Patent Publication Number: US-10786637-B2

Title: Delivery devices

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Great Britain Patent Application Nos. 1112030.0, filed Jul. 13, 2011 and 1112667.9, filed Jul. 22, 2011, each incorporated herein in its entirety. 
     TECHNICAL FIELD 
     This invention relates to delivery devices, and in particular delivery devices in which a container is provided within a chamber, and gas flow through the chamber causes powder to be dispensed from the container. 
     Administration of powdered medicaments by inhalation is frequently carried out with dry powder delivery devices (DPIs). In conventional DPIs, the powdered medicament is held in either manually-loaded single-dose capsules or blisters, which must be pierced, punctured or opened to release the dose, or a large multi-dose powder reservoir within the device from which medicament is dispensed by manually actuating a dosing and dispensing mechanism. 
     WO 98/26828 and WO 03/051439 disclose several delivery devices for use with medicament containers that have openings through which medicament is dispensed within the delivery device. The delivery devices all comprise a mouthpiece in fluid communication with a chamber, in which the medicament container is located. The chamber itself is in direct fluid communication with the exterior of the device via air inlet means. In use, air is drawn into the chamber through the air inlet means, which generates motion of the medicament container in the chamber, causing medicament to be dispensed from the container and entrained within the air flow, such that the airflow with entrained medicament is inhaled through the mouthpiece. The disclosed delivery devices include single-use devices pre-loaded with a medicament container and multi-use devices in which medicament containers may be inserted into the chamber before or between uses. 
     The delivery devices disclosed in WO 98/26828 and WO 03/051439 represent a considerable advance over the prior art, but may nonetheless be further improved. 
     SUMMARY 
     There has now been devised an improved delivery device that overcomes or substantially mitigates the above mentioned and/or other disadvantages associated with the prior art. 
     According to the first aspect of the invention, there is provided a delivery device comprising a container containing a dose of greater than 40 mg of a powder and having at least one exit orifice for dispensing the dose from the container, and a chamber adapted to receive the container in an operative configuration, the delivery device further comprising at least one gas inlet by which gas may enter the chamber and at least one gas outlet by which gas and entrained powder may exit the chamber, wherein the delivery device is operable to generate a gas flow through the chamber between the at least one gas inlet and the at least one gas outlet, which brings about orbital motion of the container within the chamber in that at least a central region of the container orbits a central axis of the chamber. 
     According to the further aspect of the invention, there is provided a container containing a dose of greater than 40 mg of a powder, and having at least one integrally formed or preformed exit orifice for dispensing the powder, the container being adapted to be received within a chamber of a delivery device that comprises at least one gas inlet by which gas may enter the chamber and at least one gas outlet by which gas and entrained powder may exit the chamber. 
     The delivery device and container according to this invention are advantageous principally because the container contains a dose of over 40 mg of a powder, which may be inhaled by the patient, without many of the disadvantages of the prior art. In particular, the present invention enables an arrangement for administering a dose of greater than 40 mg of a powder, without the need for repeated reloading or reactuation of the delivery device between inhalations, which can be inconvenient and time consuming. 
     The delivery device of this invention may be used for the delivery of any powder that is suitable for delivery by inhalation. It has been found that amounts of powder over 40 mg can be effectively administered from a single container by repeated inhalations, without the need to manipulate the delivery device between inhalations, for example by reloading or reactuation of the delivery device. In particular, the delivery device of this invention may include a container containing a dose of at least 60 mg, at least 80 mg, at least 100 mg, at least 200 mg, at least 300 mg, at least 400 mg, at least 600 mg or at least 800 mg of powder. 
     The delivery device of this invention may be used for the delivery of any powder that is suitable for oral delivery. In particular, the device may be used to administer powdered medicaments, such as antimicrobial agents including antibiotics and antifungals for the treatment of infections, and bronchodilators including salbutamol or formoterol for the treatment of asthma or chronic obstructive pulmonary disorder. The device is also suitable for administering other substances that are in the powder form, such as radioactive markers, vaccines, proteins such as insulin for the treatment of diabetes, or antibodies. The device is particularly suitable for administering osmotic agents such as mannitol for the treatment of cystic fibrosis. 
     The device may be used to administer powders consisting of one or more powdered medicaments only, or comprising powdered medicament and a powdered carrier. Carriers are generally added to powdered medicament formulations to improve their handling characteristics or act as a bulking agent, and generally do not have a medical effect. Powder formulations administered by the device may comprise any desired ratio of medicament and carrier, such as 30%, 20% or 10% w/w of powdered medicament. However, powder formulations that include a carrier typically comprise less than 5%, less than 4%, less than 3%, less than 2%, less than 1%, less than 0.5% or less than 0.2% w/w of powdered medicament, with the remainder of the formulation being made up of carrier. 
     The device may be used to administer powders that are present in a range of particle sizes. Powders that are intended to reach the lung are preferably present in respirable particle size, i.e. particle sizes that tend not to be deposited in the mouth and throat and pass into the lung. Reparable particle size is generally considered to be below 10 μm, although particles sizes below 6 μm and particularly below 5 μm are particularly effective at reaching the lung. However, particles below 1 μm in size may not be deposited effectively in the lung and be exhaled. Alternatively, particles may be present in non-respirable particle size, which tend not to reach the lung and are instead deposited in the mouth and throat. Non-respirable particle size is generally considered to be greater than 10 μm, more usually greater than 40 μm and generally around 50 μm. 
     The powders administered by the delivery device of this invention may comprise a range of particle sizes, for example comprising a combination of particles of respirable and non-respirable particle sizes. For example, the device may be used to administer powder comprising a medicament that is substantially present in respirable particle size and a carrier that is substantially present in non-respirable particle size, although carrier may also be present in respirable particles size. The powder is preferably entirely of respirable particle size, particularly where larger doses are administered, in order to avoid inducing a cough response because of powder deposition in the throat. 
     In presently preferred embodiments, the delivery device includes a container containing a dose of greater than 40 mg, or at least 60 mg, at least 80 mg, at least 100 mg, at least 200 mg, at least 300 mg, at least 400 mg, at least 600 mg or at least 800 mg of respirable particles. 
     The container is preferably not completely filled with a powder, such that the powder may move within the container during use. In particular, the container preferably includes a headspace that allows the powder to flow and tumble within the container, facilitating emission of the powder from the at least one exit orifice. For example, headspace preferably accounts for at least 5% of the internal volume of the container. In presently preferred embodiments, however, the headspace accounts for between 20% and 40% of the internal volume of the container. However, effective levels of powder emission may still be achieved where no headspace is present, particularly where the powder is uncompacted within the container. 
     The container is preferably adapted to restrict the emission of powder from the container, such that powder is emitted from the container steadily as it is undergoing motion. This is advantageous over conventional delivery devices, in which the entire powder dose is typically dispensed as soon as the patient starts to inhale, principally because steady powder emission is less likely to induce a cough response. It may therefore be possible to deliver a greater quantity of powder in each inhalation relative to conventional delivery devices. 
     The restriction of powder emission from the container may be achieved by the one or more exit orifices being of a relatively small size. The specific size of the one or more exit orifices may be selected to provide a pre-determined rate of powder emission from the container, which may depend on the flow properties of the particular powder. Where the motion of the container is brought about by the gas flow generated by the inhalation of a patient, the emission rate is preferably such that powder is steadily emitted from the container, e.g. at a substantially uniform rate, during the majority of the inhalation, and most preferably during substantially the entire inhalation. The one or more exit orifices preferably have a combined cross-sectional area of less than 1 mm 2 , more preferably less than 0.5 mm 2 , and most preferably less than 0.3 mm 2 . 
