HK1260356A1 - Disposable monodose inhaler for powdered medicaments - Google Patents

Description

Disposable single dose inhaler for powdered medicaments

Technical Field

The present invention relates to an inhaler for powdered medicaments, in particular a disposable single dose inhaler.

Background

It is known that administration of a drug in the form of an inhaled powder is an effective and non-invasive way of providing the patient with the drug he/she needs. For this reason, several devices have been designed for administering powdered medicaments, usually in the form of reusable multidose inhalers. An example of such an inhaler is disclosed in US 5301666.

However, this type of inhaler has various drawbacks: a rather high cost; the unusual complexity, which makes its use very difficult, especially for elderly patients; over time, it is difficult to maintain it in a satisfactory hygienic condition; the risk of the powdered medicament not being delivered correctly due to thickening or formation of the film by moisture or other factors; in fact, most drugs do not typically reach the lungs of a patient because they are deposited on the walls of the mouth and throat.

To overcome these drawbacks, a single dose inhaler disclosed in US 5669378 was developed, which has a much simpler and cheaper structure and can therefore be used as a disposable inhaler. In this way, there is no risk of poor hygiene and deterioration of the drug, and the difficulty of use is much lower.

In fact, this type of inhaler is essentially constituted by a tubular body with a first portion adapted to contain a cartridge containing the drug, which is connected to a second portion by a grid for delivering the powder to be put into the mouth of the patient. To release the powder from the cartridge, a button is provided having a spike adapted to pierce a spike placed in a suitable support member, with a button support spring arranged between the button and the cartridge support member to prevent premature piercing of the cartridge. Although this disposable single dose inhaler is a significant improvement over previous multi-dose inhalers, it is not without its drawbacks.

First, it does not solve the problem of drug deposition in the oropharyngeal cavity before reaching the lungs. Thus, if a patient does not obtain his/her desired relief from the drug, he/she tends to administer another dose to him/herself prematurely and risks various unpleasant side effects due to overdosing. In addition, the drug deposited in the oropharyngeal cavity may cause problems such as pain, cough, dryness, and the like.

Secondly, it still requires the assembly of the above three components (button, spring, cartridge support) in the housing part, which implies a certain manufacturing cost and risk of failure in case of defective assembly.

In order to overcome these drawbacks, another single-dose inhaler has been developed, as described in EP 1799289, which has an even simpler and cheaper structure and, above all, is provided with a downcomer in the delivery section and is suitable for housing an automatic perforated cartridge. Thanks to this inhaler structure, a secondary air flow delivered by the downcomer is obtained, which supports and guides the primary air flow carrying the powdered medicament, so that it can flip over the patient's tongue. In this way, excessive deposition of the drug in the oropharyngeal cavity is prevented and a better therapeutic effect is obtained due to the greater amount of drug reaching the lungs.

The presence of the secondary air stream provides another advantage in that the drug is better separated from the excipient (typically lactose) due to the secondary air stream impinging on and directing the primary air stream. Furthermore, the inhaler is adapted to accommodate an auto-piercing cartridge, such as the cartridge disclosed in EP 1409365, whereby other components for piercing the cartridge described in the above-mentioned prior art inhaler can be omitted.

Although this disposable single dose inhaler is a significant improvement over the previous inhaler described in US 5669378, it is not without its drawbacks.

In fact, the main feature of a dry powder inhaler is that it is directly activated when the patient inhales and the drug is inhaled while the patient inhales, and therefore the key to the perfect performance of the device is the inhaler design, which must ensure minimum resistance in the delivery flow and the formation of turbulence, thus ensuring good separation of the drug from the excipient.

In the case of the single dose inhaler described in EP 1799289, it was found that in patients with asthma or poor respiratory capacity, the performance of the device is not optimal in terms of both the dispersion of inhalable drug particles and the creation of resistance in the flow.

Another drawback is that it is difficult, especially for elderly patients, to correctly position and block the self-piercing cartridge on the housing part of the inhaler so that there is no problem during the cartridge opening phase and all the medicament falls within the designated area.

Another drawback derives from the fact that in said inhalator, the baffle separating the lower duct from the upper duct in the delivery duct extends up to the end of the delivery duct placed in the mouth of the patient, through which the primary charge flows. Thus, it may occur that the patient's tongue blocks the outlet of the downcomer, preventing secondary air flow delivery when the patient inhales to inhale the drug.

