Patent Description:
Inhalers have been widely used in the pharmaceutical field for treatment of respiratory and/or other diseases. Numerous drugs, medications and other substances are inhaled into the lungs using the inhalers for rapid absorption of the drug etc. in the blood stream and for local action in the lung.

Inhaled drugs fall into two main categories, one being in the form of liquids, including suspensions, and the other being powders. The choice of liquids or powders depends on the characteristics of the drugs, medications, etc. to be inhaled.

The most common type of inhaler is the pressurized metered-dose inhaler. In this type of inhaler medication is most commonly stored in solution in a pressurized canister that contains a propellant, although it may also be a suspension. The canister is attached to a plastic, hand-operated actuator. On activation, the metered-dose inhaler releases a fixed dose of medication in aerosol form.

Another kind of inhaler is a nebulizer, which supplies medication as an aerosol created from an aqueous formulation.

The kind referred to herein is yet another type, in the form of a dry powder inhaler. A dry powder inhaler releases a pre-metered, capsuled, dose or a device-metered dose of powdered medication that is inhaled through the inhaler. Inhalers with a device-metered dose of powdered medication are normally inhalers with a medication reservoir containing powdered medication, from which metered doses are withdrawn through the use of different dose metering arrangements, the doses then being inhaled.

Dry powder inhalers need to deliver a particle size that is predominantly below <NUM> microns, and preferably between <NUM> micron and <NUM> microns, for maximum effectiveness. However, such small particles are often very cohesive due to high surface energy. Agglomeration may be worsened by moisture and / or when the medication comprises more than one active substance, since the different active substances may have such properties as to form agglomerations with each other or with pharmaceutical carriers etc. Agglomeration of small particles is a problem which results in the active particles leaving the inhaler as large agglomerates.

<CIT> relates to a device in powder inhalators intended to be used for local administration of drugs to the respiratory tract and lungs of a patient.

As such, there exists a need for an improved dry powder inhaler device in which effective and satisfactory dispersion of the dry powder is obtained and which inhaler efficiently facilitates deaggregation and dispersion.

<CIT>, <CIT>, <CIT>, and <CIT> disclose prior art inhalers.

Accordingly, the present invention preferably seeks to mitigate, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination and solves at least the above mentioned problems by providing a dry powder inhaler as defined in claim <NUM>. Further advantageous embodiments are disclosed below and in the appended patent claims.

These and other aspects, features and advantages of which the invention is capable will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which.

The following description focuses on embodiments of the present invention applicable to a medicament inhaler <NUM>, and in particular to a dry powder drug inhaler with more than one medicament reservoir, such as two medicament reservoirs. However, it will be appreciated that the invention is not limited to this application but may be applied to many other inhalers having an inlet and an outlet, as well as a medicament reservoir.

<FIG> illustrate a dry powder drug inhaler <NUM>. The dry powder drug inhaler <NUM> comprises air inlets <NUM> and an air outlet <NUM>. The outlet <NUM> is arranged in a zone of a proximal end <NUM> of the dry powder drug inhaler <NUM> while the inlets <NUM> are arranged at a zone in an opposite distal end <NUM> of the dry powder drug inhaler <NUM>. The outlet <NUM> is arranged centrally along the longitudinal axis of the dry powder drug inhaler <NUM>. The inlets <NUM> may be arranged at the periphery of the dry powder inhaler <NUM> in a radial position in relation to the longitudinal axis of the dry powder drug inhaler <NUM>, such that the inlets <NUM> lead inhaled air transversally and radially towards the central portion of the dry powder inhaler <NUM>.

Although not illustrated in <FIG>, the inlets <NUM> may also be positioned with a direction that is parallel to the central axis of the dry powder inhaler <NUM>.

The number of inlets and outlets may be different from what is disclosed in <FIG>. The number of inlets may for example be adjusted in accordance with needs and specific inhaler design such that a number of smaller air inlets, for reducing pressure fall over the inhaler, are arranged circumferentially on the dry powder inhaler <NUM>. In a similar manner the number of air outlets may be adjusted in accordance with needs and specific inhaler design.

The different parts of the dry powder inhaler <NUM> may be manufactured in a suitable material, such as injection moldable plastics, such as thermoplastics.

The dry powder inhaler <NUM> comprises three major parts in the form of (i) an upper proximal reservoir housing <NUM> with an inhalation chimney <NUM>, (ii) a dosage mechanism <NUM> comprising a dose disc <NUM> having at least one cavity <NUM>, a mixing and deaggregation chamber <NUM> adjacent to the at least one cavity <NUM>, and a conduit <NUM> extending distally from the chamber <NUM>, and (iii) a lower distal twister <NUM> which in some embodiments may comprise a floor disc <NUM>. The reservoir housing <NUM> and the twister <NUM> cooperate so as to house the dosage mechanism <NUM> and the floor disc <NUM> in between housing <NUM> and twister <NUM>. The chimney <NUM> of the reservoir housing <NUM> cooperates with the conduit <NUM> of the dosage mechanism <NUM> such that the dose disc <NUM> may be rotated between a dose administering position and a dose collecting position when the reservoir housing <NUM> is rotated. The floor disc <NUM> is connected to twister <NUM> so that floor disc <NUM> only moves when twister <NUM> is rotated as will be described further below. This may be accomplished by connecting the floor disc <NUM> and the twister <NUM> via interconnecting grooves and ribs, or letting the twister <NUM> extend longitudinally around the floor disc <NUM> as disclosed for example in <FIG>. Preferably, the rotation of the dose disc <NUM> has two end positions corresponding to the dose administering position and the dose collecting position in its relation with the reservoir housing <NUM> in a known manner.