     The restriction of powder emission from the container may be achieved by other means, such as restricting the motion of the powder within the container with one or more formations on the interior of the container. Therefore, according to a further aspect of the invention, there is provided a container for containing a dose of a powder having at least one exit orifice for dispensing the powder, the container being adapted to be received within a chamber of a delivery device that comprises at least one gas inlet by which gas may enter the chamber and at least one gas outlet by which gas and entrained powder may exit the chamber, wherein the container comprises one or more internal formations for restricting the motion of powder within the container. 
     These one or more formations may sufficiently restrict powder emission from the container alone such that there is no need for the exit orifices to be of a relatively small size. The one or more formations may take any suitable form but are preferably projections projecting from the internal wall of the container into the interior of the container, such as walls or baffles. The one or more formations preferably partially divide the internal volume of the container into a number of sub-chambers with the passage of powder between each sub-chamber being permitted through gaps or openings in or between the one or more formations. In particularly preferred embodiments, the sub-chamber or chambers in which the one or more exit orifices are located are separate from the sub-chamber or chambers that initially contain the majority of the powder. 
     In addition, the container may be provided with one or more formations on its exterior surface for increasing gas flow resistance. Therefore, according to yet a further aspect of the invention, there is provided a container for containing a dose of a powder having at least one exit orifice for dispensing the powder, the container being adapted to be received within a chamber of a delivery device that comprises at least one gas inlet by which gas may enter the chamber and at least one gas outlet by which gas and entrained powder may exit the chamber, wherein the container comprises one or more external formations for increasing gas flow coupling. 
     Increased coupling between the gas flow and the container may improve the efficiency of the device and/or influence the motion of the container by increasing the friction between the gas flow and the container. These one or more formations are preferably located on the circumferential wall of the container, which is where the gas flow may apply the greatest rotational force to the container. The formations preferably do not project substantially beyond the circumferential surface of the container such that they do not substantially interfere with the motion of the container. The one or more formations preferably comprise a textured surface and most preferably a series or grooves and/or ridges. In one particularly preferred embodiment, the circumferential wall of the container is provided with a series of grooves and ridges that are aligned perpendicularly to the direction of the gas flow. 
     The delivery device of the type disclosed in WO 98/26828 is particularly suitable for use in the present invention. 
     This gas flow through the chamber between the at least one gas inlet and the at least one gas outlet may be generated by any suitable means, but is generally generated by a patient inhaling through the delivery device. Alternatively, or in addition to inhalation, gas flow may be generated from a pressurised source of gas. Furthermore, the device may form a component of a breathing circuit or the like, in which case gas flow through the device may be generated by the gas flow through the breathing circuit. The motion of the container within the chamber preferably causes powder to be emitted from the at least one exit orifice in the container, become entrained in the gas flow through the chamber, and exit the chamber through the at least one gas outlet. 
     The container preferably travels circumferentially around a central axis of the chamber, with the container substantially remaining in contact with a circumferential wall of the chamber. One particular benefit of this form of motion is the milling of the powder between the container and the circular wall of the chamber once it is emitted from the container, which enhances deagglomeration of the powder. 
     The orientation of the container may remain substantially constant relative to the central axis of the chamber during orbital motion. 
     The orbital motion is preferably such that all parts of the container undergo orbital motion. The container may also undergo rotational motion, in which the container rotates substantially about its own central axis. Rotational motion of the container may occur concurrently with orbital motion, in which case the container may rotate in rolling contact with a circumferential wall of the chamber in a substantially epicyclic fashion as at least a central region of the container orbits a central axis of the chamber. It has been found that epicyclic motion of the container results in efficient powder emission. The container may also, or instead, rotate in the opposite direction, ie in non-rolling contact with the circular wall of the chamber, whereby the container substantially skids against the chamber wall. 
     Motion of the container may include both epicyclic and skidding motion as the container may not couple effectively with the wall of the chamber as it orbits. The balance between epicyclic and skidding motion is influenced by the relative dimensions of the container and the chamber, and dimensions that favour epicyclic motion over skidding motion are generally preferred as this form of motion gives the most efficient powder emission from the container. However, dimensions that favour skidding motion may be appropriate where a relatively low level of powder emission is desired. 
     The container and chamber may have any overall shape that allows the container to undergo motion suitable to cause powder emission from the one or more exit orifices. However, the container and chamber preferably have substantially circular cross-sections, which have been found to be effective in permitting rotational and orbital motion of the container. 
     The ratio between the container diameter and the chamber diameter has been found to influence the balance between epicyclic and skidding motion. In the case of cross-sectional shapes that are irregular or have non-uniform diameters, the diameter may be considered to be the mean distance of the exterior surface of the container from the centre of mass of the container in a particular plane, such as in the plane in which container moves. However, the container and chamber preferably have an essentially circular cross-section, ie cross-sections with an essentially uniform diameter, which has been found to be particularly effective in permitting rotational and orbital motion of the container. 
     In preferred embodiments, the chamber is generally cylindrical, and preferably has a diameter greater than its height. The upper and lower end walls of the cylinder may be substantially flat, or one or both end walls may be either convex or concave. 
     The device may include formations for restricting the motion of the container within the chamber. For example, the chamber and/or the container may comprise formations that retain the container on its own axis, thereby preventing orbital motion of the container while allowing rotational motion. This may improve the efficiency of the device in bringing about rotation of the container as gas flow within the chamber is not used to push the container on an orbital path around the chamber. These formations may comprise a spindle to which the container is mounted, or projections or recesses located on the end walls of the container that engage with complementary projections or recesses located on the end walls of the chamber, which retain the container substantially on its central axis and allow rotation of the container about that axis. 
     The at least one gas inlet of the device is preferably arranged such that gas enters the chamber substantially tangentially, for example so as to generate a turbulent rotating body of gas in the chamber, which facilitates the orbital motion of the container within the chamber. There are preferably provided a plurality of gas inlets, most preferably opening into the chamber at substantially equiangularly spaced positions. The gas inlets may include narrowed portions to act as venturi and thereby increase the speed of the gas flow into the chamber. 
     It is particularly preferred that a part of the wall of the chamber into which the gas inlets open should be continuous and unbroken in order to inhibit any tendency for the movement of the container to be affected by the edges of the gas inlet openings. In preferred embodiments, the gas inlets open into the circumferential wall of the chamber, but have a depth which is less than the height of that wall so at least part of the wall, such as the lower and/or upper part of that wall, forms an uninterrupted annular surface. 