Another drawback arises from the risk that the patient introduces the delivery conduit into his/her mouth over a length that is too short or too long, whereby the inhaler may slip out of the patient's mouth or almost completely enter the mouth when inhaling air, and in both cases affect the drug delivery. Furthermore, involuntary ingestion of the inhaler also carries the risk of suffocation for the patient.

Disclosure of Invention

It is therefore an object of the present invention to provide a disposable single dose inhaler without the disadvantages described. Said object is achieved by an inhaler similar to that described in EP 1799289, but provided with a support base for the self-piercing cartridge formed in the housing part, in which support base a directional flow channel is formed, which extends between at least three air inlets and a powder drop area at the bottom of the housing part. Other preferred features of the inhaler involve shortening the baffle separating the downcomer from the upper duct so that it does not extend to the end of the delivery duct, providing an external flange on the delivery duct that limits the depth in the intake opening, and creating a plurality of separate air inlet regions for feeding the downcomer through an air intake opening formed in the distal end of the downcomer.

A first important advantage of the present inhaler is achieved by the presence of a directional flow path which, during inhalation by the patient, even under low suction conditions, contributes to the formation of vortices which intersect in the region of the drop of powder, creating turbulence which will result in very high flow rates, promoting dispersion of the inhalable drug particles and thus increasing the rate of inhalation of the drug.

A second significant advantage of this inhaler is that it is easy to install the self-piercing cartridge and the high stability of the cartridge is ensured by the support base, so that the cartridge can be factory pre-mounted on the inhaler, whereby even patients who have difficulty in grasping and opening the cartridge do not risk spreading the powder outside the intended dripping area.

Another advantage of the inhaler derives from the fact that the shortened dividing baffle of the delivery duct ensures that the secondary air flow is always delivered, since the secondary air flow will start its work of supporting the primary air flow even before reaching the end of the delivery duct placed in the patient's mouth. Furthermore, the multiple zones of the air inlet of the downcomer ensure that the secondary air flow has a sufficient flow rate and minimal resistance for the air to slide smoothly within the downcomer.

Another advantage of such an inhaler is that the external flange of the delivery conduit, which defines the exact introduction depth of the inhaler in the patient's mouth, ensures greater safety and ease of use, thereby achieving optimal drug delivery and preventing ingestion risks.

Drawings

Further advantages and features of the inhaler of the present invention will become apparent to the skilled person from the following detailed description of an embodiment of the inhaler of the present invention with reference to the accompanying drawings, wherein:

FIG. 1 is a top perspective view of the inhaler from the distal end thereof;

FIG. 2 is a bottom perspective view of the inhaler as seen from the distal end of the inhaler;

FIG. 3 is a front perspective view of the inhaler as seen from the proximal end of the inhaler;

FIG. 4 is a top plan view of the inhaler;

FIG. 5 is a view similar to the front with the cartridge mounted on the inhaler;

figure 6 is a cross-sectional view of the inhaler taken along its longitudinal mid-plane with the cartridge mounted on the inhaler;

fig. 7 is a view similar to the previous with the cartridge open for delivery of the powder;

figure 8 is a top perspective view of the airflow through the inhaler when the inhaler is in operation.

Detailed Description

With reference to the figures, it can be seen that the disposable inhaler according to the invention is generally constituted by a substantially tubular hollow body having a first portion 1 (fig. 5-7) for containing a cartridge C of powdered medicament and a second portion 2 for delivering the medicament through a delivery conduit 3, the end of the delivery conduit 3 being suitable for being placed in the mouth of a patient. Said duct 3 is horizontally divided by a dividing baffle 4 into an upper duct 3a and a lower duct 3b, the upper duct 3a delivering a primary flow FP of powder-carrying air (indicated by the dashed arrows in fig. 7), the lower duct 3b delivering a secondary flow FS of powder-free air (indicated by the white arrows in fig. 7) supporting and guiding the primary flow FP of air during inhalation.

The connection between the powder drop area 5 on the bottom of the first part 1 and the upper duct 3a is achieved by means of a grid 6, the grid 6 being dimensioned to prevent passage of cartridge fragments that will fall from the cartridge when the powder is released. The purpose of the grid 6 is, moreover, to ensure a relatively uniform diffusion of the particles in the direction of the user's respiratory tract with the aid of the formation of turbulences and to facilitate the separation and dispersion of any powder agglomerates, while at the same time separating the drug particles from the excipient particles so that they can better reach the lungs.