The dose administering position is illustrated in <FIG>. In the dose administering position, the inlets <NUM> are in communication with the mixing and deaggregation chamber <NUM> via air channels <NUM>. The air channels <NUM> direct the flow of air from inlets <NUM> initially downwards onto cavities <NUM> in the dose disc <NUM>. Hence, in the dose administering position the cavities <NUM> may lie underneath and in line with the air channels <NUM>, in particular in line with a longitudinal section <NUM> of the air channels <NUM>. In addition, in the dose administering position the cavities <NUM> may be arranged flush with a transversal section <NUM> of a respective air channel <NUM> and may be arranged partially in line with a longitudinal section <NUM> of a respective air channel <NUM>. The combination of an air flow A from channels <NUM> and the medicament M from cavities <NUM> then flows radially to the chamber <NUM> via the transversal section of the air channel <NUM> as will be described further below with respect to <FIG> and <FIG>. When the dose disc <NUM> is rotated into a dose collecting position (not shown), the chamber <NUM> and the cavities <NUM> are rotated away from communication with the inlets <NUM> and air channels <NUM>. Instead, the cavities <NUM> are rotated into medicament reservoir <NUM> and medicament reservoir <NUM> disclosed in <FIG>, wherein the cavities <NUM> may collect a medicament housed in the reservoirs <NUM> and <NUM>. The medicament contained in the medicament reservoir <NUM> may be a medicament different from the medicament contained in the medicament reservoir <NUM>. Due to the presence of two reservoirs <NUM> and <NUM>, the inhaler <NUM> may deliver two substances in one inhalation, the two substances otherwise being incompatible meaning that these two substances would not be possible to be comprised in one joint reservoir. Thus, the dry powder inhaler device <NUM> can effectively and satisfactorily disperse two dry powders and can administer a medicament comprising two or more substances which are incompatible in a mixture or are preferably stored in separate reservoirs for other reasons.

It is possible to arrange the dose disc <NUM> and the cavities <NUM> thereof such that when a first set of two cavities <NUM> lie underneath the air channels <NUM>, i.e. in a dose administering position, a second set of two cavities <NUM> are positioned in the medicament reservoirs <NUM>, <NUM> respectively. In this arrangement the inhaler has two medicament reservoirs, two air inlets, and one dose disc with four cavities. Additionally, the distribution of the cavities <NUM> on the dose disc <NUM> is such that the dose disc <NUM> may be rotated in one direction only meaning that when the second set of two cavities <NUM> lie underneath and in line with the air channels <NUM>, the first set of cavities <NUM> are positioned in the medicament reservoirs <NUM>, <NUM> respectively. It is also possible for the dose disc <NUM> to be rotated in a first direction so that cavities <NUM> lie underneath the air channels <NUM> in a dose administering position, and then for the dose disc <NUM> to be rotated in the opposite direction into the dose collecting position, and thereafter again for the dose disc to be rotated in the first direction back into the dose administering position. When the dose disc <NUM> is rotated in a first direction into the dose administering position and the opposite direction into the dose collecting position, the dose disc <NUM> may have rotational stops in the dose administering position and the dose collecting position, respectively, to ensure accurate alignment of the cavities <NUM> under air channels <NUM> and positioning in the medicament reservoirs <NUM>, <NUM> respectively.

It is also envisioned that an inhaler provided with more than two, such as three, four, five, or six, reservoirs <NUM>, <NUM> with the same arrangement of inlets, outlets, air channels, dose disc, cavities etc., is within the ambit of the present invention. For example, the inhaler <NUM> may have three medicament reservoirs <NUM>, three air inlets <NUM>, and a dose disc with three cavities <NUM>. Alternatively, the inhaler <NUM> may have four medicament reservoirs <NUM>, four air inlets <NUM>, and a dose disc with four cavities <NUM>. It is preferred however that the inhaler <NUM> have two air inlets <NUM>, two air channels <NUM>, one air outlet <NUM>, two medicament reservoirs <NUM>, <NUM>, and one dose disc <NUM> with two cavities <NUM>.

It is also envisioned that the inhaler <NUM> may be provided with a different dosage mechanism than the one disclosed above, for example electrical drive of different parts, and using paddles instead of the dose disc <NUM>. However, use of the dosage mechanism <NUM> having the dose disc <NUM> and its cooperation with chimney <NUM> of the upper housing <NUM> and the reservoirs <NUM>, <NUM> allows for a very cost effective solution while simultaneously ensuring high dose accuracy and the other benefits disclosed herein.

The air channels <NUM> have a first proximal conformation <NUM> as disclosed in the embodiment in <FIG>. The proximal conformation <NUM> is such that the air channels <NUM> start at inlets <NUM> and extend downstream (during inhalation) in a central and transversal direction, where after they bend downwards at a right angle (<NUM> degrees) to longitudinal sections <NUM> of the air channel <NUM> extending in a longitudinal and distal direction before connecting to transversal sections <NUM> of the air channel <NUM> via a second distal convention <NUM>. In this way, when medicament lies in the cavities <NUM>, the medicament is arranged flush with the transversal sections of the air channel <NUM> and the air flow direction will facilitate initial deaggregation of the medicament from the cavities <NUM>. This facilitates that the medicament in the cavities <NUM> will be dispersed into the air flow and enters into the chamber <NUM>.

Still referring to <FIG>, the inhaler <NUM> according to the exemplary embodiments further comprises a turbulence enhancing protrusion (TEP) <NUM> disposed in the air channel <NUM> proximally above the cavity <NUM>, in particular the TEP <NUM> may comprise a substantially rectangular bar disposed to extend from the transversal section <NUM> into the convention <NUM> and thus form a leading edge in respect of the downstream air flow in the longitudinal section <NUM>. The TEP being configured to augment dissipation of medicament from cavity <NUM> in the dose administrating position by the facilitation of turbulence i.e. velocity fluctuations and disordered flow in layers of a fluid flow adjacent the cavity and at least partially inside the cavity. Thus, in one embodiment the number of TEPs <NUM> may equate to the number of cavities <NUM> so that a medicament cavity <NUM> is associated with a respective TEP <NUM> in the dose administrating position.

The geometrical shape and dimensions of the respective TEP <NUM> may be adapted in accordance with one or more parameters, for example the internal geometries of the inhaler <NUM> including the air channels <NUM>, characteristics of the medicament to be dissipated or parameters relating to the user such as mass flow of air through the inhaler or air channel <NUM> caused by the user applying a pressure difference over the TEP as fluid is inhaled fluid from outlet <NUM> and fluid enters inlet <NUM>.