     The at least one gas outlet may take any suitable form provided that, in use, it retains the container within the chamber whilst permitting gas and entrained powder to pass out of the chamber. In preferred embodiments, the gas outlet means comprises a mesh or grid formed in part of the chamber wall. Most preferably, the mesh or grid lies in a plane substantially parallel to the plane in which container moves. For example, where the chamber is substantially drum shaped, the mesh or grid may be formed in the end walls of the chamber. 
     In particularly preferred embodiments, the grid or mesh should extend over only part of the lower wall of the chamber, most preferably the central part of the upper or lower wall. The radial outer part of the upper or lower wall is therefore preferably solid, which facilitates the generation of a turbulent rotating body of gas around the circumferential edge of the chamber and increases the residency time of the gas and entrained powder in the chamber, which enhances milling of the powder between the container and chamber wall, improving powder deagglomeration. Most preferably, the solid outer part of the upper or lower wall forms an annulus having a width corresponding to at least 15% of the radius of that wall, more preferably at least 20%. 
     Gas and entrained powder may exit the device by any suitable means but preferably exit the device via a suitable opening. The device is most commonly intended to administer a powder directly to a patient by oral inhalation, in which case the opening may comprise a mouthpiece for engagement with the mouth of a patient. However, administration may be by any other suitable means and, in particular, may be by nasal inhalation, in which case the opening may comprise a nosepiece for engagement with the nose of a patient. Administration may also be through a breathing circuit or the like, in which case the opening may comprise a means for connecting the device with such a circuit. The opening is preferably formed at the open end of a passageway or conduit which communicates with the chamber via the at least one gas outlet. A particularly preferred arrangement is provided if the passageway or conduit is oriented parallel to the axis of rotation of the container in the chamber, but in other embodiments the passageway or conduit may be oriented substantially orthogonally to that axis. 
     The device may be manufactured from materials conventionally utilised in devices for orally administering powders. For example, the device may be manufactured from a plastics material such as acrylonitrile butadiene styrene (ABS), polycarbonate, a polyolefin such as polypropylene or polyethylene, or any other suitable plastics material. Other suitable materials include metals such as aluminium and stainless steel. Combinations of different materials may be used, with each component being formed from the most suitable material or materials. 
     Embodiments of the device may be configured for repeated use. In such cases, means are provided for introducing a container into the chamber before each use and removing the container after use. For example, the chamber may be provided with a removable cover, which may have a snap fit or hinged connection to the rest of the device such that it can be opened to insert a container into the chamber, closed during use of the device and then opened again for removal of the spent container. However, in preferred embodiments, the device is for single use, in which case the device may be supplied pre-loaded with a container. 
     The device and the container may include substantially transparent portions to allow the patient to view the interior of the container to see how much powder remains. The substantially transparent portions may be formed of any suitable materials, but are preferably formed of polycarbonate or acrylic. The interior surface of the container behind the substantially transparent portion may have colour that contrasts with the colour of the powder to give a clearer indication of when the container is empty. A lens may also be integrated into the substantially transparent portion of the device to enhance visibility. 
     Whilst the delivery device is intended primarily for use in which inhalation by the patient leads to the necessary motion of the container and emission of the powder from the container, a source of pressurised air or other gas may be used to produce or assist in bringing about motion of the container. This arrangement is particularly preferable where the mass of the container is too great to be effectively driven by the gas flow generated by a patient. For example, the delivery device may include a source of compressed gas, which facilitates dispensing of the powered formulation to the patient, via a spacer chamber. The delivery device may also be intended for engagement with a ventilator system, in which case the motion of the container may be brought about by the gas flow through the ventilator system. 
     In preferred embodiments, the container is generally cylindrical, and preferably has a diameter greater than its height. This arrangement facilitates manufacture and charging of the container with the powder. In addition, this arrangement may be adapted to maintain the container in an upright orientation relative to the chamber. 
     The upper and lower end walls of the cylinder may be substantially flat, or one or both end walls may be either convex or concave. However, the upper and lower end walls of the container are preferably convex to reduce the contact area between the container and the chamber, thereby reducing friction between the components as the container undergoes motion. In addition, it is particularly preferable that the surface of the container that is adjacent to the mesh or grid is convex to prevent the container lying flat on the grid or mesh, which could lead to the container being immobilised on the grid or mesh by suction. 
     In other embodiments, the container may be substantially spherical in order to reduce the amount of material required to construct the container, and hence reduce the weight of the container. 
     The container may have any suitable construction, but is preferably formed of a number of cooperating components. Most preferably, the container is formed from two cooperating components fastened together by any suitable means, such as by snap fit, screw fit, bayonet or ultrasonic welding. The container may also be formed as a single component with the two cooperating components being connected by a hinge. The container preferably comprises a cup component and a lid component, where the lid component is engageable with the cup component, and the cup component and a lid component define the internal volume of the container. In a preferred embodiment, the cup component is of generally cylindrical construction, open at one end, and a lid component fastens over the open end of the cup, thereby completing the cylindrical container. The preferred fastening means in this embodiment is a snap fit, either circumferentially or by means of a central pin. 
     In the cup and lid embodiment, the cup component is preferably adapted to receive the dose of powder during manufacture, prior to engagement of the lid component with the cup component to form the assembled container. The cup component may be formed with a greater internal volume than is occupied by the dose of powder, in order to reduce the risk of powder being spilt during filling. In this arrangement, at least, the cup component preferably has a greater internal volume than the lid component. 
     The container may have only a single compartment in which powder is contained. The container may also comprise two or more compartments, particularly where two or more different powders are to be administered as each powder may be contained in a separate compartment, although the same powder may be contained in each compartment. Where multiple compartments are present, each compartment preferably has at least one exit orifice. 
     The one or more exit orifices in the container may be formed in one or both of the components or may alternatively be defined between the two components. The at least one exit orifice may be preformed in the container, in that the at least one exit orifice is created in the container prior to its introduction into the delivery device. Most preferably, however, the at least one exit orifice is integrally formed with the container, in that the at least one exit orifice is created in one or more components of the container during their manufacture. For example, the at least one exit orifice may be formed during the moulding of one or more components of the container. In this arrangement, the at least one exit orifice is preferably closed by a closure member before the container is brought into an operative configuration. 
     The at least one exit orifice may be positioned on a part of the container that is furthermost from the axis of orbital motions and/or the axis of rotational motion of the container, during use. In addition, or alternatively, the at least one exit orifice may be positioned on a surface of the container that faces substantially outwardly relative to the axis of orbital motions and/or the axis of rotational motion of the container, during use. Most preferably, a plurality of exit orifices is provided, for example two exit orifices. The exit orifices may advantageously be disposed around the circumference of the cylindrical container, preferably at substantially equiangularly spaced locations. 
     The container may be formed from any suitable material or combination of materials with the most preferred materials being relatively lightweight, to reduce the gas flow required to move the container, and sufficiently resilient to withstand relatively high rotational speeds of the container within the chamber. The container is preferably moulded from plastic materials such as acrylonitrile butadiene styrene (ABS), polycarbonate, a polyolefin such as polypropylene or polyethylene, and others. 
