MEDICAMENT INHALER DEVICE
The present invention relates to apparatus for administering medicament and particularly, but not exclusively, to apparatus for administering powdered or volatile composition by oral inhalation.
Inhalers conventionally known in the art for administering doses of dry powdered medicament are generally designed for convenient handling and effective inhalation of the medicament dose. Inhalers for use with containers of dry powdered medicament are typically designed in such a way as to require a piercing of the container so that inhalation of the medicament can be effected. However, on continuous usage and cleaning of such devices, there often occurs operational difficulty as a result of rusting of the piercing mechanism which, in turn, results in an improper piercing of a container and decreases the efficiency of the drug delivery. It will be understood that the rusting of the piercing mechanism is a consequence of a frequent exposure of the piercing mechanism to cleaning solvents/agents and general moisture. Furthermore, as a consequence of piercing a container, fragmentation of a container shell results in a risk of inhalation of shell fragments.
Certain devices known in the art operate to break a container of medicament when parts of the device are rotated relative to one another. On inhalation by a patient, air travels through an inlet into a chamber wherein the air is redirected through 180° before passing through a mouthpiece.
Prior art document US 2003/0000523 Al discloses an inhaler device comprising an inhaler body defining a recess for receiving a container in which a substance to be inhaled is contained. A nosepiece communicating with the container is also provided together with a perforating element which is coupled to the inhaler body and provided for perforating the container so as to allow an outside air flow to be mixed with the container content and inhaled through the nosepiece.
Prior art document EP 1 238 680 Bl discloses an inhaler device for dispensing powdered medicament contained in a container. The inhaler comprises a compartment for receiving a container and a cutting element for cutting or perforating the container and thereby releasing medicament contained within the container. The inhaler further comprises a grid for catching pieces of container while allowing passage of medicament to be inhaled. The inhaler may be equipped with disposable accessories to be placed into the mouth.
Prior art document EP 0 837 710 discloses a cartridge having an integrated metering device which comprises at least one metering cavity for receiving a predetermined quantity of pharmaceutical powder. The integrated metering device is capable of being moved out of a filling position into an emptying position approximately transversely with respect to the flow direction of the pharmaceutical powder. An inhaler is also disclosed for use with the cartridge.
It is an object of the present invention to provide an inhaler which is both inexpensive and convenient to manufacture and which ensures an effective dispensing of medicament upon inhalation by a user.
It is a further object of the present invention to provide an inhaler which is both simple in construction and simple to use.
A first aspect of the present invention provides a device as recited in the appended independent claim 1. A device comprising further novel and advantageous features is provided as recited in any of the appended dependent claims 2 to 21.
A second aspect of the present invention provides a device as recited in the appended independent claim 22. A device comprising further novel and advantageous features is provided as recited in any of the appended dependent claims 23 to 40.
A device is described hereinafter for orally administering a composition by inhalation, the device comprising a body defining a chamber for receiving composition to be inhaled; a mouthpiece providing fluid communication to said chamber and through which composition received in said chamber may, in use, be inhaled; and at least one air inlet providing fluid communication to said chamber and through which air may, in use, be admitted into said chamber in response to an inhalation of composition through said mouthpiece; the device being characterised by means for imparting a cyclonic motion onto air within said chamber.
It will be understood therefore that, through use of the present invention, medicament composition received in said chamber will, upon inhalation by a user, be exposed to an air flow having a cyclonic motion. This particular motion ensures that a high proportion of medicament within said chamber becomes entrained in the air flow passing through said chamber and into the mouthpiece. The cyclonic motion thereby ensures that an improved level of medicament is inhaled as compared with prior art devices.
Ideally, said cyclonic motion means imparts cyclonic motion onto air immediately as said air enters said chamber. It is also preferable for said cyclonic motion means to comprise said air inlet. Said air inlet may be oriented so as to admit air into said chamber in a direction skewed. Also, said air inlet may extend through a side wall of said chamber and said cyclonic motion may comprise a curved surface defining said chamber. It is also desirable for said body to comprise first and second portions each having a cylindrical member, the cylindrical member of the second body portion being telescopically received in the cylindrical member of the first body portion. Furthermore, said air inlet may be defined by an aperture in said first body portion and an end of the cylindrical member of the second body portion which locates adjacent said aperture. Means may be provided on the first body portion for holding a container of composition within said chamber. Also, an abutment member may be provided on the second body portion, the abutment member being located so that, in use, a container of composition held in said
container holding means and projecting therefrom into said chamber is engaged by the abutment member when the first and second body portions are rotated relative to one another, the engagement assisting with release of composition from the container of composition. The abutment member is ideally located in the cylindrical member of the second body portion.