The provision of a TEP <NUM> may have a throttling effect and causing a pressure drop in the air channels <NUM> aft the TEPs <NUM>. However, benefits include of improved deaggregating effect and dissipation of medicament.

In fluid dynamics, an eddy is the swirling of a fluid and the reverse current created when the fluid is in a turbulent flow regime. Referring to <FIG>, the moving fluid in the air channel <NUM> creates a space devoid of downstream-flowing fluid on a downstream side of the TEP <NUM> adjacent the cavity <NUM>. Fluid behind or below the TEP <NUM> i.e. in proximity of the trailing edges, flows into the void creating a swirl of fluid on each edge of the TEP and/or the trailing edges, followed by a short reverse flow of fluid behind the TEP flowing upstream toward the back/trailing edges of the TEP <NUM>, <NUM>. Eddies are swirl regions which may transport mass, momentum and energy to other regions of flow whereas the so-called Eddy motion of particles refers to the motion of particles in layers of lower velocity to an adjacent layer of higher velocity.

The achieved turbulent flow regimes typically also provide increased shear stress in the fluid, in particular larger wall shear stress than in laminar flow regimes. Considering that the cavity <NUM> is arranged along the wall of the air channel <NUM>, the larger shear stress may thus benefit the dissipation of medicament from the cavity <NUM>.

The transition to a turbulent flow regime in a flow depends mainly to ratio between inertial forces to viscous forces in fluid. Thus, an object of the TEP <NUM> is to increase inertial forces in fluid e.g. by the formation of Eddie motions causing fluctuations in the values of velocity, temperature, pressure and density in the fluid.

These effects may advantageously be applied to enhance the dissipation of medicament from the cavity <NUM> by causing motion of medicament particles in a stationary or low velocity layer to an adjacent layer of higher velocity i.e. motion of a particle form the cavity <NUM> in a direction which may substantially transverse the general flow direction in the air channel <NUM>. Thus, these effects aid in solving the problem of deaggregating and mixing medicament particles from a cavity <NUM> which borders to the air channel <NUM> in the dose administrating position wherein the cavity <NUM> is arranged underneath the air channel <NUM>.

Referring to <FIG>, a simple implementation form of the invention may comprise the inhaler <NUM>, having an air channel <NUM> extending between the air inlet <NUM> and the air outlet <NUM> with the cavity <NUM> arranged in the air channel <NUM>, typically flush with the air channel <NUM> as disclosed in <FIG> and <FIG>. The TEP <NUM> being arranged immediately upstream the cavity <NUM>, such as to accomplish regions of turbulent flow regime in the region of the cavity <NUM>, in particular immediately above and inside the cavity <NUM>; pushing air of high velocity into the cavity <NUM>.

<FIG> and <FIG> shows an exemplary implementation form of the disclosure wherein the TEP <NUM> may advantageously be disposed in a suspended configuration in the air channel <NUM> to protrude into the air channel <NUM> from a locality opposing or partially opposing the cavity <NUM> so that the TEP <NUM> extends from an attached end to at least one free end, in a direction transverse the direction of the air channel <NUM> i.e. in a longitudinal direction of the inhaler <NUM>, and towards the cavity <NUM>. In one aspect, the TEP <NUM> or at least a part thereof extends directly towards the cavity <NUM> i.e. pointing at the cavity <NUM>. Thereby, a fluid flow A, such as air in the air channel <NUM>, may be divided upstream an anterior edge <NUM> of the cavity by means of at least one leading edge <NUM>, <NUM> of the TEP <NUM>. In addition, thereby, the divided fluid flow may again coincide aft the at least one trailing edge <NUM>, <NUM> of the TEP <NUM> which may be adjacent the extent of the cavity <NUM>, hence between the upstream anterior edge of the cavity <NUM> and the downstream posterior edge of the cavity <NUM>. Accordingly, the TEP <NUM> may effectively disrupt the flow and cause local reverse flow above and in the cavity <NUM>. Also, the TEP may effectively work as half open throttling valve, causing accelerations in the air flow about the TEP <NUM> i. due to the pressure gradient over the TEP <NUM> and thus increased fluid velocities and increased ratio of inertial forces to viscous forces in the fluid a the region of the cavity <NUM>, in particular above and inside the cavity <NUM>. Accordingly, the TEP <NUM> may effectively facilitate transition to a turbulent flow regime at least aft a trailing edge or edges <NUM>, <NUM> of the TEP <NUM> where disordered flow and velocity fluctuations are prone to be generated.

The TEP <NUM> extends in a central and transversal direction of the inhaler <NUM> from a longitudinal leading edge of the TEP <NUM> to a longitudinal trailing edge of the TEP <NUM> in respect of the fluid flow A in the air channel <NUM> from the air inlet <NUM> to the air outlet <NUM> and in a central and transversal direction of inhaler <NUM>.

In the dose administering position, the cavity <NUM> may extend downstream in respect of the longitudinal trailing edge of the TEP <NUM> as disclosed in <FIG>.

In some embodiments the TEP <NUM> may extend at least to a centre axis or centre point of the air channel <NUM>. The longitudinal leading edge <NUM> may have a length to height ratio ranging from [Q: Input needed in relation to dimensions] or corresponding to <NUM>/<NUM> - <NUM>/<NUM> of the diameter of the air channel <NUM>.

The TEP <NUM> may comprise a rectangular or substantially rectangular bar-shape having one or more rounded corners and/or edges. The TEP <NUM> may have a thickness in the range of [Q: Input needed] The TEP <NUM> may be tapered in that the distance between the longitudinal edges <NUM>, <NUM> may decrease in the direction into the air channel <NUM>.

In the dose administering position, the longitudinal leading edge <NUM> may be arranged upstream in respect of the cavity <NUM>. In the dose administering position, the cavity <NUM> may extend downstream in respect of the longitudinal trailing edge <NUM>. In one exemplary embodiment the longitudinal trailing edge <NUM> is arranged between an upstream anterior edge of the cavity <NUM> and a posterior downstream edge of the cavity <NUM>. In other exemplary embodiments the longitudinal leading edge <NUM> may be arranged upstream or in line with the anterior upstream edge of the cavity <NUM>.