     The container may include a non-solid component, such as a component formed of a sheet material such as metal foil or plastic film. Such components may be fastened to other components of the container by any suitable means, such as with adhesives, heat sealing or ultrasonic welding. In one particular embodiment of a container comprising a component formed of a sheet material, the container comprises a solid cup moulded from plastics material and a lid formed of a sheet material which seals the open end of the cup component. 
     The preferred materials for forming the container may be substantially impermeable to moisture, in order to protect the powder from being spoiled by moisture when the one or more openings are sealed. This may reduce or eliminate the need for secondary packaging, thus reducing the complexity of the manufacturing operation and also simplifying use of the device. In general, materials with lower moisture permeability are preferred as a lower thickness is required to provide an effective moisture barrier, leading to a reduction in weight and hence to a reduction in the gas flow necessary to cause the container to move. However, the container or system may be provided in a moisture proof packet, thereby making it unnecessary for the container to be substantially impermeable to moisture. 
     The volume occupied by the container is preferably at least 25% of the volume of the chamber. This has been found to restrict the free volume within the container and consequently increase the velocity of the gas flow in the chamber, resulting in improved powder emission from the container, and increased particle collisions. This arrangement may also increase the degree of milling of the powder between the container and the chamber wall, during use, which may result in improved deagglomeration. It is believed that the container occupying at least 25% of the volume of the chamber is particularly advantageous over the prior art, although more preferably the container occupies at least 35% of the volume of the container. Furthermore, arrangements in which the container occupies between 50% and 72% and more particularly between 55% and 65% of the volume of the container have been found to be particularly advantageous. 
     It is believed that the diameter of the container being at least 50%, and more preferably at least 60%, of the diameter of the chamber promotes epicyclic motion of the container. Furthermore, arrangements in which the diameter of the container is between 70% and 85%, or more particularly between 75% and 80%, of the diameter of the chamber have been found to be particularly effective in promoting epicyclic motion of the container. In one particularly preferred embodiment, which has been found to promote epicyclic motion, the container has a diameter of 18 mm and the chamber has a diameter of between 22 mm and 24 mm, most preferably 23 mm. 
     The diameters of the container and the chamber are preferably chosen to provide sufficient clearance between the container and the chamber to allow sufficient motion of the container to bring about the desired level of powder emission from the at least one exit orifice. The minimum effective clearance depends on the desired powder emission rate and flow properties of the powder, but the diameter of the container must be less than the diameter of the chamber and in general is no greater than 99% or no greater than 95% of the diameter of the chamber. 
     In a presently preferred embodiment, the delivery device has a pre-use configuration in which the container is accommodated, at least partially, within a storage enclosure in a wall of the chamber, the delivery device having a deployment member adapted to put the delivery device in an operative configuration by displacing the container from the storage enclosure into the chamber, such that the container is movable within the chamber, in use, the deployment member being adapted to at least partially occupy the storage enclosure in the operative configuration. 
     The storage enclosure is preferably adapted to retain the container at least partially therein, in the pre-use configuration, such that the one or more exit orifices of the container are sealed. In particular, the exit orifices are preferably sealed to a sufficient extent that the powder is retained within the container in the pre-use configuration. 
     The container is preferably retained within the storage enclosure by means of an interference fit between the container, and an interior surface of the storage enclosure. However, alternative, or indeed additional, retaining formations may be provided. In preferred embodiments, the container is retained in a manner that prevents the container being inadvertently dislodged from the storage enclosure during normal handling, in the pre-use configuration. In presently preferred embodiments, the interference fit between the container, and an interior surface of the storage enclosure, acts to seal the one or more exit orifices of the container. 
     The delivery device is preferably adapted to prevent the ingress of moisture into the container. Where the delivery device is a single-use device, this may be achieved by supplying the delivery device in packaging formed of a material with a low moisture vapour transmission rate, such as a sealed foil packet, which is opened by the patient before use. In this case there is no need for the container to be substantially impermeable to moisture. 
     Alternatively, where the delivery device is a multi-use device and therefore cannot be sealed in moisture impermeable packaging before each use, the delivery device itself is preferably arranged to prevent unacceptable ingress of moisture into the container, for example to prevent spoiling of the powder within the container before use. In particular, where the container includes one or more exit orifices, and these one or more exit orifices are sealed until the device is used, which may be achieved by the fit between the container and an interior surface of the storage enclosure, this seal is preferably sufficient to prevent the ingress of an unacceptable amount of moisture into the container. The moisture resistance of the container may also be improved by spray-coating the surface of the container with a moisture resistant material, which is particularly preferable where the material of the container has a relatively high MVTR. 
     The container and/or the interior surface of the storage enclosure are preferably relatively compliant to improve the seal between these surfaces. In addition, the container and recess are preferably formed of materials with a low moisture vapour transmission rate. The desired compliance of the container and/or the interior of the storage enclosure may be achieved by these components having movable portions, and preferably resiliently movable portions, eg formed by a hinged arrangement. In particular, the compliance of the interior surface of the storage enclosure that engages the container may be increased by the presence of a groove that circumscribes the storage enclosure opening, and defines an inner wall located between the groove and the storage enclosure opening, which is deformable outwardly, preferably resiliently, to accommodate the container. 
     Alternatively, the container and/or the storage enclosure may include a compliant member formed of a less rigid material than the remained of the component, such as an elastomeric material. In particular, the portion of the interior surface of the storage enclosure that engages the container may be provided with a compliant member formed of silicone or thermoplastic elastomer (TPE). The compliant member may be formed in a two-step injection moulding process, in which the components forming the storage enclosure are moulded in the first step and the compliant member is moulded onto one or more of those components in the second step. Alternatively, the compliant member may be bonded to the interior surface of the storage enclosure by other means, such as with an adhesive or by heat welding. The compliant member could instead, or in addition, be provided on the corresponding portion of the exterior surface of the container. 
     The compliant member may compensate for dimensional variations in components commonly encountered in high volume manufacturing. In particular, relatively large dimensional variations in the components may affect the interference fit between the container and an interior surface of the storage enclosure, either allowing the container to become dislodged from the storage enclosure or conversely resulting in the force required to overcome the interference fit being increased to undesirable levels. Increasing the compliance of the container and/or the interior of the storage enclosure may compensate for greater dimensional variation in the components and ensure that an effective fit is maintained. In particular, where a particularly high level of compliance is required, the storage enclosure may comprise a compliant member that includes a particularly compliant formation, such as a lip seal. 
     The deployment member is preferably movably mounted relative to the chamber, such that the deployment member displaces the container from the storage enclosure on movement from a pre-use position to an operative position. The deployment member preferably contacts the container, and urges the container from the storage enclosure, on movement of the deployment member from the pre-use position to the operative position. The deployment member may be moved manually by the user, or may be moved by a deployment mechanism that is activated by the user. 
