WO2005016422A1

WO2005016422A1 - Inhalator for dispensing powdery medicaments

Info

Publication number: WO2005016422A1
Application number: PCT/FI2004/000478
Authority: WO
Inventors: Marko JÄRVIÖ; Marko Puruskainen
Original assignee: Lite On Mobile Oyj
Current assignee: Lite On Mobile Oyj
Priority date: 2003-08-15
Filing date: 2004-08-13
Publication date: 2005-02-24
Anticipated expiration: 2006-02-15
Also published as: FI20031158A7; FI20031158L; FI20031158A0

Abstract

The invention relates to an inhalator for dispensing powdery medicaments, which inhalator has a medicament container (3) for storing the medicament to be dispensed, an air duct (6), to which the dosages are brought for transfer by means of air flowing in the air duct (6) to the respiratory organs, and a dispenser (5) for dispensing the dosage and transferring it from the medicament container (3) to the air duct (6). The dispenser (5) has preferably conical dispensing openings (5c) leading through it and expanding in the flow direction of air, which when at the medicament container (3) can be filled with the powdery medicament and which, correspondingly, when at the air duct (6), open substantially upward in the normal operating position of the inhalator so that air flowing through the dispensing openings (5c) transports the powdery medicament onward along the air duct (6).

Description

INHALATOR FOR DISPENSING POWDERY MEDICAMENTS

BACKGROUND OF THE INVENTION [0001] The invention relates to an inhalator for dispensing powdery medicaments, which inhalator has a medicament container for storing the medicament to be dispensed, an air duct, to which the dosages are brought for transfer by means of air flowing in the air duct to the respiratory organs, and a dispenser for dispensing the dosage and transferring it from the medicament container to the air duct, the dispenser having a dispensing part, which has preferably conical dispensing openings leading through it and expanding in the flow direction of air and which is movable to the medicament container and, correspondingly, to the air duct in such a manner that the dispensing openings open toward the medicament container and can, when at the medicament container, be filled with a powdery medicament, and, correspondingly, when at the air duct, open essentially upward in the normal operating position of the inhalator so that air flowing through the dispensing openings transports the powdery medicament onward along the air duct. [0002] Inhalators are used for dispensing medicaments in such a manner that during inhalation, a desired amount of medicament is transferred with air flowing through the inhalator to the respiratory organs and in that way to the human body. Upon dispensing powdery medicaments, great accuracy is required of an inhalator in order for the dosages to be precisely of the desired amount. In a typical implementation, a suitable amount of powdery medicament is brought to a given dosage space by moving inhalator parts in relation to each other, after which, when air is sucked through the inhalator, the air flowing through the medicament-containing space carries the medicament to the patient's respiratory organs. EP 0 547 429 and EP 0 883 415 disclose some known inhalator solutions. [0003] In one known inhalator solution, the medicament is dispensed by turning the disc-like dispensing part of the dispenser, comprising several small, conical dispensing openings, to the medicament-containing space, whereby the medicament fills the interior of the openings, after which the dispensing part formed by the conical openings and filled with medicament is turned to the flow duct. Thus, when inhaled through the inhalator, air carries the medicament with it when passing through the dispensing openings. The problem with this solution is that when the dispensing part is turned at the air flow duct, part of the powdery medicament always falls through the smaller opening below the conical openings into the interior of the inhalator, which results in loss of medicament, although most of the medicament remains in the openings. At the same time, the medicament makes the interior of the inhalator dirty, and occasionally, when air flows through the inhalator, an unduly large amount of medicament may be detached from the inhalator interior along with the air flow, whereby the dosage may significantly exceed what is intended. Further, manufacturing such inhalators requires extremely accurate tolerances and, particularly with respect to the mixture of medicament and air, optimal conditions, as well as air ducts that allow as little dirt as possible. It is difficult to realize all these details, particularly in view of the manufacturing technique itself dictating the feasible practical limits to the tolerances.

BRIEF DESCRIPTION OF THE INVENTION [0004] An object of the present invention is to provide an inhalator with which medicament can be dispensed more accurately than before, and in which the interior of the inhalator does not get dirty as easily as before and the loss of medicament is not as great. The inhalator according to the invention is characterized in that when the dispensing openings are at the air duct and when the inhalator is essentially in its operating position, there is below the openings a space, on whose collecting surface, which is formed by the bottom of the space, the medicament dispensed through the dispensing openings falls, and that during inhalation, air flows to the air duct through said space so that the air flowing through the space takes the medicament that has fallen on the collecting surface along through the dispensing openings and on to the respiratory organs. [0005] An essential idea of the invention is that a collecting surface is formed in the convergent direction of the convergent dispensing openings of the dispenser, i.e. below the openings in the operating position, on which collecting surface the medicament detaching from the more narrow end of the dispensing openings falls, and the incoming air flow is conducted in such a manner that when arriving, it flows along the collecting surface and carries the medicament that has fallen on the surface with it when it proceeds through the dispensing openings and further to the respiratory organs via the air duct. According to a preferred embodiment of the invention, said collecting surface forms part of the wall of the transverse air duct, i.e. its lower surface in the operating position. [0006] An advantage of the invention is that the medicament falling through the convergent, such as conical, dispensing openings of the dispensing part cannot fall into the inside of the inhalator but stays in the air flow duct, being thus forced along the air flow. Thus, the interior of the inhalator getting dirty may be significantly reduced at the same time ass the loss of medicament can be made significantly smaller than before. Likewise, when the medicament that has fallen is used immediately during inhalation, the dosage received at a time is much more accurately of the desired amount than known dosages.