According to further aspects shown in <FIG>, the inhaler <NUM> may comprise one or more air channels <NUM> wherein each air channel <NUM> includes a longitudinal section <NUM> extending in a longitudinal and distal direction from the air inlet <NUM> via a first proximal conformation <NUM> and towards the cavity <NUM> where connecting to a transversal section <NUM> extending in a central and transversal direction via a distal conformation <NUM>, which conformation <NUM> may be a right-angle conformation. The cavity <NUM> may be disposed in the further distal conformation <NUM> and may be aligned with the longitudinal section <NUM>. The cavity <NUM> may be extending over a surface corresponding to the cross sectional area of the longitudinal section <NUM> or substantially corresponding to the cross sectional area of the longitudinal section <NUM>. Alternatively, the cavity <NUM> may be disposed downstream the distal conformation <NUM> or partially downstream the distal conformation <NUM> so that the cavity <NUM> is partially in the distal conformation <NUM> and thus partially aligned with the longitudinal section <NUM> and partially extending into the transversal section <NUM> as disclosed in <FIG>. The air channel <NUM> may extend from the distal second conformation <NUM> and radially inwards to a third central conformation <NUM> connecting to conduit <NUM> as shown in <FIG>.

The TEP <NUM> may have substantially rectangular shape as disclosed in Fig. <NUM>-12b, having one or more free ends or edges <NUM>, <NUM>. The TEP <NUM> may have the shape of a straight or flat bar having two parallel or substantially parallel main surfaces which may be a frontal side surface <NUM> and a dorsal side surface <NUM> respectively in relation to the direction of the flow A, and a thickness providing at least three edge-surfaces <NUM>, <NUM>, <NUM> or edges, in some embodiments four side surfaces or edges <NUM>, <NUM>, <NUM>, <NUM>. Other shapes of the TEP have been contemplated such airfoil shapes or bow-shapes. These edges <NUM>, <NUM>, <NUM>, <NUM> may cause separation of the flow A and thus facilitate regions of reverse flow and turbulent flow regime as disclosed in <FIG>.

The TEP <NUM> may extend from its point of attachment in a transverse direction of the inhaler <NUM> and comprises an edge making a transverse leading edge <NUM> with respect of a flow A in the air channel <NUM>, in particular with respect of the air flow A in the longitudinal section <NUM>. Correspondingly, the TEP <NUM> may have a transverse trailing edge <NUM> typically extending in parallel or substantially in parallel with the transverse leading edge <NUM>. The transverse leading edge is thus a proximal leading edge <NUM> and the transverse trailing edge a distal trailing edge <NUM> in relation to the proximal end <NUM> of the inhaler <NUM>.

During use, air is typically expelled from an air outlet <NUM> at a proximal end <NUM> of the inhaler <NUM> through inhalation by a user whereby a pressure difference in the conduit <NUM> and air channels <NUM> causes air to enter the air inlets <NUM> and flow downstream into the longitudinal sections of the air channel <NUM> and to the adjoining transversal sections <NUM>. According to aspects, the TEP <NUM> is disposed at least partially in the conformations <NUM> which constitutes conformations between the longitudinal sections <NUM> and the transversal sections <NUM> of the air channels <NUM>. The TEP <NUM> may have a first free end protruding into the flow A flowing from the air inlet <NUM> and flowing downstream towards to the cavity <NUM> as disclosed in <FIG>. Thus, the first free end or a portion thereof comprises a transverse leading edge in the form of a proximal leading edge <NUM> in respect of downstream flow in a longitudinal and distal direction of the inhaler <NUM>. With the proximal leading edge <NUM> being arranged in the flow path between the air inlet <NUM> and the cavity <NUM> the opposite corresponding distal trailing edge <NUM> or portion thereof is also arranged in the flow A between the air inlet <NUM> and the cavity <NUM>. However a portion of the proximal leading edge <NUM> may typically be used as means for suspending the TEP <NUM>, i.e. a portion of the leading edge <NUM> may be attached to the inner wall of the air channel <NUM> and thus, the distal trailing edge <NUM> typically has a longer extent than does the proximal leading edge <NUM> in the embodiment disclosed in <FIG>. The proximal leading edge <NUM> and the distal trailing edge <NUM> respectively may be parallel. The said first free end may further comprise a longitudinal edge in the form of a longitudinal leading edge <NUM>. A second free end of the TEP may protrude towards the cavity <NUM> may comprise the transverse trailing edge <NUM>. According to aspects, the TEP <NUM> is so dimensioned that a gap <NUM> is defined between the distal trailing edge <NUM> and the cavity <NUM>. The gap <NUM> is thereby an intermediate gap between the distal trailing edge <NUM> and the dose disc <NUM> and/or the top medicament layer held in the cavity <NUM>. The gap <NUM> may have a length in the range of [Q: approximate dimensions?] measured from the distal trailing edge <NUM> to the dose disc <NUM> adjacent the air channel <NUM> or the top medicament layer in the cavity <NUM>.

The further two edges defined on the TEP <NUM> in relation to the flow A in the air channel <NUM>; the longitudinal leading edge <NUM> with respect of the flow in the air channel <NUM>, in particular with respect of the downstream flow in a central and transversal direction of the inhaler <NUM>, i.e. in the transversal section <NUM>; the longitudinal trailing edge <NUM> typically extending in parallel with the longitudinal leading edge <NUM> and connecting the proximal leading edge <NUM> to the distal trailing edge <NUM>. The TEP <NUM> may however be tapered such that the distance between longitudinal edges <NUM>, <NUM> decrease in a direction towards the cavity <NUM>.

The proximal leading edge <NUM> may constitute a flat or square edge having a flat surface while the distal trailing edge <NUM>, longitudinal leading edge <NUM> and longitudinal trailing edge <NUM> may typically feature rounded edges having curved surfaces.

