330. In this example, the at least one wall 334 is sloped, with a sloped upper edge 225 which slopes downwards, in the negative z direction towards the slot 332. The illustrated wall 334 is sloped on either side of the slot 332. When the projection 432 contacts the sloped upper wall 334, the slope causes it to move I cam down the slope and into the slot 332 where it is received as is seen in FIG. 6b. Therefore, the slot 332, projection 432 and wall 334 are configured to ensure alignment of the nozzle hole 112 and mouthpiece opening 340 so that a spray of medicant can be emitted. This connection is simple and does not require the user to correctly align the slot 332 and projection 432. Instead the nozzle unit 400 and inhaler body 300 self-align. In this example, when the second connector 130 is received by the base 330, the second connector 130 is configured to mate with the body 300 of the inhaler 600. In some examples, the second connector 130 is received by the body 300 in a friction fit, such as a tolerance fit. The first connector 120 and second connector 130 are configured such that a greater force, in a direction parallel to a stem of the canister, is required to disconnect the canister 200 and nozzle unit 100, 400 than is needed to disconnect the body 300 and nozzle unit 100, 400. As such, in some examples the first connector 120 and second connector 130 are configured such that a mechanical connection between the nozzle unit 100, 400 and the canister 200 is stronger than a mechanical connection between the nozzle unit 100, 400 and the body 300. In the illustrated example, the at least one projection 426 and at least one recess 226 that connect the canister 200 and nozzle unit 100, 400, form a stronger mechanical connection than the mating connection (friction fit I tolerance fit) which connects the nozzle unit and inhaler body 300. Embodiments of the disclosure making it easier to disconnect the nozzle unit 100, 400 and body 300, for example by pulling on the canister 200. This helps to prevent the nozzle unit 100, 400 from being stuck inside the inhaler body 300. This could lead to both the nozzle unit 100, 400 and body 300 being thrown away when it is time to replace the nozzle unit 100, 400, increasing waste. This example allows this to be achieved without needing to make any modifications to the canister 200, and without needing to permanently attach the canister 200 and nozzle unit 100, 400. In some example, the nozzle unit 100, 400 and inhaler body 300 can be disconnected without the use of a tool, whilst the nozzle unit 100, 400 and canister 200 cannot be disconnected without the use of a tool. In the illustrated example, the nozzle unit 400 is sized and shaped such that it cannot pass through the mouthpiece opening 340 of the body 300. This improves user safety as it reduces the chance of a user chocking on, or inhaling, the nozzle unit 400. FIG. 7 illustrates a cross-sectional view of the first example of an inhaler 600 according to embodiments of the disclosure. It can be seen that the body 300 is configured so that when the canister 200 and nozzle unit 400 are received in the body chamber 320, the body 300 at least partially surrounds the canister 200 and nozzle unit 400 such that there is not enough space between the body 300 and first connector 120 for the first connector 120 to resiliently deflect to allow disconnection of the nozzle unit 400 and canister 200. In the illustrated example, this is caused by the at least one ridge 312 and main body 310 of the inhaler body 300 making the chamber 320 too small for the at least one arm 424 of the nozzle unit 400 to deflect. This causes the at least one projection 426 to remain within the recess 226 of the canister 200 and so the canister 200 and nozzle unit 400 remain connected. This makes it more difficult for the nozzle unit 400 to become detached from the canister 200 and stuck within the inhaler body 300. FIG. 8 illustrates a view of the first example of an inhaler 600 according to embodiments of the disclosure. In FIG. 8, the nozzle unit 400 has become stuck within the inhaler body 300. In this example the body 300 comprises an opening 314 at the bottom of the base 330. This allows access to the nozzle unit 400 when the nozzle unit 400 and body 300 are connected. An object may be inserted into the opening 314 to push the nozzle unit 400 and so disconnect the nozzle unit 400 and body 300. This may involve the object being received in a bottom alcove 415 of the nozzle unit 400. In the illustrated example, the canister stem 230 is about to be used to disconnect the nozzle unit 400 and body 300. The opening 314 is sized and shaped to allow the canister stem 230 to pass through the opening 314 and so contact the nozzle unit 400. The illustrated opening 314 is similar in size to the canister stem 230. The opening 314 has a diameter which is similar to the diameter of the stem 230. In this example the bottom alcove 415 is sized and shaped to allow the canister stem 230 to be received, and the alcove 416 is also similar in size to the canister stem 230. FIGs 9 and 10 shows a second example of a canister 900 and a third example of a nozzle unit 1000 according to embodiments of the disclosure. FIG. 9 shows the nozzle unit 1000 and canister 900 in a disconnected state. FIG. 10 shows the nozzle unit 1000 and canister 900 in a connected state. FIG. 11 shows a second example of an inhaler 1100 which comprises the second example of a canister 900, the third example of a nozzle unit 1000, and the first example of an inhaler body 300. The second example of a canister 900 may comprise some or all of the features of the first example of a canister 200. The second example of a canister 900 is similar to the first example of a canister 200 with a number of differences. The illustrated canister stem 230 comprises at least one recess 932. The at least one recess 932 of the stem 230 is for receiving corresponding projection(s) 1018 of the nozzle unit 1000 to connect the nozzle unit 1000 and canister 900 together. In this example, the stem 230 comprises an annular recess I ring 932. The annular recess 932 is located in a plane defined by the y and x dimensions. The third example of a nozzle unit 1000 may comprise some or all of the features of the first and second examples of a nozzle unit 100, 400. The third example of a nozzle unit 1000 is similar to the second example of a nozzle unit 400 with a number of differences. The illustrated first connector 120 of the nozzle unit 1000 comprises at least one projection 1018 configured to be received by the corresponding at least one recess 932 of the canister stem 230. The illustrated at least one projection 1018 is located within the recess 416 of the nozzle unit 1000. The illustrated at least one projection 1018 comprises two projections 1018 located at substantially opposite sides of the recess 416. The projections 1018 have a substantially rectangular shape. In other examples, there may be a different number of the projections 1018, and the of the projections 1018 may have