     At least an end portion of the deployment member is preferably movable within a side wall of the storage enclosure, which may have the form of a sleeve, such that movement of the deployment member from a pre-use position to an operative position displaces the container from the storage enclosure. In presently preferred embodiments, the deployment member defines a wall of the storage enclosure in the pre-use configuration. In particular, the deployment member preferably defines an end wall of the storage enclosure. 
     The deployment member may be movably mounted relative to the chamber in any suitable manner. In presently preferred embodiments, the deployment member is slidably mounted relative to the chamber, for example within a sleeve that defines a side wall of the storage enclosure. However, the deployment member could be moved by operation of a threaded connection, for example within a sleeve that defines a side wall of the storage enclosure. 
     The deployment member is preferably retained in a pre-use position by retaining formations, which are preferably adapted to maintain the deployment member in the pre-use position during normal handling. These retaining formations are preferably adapted to be overcome by a user purposively moving the deployment member into an operative position. The retaining formations preferably have the form of a cooperating projection and recess, which are engaged in the pre-use configuration with a snap fit. The retaining formations may be adapted to enable movement of the deployment member into an operative position, but prevent other movement, such as removal of the deployment member from the delivery device, without damaging the delivery device. 
     The deployment member is preferably movable towards a mouth of the storage enclosure, through which the container is released into the chamber. The storage enclosure preferably reduces in volume as the deployment member is moved from a pre-use position to an operative position, until at least the container is displaced into the chamber, and hence the deployment member at least partially occupies the storage enclosure. 
     In the operative configuration, the storage enclosure is preferably reduced sufficiently in volume that the gas flow within the chamber, in use, is not adversely affected by the presence of the storage enclosure. The storage enclosure is preferably reduced in volume by at least 30%, more preferably by at least 50%, and most preferably by at least 70%. In presently preferred embodiments, however, the storage enclosure is preferably substantially removed from the wall of the chamber by means of the deployment member being accommodated within a mouth of the storage enclosure, preferably such that the deployment member provides a surface of the chamber that is substantially flush with the adjacent surfaces of the wall of the chamber. 
     The deployment member is preferably retained in its operative position, during use. In particular, the deployment member may be retained by means of the engagement between the deployment member and the wall defining the storage enclosure, for example by an interference fit or a threaded connection. However, in addition, the deployment member is preferably adapted to be retained in its operative position either permanently, for example in a single-use device, or until actuation of an indexing mechanism of the delivery device. 
     The deployment member is preferably retained in the operative position by retaining formations. In presently preferred embodiments, the deployment member is retained by a wall defining the storage enclosure, in the operative position, by cooperating retaining formations. The retaining formations preferably have the form of a cooperating projection and recess, which are engaged in the operative configuration with a snap fit. Where the delivery device is a single-use, disposable device, the retaining formations may be adapted to prevent further movement of the deployment member, without damaging the delivery device. 
     In a presently preferred embodiment, the deployment member defines at least part of an inhalation passageway of the delivery device, through which gas and entrained powder exit the device. The deployment member may comprise a wall that forms part of the wall of the chamber, in the operative configuration, and in which one or more of the gas outlets are formed, such that gas and entrained powder flow through that wall, in use. Where the chamber has the shape of a drum, the deployment member preferably comprises a wall that forms part of an end wall of the chamber. The deployment member may define an inhalation passageway that extends from the wall in which the one or more of the gas outlets are formed. The deployment member may also define the opening through which gas and entrained powder are withdrawn from the device in use, and may comprise as a mouthpiece, nosepiece or a means for engaging the device with a breathing circuit or the like. This arrangement is particularly advantageous in that it reduces the number of components required to provide the delivery device. 
     In this embodiment, the deployment member is preferably moveably mounted within a sleeve that extends from an exterior surface of a wall of the chamber. A seal is preferably formed between the exterior surface of the deployment member and the interior surface of the sleeve, such that gas and entrained powder does not leak between these surfaces. This seal may take the form of any suitable sealing arrangement, such as integral sealing ridges on one of the surfaces, such as radiused sealing ridges. 
     Where the deployment member is moveably mounted within a sleeve, the deployment member may be received within the sleeve to a greater extent in the operative position, relative to the pre-use position. The deployment member may therefore include indications that are visible in the pre-use configuration, and hidden in the operative configuration, for example by the sleeve, in order to indicate the status of the delivery device. Other embodiments may include different indications of the status of the delivery device. 
     The storage chamber and the container may form an integral part of the delivery device. In particular, the delivery device may be a single-use, disposable delivery device, or may be a multi-dose delivery device, in which one or more containers are retained within the delivery device until use. Alternatively, the storage enclosure and the container may form a package, which is engageable with the delivery device prior to use. This arrangement enables packages to be supplied to a user, for use with a reusable delivery device. In this arrangement, the delivery device may not retain any containers prior to use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A preferred embodiment of the invention will now be described in greater detail, by way of illustration only, with reference to the accompanying drawings, in which 
         FIG. 1  is a side view of a delivery device according to the invention; 
         FIG. 2  is a cross-sectional view of the delivery device, along the line II-II in  FIG. 1 ; 
         FIG. 3  is a side view of the delivery device in its operative configuration; 
         FIG. 4  is a cross-sectional view of the delivery device in its operative configuration, along the line IV-IV in  FIG. 3 ; 
         FIG. 5  is a first exploded view of the delivery device; 
         FIG. 6  is a second exploded view of the delivery device; 
         FIG. 7  is a side view of a body, which forms part of the delivery device; 
         FIG. 8  is a plan view of the body; 
         FIG. 9  is a cross-sectional view of the body; 
         FIG. 10  is a side view of a cap, which forms part of the delivery device; 
         FIG. 11  is an underside view of the cap; 
         FIG. 12  is a cross-sectional view of the cap; 
         FIG. 13  is a side view of a mouthpiece, which forms part of the delivery device; 
         FIG. 14  is a plan view of the mouthpiece; 
         FIG. 15  is a cross-sectional view of the mouthpiece, along the line XXV-XXV in  FIG. 13 ; 
         FIG. 16  is a cross-sectional view of a second embodiment of a delivery device according to this invention; 
         FIG. 17  is a cross-sectional view of the second embodiment of the delivery device in its operative configuration; 
         FIG. 18  is a close-up view of region A of  FIG. 16 ; 
         FIG. 19  is a close-up view of region B of  FIG. 17 ; 
         FIG. 20  is an exploded side view of a container, which forms part of the delivery device; 
         FIG. 21  is an exploded perspective view of the container; 
         FIG. 22  is an exploded cross-sectional view of the container; 
         FIG. 23  is a side view of the container; 
         FIG. 24  is a perspective view of the container; 
         FIG. 25  a cross-sectional view of the container; 
         FIG. 26  is a perspective view of a second embodiment of the cup portion of a container; 
         FIG. 27  is a perspective view of a third embodiment of the cup portion of a container; 
         FIG. 28  is a perspective view of a fourth embodiment of the cup portion of a container; 
         FIG. 29  is a perspective view of a fifth embodiment of the cup portion of a container; and 
         FIG. 30  is a diagrammatic representation of the motion of the container when the delivery device is in use. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       FIGS. 1 to 6  show a first embodiment of a delivery device according to the present invention, which is generally designated  100 . The delivery device  100  comprises body  20  and mouthpiece  60  components formed in a high density polyethylene, and a cap  40  component formed in a polycarbonate, each formed by injection moulding. The delivery device  100  also includes a container that is generally designated  80  in the drawings. 