The longitudinal leading edge <NUM> may be arranged upstream the corresponding longitudinal trailing edge <NUM>. Typically, the longitudinal leading edge <NUM> is arranged in the distal convention <NUM> and makes a leading edge with respect to a fluid flow directed along the transversal section <NUM> and is disposed upstream the cavity <NUM>. The longitudinal trailing edge <NUM> typically extending in parallel with the leading edge <NUM> and being disposed above the cavity <NUM>, in particular in close vicinity of the anterior edge of the cavity <NUM>. Generally, the fluid flow A in the air channel <NUM> will make a substantially diagonal flow path in respect of the substantially rectangular shaped TEP <NUM>, hence diagonally over the two opposing main surfaces of the TEP <NUM>; the frontal surface <NUM> facing upstream the flow in flow channel <NUM> and the dorsal surface <NUM> facing downstream the TEP in flow channel <NUM>. However, a diagonal flow obviously comprises a respective longitudinal and transverse component which is accomplished by means of providing an air channel <NUM> having a longitudinal section <NUM> connecting to a transversal section <NUM>. This arrangement will thus facilitate a flow A having a lateral component and a vertical component above the cavity <NUM> which causes increased fluid flow inside the cavity <NUM> being arranged underneath the air channel <NUM> in the dose administering position.

In a further possible implementation form of the invention, the air channel <NUM> comprises the longitudinal section <NUM> extending in a longitudinal and distal direction from the air inlet <NUM> to the transversal section of the air channel <NUM> via the distal conformation <NUM>. The conformation <NUM> may be comprised of a portion of the longitudinal section <NUM> and a portion of the transversal section <NUM>. The transversal section <NUM> may extending in a central and transversal direction of the inhaler along the dose disc <NUM> and passing the cavity <NUM>.

The proximal leading edge of the TEP may protrude into the longitudinal section. A portion of the proximal leading edge <NUM> may be attached to the inhaler <NUM>, in particular an inner wall of the air channel <NUM> or a medicament scraper <NUM>. Thus, in a possible implementation form of the invention, the distal trailing edge <NUM> is longer than the proximal leading edge <NUM> and the longitudinal leading edge <NUM> is longer than the longitudinal trailing edge <NUM> as shown e.g. in <FIG> and <FIG>.

In the implementation forms shown in <FIG> and <FIG> also the longitudinal leading edge <NUM> is at least to some extend longer than the longitudinal trailing edge <NUM>.

In <FIG> the cavity <NUM> is arranged in the dose administering position, whereby the distal trailing edge <NUM> may extend at least partially upstream the cavity <NUM>, thus the free trailing edge <NUM> may at least partially oppose the cavity <NUM>. Also, the longitudinal trailing edge <NUM> may be aligned above/over the cavity <NUM> in this position.

The TEP <NUM> may extend in a longitudinal and distal direction of the inhaler <NUM> from the proximal transverse leading edge of the TEP <NUM> to the distal transverse trailing edge of the TEP <NUM> in respect of a fluid flow in the air channel <NUM>, in particular in respect of a fluid flow from the air inlet <NUM> through the longitudinal section <NUM> at least to the distal conformation <NUM>.

A fluid flow, such as air flow A through the distal conformation <NUM> comprise a vertical component and a horizontal component, the fluid flow A in the beginning of the transversal section <NUM>; in close proximity of the cavity <NUM>, flowing about the TEP <NUM> and in the gap <NUM>, may also comprise a vertical and/or distal component as disclosed in <FIG>. Thus, the distal trailing edge <NUM> may constitute a trailing edge in respect of flow also in the transversal section <NUM>.

In the dose administering position, the distal trailing edge <NUM> of the TEP <NUM> may be arranged in respect of the cavity <NUM> with the gap <NUM> there between, the gap <NUM> being in the range of <NUM> to <NUM> / uniform or substantially uniform along the extent of the gap <NUM>.

Still referring to <FIG>, the proximal leading edge <NUM> extends in a straight, or substantially straight transversal direction and constitute a transversally extending leading edge <NUM>. Correspondingly, the distal trailing edge <NUM> may extend in a straight, or substantially straight transversal direction and may constitute an extending trailing edge <NUM>, thereby forming leading- and trailing edges in respect of a flow direction in the longitudinal section <NUM> from an air inlet <NUM> to the distal conformation <NUM>.

<FIG> shows an implementation form of the invention wherein the TEP <NUM> is pivoted and angle θ in relation to the direction of the air channel <NUM> resulting in an angled positon also shown in <FIG> and <FIG>. The TEP <NUM> is preferably fixedly attached in its position relative the air channel <NUM> and is thus not adjustable. The angled position of the TEP <NUM> may facilitate a throttling effect of the TEP <NUM> wherein the flow A is separated along the edges <NUM> and <NUM>. The angled configuration further accomplishes that the flow A is separated over a greater width of the air channel <NUM> and along a greater extent of the air channel <NUM> and thus, turbulence is generated over a larger portion of the surface of the cavity <NUM>.

<FIG> shows various embodiments of the TEP <NUM> which may be formed as an integral part of the medicament scrapper <NUM>. In <FIG> it is illustrated a medicament scrapper absent a TEP and <FIG> illustrates a medicament scrapper <NUM> featuring the TEP <NUM> disposed in the air channel <NUM>, extending from transversal section <NUM> into the conformation <NUM> and/or the longitudinal section <NUM>. As can be derived from <FIG>, the TEP <NUM> may be configured pivoted in relation to the air channel <NUM> so as to make an angle θ in respect of the direction of the transversal section <NUM> of the air channel <NUM>.

<FIG> shows various embodiments of the TEP <NUM> having different dimensional properties. In <FIG> shows a configuration wherein the bar <NUM> has an angled configuration and extends approximately halfway into the longitudinal section <NUM> of the air channel <NUM>, <FIG> shows a configuration wherein the bar <NUM> extends at least halfway into the longitudinal section <NUM> of the air channel <NUM>, <FIG> shows a configuration wherein the bar <NUM> is not in an angled configuration and extends less than halfway into the longitudinal section <NUM> of the air channel <NUM>, <FIG> shows a configuration wherein the bar <NUM> is configured with a large angle in respect of the direction of the transversal section <NUM> of the air channel <NUM> and <FIG> shows a configuration wherein the bar <NUM> has an increased width corresponding to approximately <NUM>% of the width of the longitudinal section <NUM> of the air channel <NUM> and approximately <NUM>% of the width of the transversal section <NUM> of the air channel <NUM>. The skilled reader will appreciate that the invention is not limited to the embodiments of <FIG> which may be combined to yield yet further embodiment.