BRIEF DESCRIPTION OF THE FIGURES _. [0007] The invention will be described in greater detail with reference to the attached drawings, of which Figures 1a and 1 b show schematically an inhalator according to the invention, partly cut out in the dispensing and inhalation positions, respectively; and Figure 2 shows a second inhalator according to the invention, partly cut out in the inhalation position.

DETAILED DESCRIPTION OF THE INVENTION [0008] Figures 1a and 1b show schematically an inhalator according to the invention, partly cut out in the dispensing and inhalation positions, respectively. The inhalator comprises an upper frame 1 and a lower frame 2, which are connected to each other rotatably around the longitudinal axis of the inhalator, i.e. around axis A according to Figure 1 , which is substantially vertical in the operating position. This rotatability is needed for dispensing medicament to the dispenser, and correspondingly for transferring the medicament in the dispenser to the air duct. The upper frame 1 and the lower frame 2 may consist of one or more parts connected to each other, depending on the manufacturing technique. The frames are connected to each other immovably in the direction of axis A but rotatably around it. Inside the upper frame 1 there is, immovably in relation thereto, a medicament container 3 in which the powdery medicament to be inhaled is stored and which is closed by its upper end, for example with a plug 4. Below the medicament container 3, there is a dispenser 5, which comprises a disc-like dispensing part 5a and a solid shutoff part 5b, shown by way of example. The dispenser 5 is connected unrotatably by means of a stud 2a, for example, or by some other means in relation to the lower frame 2 in such a manner that it rotates around axis A in relation to the upper frame when the frames are turned relative to each other. The dispensing part can be turned to the medicament container 3 by turning the frames 1 and 2 in relation to each other for dispending medicament, and correspondingly it can be turned away from the medicament container and to the air duct 6 when filled with medicament. Correspondingly, the shutoff part 5b is turned simultaneously to the air duct and to the medicament container. This will be explained in detail later. Below the dispenser 5, a support member 7 is mounted unrotatably relative to the upper frame, the dispenser 5 moving against the surface of the support member between the support member and the medicament container. The support member 7 is pressed toward the medicament container with a spring 8 between the lower frame 2 and the support member 7. The support member 7 has at the medicament container 3 a solid surface, so that the medicament cannot fall out of the medicament container through the dispensing openings 5c in the dispenser 5. [0009] Figure 1a shows a case where the dispenser 5 is turned to the dispensing position by turning the frames 1 and 2 in relation to each other around the vertical axis A of the inhalator. In this case, the dispensing openings 5c of the dispenser 5 are located below the medicament container 3 and in connection with the interior of the medicament container 3. The medicament in the interior of the medicament container 3 can flow to the dispensing openings 5c of the dispenser 5 and fill them at the same time as the solid surface of the support member 7 against the dispenser 5 prevents the powdery medicament from falling through the dispensing openings 5c. The dispensing openings 5c are shaped away from the medicament container 3, i.e. in the operating position to be downwardly convergent, such as conical. This is necessary in order for the powdery medicament to stay in the dispensing opening and not to fall through it when the dispenser 5 is turned to the air duct for inhalation. The surface at the lower end of the medicament container 3 is, on the other hand, firmly against the surface of the dispenser 5. Thus, when the dispenser 5 is turned away from the dispensing position, the lower edge of the medicament container 3 wipes off the excessive medicament from the top of the dispensing openings of the dispenser 5. The dispenser 5 can thus carry with it only such an amount of medicament that fits in its several dispensing openings 5c, and thus the dosage transferred from the medicament container 3 is always of the same size. When turned away from below the medicament container 3, the dispenser 5 turns to the air duct at the same time as the continuous, solid shutoff part 5b connected to the dispenser turns to the medicament container 3, closing the lower surface of the medicament container 3 and preventing the medicament from discharging from the container. [0010] When the dispenser 5 is turned to the inhalation position, the dispensing openings 5c turn to the air duct 6, as indicated by Figure 1 b. Thus, below the dispensing openings 5c, in the operating position of the inhalator, there is a space 9 which forms part of the air duct. Correspondingly, from above the dispensing openings 5c the air duct 6 continues to the upper end of the inhalator, from where the air is sucked through the inhalator. Despite the design of the dispensing openings 5c, some medicament falls out of them, ending up, in this case, at the bottom of the space 9 below the dispensing openings 5c, i.e. on the collecting surface 9a. In this way, no medicament can fall to the inside of the rest of the inhalator structure to make it dirty. [0011] At the space 9 on one side, there is an inlet opening 10 through which air can flow into the space 9 below the dispensing openings 5c of the dispenser 5 in the transverse direction of the dispensing openings. Thus, when sucked from the upper end of the air duct, air flows through the inlet opening 10 to the space 9, carrying with it the medicament that has fallen to the bottom of the space 9, i.e. the collecting surface 9a. Further, the air flows through the dispensing openings 