     The delivery device  100  is a single-use, disposable device, which is supplied in sealed, foil packaging, which prevents the ingress of moisture. The delivery device  100  is supplied with the container  80  loaded with a dose of approximately 400 mg of powder. In particular, the specific powder for this embodiment of the invention is mannitol, formulated as a dry respirable powder. For clarity, the powder has been omitted from the drawings. The delivery device  100  is adapted to deliver the dose of powder contained within the container  80  in a single use, through several inhalations, as discussed in more detail below. The delivery device  100  is adapted to then be discarded. 
       FIGS. 1 and 2  show the delivery device  100  in its pre-use configuration, with the container  80  in a storage position.  FIGS. 3 and 4  show the delivery device  100  in its operative configuration, with the container  80  deployed into a cylindrical chamber  110  defined by a combination of the body  20 , cap  40  and mouthpiece  60  components. In particular, the chamber  110  comprises an outer end wall defined by the cap  40 , an inner end wall defined by the body  20  and the mouthpiece  60 , and a cylindrical side wall defined by the body  20  and the cap  40 . Each of the components  20 ,  40 ,  60  of the delivery device  100 , and their relative arrangements, are described in more detail below. 
     The body  20  is shown in isolation, and in greater detail, in  FIGS. 7 to 9 . The body  20  comprises a cylindrical wall  24  and a cylindrical sleeve  32  of reduced diameter, which are arranged co-axially and extend from each side of an annular support  22 . 
     The cylindrical wall  24  of the body  20  forms the majority of the side wall of the cylindrical chamber  110 , in the delivery device  100 , and includes three evenly spaced gas inlet slots  26  through which gas may enter the chamber  110 , in use. Each of the gas inlet slots  26  extend from the end of the cylindrical wall  24  remote from the annular support  22 , to a position approximately three quarters of the way towards the annular support  22 . The gas inlet slots  26  each have the form of a passageway through the cylindrical wall  24 , which extends in a generally tangential direction relative to the chamber  110 . In particular, each gas inlet slot  26  is arranged to introduce a flow of gas along the interior surface of the cylindrical wall  24 , and hence the chamber  110 , such that gas that flows into the chamber from the three gas inlet slots  26 , in use, are directed around the circumference of the chamber  110 , thereby generating a turbulent rotating body of gas within the chamber  110 . 
     The cylindrical sleeve  32  of the body  20  extends from the annular support  22  in the opposite direction to the cylindrical wall  24 . The sleeve  32  has an open outer end  34 , the rim of which has three evenly-spaced, inwardly-facing projections  36 . Notches  38  are located in the rim of the sleeve  32  on both sides of each projection  36 , which allow the regions of the sleeve  32  in which the projections  36  are located to bend more freely. In particular, these regions of the sleeve  32  have the form of elastically deformable arms, with the inwardly-facing projections  36  at the distal ends of those arms. 
     The cap  40  is shown in isolation, and in greater detail, in  FIGS. 10 to 12 . The cap  40  comprises a circular end wall  42 , which forms the outer end wall of the cylindrical chamber  110 . The end wall  42  is substantially transparent to allow a user to view the interior of the chamber  110 . 
     The cap  40  also has a peripheral skirt  44 , which extends generally perpendicularly from the end wall  42 . The skirt  44  is arranged to connect the cap  40  to the end of the cylindrical wall  24  of the body  20 , such that the body  20  and the cap  40  define the side wall and outer end wall of the chamber  110 . 
     The skirt  44  has a proximal portion  46  and a distal portion  48 . The proximal portion  46  extends generally perpendicularly from the periphery of the end wall  42 , and defines an end portion of the side wall of the chamber  110 . In particular, an internal shoulder  50  is formed between the proximal and distal portions  46 ,  48  of the skirt  44 , which has a downwardly facing surface substantially parallel to the plane of the end wall  42 , and which abuts the end of the cylindrical wall  24  of the body  20 . The internal diameter of the proximal portion  46  is substantially equal to that of the cylindrical wall  24  of the body  20 , such that the chamber  110  has a uniform diameter. 
     The distal portion  48  has a slightly increased diameter relative to the proximal portion  46 , and extends from the end of the proximal portion  46 . The inwardly facing surface of the distal portion  48  has a diameter that is substantially equal to the diameter of the external surface of the cylindrical wall  24  of the body  20 , such that the cylindrical wall  24  of the body  20  is received within the distal portion  48  of the skirt  44 , with the upper surface of the cylindrical wall  24  abutting the interior shoulder  50 . The cap  40  is locked in place by a number of projections  54  on the inwardly facing surface of the distal portion  48  of the skirt  44 , which engage corresponding recesses  28  located at the upper end of the outer surface of the cylindrical wall  24  with a snap fit. 
     The internal surface of the skirt  44  further includes three tangential projections  52  that are received within the upper ends of the gas inlet slots  26  in the cylindrical wall  24  of the body  20 . The tangential projections  52  occupy end portions of the slots  26 , with a close fit, restricting the gas inlets defined by the slots  26  to those portions of the gas inlet slots  26  that are free of the projections  52  of the cap  40 , arranged in an intermediate region of the circumferential wall of the chamber  110 . 
     The mouthpiece  60  is shown in isolation, and in greater detail, in  FIGS. 13 to 15 . The mouthpiece  60  comprises a connection portion  62  and an outlet portion  64 , which together define an inhalation passageway  66 . In particular, the inhalation passageway  66  defined by the interior surfaces of the mouthpiece  60  has a generally circular cross-sectional shape, and a gradually increasing diameter as it extends to the end located in a patient&#39;s mouth, in use. 
     The connection portion  62  has an end wall  70 , at an inner end of the mouthpiece  60 , which defines an inlet to the inhalation passageway  60 . In particular, the end wall  70  has the form of a circular disc, with thirty-two circular openings  72  formed therein. The circular openings  72  are arranged in two concentric circles at radii approximately midway between the centre of the end wall  70  and its outer edge. These circular openings  72  provide fluid communication between the chamber  110  and the inhalation passageway  66  of the mouthpiece  60 , when the delivery device  100  is in its operative configuration. 
     The connection portion  62  has a substantially circular cross-section, and an external diameter substantially equal to the internal diameter of the sleeve  32  of the body  20 . In particular, the connection portion  62  of the mouthpiece  60  is slidably mounted within the sleeve  32  of the body  20 , as illustrated in  FIGS. 1 to 4 . However, the permitted movement of the mouthpiece  60  relative to the body  20  is restricted by corresponding grooves  74 , 76  and projections  36  formed on the mouthpiece  60  and body  20  respectively, as discussed in more detail below. 
     The outlet portion  64  of the mouthpiece  60  is arranged co-axially with the connection portion  62 . The outlet portion  64  has a substantially elliptical outer wall, which is shaped to facilitate engagement with the mouth of a patient. The width of the outlet portion  64  is greater than the internal diameter of the sleeve  32 . The outlet portion  64  of the mouthpiece  60  also has a substantially cylindrical inner wall, which together with the connection portion  62  defined the inhalation passageway  66  of the delivery device  100 . 
     The inner and outer walls of the outlet portion  64  are joined on the minor axis of the elliptical outer wall, but are separated to each side of that axis, such that two auxiliary gas passageways are defined on each side of the inhalation passageway  66  in the outlet portion  64  of the mouthpiece  60 . These two auxiliary gas passageways are open at the outer end of the mouthpiece  60 , through which the patient inhales, but are substantially closed at the other end of the outlet portion  64  of the mouthpiece  60  by end walls that join the inner and outer walls of the outlet portion  64 . A small bleed hole  65  is formed in each of these end walls, at the end of each auxiliary gas passageway, such that the patient draws some atmospheric air into the mouthpiece  60  during inhalation. 
     The external surface of the connection portion  62  of the mouthpiece  60  includes inner and outer circumferential grooves  74 ,  76 . An outer groove  76  is disposed adjacent to the outlet portion  64  of the mouthpiece  60 , and an inner groove  74  is disposed approximately midway between the end wall  70  and the outlet portion  64  of the mouthpiece  60 . The connection portion  62  of the mouthpiece  60  is received within the sleeve  32 , with the inwardly extending projections  36  of the sleeve  32  engaging one of the grooves  74 ,  76  with a snap fit, depending on whether the delivery device  100  is in its pre-use or operative configuration, which retains the mouthpiece  60  in place within the sleeve  32 . 