<FIG> shows various exemplary embodiments of the TEP <NUM> having different depths. The TEP <NUM> in <FIG> features a depth corresponding approximately to half the height of the transversal section <NUM>, in a longitudinal direction of the inhaler <NUM>, or approximately half the height of the medicament scrapper <NUM>. The TEP <NUM> in <FIG> features a depth corresponding approximately to <NUM>% of the height of the transversal section <NUM>, in a longitudinal direction of the inhaler <NUM>, or approximately <NUM>% of the height of the medicament scrapper <NUM>.

The transverse trailing edge <NUM> may extend at least partially along the length of the cavity <NUM> and upstream the cavity <NUM> in the dose administering position or extend from the transversal section <NUM> and at least partially into the longitudinal section <NUM> alternatively extend exclusively into the longitudinal section <NUM> and/or the convention <NUM>.

In the dose administrating position, the distal trailing edge of the TEP <NUM> may be arranged at least partially opposing the cavity <NUM>. The TEP <NUM> may disposed at least partially in the distal convention <NUM> connecting the longitudinal section of the air channel <NUM> to the transversal section of the air channel <NUM>. The distal trailing edge <NUM> may have a length corresponding to <NUM>/<NUM> - <NUM>/<NUM> of the diameter of the air channel <NUM>, or being in the range of [Q: Any preferred dimensions?].

The TEP <NUM> may extend from an attached proximal end of the TEP to at least one free end, wherein the free end comprises three free edges <NUM>, <NUM>, <NUM> arranged substantially perpendicular in respect of each other.

The TEP <NUM> may extend from an attached proximal end to a first free end and to a second free end. The first free end and the second free end may be arranged substantially perpendicular. The first fee end may extend in a longitudinal direction and the second free end may extending in a transverse direction. Thus, the TEP <NUM> may comprise at four edges <NUM>, <NUM>, <NUM>, <NUM> wherein all four edges <NUM>, <NUM>, <NUM>, <NUM> may be arranged substantially perpendicular each other.

In a preferred embodiment, the cavity <NUM> extends further downstream in the transversal section of the air channel <NUM> than does the longitudinal trailing edge of the TEP <NUM>. In a further preferred embodiment, the longitudinal leading edge <NUM> extends along the longitudinal section of the air channel <NUM> so that a gap <NUM> is defined between the transversal trailing edge <NUM> and the cavity <NUM> as has been explained above.

The skilled reader will appreciate that the disclosed invention is not limited to inhalers featuring both a longitudinal section <NUM> and a transversal section <NUM> but may be implemented in any inhaler to enhance dissipation of medicament from a cavity <NUM> arranged in an air channel <NUM> having an air inlet connecting to an air outlet <NUM>.

In a further aspect, the TEP may configured to locally decrease a cross sectional area of the air channel <NUM>, thereby a throttling effect is accomplished, thus increasing the velocity of a fluid flowing about and passing the TEP <NUM> whereby the increased velocity further enhances the dissipation of medicament from the cavity <NUM>. This may be achieved i. by varying the dimensions of the TEP <NUM> e.g. by means of varying the width, length or depth respectively.

The TEP <NUM> may be centrally arranged in the cross section of the air channel <NUM> and/or above the cavity <NUM> and divert the flow in the air channel <NUM> into three flows; to the left hand side and to the right hand side and underneath the TEP in the interspace <NUM> as illustrated in <FIG> and <FIG>.

In some aspects, the TEP <NUM> is pivoted about a longitudinal axis thereof, such as to make an angle of incidence θ with respect of the transverse section of the air channel <NUM> as illustrated in <FIG>. Thus, with this particular configuration, the fluid, such as air, is prone to propagate according to the path of least resistance and thus causing formation of pressure and velocity gradients around the TEP <NUM> which efficiently cause a turbulent flow regime within a region thereof.

The TEP <NUM> may pivoted about a longitudinal axis thereof to form an angle θ in respect of the direction of the transversal section of the air channel <NUM> as disclosed in <FIG>. The angle θ may be in the range of <NUM> to <NUM> degrees. The angle θ may be variable for example to increase or decrease the respective velocities and pressures on each side of the TEP <NUM> so as to facilitate turbulence and formation or eddies at the desired location in the air channel <NUM>. The angle θ may in other aspects be adapted in accordance with the properties of the medicament in a specific cavity <NUM>. It has been contemplated that an inhaler <NUM> for example with two cavities each holding a respective medicament with different properties may also have TEPs <NUM> with tailored individual properties such as angle, length, depth and thickness.

Accordingly, the TEP <NUM> may effectively facilitate accelerations in the air flow about the TEP <NUM> and thus increased fluid velocities and increased ratio of inertial forces to viscous forces in the fluid above the cavity <NUM>.

The entity providing the suspending of the TEP <NUM> may in some aspects include a medicament scrapper <NUM> as disclosed in <FIG>. According to aspects the TEP <NUM> constitutes an appendix extending from the medicament scrapper <NUM> and being formed as an integral part of the medicament scrapper <NUM>. The medicament scrapper <NUM> may form an interproximal section of the air channel <NUM> or air channels associated with the cavities <NUM> and constituting at least part of a section of the air channel <NUM> being in close proximity of the cavity <NUM>. However, other configurations are contemplatable.

The proximal leading edge <NUM>, or a portion thereof, may be attached to a medicament scraper so that the TEP <NUM> is protrudes from the medicament scraper <NUM>. In preferred embodiment, the TEP <NUM> forms an integral part or appendix of the medicament scrapper <NUM>.