The suction of the air forming the primary powder laden air flow PF takes place through at least three air inlets 7, the air inlets 7 serving as inlets to said powder drop zone 5; preferably, the central air inlet is centered on the longitudinal mid-plane of the inhaler in the distal position, and the other two lateral air inlets are symmetrically arranged with respect to said mid-plane. The suction of the air forming the secondary supporting air stream FS is performed through an air inlet 8 formed at the distal end of the downcomer 3 b.

The flows F entering through the three inlets 7 are combined to form a primary air flow FP which conveys the powder from the area 5 through the grille 6 along the upper conduit 3a into the mouth of the patient, being supported by the secondary air flow FS coming from the lower conduit 3b when entering the mouth.

A first novel aspect of the inhaler according to the present invention consists in the presence of a supporting seat for supporting the cartridges C, said seat being formed in the first portion 1 by a plurality of horizontal supporting surfaces 9, said horizontal supporting surfaces 9 being preferably formed on a plane corresponding to the top of the upper conduit 3a, as shown in the cross-sections of figures 6 and 7. The vertical wall 10 connecting said horizontal surface 9 with the powder drop zone 5 on the bottom of the first part 1 defines three flow channels 11 extending between the three inlet openings 7 and said zone 5.

More specifically, the longitudinal axes of the two channels 11 extending from the lateral air inlet 7 form an angle α (fig. 4) with the median plane, which is indicatively equal to 55 °, but can vary by ± 20%. With this orientation of the channels 11, the air flows F from the three air inlets 7 converge substantially at the point of the area 5 where most of the powder falls, i.e. in correspondence of the position of the area P on which the patient exerts finger pressure to open the cartridge C (fig. 5-7). In this way, it is possible to obtain a sufficient turbulence, as shown in fig. 8, which is sufficient to achieve the dispersion of the inhalable medicament particles even under low suction conditions.

Note that in the case of a large number of air inlets 7, for example four or five, they will always be formed, preferably symmetrically with respect to the mid-plane, in a position such that the aforementioned region P is located between the intersections of the axes of the channels 11. Furthermore, although the walls 10 of the channels 11 are depicted as being parallel to each other, they may also be diverging or converging in order to further condition and direct the flow F entering from the inlet 7, the inlet 7 preferably having at least 6.4mm²Cross section of the channel.

The peripheral wall 12 of the first part 1 extends above the support base in the upper part of the first part 1, which peripheral wall 12 is provided with coupling means for achieving an easy and effective blocking of the cartridge C on the inhaler. More specifically, in correspondence with each support surface 9, the wall 12 has a zone 12a of reduced thickness, which zone 12a gives the wall 12 an elastic flexibility, and at the centre of each zone 12a triangular tooth 12b is formed, projecting inwards. Such teeth 12b are formed with an inclined surface extending from the top of the wall 12 towards the support base and ending at the bottom in a horizontal base, so as to form a cone for insertion from above the cartridge C and block it on the support base (fig. 5-7).

Note that, in order to ensure the necessary flexibility of the zone 12a carrying the blocking tooth 12b, the support surface 9 is formed spaced apart from the zone 12a, leaving an empty space 13 around each tooth 12 b. Furthermore, the base of the tooth 12b is positioned slightly above the plane of the support base, taking into account the thickness of the peripheral edge of the cartridge C engaged with the tooth 12 b.

In practice, the cartridges C are positioned on the inhaler by means of a fully automatic production line, exerting a defined pressure on the peripheral edge of the cartridges C, which causes the four elastic areas 12a to be pushed outwards and then returning to their original position during the step of blocking the cartridges C on the inhaler by engaging the four teeth 12b of the edge of the cartridges C. In this way, during the steps of automated production, each individual cartridge C is assembled with the inhaler after being filled and sealed, resulting in a single-dose disposable device for inhalation of powdered medicaments, which is easy for anyone to use.

The wall 12 also encloses a distal portion 9 'of the top of the upper guide tube 3a, said distal portion 9' thus being part of the support base of the cartridge C. Also part of their support base are three vertical baffles 14 which extend the entire height of the grille 6 and divide it into four air inlet zones to divide and align the primary air flow FP coming from the zone 5, said baffles 14 being preferably arranged to obtain inlet zones of the same width.