different positions and shapes. In some examples, the first connector 120 also comprises at least one resiliently deflectable member 1019. In the illustrated example, one of the projection 1018 is positioned on the at least one resiliently deflectable member 1019. The resiliently deflectable member 1019 can deflect outwards to allow the stem 230 to be received by the nozzle recess 416. Various other examples of means for connection between the canister 200, 900 and nozzle unit 100,400, 1000 fall within the scope of the claims. Some examples of which are set out below. In some example, the stem 230 comprises at least one projection and the nozzle unit 100, 400, 1000 comprises at least one recess for receiving this at least one projection. In some examples, the recess 416 of the nozzle unit 100, 400, 1000 comprises knurls, teeth and / or barbs to aid in retaining the stem 230. In some examples a pin is used to lock the nozzle unit 100, 400, 1000 and canister 200, 900 together. In some examples, the nozzle recess 416 is internally threaded and the stem 230 has a corresponding external thread. In these examples the nozzle unit 100, 400, 1000 and canister 200, 900 are screwed together. In some examples, the nozzle unit 100, 400, 1000 and canister 200, 900 are connected using adhesive. The features described may be operationally coupled and any number or combination of intervening elements can exist (including no intervening elements). Where a structural feature has been described, it may be replaced by means for performing one or more of the functions of the structural feature whether that function or those functions are explicitly or implicitly described. The term ‘comprise’ is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising Y indicates that X may comprise only one Y or may comprise more than one Y. If it is intended to use ‘comprise’ with an exclusive meaning then it will be made clear in the context by referring to “comprising only one...” or by using “consisting”. In this description, the wording ‘connect’, ‘couple’ and ‘communication’ and their derivatives mean operationally connected / coupled / in communication. It should be appreciated that any number or combination of intervening components can exist (including no intervening components), i.e., so as to provide direct or indirect connection / coupling / communication. Any such intervening components can include hardware and / or software components. As used herein, the term "determine / determining" (and grammatical variants thereof) can include, not least: calculating, computing, processing, deriving, measuring, investigating, identifying, looking up (for example, looking up in a table, a database or another data structure), ascertaining and the like. Also, "determining" can include receiving (for example, receiving information), accessing (for example, accessing data in a memory), obtaining and the like. Also, "determine / determining" can include resolving, selecting, choosing, establishing, and the like. In this description, reference has been made to various examples. The description of features or functions in relation to an example indicates that those features or functions are present in that example. The use of the term ‘example’ or ‘for example’ or ‘can’ or ‘may’ in the text denotes, whether explicitly stated or not, that such features or functions are present in at least the described example, whether described as an example or not, and that they can be, but are not necessarily, present in some of or all other examples. Thus ‘example’, ‘for example’, ‘can’ or ‘may’ refers to a particular instance in a class of examples. A property of the instance can be a property of only that instance or a property of the class or a property of a sub-class of the class that includes some but not all of the instances in the class. It is therefore implicitly disclosed that a feature described with reference to one example but not with reference to another example, can where possible be used in that other example as part of a working combination but does not necessarily have to be used in that other example. Although examples have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the claims. Features described in the preceding description may be used in combinations other than the combinations explicitly described above. Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not. Although features have been described with reference to certain examples, those features may also be present in other examples whether described or not. The term ‘a’, ‘an’ or ‘the’ is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising a / an / the Y indicates that X may comprise only one Y or may comprise more than one Y unless the context clearly indicates the contrary. If it is intended to use ‘a’, ‘an’ or ‘the’ with an exclusive meaning then it will be made clear in the context. In some circumstances the use of ‘at least one’ or ‘one or more’ may be used to emphasis an inclusive meaning but the absence of these terms should not be taken to infer any exclusive meaning. The presence of a feature (or combination of features) in a claim is a reference to that feature or (combination of features) itself and also to features that achieve substantially the same technical effect (equivalent features). The equivalent features include, for example, features that are variants and achieve substantially the same result in substantially the same way. The equivalent features include, for example, features that 18 perform substantially the same function, in substantially the same way to achieve substantially the same result. In this description, reference has been made to various examples using adjectives or adjectival phrases to describe characteristics of the examples. Such a description of a characteristic in relation to an example indicates that the characteristic is present in some examples exactly as described and is present in other examples substantially as described. The above description describes some examples of the present disclosure however those of ordinary skill in the art will be aware of possible alternative structures and method features which offer equivalent functionality to the specific examples of such structures and features described herein above and which for the sake of brevity and clarity have been omitted from the above description. Nonetheless, the above description should be read as implicitly including reference to such alternative structures and method features which provide equivalent functionality unless such alternative structures or method features are explicitly excluded in the above description of the examples of the present disclosure. Whilst endeavoring in the foregoing specification to draw attention to those features believed to be of importance it should be understood that the Applicant may seek protection via the claims in respect of any patentable feature or combination of features hereinbefore referred to and / or shown in the drawings whether or not emphasis has been placed thereon. l / we claim:

Claims

1. A nozzle unit for an inhaler, the nozzle unit comprising:a nozzle for dispensing medicant;a first connector for connecting the nozzle unit to a medicant canister; anda second connector for connecting the nozzle unit to a body of the inhaler;wherein the first connector and second connector are configured such that a greater force is required to disconnect the canister and nozzle unit than to disconnect the body and nozzle unit.

2. The nozzle unit of claim 1, wherein the first connector and second connector are configured such that a greater force, in a direction parallel to a stem of the canister, is required to disconnect the canister and nozzle unit than to disconnect the body and nozzle unit.

3. The nozzle unit of claim 1 or 2, wherein the first connector and second connector are configured such that a mechanical connection between the nozzle unit and the canister is stronger than a mechanical connection between the nozzle unit and the body.

4. The nozzle unit of claim 1, 2 or 3, wherein the first connector comprises a clip.

5. The nozzle unit of any of the preceding claims, wherein the first connectorforms at least part of a snap-fit connector.

6. The nozzle unit of any of the preceding claims, wherein the first connector comprises at least one projection configured to be received by at least one recess of the canister.

7. The nozzle unit of any of the preceding claims wherein the first connector is configured to connect to a main body of the canister.

8. The nozzle unit of claim 7, when dependent on claim 6, wherein the first connector is configured so that the at least one projection is received by an annular recess of the main body of the canister.

9. The nozzle unit of claim 8, wherein the annular recess is perpendicular to the stem of the canister, and wherein the first connector is configured so that the at least one projection is received substantially in the half of the annular recess closest to the stem.

10. The nozzle unit of claims 7 to 9, wherein the first connector is configured to atleast partially surround the main body of the canister.

11. The nozzle unit of claims 7 to 10, wherein the first connector comprises at least one member configured to extend at least partially around the main body of the canister, wherein the at least one member comprises the at least one projection.

12. The nozzle unit of claim 11, wherein the at least one member comprises at least one arm, wherein the at least one arm is resiliently deflectable for connection and disconnection of the nozzle unit to the canister.

13. The nozzle unit of any of the preceding claims, wherein the first connectorcomprises at least one slot, and wherein the first connector is configured such that the at least one slot extends at least partially in a direction parallel to the stem when the canister is connected to the nozzle unit.

14. The nozzle unit of any of the preceding claims, wherein the second connector is configured to be received by a slot of the inhaler body.

15. The nozzle unit of claim 14, wherein the second connector comprises at least one projection configured to be received by the slot of the inhaler body.

16. The nozzle unit of any of the preceding claims, wherein the second connector is configured to mate with the body.

17. The nozzle unit of any of the preceding claims, wherein the second connector is configured to be received by the body in a tolerance fit.

18. The nozzle unit of any of the preceding claims, wherein the nozzle unit is sized and shaped such that it cannot pass through a mouthpiece opening of the body.

19. An inhaler for dispensing a medicant, the inhaler comprising:the nozzle unit of any of claims 1 to 18; andthe body;wherein the body defines a chamber for receiving the nozzle unit and the canister, and wherein the body comprises a mouthpiece opening.

20. The inhaler of claim 19, wherein the body comprises a base which comprises a slot and at least one wall, and wherein the base comprises a cavity for receiving the nozzle.

21. The inhaler of claim 20, wherein the at least one wall is sloped.

22. The inhaler of claims 19 to 21, wherein the body is configured such that whenthe canister and nozzle unit are received in the chamber, the body at least partially surrounds the canister and nozzle unit such that there is not enough space between the body and first connector for the first connector to resiliently deflect to allow disconnection of the nozzle unit and canister.

23. The inhaler of claims 19 to 22, wherein the body comprises an opening at the bottom of the base, which allows access to the nozzle unit when the nozzle unit and body are connected.

24. The inhaler of claims 19 to 23, wherein the inhaler is metered dose inhaler, and the inhaler further comprises the canister.

25. An inhaler for dispensing a medicant, the inhaler comprising:a nozzle unit; anda body;wherein the body defines a chamber for receiving the nozzle unit and the canister, and wherein the body comprises the mouthpiece opening;wherein the nozzle unit comprises: a nozzle for dispensing medicant; and a5 connector for detachably connecting the nozzle unit to a body of the inhaler; andwherein the nozzle unit is sized and shaped such that it cannot pass though mouthpiece opening.

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