Also, grate means may be provided for restricting entry into the mouthpiece of a container of composition. Furthermore, said cyclonic motion means may generate a vortex which, as a whole, passes along a generally circular or part circular path within said chamber. In other words, the vortex is itself deflected along a generally circular or part circular path. As a result, a primary current (a flow passing along the circular or part circular path) and a secondary current (the vortex) are generated. The term vortex will be readily understood by a person skilled in the art and refers to a swirling body of fluid.
The present invention thereby provides the advantage over the prior art of enhanced effectiveness in dispensing medicament by inhalation.
Embodiments of the present invention will now be described with reference to the accompanying drawings, in which:
Figure 1 is a cross-sectional side view of an inhaler device according to the present invention;
Figure 2 is a front view of a top body portion of the inhaler device of Figure 1;
Figure 3 is a side view of the top body portion of Figure 2;
Figure 4 is a top view of the top body portion of Figure 2;
Figure 5 is a top view of a bottom body portion of the inhaler device of Figure 1 ;
Figure 6 is a cross-sectional side view of the bottom body portion taken along line A- A of Figure 5.
Figure 7 is a cross-sectional side view of a modified version of the inhaler shown in Figure 1 ; and
Figure 8 is a top view of a bottom body portion of the modified inhaler of Figure 7.
A cross-sectional side view of an inhaler device 2 according to the present invention is shown in Figure 1 of the accompanying drawings. The device 2 comprises an upper body portion 4 and a lower body portion 6. A cylindrical wall 8 of the upper body portion 4 receives a cylindrical wall 10 of the lower body portion 6. The relative dimensions of the cylindrical walls 8, 10 are such that the upper and lower body portions 4, 6 securely engage one another without undue play whilst allowing the body portions 4, 6 to be rotated relative to one another. The upper and lower body portions 4, 6 are retained in their assembled positions relative to one another as shown in Figure 1 by means of one or more clip members which locate in a recess. The or each clip member 12 is provided on one of the first and second body portions 4, 6 for removably locating in the recess 14 which is provided in the- other of the first and second body portions 4, 6. In the inhaler device 2, three clip members 12 are provided equidistant circumferentially along the cylindrical wall 8 of the upper body portion 4 and extend radially inwardly into a circumferentially extending recess 14 provided in the exterior surface of the cylindrical wall 10 of the lower body portion 6. The lower body portion 6 is thereby retained in a desired axial position relative to the upper body portion 4 with relative rotation of the two portions 4, 6 being unrestricted. In an alternative embodiment (not shown), the three clip members are provided on the lower body portion 6 and the circumferentially extending recess 14 is provided in the upper body portion 4.
The lower body portion 6 further comprises a dish-shaped wall 16 (U-shaped in cross-section) which is circumferentially joined to the cylindrical wall 10 of the lower body portion 6. The dish-shaped wall 16 thereby closes the longitudinal bore formed by the cylindrical wall 10. In use, the dish-shaped wall 16 acts to cradle medicament fallen from a container of medicament. In an alternative embodiment, the wall 16 is planar (i.e. flat rather than dish-shaped.
As can be seen from Figures 5 and 6 of the accompanying drawings, the lower body portion 6 further comprises an abutment member 20 which is located adjacent an upper edge 22 of the lower body portion 6 and which extends a short distance radially inwards from the outer perimeter of the dish-shaped wall 16. As will be understood from the forthcoming description, the abutment member 20 need only extend a sufficient distance to ensure it engages with a container of medicament projecting into the lower body portion 6 from a container holder 24. The purpose of the abutment member 20 is to abut such a container upon relative rotation of the two body portions 4, 6 and, upon further rotation, to open the container and thereby release medicament held therein. As such, the abutment member 20 must have sufficient structural integrity to open a container without itself becoming damaged.