     As shown clearly in  FIG. 15 , the grooves  74 ,  76  have a chamber-side wall that is orientated generally perpendicularly to the longitudinal axis of the mouthpiece  60 , and its direction of movement, in use, and an outlet-side wall that is inclined relative to the chamber-side wall. As shown in  FIGS. 2, 4 and 9 , the corresponding projections  36  of the body  20  have a similar shape. 
     As shown clearly in  FIGS. 2 and 4 , the projections  36  at the end of the sleeve  34  of the body  20  are received within the inner groove  74  of the mouthpiece  60 , with a snap fit, when the mouthpiece  60  is in its pre-use position. In this configuration, the end wall  70  of the mouthpiece  60  is set back from the annular support  22  of the body  20 , such that the lower surface of the chamber  110  comprises a generally cylindrical recess defined by an inner portion of the sleeve  32  and the end wall  70  of the mouthpiece  60 . 
     In this pre-use configuration, the inner groove  74  and the projections  36  are configured to prevent movement of the mouthpiece  60  away from the body  20 , and hence prevent removal of the mouthpiece  60  from the delivery device  100 . However, the inner groove  74  and the projections  36  are configured to enable movement of the mouthpiece  60  towards the body  20 , until the projections  36  of the sleeve  32  are received, with a snap fit, within the outer groove  76  of the mouthpiece  60 , such that the mouthpiece  60  is in its operative position. 
     In use, the mouthpiece  60  is deployed from the pre-use position to the operative position by pressing the mouthpiece  60  into the sleeve  32  with sufficient force to overcome the snap fit between the inner groove  74  and the projections  36 . The force required to overcome this snap fit is sufficiently high that the risk of accidental deployment of the mouthpiece  60  is low, but is sufficiently low that the mouthpiece  60  can be reasonably moved by hand. 
     The notches  38  located in the sleeve  32  on both sides of each projection  36  allow the projections  36  to be urged outwardly during deployment of the mouthpiece  60 , without deformation of the remainder of the sleeve  32 . Once the snap fit is disengaged, as discussed above, the mouthpiece  60  is able to travel further into the sleeve  32  until the projections  36  engage the outer groove  76  with a snap fit, locking the mouthpiece  60  in the operative position. The snap fit between the outer groove  76  and the projections  36  does not allow the mouthpiece  60  to be returned to the pre-use position, and the greater external diameter of the outlet portion  64  of the mouthpiece  60  prevents the mouthpiece  60  being pushed any further into the sleeve  32 . The mouthpiece  60  is therefore securely locked in the operative position once the snap fit between the outer groove  76  and the projections  36  has been engaged. 
     In this operative configuration, the connection portion  62  of the mouthpiece  60  is entirely received within the sleeve  32  of the body  20 , and the outlet portion  64  of the mouthpiece  60  is disposed adjacent to the end of the sleeve  32 . In addition, the end wall  70  of the mouthpiece  60  is aligned with the annular support  22  of the body  20 , such that these components define a substantially flat end wall of the chamber  110 . In particular, the chamber  110  is substantially cylindrical in this configuration. 
     In addition, two circumferential ridges  78  extend around the external surface of the connection portion  62  between the inner groove  74  and the end of the mouthpiece  60 . In particular, one of the circumferential ridges  78  is disposed at the end of the mouthpiece  60 , and the other circumferential ridge  78  is disposed adjacent to the inner groove  74 . These circumferential ridges  78  improve the seal against the interior surface of the sleeve  34  of the body  20  to reduce the risk of gas flow leakage into the chamber  110  of the delivery device  100  during use. 
     The container  80  is shown in isolation, and in greater detail, in  FIGS. 20 to 25 . The container  80  is substantially drum shaped, and comprises a cup portion  82  that is open at one end, and a lid  92  that closes the open end of the cup portion  82 . 
     The cup portion  82  of the container  80  comprises an end wall  84  having a convex exterior surface, and a generally cylindrical side wall  86  that is open at one end. An inwardly extending ridge  88  is provided at the open end of the cup portion  82 , extending from the interior surface of the side wall  86 . Two slots  90  are also formed in the side wall  86 , extending from the open end, on opposite sides of the cup portion  82 . 
     The lid  92  of the container  80  has an end wall  94  with a convex exterior surface, and a peripheral skirt  96  that engages the inwardly extending ridge  88  of the cup portion  82  to connect the cup portion  82  and the lid  92  together. The skirt  96  partially obstructs the two slots  90  in the side wall  86  of the cup portion  82 , when the container  80  is assembled, leaving a small opening  98  in each slot  90  from which powder is dispensed, in use, as discussed in more detail below. 
     Further embodiments of the cup portions  182 ,  282 ,  382  of containers  80  are shown in  FIGS. 26 to 28 , which comprise internal baffles  89  that divide the internal compartment of the container  80  into a number of sub-chambers. The baffles  89  include gaps  89   a  or openings  89   b  that allow restricted powder flow between these sub-chambers. The flow of powder within the container  80  while the delivery device  100  is operated is restricted by the baffles  89 , such that powder emission from the openings  98  of the container  80  is restricted as the container  80  undergoes motion. 
     Yet a further embodiment of the cup portion  482  of a container  80  is shown in  FIG. 29 , in which the side wall  86  comprises a textured portion  86   a  formed of a series of ribs, aligned with the cylindrical axis of the container  80 . The textured portion  86   a  improves coupling between the container  80  and the gas flow through the chamber  110 , which modifies the motion of the container  80  while the delivery device  100  is operated. The side wall  86  of the cup portion  482  also comprises a smooth portion  86   b  adjacent to the rim of the cup portion  482  and the slots  90 , which allows effective sealing of the openings  98  and a secure interference fit with the internal surface of the sleeve  32  adjacent to the annular support  22 . 
     The exterior diameter of the container  80  is substantially equal to the internal diameter of the sleeve  32 , such that the container  80  is retained with an interference fit within the sleeve  32  in the pre-use configuration. 
     As shown clearly in  FIG. 2 , when the mouthpiece  60  is in its pre-use position, the container  80  is retained at least partially within the recess in the lower surface of the chamber  110  by an interference fit between the side wall  86  of the container  80  and internal surface of the end of the sleeve  32  adjacent the annular support  22 . In this configuration, the lid  92  of the container  80  is in contact with the end wall  70  of the mouthpiece  60 . 
     The interference fit between the container  80  and the interior surface of the sleeve  32  is sufficiently secure to prevent the container  80  becoming inadvertently dislodged, ie without movement of the mouthpiece  60  into the operative position. The engagement between the side wall  86  of the container  80  and the sleeve  32  also seals the openings  98  sufficiently to prevent any powder escaping from the container  80  in the pre-use configuration. 
     A second embodiment of a delivery device according to this invention, generally designated  200 , is shown in a pre-use configuration in  FIG. 16  and an operative configuration, in which the container  80  is deployed into a chamber  110 , in  FIG. 17 . The second embodiment of the delivery device  200  is of essentially the same construction as the first embodiment 100, but further includes an annular groove  222  in the annular support  22  that circumscribes the opening at the upper end of the sleeve  32 . The groove  222  defines a thin portion of material  224  of increased deformability around the rim of the opening at the upper end of the sleeve  32  that receives the container  80  while the delivery device  200  is in the pre-use configuration. The thin portion  224  comprises a ridge that extends into the opening at the upper end of the sleeve  32 , such that this opening has a slightly reduced diameter around its rim. The rim of the opening at the upper end of the sleeve  32  is shown in greater detail in  FIG. 18 , in which the delivery device  200  is in the pre-use configuration, and in  FIG. 19 , in which the delivery device  200  is in the operative configuration. 
     When the delivery device  200  is in its pre-use configuration, the container  80  is retained in the opening at the upper end of the sleeve  32  by an interference fit between the side wall  86  of the container  80  and the inwardly extending ridge on the thin portion  224 . The thin portion  224  is able to deflect into the groove  222 , allowing it to accommodate small dimensional variations in the container  80 , which are often encountered in high volume manufacturing. This arrangement improves sealing of the openings  98  and security of the interference fit between the side wall  86  of the container  80  and the sleeve  32  when the delivery device  200  is in its pre-use configuration.  FIG. 18  shows a small overlap between the side wall  86  of the container  80  and the inwardly extending ridge on the thin portion  224 , indicating the degree of interference between the container  80  and the thin portion  224 . 