Similarly, in the second novel aspect of the present inhaler, the air inlet 8 of the downcomer 3b is divided into a plurality of air inlet zones, preferably always of the same width, by a series of elongated baffles 15 (five in the illustrated example, but they may be one to seven) extending below the powder drop zone 5, so as to promote the sliding of the secondary air flow FS by preventing the occurrence of any resistance. Furthermore, these elongated baffles 15 are also ergonomic in that they prevent the fingers of the patient holding the inhaler from closing (even only partially) the air inlet 8, thereby reducing the flow rate and efficiency of the secondary air flow FS.

As previously mentioned, the secondary air flow FS supports the primary air flow FP and prevents powder from depositing also by gravity on the patient's tongue or other walls of the oropharyngeal cavity. This support and guide function is particularly important in cases where the patient holds the distal end of the inhaler leaning too far upwards.

This can be increased or decreased by varying the ratio between the cross-section of the air inlets 7, 8 and/or the inlet cross-section of the ducts 3a, 3b (meaning the actual clear cross-section of the passage of the grille 6 and the baffle 15), which can be increased or decreasedA supporting effect and an effect of separating the drug from the excipient. More specifically, the minimum inlet cross-section of the upper duct 3a is 25.6mm²20% and the minimum inlet cross section of the downcomer 3b is 14.3mm²20%, the ratio of the sections may vary from 1:1 to 9: 1.

In other words, the two flows FP, FS can be adjusted by the design of the various parts of the inhaler in order to obtain several embodiments with different inhalation characteristics for different specific applications. In the design parameters, in a third novel aspect of the inhaler, there is also a distance d (fig. 6) between the proximal end of the delivery conduit 3 and the proximal end of the separation baffle 4, which is preferably between 4 and 7 mm.

As previously mentioned, a fourth novel aspect of the present inhaler is the presence of an external flange on the delivery conduit (not shown in the figures) which limits the depth of introduction of the delivery conduit into the mouth. The flange may be made as an integral part of the inhaler or it may be a separate element that is mounted on the inhaler by the patient, in which case the delivery conduit is provided with coupling means for the flange, e.g. a seat into which the flange can engage.

It is therefore evident that the embodiments of the inhaler according to the invention described and illustrated above are only examples susceptible of various modifications. In particular, although the parts 1, 2 are shown connected at 90 °, it is obvious that the whole of the inhaler can also be realized with a smaller angle between said parts, for example 45 ° or 60 °.

Furthermore, the number, shape and arrangement of the air inlets 7 can be freely varied, and therefore the air inlets 7 can be very different from the above-described protruding semicircular shape. For example, the air inlet 7 can be a simple opening of any shape, formed in the lower wall of the first portion 1 below the support base.

Claims (22)

1. Inhaler for powdered medicaments consisting of a substantially chimney-shaped hollow body having a first part (1) for containing a cartridge (C) of powdered medicament and a second part (2) connected substantially perpendicularly to the first part (1) for delivering the medicament by a primary air Flow (FP) carrying the powder along a delivery conduit (3) from an internal powder drop zone (5) located at the bottom of the first part (1), the end of the delivery conduit (3) being adapted to be placed in the mouth of a patient, the delivery conduit (3) being horizontally divided by a dividing baffle (4) into an upper conduit (3a) and a lower conduit (3b), the upper conduit (3a) delivering the primary air Flow (FP), the lower conduit (3b) delivering a powder-free secondary air Flow (FS), the introduction of the air forming the primary air Flow (FP) is achieved through at least three air inlets (7), at least two of said at least three air inlets (7) being lateral air inlets (7) arranged symmetrically with respect to the longitudinal mid-plane of the inhaler, the introduction of the air forming the secondary air Flow (FS) being achieved through air inlets (8) formed at the distal end of the downcomer (3b), the inhaler being characterized in that it further comprises a support base for the cartridges (C) within the first portion (1), in which support base directional flow channels (11) with respective longitudinal axes are formed, said directional flow channels (11) extending between said at least three air inlets (7) and the internal powder drop area (5).

2. Inhaler according to claim 1, characterized in that the longitudinal axis of the channel (11) extending from the lateral air inlet (7) for the primary air Flow (FP) forms an angle (a) of 55 ° ± 20% with the longitudinal mid-plane.