It will be understood with reference to Figure 1 of the accompanying drawings that the section of cylindrical wall 10 located below the circumferential recess 14 is, in use, held by a patient to assist in rotating the lower body portion 6 relative to the upper body portion 4 and thereby opening a container to release medicament to be inhaled.
With reference to Figures 2 to 4 of the accompanying drawings, it will be seen that the upper body portion 4 comprises a cylindrical wall 8 which is closed, at least in part, by a stepped transversely extending wall. The stepped wall comprises an outer annular part 26 extending inwardly from the cylindrical wall 8, and further
comprises a circular part 28 joining the annular part by means of an upward step 30.
An outlet aperture 32 is provided in the circular part 28. A grate 34 covers the outlet aperture 32 so as to allow a passage of air and medicament therethrough but to prevent the passage of a medicament container. A mouthpiece tube 18 having an oval-section extends upwardly from the circular part 28 and surrounds the outlet aperture 32.
A medicament container inlet aperture 36 is also provided in the circular part 28 for receiving and holding a container containing medicament to be inhaled. A tubular member 38 surrounds the container aperture 36 and, in use, surrounds and protects a container held in the container aperture 36 and extending upwardly from the circular part 28.
Two inlet apertures 40 are provided in the annular part 26 of the upper body portion 4 and are located diametrically opposite to one another (see Figures 2 and 4). With reference to Figure 1 of the accompanying drawings, it will be understood that the upper edge 22 of the lower body portion 6 is in abutment with or in close proximity to the annular part 26 of the upper body portion 4. As such, the upper edge 22 of the lower body portion 6 overlies the apertures 40. At least a part of the upper edge 22 may extend radially from a radially outer edge of each aperture 40 to a radially inner edge of each aperture 40 so as to overlie the whole of each aperture 40. As will be understood from the following description, when the upper edge 22 abuts the upper body portion 4 and wholly overlies the apertures 40, all air entering the inhaler is admitted via grooves 42 extending from the apertures 40.
Also, the radial dimension of the upper edge 22 may be insufficient to extend from a radially outer edge of an inlet aperture 40 to a radially inner edge of the aperture 40. In one embodiment (not shown), the upper edge 22 of the lower body portion
6 does not extend radially inwardly to the radially inner edges of the apertures 40 and, as a consequence, a radially inward area of the apertures 40 provides a flow path, for some of the incoming air, directly into the inhaler device. This alternative arrangement can advantageously generate a vortex flow of air by encouraging (through use of said radially inward area of the apertures) incoming air to enter the chamber over the upper edge 22.
Regardless of whether or not the upper edge 22 extends radially across the whole of the apertures 40, a groove 42 extending from each aperture 40 is provided in the underside 44 of the annular part 26. Each groove 42 extends from the associated inlet aperture 40 to the radially inward edge of the annular part 26 so as to provide a flow path into the inhaler device 2 between the adjacent upper and lower body portions 4, 6. Each groove 42 extends tangentially relative to the longitudinal axis 46 of the inhaler device 2. As such, it will be understood that air admitted into the inhaler device 2 flows into the inlet apertures 40 in a tangential direction along the circular wall formed by the step 30 between the annular and circular parts 26, 28 of the upper body portion 4. The inlet apertures 40 in combination with the grooves 42 and circular wall 30 thereby cooperate to provide a cyclonic flow of air within the inhaler device 2. It will however be appreciated that the grooves 42 may be arranged with a different orientation to that shown and described herein so that a cyclonic air flow having a different flow characteristic is generated. In the case where the upper edge 22 of the lower body portion 6 does not extend to the radially inner edges of the inlet apertures 40, a flow of air about the longitudinal axis 46 of the inhaler 2 may be generated which itself is swirling as a vortex about the tangential direction of flow.
The device may be manufactured from any suitable material, for example, any suitable plastics material.