In addition, the present invention also address the problem of agglomeration of aggregated medicament commonly associated with prior art deaggregating deflectors. As have been mentioned, moisture and the cohesive forces of medicament particles typically exacerbate the agglomeration propensity of medicament on interior parts of inhalers, in particular on the deflectors. This problem is mitigated with respect of the TEP <NUM> according to the invention by means of arranging the TEP upstream or at least partially upstream in relation to the cavity <NUM>. According to some embodiments, the TEP according to the invention does not feature a leading edge disposed downstream of the cavity <NUM> and thus medicament particles substantially will not propagate about the TEP but rather further downstream the TEP upon dissipation into the air channel <NUM>.

A throttling effect of the TEP <NUM> may be achieved and the effect manipulated by varying the thickness of the TEP <NUM> and thus, the ratio between the cross sectional area of the air channel <NUM> and the TEP <NUM> arranged therein respectively may be varied for optimal effect.

Also, the longitudinal depth of the TEP i.e. the length with which it extends from its attached end into the air channel <NUM> may be optimized so that optimal deaggregating effect of the TEP <NUM> is achieved.

The cavity <NUM> may have circular shape or a substantially circular shape having a diameter substantially corresponding the diameter or the air channel <NUM>, in particular the longitudinal section <NUM> and/or the transversal section <NUM>.

This arrangement means for example that the reservoirs <NUM>, <NUM> may comprise a dry powder medicament in the form of a micronized formulation or a carrier based formulation, or mixtures thereof. The inhaler <NUM> may then for example comprise a dry powder medicament in form of a micronized formulation in the first reservoir <NUM> and a free-flowing dry powder medicament in form of a carrier based formulation in the second reservoir <NUM>.

It may not necessary for the air channels <NUM> to have a strictly right angle conformation as illustrated in <FIG>. The air channels <NUM> could also curve inwards and downwards from inlets <NUM> before ending above and in line with the cavities <NUM>. Other air channel conformations are considered within the ambit of the invention provided the inhaled air flow facilitates deaggregation of the medicament from the cavities <NUM>.

Depending on the medicament to be administered, and the formulation thereof, the cavities <NUM> may take the form of a single circular shape when viewed from directly above or below the inhaler <NUM> as illustrated by the semi-circular shape of cavities <NUM> in <FIG>. The single circular shape will be of approximately the same size and shape as the air channel <NUM>. This will be most suitable when the medicament is not readily susceptible to aggregation and / or a large dose is desired. Other medicaments which tend to aggregate more may form an undesirable "plug" in the cavity <NUM> which is not readily dispersible during inhalation. Then it may be preferable to make several cavities <NUM> each having a relatively smaller diameter than a single circular shape as illustrated in <FIG>. The several smaller cavities will continue to lie underneath one of the air channels <NUM> which remains unchanged in size and shape. An inhaler with several smaller cavities lying underneath one air channel <NUM> also allows for delivery of a smaller amount of powder. This feature also adds the possibility to combine or adapt the inhaler <NUM> for deliverance of micronized formulations and/or carrier based formulations.

The reservoirs <NUM>, <NUM> may be provided with medicament scrapers <NUM> illustrated in <FIG> and <FIG>. The scrapers <NUM> are suspended at the bottom of the reservoirs <NUM>, <NUM> such that they bear upon the dose disc <NUM>. The scrapers <NUM> will pass over the cavities <NUM> of the dose disc <NUM> so that excessive medicament is removed from the cavities <NUM> to ensure correct dose volume. The scrapers <NUM> will also aid in compacting medicament in the cavities <NUM> which will improve retention of medicament in cavities <NUM> when the dose disc has been rotated into the dose administering position. Since the scrapers <NUM> are suspended at the bottom of the reservoirs <NUM>, <NUM> they will automatically slide along the upper proximal surface of the dose disc <NUM>, when the dose disc <NUM> is rotated between the dose administering position and dose collecting position. Preferably, each reservoir <NUM>, <NUM> has a number of scrapers evenly distributed along the bottom of the reservoirs <NUM>, <NUM>. In this way the scrapers do not only aid in obtaining correct dose volume and dose compacting but also aid in distributing medicament at the bottom of the reservoirs <NUM>, <NUM>. The number of scrapers per reservoir <NUM>, <NUM> could for example be selected in the interval of <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM>. It is also envisioned that the scrapers are arranged in an uneven distribution in the reservoirs <NUM>, <NUM> if certain reservoirs are configured such that an uneven distribution of the scrapers will have a beneficial effect on the medicament distribution along the bottom of the reservoirs <NUM>, <NUM>.

During inhalation the medicament is emptied radially from the cavity <NUM> with the air flow from the air channels <NUM> into the chamber <NUM> wherein the air/medicament streams from the different air channels <NUM> and cavities <NUM> will cross, such that the medicament agglomerates will collide to increase deaggregation, where after a jet stream of finely dispersed medicament and air will continue through conduit <NUM> and inhalation chimney <NUM> out of the inhalator <NUM> through outlet <NUM> and into the lungs of the user. This radial emptying of the cavities <NUM> was described further above with respect to <FIG>. The conduit <NUM> and the chimney <NUM> increases jet formation, allowing for a maintained low aggregation of medicament, hence increasing potential of medicament to reach far into the lungs of the patient. The conduit <NUM> and chimney <NUM> are generally tubular, but could optionally be provided with diverters, to further increase jet creation. Such diverters could be bumps or spiral-shaped ridges, extending along the length of the conduit and / or chimney from the chamber <NUM> to the air outlet <NUM>. The chimney <NUM> does not necessarily have to be directed upwardly; it can just as well be directed downwardly or to the sides, whereby the outlet <NUM> is instead positioned at the bottom or on the sides, respectively. Additionally, the chimney <NUM> does not have to be generally tubular, but could be bent or sinus-shaped, depending on where on the inhaler <NUM> it is preferred to position the outlet <NUM>. For flow characteristics and dose reliability and maintenance, it is however preferred to have it directed upwardly and generally tubular with optional diverters. The general shapes of the conduit <NUM> and the chimney <NUM> may also be such as to have differences in cross-sectional area, such as is present in a cone-shaped chimney. In this way, the flow velocity in the conduit and chimney may be regulated so as to help in deaggregation at chosen parts.