3. Inhaler according to claim 1 or 2, characterized in that there are three air inlets (7) for the primary air Flow (FP) and in that the longitudinal axes of the channels (11) converge at a point of the internal powder drop zone (5) which substantially corresponds to the position of the region (P) of the cartridge (C) where the patient exerts finger pressure to open the cartridge (C).

4. Inhaler according to claim 1 or 2, characterized in that there are more than three air inlets (7) for the primary air Flow (FP) arranged symmetrically with respect to the longitudinal mid-plane and in such a position that the region (P) of the cartridge (C) on which the patient exerts finger pressure to open the cartridge (C) is comprised between the intersections of the longitudinal axes of the channels (11).

5. Inhaler according to claim 1 or 2, characterized in that the support base comprises a plurality of horizontal support surfaces (9) protruding within the first part (1).

6. Inhaler according to claim 1 or 2, characterized in that the connection between the inner powder drop zone (5) and the upper duct (3a) is realized by a grille (6).

7. An inhaler according to claim 6, further comprising three vertical baffles (14) extending along the entire height of the grille (6) and dividing the grille into four air inlet regions.

8. Inhaler according to claim 1 or 2, characterized in that the separation baffle (4) is shorter than the delivery duct (3) by a distance (d) comprised between 4 and 7 mm.

9. Inhaler according to claim 5, characterized in that the first part (1) comprises a peripheral wall (12) extending above the support base and provided with coupling means for blocking the cartridges (C) on the inhaler.

10. Inhaler according to claim 9, characterized in that the peripheral wall (12) has, in correspondence of each horizontal support surface (9), an elastic zone (12a) of reduced thickness, the elastic zone (12a) having a central triangular tooth (12b) projecting on the inside, the central triangular tooth (12b) being formed with an inclined surface extending from the top of the peripheral wall (12) towards the support base and a horizontal bottom base, so as to achieve a tapering for insertion from above the cartridge (C) and a blocking of the cartridge on the support base.

11. Inhaler according to claim 1 or 2, characterized in that the air inlet (8) of the downcomer (3b) is divided into a plurality of air inlet zones by one or more elongated baffles (15) extending below the internal powder drop zone (5).

12. An inhaler according to claim 1 or 2, characterized in that the smallest channel cross section of the upper duct (3a) is 25.6mm ± 20%, the smallest channel cross section of the lower duct (3b) is 14.3mm ± 20%, and the ratios between the sections vary within the range of 1:1 to 9: 1.

13. Inhaler according to claim 1 or 2, characterized in that the air inlet (7) for the primary air Flow (FP) is constituted by a protrusion formed in the lower wall of the first part (1), below the support base.

14. Inhaler according to claim 1 or 2, characterized in that it further comprises an external flange on the delivery duct (3) dimensioned to prevent the patient from ingesting the inhaler.

15. Inhaler according to claim 14, characterized in that the external flange is made as an integral part of the inhaler or as a separate element mounted on the inhaler by means of coupling means formed on the delivery duct (3).

16. An inhaler according to claim 1, characterized in that all of the air inlets (7) for the primary air Flow (FP) are arranged symmetrically with respect to the longitudinal mid-plane of the inhaler and one of the air inlets (7) extends across the longitudinal mid-plane.

17. An inhaler according to claim 5, characterized in that the horizontal support surface (9) is formed on a plane corresponding to the top of the upper duct (3a) so that a distal portion (9') of the upper duct (3a) also constitutes part of the support base.

18. An inhaler according to claim 3, wherein the support base comprises a plurality of horizontal support surfaces (9) protruding within the first portion (1).

19. An inhaler according to claim 4, wherein the support base comprises a plurality of horizontal support surfaces (9) protruding within the first portion (1).

20. Inhaler according to claim 18, characterized in that the horizontal support surface (9) is formed on a plane corresponding to the top of the upper duct (3a) so that the distal portion (9') of the upper duct (3a) also constitutes a part of the support base.

21. Inhaler according to claim 19, characterized in that the horizontal support surface (9) is formed on a plane corresponding to the top of the upper duct (3a) so that the distal portion (9') of the upper duct (3a) also constitutes a part of the support base.

22. Single-dose disposable device for inhaling powdered medicaments, characterized in that it comprises an inhaler according to any one of claims 9 to 21 and an auto-perforated cartridge of powdered medicament blocked on the supporting base of the inhaler.