In use of the inhaler 2, the upper and lower body portions 4, 6 are firstly separated so as to empty the inhaler of the medicament container. The two body portions 4,
6 are then reassembled with the clip members 12 resiliently snap fitting into the circumferential recess 14 (see Figure 1). A chamber 48 is thereby defined between the dish-shaped wall 16 and the annular part 26, circular part 28 and step 30. The inhaler device 2 is then loaded with a container of medicament by placing the container (not shown in the accompanying drawings) into the tube 38. The container is held by the container aperture 36 and is thereby prevented from dropping into the chamber 48. The length of the container tube 38 is such that, when the container is pushed into the container aperture 36 so that the upper end of the container is level with the upper end of the container tube 38, the lower end of the container extends into the lower body portion 6 so as to be engageable by the abutment member 20. The upper and lower body portions 4, 6 are then grasped by the user and rotated relative to one another so that the abutment member 20 engages and opens the container. Medicament contained in the container is thereby released into the chamber 48.
Once medicament has been released into the chamber 48, the user places the mouthpiece 18 into the mouth so that air may be inhaled via the chamber 48. As the user inhales, air is admitted into the chamber 48 through the inlet apertures 40. As will be understood from the above description, means are provided for imposing a cyclonic motion onto air admitted into the chamber 48. The resulting cyclonic motion within the chamber 48 ensures that medicament released into the chamber 48 from the opened medicament container is effectively entrained into the air flow entering the mouthpiece 18. Whilst the grate 34 allows the passage of air and entrained medicament therethrough, the apertures forming the grate 34 are sufficiently small to prevent passage of the medicament container which may fall into the chamber 48 upon opening or subsequently during inhalation.
The chamber 48 has a volume of such a size that, in use, upon a single inhalation through the chamber by a patient, the medicament within the chamber is inhaled by the patient. The volume of the chamber 48 is such that, on inhalation by a patient, a fluid pressure drop is induced at the point of inhalation. In comparison
to a prior art inhaler, at a constant pressure drop of 4kPa, the flow rate in the prior art inhaler is 45 litres per minute (1/min) whereas the flow rate in the present inhaler device 2 is 60 1/min. Movement of the air within the chamber is thereby induced and this results in a suspension of medicament particles within the air inhaled by the patient.
In comparison to a prior art inhaler, the volume of the chamber of the present device 2 is smaller than the volume of the chamber of the prior art inhaler. This smaller volume also contributes to improving the performance of the device.
The volume of the chamber of the present device 2 may preferably be from 1611 mm3 to 6444 mm3.
Once the dose of medicament within the chamber 48 has been inhaled, the upper and lower body portions 4, 6 may be separated and the chamber 48 emptied before reassembly and loading with a fresh container.
The following cascade data illustrates the improved performance of the inhaler of Figures 1 to 6 over a prior art inhaler.
The cascade analysis gives a value of Fpd (Fine particle dose) / % Fpf (fine particle fraction) which gives a value of particles which have probability of reaching the lungs.
The test was done according to USP using Cascade impactor.
The present invention is not limited to the specific embodiments described above. Alternative arrangements will be apparent to a reader skilled in the art. For example, a cover may be provided for closing the mouthpiece 18. The cover may be integral with one of the body portions 4, 6 or may be a separate component. Furthermore, the cover may have a generally cylindrical shape with one end thereof closed by a transversely extending wall, the diameter of the cylinder being approximately the same as that of the cylindrical wall 8 of the upper body portion 4. This cover may resiliently snap fit to the cylindrical wall 8 and extend upwardly therefrom so as to cover both the mouthpiece 18 and the container tube 38. The primary purpose of the cover is to prevent dust from entering the inhaler device. Alternative arrangements of cover will be apparent to a skilled person.
Also, the mouthpiece and/or the means for receiving and holding a medicament container may be removably secured to the remainder of the inhaler. This may be achieved by means of a releasable connection such as that provided by interengaging screw threads or a snap fit or interference fit connection. Furthermore, the interior of the mouthpiece may be provided with a guide vane 100 (for example, a helical or spiral ramp) which has the effect of imparting, inducing or maintaining a cyclonic flow in air inhaled therethrough (see Figure 7). Guide vanes 102 may also be provided in the chamber 48 for encouraging incoming air to follow a cyclonic path or for inducing or maintaining a cyclonic flow in the incoming air. The guide vanes 102 may have a cylindrical or part- cylindrical shape and may be mounted by suitable means 104 (for example, one or more slender rod) to the lower body portion 6 (see Figures 7 and 8).