During use of the inhaler <NUM> the user will then simply rotate the upper housing <NUM> in one direction and thus the dose disc <NUM> into a dose collecting position if the dose disc is in a dose administering position. Thereafter, the upper housing <NUM> and the dose disc <NUM> are rotated preferably into the opposite direction to reach the dose administering position. If the dose disc <NUM> is already in the dose collecting position then of course the first rotation into the dose collecting position may be omitted. During these rotations, the scraper <NUM> will fill the cavities <NUM> of the dose disc <NUM> in the reservoirs <NUM>, <NUM>. After the dose disc <NUM> has been rotated into the dose administering position the cavities <NUM> are filled with medicament - optionally two different medicaments - and lie underneath the air channels <NUM>. Then the user puts his/her mouth at outlet <NUM> and inhales. During inhalation air A will enter the inhaler <NUM> through inlets <NUM> and flow through air channels <NUM> to disperse and carry therewith the medicament(s) M from the cavities <NUM> in a radial direction in accordance with the arrows shown in <FIG>, <FIG> and <FIG>. The air/medicament flow AM will then enter the chamber <NUM>. In the chamber <NUM>, the air/medicament flows AM from the air channels <NUM> and cavities <NUM> will cross each other or coincide with each other, such that deaggregation of the medicaments M will increase which may increase dose uniformity since the need for diverters then is decreased. The flow characteristics, such as jet stream formation, will also increase. This feature allows the possibility to combine or adapt the inhaler <NUM> for deliverance of micronized formulations and/or carrier based formulations. Of course, it is also possible to combine the feature of crossing or coinciding flows from the two air channels <NUM> with diverters, even though the need thereof is decreased. Thereafter, the air/medicament flow AM - now comprising air/medicament flows from both air channels <NUM> and cavities <NUM>, will go up through the conduit <NUM>, the inhaler chimney <NUM>, and finally through outlet <NUM> into the lungs of the user. A similar sequence of steps is then repeated the next time the inhaler <NUM> is required i.e. the user rotates the upper housing <NUM> and thus the dose disc <NUM> into a dose collecting position to fill the cavities <NUM> with a medicament(s) then the user rotates the dose disc <NUM> back into the dose administering position and inhales at outlet <NUM> as described immediately above.

The structure of, and functional relationship between, the cavities <NUM>, reservoirs <NUM>, <NUM> and the separate dose collecting and dose administering positions allows for no risk of multiple dosing by the user. In use the medicaments remain in the cavities <NUM> until inhalation. If inhalation is not commenced or is no longer required by the user, the cavities <NUM> carrying the medicaments may be rotated back into the reservoirs <NUM>,<NUM>.

According to a further aspect, the invention relates to a method for dissipating medicament from a cavity (<NUM>). The cavity (<NUM>) may be disposed underneath an air channel (<NUM>) of a dry powder inhaler (<NUM>) and the air channel (<NUM>) connecting an air inlet (<NUM>) to an air outlet (<NUM>). The method may comprise providing a dry powder medicament in the cavity (<NUM>) and providing a turbulence enhancing protrusion (<NUM>) disposed to protrude into the air channel (<NUM>), upstream the cavity (<NUM>) preferably at least partially upstream of the cavity (<NUM>). During use, a pressure difference may be applied over the turbulence enhancing protrusion (<NUM>) e.g. by a user ingesting air from the inhaler (<NUM>), in particular from the outlet (<NUM>) thereby causing an air flow through the inlet (<NUM>) and through the air channel (<NUM>). As the caused air flow through the air channel (<NUM>) is incur with the one or more of the leading edges (<NUM>, <NUM>) and/or trailing edges (<NUM>, <NUM>), this will have the effect that the regime of the air flow will be disrupted, causing or enhancing turbulence aft the respective edge (<NUM>, <NUM>, <NUM>, <NUM>).

The air flow in the air channel (<NUM>) may have a longitudinal direction and a transverse direction in relation the inhaler (<NUM>), thus a longitudinal component and a transverse component being parallel the extent of the cavity (<NUM>). The turbulence enhancing protrusion (<NUM>) man have a proximal leading edge (<NUM>) and a distal trailing edge (<NUM>) with respect of the longitudinal component and a leading edge (<NUM>) and a trailing edge (<NUM>) with respect of the transversal component. Typically, the longitudinal component is vertical or substantially vertical and the transverse component is horizontal or substantially horizontal during operation i.e. upon use of the inhaler.

Although, the present invention has been described above with reference to specific embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the invention is limited only by the accompanying claims.

Claim 1:
A dry powder inhaler (<NUM>) comprising:
at least one air inlet (<NUM>) at a distal end zone of said inhaler (<NUM>), at least one air outlet (<NUM>) at a proximal end zone of said inhaler (<NUM>), and an air channel (<NUM>) between said at least one air inlet (<NUM>) and said at least one air outlet (<NUM>);
at least one medicament reservoir (<NUM>);
a dosage mechanism (<NUM>) for arranging at least one dose of a medicament from said at least one medicament reservoir (<NUM>) between the air channel (<NUM>) and the air outlet (<NUM>) such that said at least one dose may be delivered upon inhalation at said air outlet (<NUM>), wherein the dosage mechanism (<NUM>) comprises a dose disc (<NUM>) with at least one cavity (<NUM>), wherein the dose disc (<NUM>) may be rotated between a dose collecting position wherein the cavity (<NUM>) is positioned in the medicament reservoir (<NUM>), and a dose administering position wherein the cavity (<NUM>) is in communication with said air channel (<NUM>);
a turbulence enhancing protrusion (<NUM>) disposed suspended into said air channel (<NUM>), characterized in that
said turbulence enhancing protrusion (<NUM>) has a leading edge (<NUM>) and a trailing edge (<NUM>) in respect of a fluid flow (A) in the air channel (<NUM>) from the at least one air inlet (<NUM>) to the at least one air outlet (<NUM>),
wherein in said dose administrating position, said cavity (<NUM>) is extending downstream said trailing edge (<NUM>).