     As the mouthpiece  60  is moved into the operative position, the circumferential ridge  78  located adjacent to the end wall  70  of the mouthpiece  60  contacts the inwardly extending ridge of the thin portion  224  causing the thin portion  224  to deflect outwardly into the groove  222 , as shown in  FIG. 19 . Accordingly, when the mouthpiece  60  reaches the operative position with the end wall  70  aligned with the annular support  22 , the thin portion  224  is deflected into the groove to such an extent that it closes off, or substantially closes off, the open end of the groove  222  from the chamber  110 . The thin portion  224  retains this position during use, thereby preventing or substantially preventing the deposition of powder in the groove  222  while the delivery device is operated. 
     The delivery device  100  is stored, transported and supplied to the patient with the mouthpiece  60  in the pre-use position, as shown in  FIG. 1 , to prevent powder escaping from the container  80  prior to use. When the patient is ready to use the delivery device  100 , the mouthpiece  60  is pressed into the operative position, which pushes the container  80  out of the recess, releasing it into the chamber  110  and unsealing the openings  98 . The delivery device  100  is then ready to dispense powder. 
     The region of the external surface of the mouthpiece  60  that is located between then inner and outer grooves  74 ,  76  is colored to contrast with the other parts of the delivery device  100 . The contrasting region  75  is visible when the mouthpiece  60  is in the pre-use position. However, when the mouthpiece  60  is deployed into the operative position, the contrasting region is hidden by the sleeve  32  and is no longer visible, providing a clear visual indication of when the mouthpiece  60  has been properly deployed and thus when the delivery device  100  is ready for use. 
     The delivery device  100  is operated by the patient inhaling through the outlet portion  64  of the mouthpiece  60 . The elliptical cross-section of the outlet portion  64  of the mouthpiece  60  facilitates engagement with the mouth of a patient to reduce gas leakage at the corners of the mouth. Inhalation by the patient draws gas into the chamber  110  through the gas inlet slots  26 . This gas exits the chamber  110  through the circular openings  72  in the end wall  70  of the mouthpiece  60 , and flows into the inhalation passageway  66  of the mouthpiece  60 , and then into the mouth and lungs of the patient. 
     The tangential arrangement of the gas inlet slots  26  causes gas drawn into the chamber  110  to be directed around its circumference, which generates a turbulent rotating body of gas within the chamber  110  that drives the motion of the container  80 . The convex upper and lower surfaces of the container  80  reduce the contact area between the container  80  and the surface of the chamber  110 , and also prevent the container  80  being sucked onto the end wall  70  of the mouthpiece  60 , thereby allowing the container  80  to move more freely within the chamber  110 . An effective sealing arrangement between the components  20 ,  40 ,  60  forming the chamber  110  prevents uncontrolled gas leakage into the chamber  110  that would produce additional turbulence and reduce the efficiency at which the gas flow within the chamber  110  causes the desired motion of the container  80 . 
     In use, emission of the powder from the openings  98  in the container  80  is brought about by motion of the container  80  within the chamber  110 . This motion is illustrated in  FIG. 30 . The turbulent rotating body of gas in the chamber  110  drives the container  80  in an orbital motion around the central axis of the chamber  110 , with the side wall  86  of the container  80  substantially remaining in contact with the circumferential wall of the chamber  110 . This orbital motion is accompanied by rotation of the container  80  about its own axis, either in rolling contact with the circumferential wall of the chamber  110  in a substantially epicyclic fashion, or in a non-rolling direction, whereby the container  80  is skidding against the chamber wall. Motion of the container  80  generally includes both epicyclic and skidding motion. The balance between epicyclic and skidding motion is influenced by the ratio of the diameter of the container  80  to that of the chamber  110 . 
     The chamber  110  has a diameter of 23 mm, relative to a diameter of 18 mm for the container  80 . This configuration promotes epicyclic motion of the container  80 , which is the most efficient form of motion for powder emission. This configuration may also provide enhanced milling of the emitted powder between the container  80  and the wall of the chamber  110  as the container  80  orbits the chamber  110 , aiding deagglomeration of the powder. 
     The container  80  is designed to be as light as possible to maximise the mass of powder that can be driven with the available gas flow. The container  80  contains about 400 mg of powder, leaving a headspace comprising about 30% of the volume of the container  80 . This headspace allows the powder to tumble within the container  80 , improving emission of the powder from the openings  98  and further aiding deagglomeration. 
     Powder is emitted from the openings  98  continuously while the container  80  is undergoing motion, allowing the delivery device  100  to deliver a substantially steady amount of powder throughout each inhalation manoeuvre, reducing the likelihood of the patient experiencing a cough reaction. 
     Powder emitted from the container  80  is entrained in the turbulent rotating body of gas in the chamber  110 , and this powder-laden gas is drawn through the openings  72  in the end wall  70  of the mouthpiece  60 , into the inhalation passage  66 . The openings  72  in the end wall  70  of the mouthpiece  60  act to reduce the rotational velocity of the powder-laden gas passing through it, such that the gas flow is substantially straightened once it enters the inhalation passageway  66 , reducing powder deposition on the internal surface of the mouthpiece  60 . 
     The bleed holes  65  located on opposite sides of the outlet portion  64  of the mouthpiece  60  provide an additional gas flow path into the mouthpiece  60 , which bypasses the chamber  110  and reduces the resistance of the delivery device  100 . The gas entering the bleed holes  65  is atmospheric air that does not contain entrained powder, and so can shield the powder-laden gas from the mouth and throat of the patient and prevent it from entering the auxiliary gas passageways, reducing powder deposition in these areas. 
     Administration of the full 400 mg dose requires a number of sequential inhalations by the patient. The number of inhalations required is typically between five and eight but may be more or less. 
     Example 
     Emitted Dose (ED) and Fine Particle Dose (FPD) Testing 
     Three delivery devices substantially as described above were provided, one having a chamber 22 mm in diameter, one with a chamber 23 mm in diameter and the last with a chamber 24 mm in diameter. 
     All containers used were 18 mm in diameter and had a single exit orifice with a cross-sectional area of around 0.18 mm 2 . The containers contained 400 mg±3 mg of mannitol formulated as a dry respirable powder. 
     The Emitted Dose (ED) and Fine Particle Dose (FPD) produced by each delivery device was tested using a standard Multistage Liquid Impinger (MSLI). 
     Each delivery device was loaded with a container and a gas flow of between 50 and 55 liters/min was drawn through the chamber in shots of around 4 seconds until the powder emission rate became negligible, generally after between 5 and 10 shots. This process was repeated several times for each delivery device. 
     The ED for each delivery device was calculated directly from the powder emission results produced by the MSLI. FPD was calculated with Copley Inhaler Testing Data Analysis Software (CITDAS) from powder emission results produced by the MSLI. The ED and FPD of each device are shown in Table 1. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Emitted Dose (ED) and Fine Particle Dose (FPD) produced by delivery 
               
               
                 devices of various chamber diameters 
               
            
           
           
               
               
               
            
               
                   
                 Emitted Dose (ED) 
                 Fine Particle Dose (FPD) 
               
            
           
           
               
               
               
               
               
            
               
                 Device 
                 Mean 
                 Range 
                 Mean 
                 Range 
               
               
                   
               
               
                 22 mm Chamber 
                 335.8 
                 313 to 347 
                 131.6 
                 128 to 135 
               
               
                 23 mm Chamber 
                 346.3 
                 338 to 352 
                 131.0 
                 115 to 146 
               
               
                 24 mm Chamber 
                 351.9 
                 350 to 354 
                 131.1 
                 118 to 139