5c, carrying with it the medicament in the openings, and proceeds along the air duct 6 to the upper end of the inhalator, until it ends up in the respiratory organs. Thus, in accordance with the invention, the loss of medicament can be substantially prevented, because the medicament that has fallen is carried along by air during the inhalation. In order for the medicament that has fallen to be transferred to the air flowing through the air duct, it is preferable that the cross-section of the transverse air duct at the collecting surface is smaller than the cross-section of the air duct after the dispenser, whereby the higher air flow rate makes the transfer of the medicament that has fallen more efficient. [0012] The dispenser 5 may be, with respect to its dispensing part, a disc-like part intended to be rotated continuously in the same direction around the vertical axis in the operating position of the inhalator. In this embodiment, the dispenser 5 comprises several groups of dispensing openings 5c, and correspondingly between them, a solid area of an appropriate size forming the shutoff part 5b. The dispenser 5 is always turned in the same direction one step at a time in such a way that at the medicament container 3 and correspondingly at the air duct there are dispensing openings 5c and correspondingly a solid shutoff part 5b of the dispenser 5 alternately in one group, the shutoff part 5b closing the opening(s) of the medicament container 3. [0013] The dispenser 5 may also be designed to operate in such a manner that it is moved with a reciprocating turning movement alternately to the medicament container 3 and to the air duct 6. In the latter case, the dispenser 5 has correspondingly a solid shutoff part which turns below the medicament container 3, closing the medicament into the medicament container 3. In this embodiment, only one group of dispensing openings 5c is required, and the dispenser 5 may be only a reciprocatingly turning disc-like component of a disc-like structure. [0014] Further, the dispenser can be designed to operate with a reciprocating straight movement. In such a case, the dispenser 5 comprises a shutoff part 5b and a dispensing part 5a having dispensing openings 5c, positioned successively in the direction of movement. Between the dispenser and the inhalator frame, there is most preferably a spring which attempts to push the dispenser 5 to the inhalation position. The dispenser thus tends to be in the inhalation position, whereby the dispensing openings 5c are at the air duct 6. When medicament is to be dispensed, the dispenser is pushed to another position, whereby the dispensing openings 5c move to the medicament container 3 and are filled with medicament. When the dispenser 5 is allowed to return to the original position, the dispensing openings 5c move to the air duct 6, whereby the medicament falling from them falls onto the collecting surface 9a and is transferred, in the above-described manner, along with flowing air during inhalation through the dispensing openings to the respiratory organs. It is preferable to implement the dispenser 5 in such a manner that it is pushed in to the dispensing position when a protective cover known as such and not shown is mounted on the inhalator. Thus, when the protective cover is removed, the spring pushes the dispenser to the inhalation position, where it stays reliably during the inhalation, retained by the spring. Instead of a plate-like dispensing part 5a, for instance a conical or other dispensing part may be used, as far as it has dispensing openings through it and it can be moved to the medicament container to dispense medicament, and correspondingly away from the container and to the air duct when filled with the medicament. [0015] Figure 2 shows another inhalator according to the invention in the inhalation position and partly cut out. In this embodiment, air to the space 9 flows not directly from an opening from the outside on the side but from the interior of the inhalator through an opening 10'. Also in this embodiment, the medicament falling from the dispensing openings ends up at the bottom of the space 9, from where an air flow takes it with it. Further, the air may come from the interior of the inhalator through openings 10" which are at the edges of the space 9 and connected to the interior of the inhalator, as far as the air flow causes the medicament fallen to the bottom of the space 9 to be carried along, as described earlier. Also different combinations of air inlet openings from the inside and outside of the inhalator are feasible. [0016] In the above description and the drawings, the invention is shown only by way of example, and it is not in any way limited to this. The lower end of the medicament container 3 may comprise one or more openings, through which the medicament can flow into the dispensing openings 5c of the dispenser. Likewise, it may comprise different sealing and scraping members that scrape the excessive medicament from the top of the dispensing openings 5c. The medicament container 3 may be closed by the end opposite to the dispenser with a separate plug, but it may also be originally made closed at that end, in which case the medicament container is filled with medicament from the opposite end. [0017] Different embodiments of either a continuously rotating or a reciprocatingly moving dispenser are feasible, but what is essential is that there is below the dispensing openings of the dispenser a space connected to the air duct, on the collecting surface of which medicament falls and which is dimensioned in relation to the air flow in such a way that during inhalation, the air flow carries with it the medicament that has fallen. In a manner known per se, the inhalator may also be provided with a mechanism indicating the used dosages, implemented for instance with a wheel or the like which is turned to a given extent per each loading time, for example.

Claims

CLAIMS 1. An inhalator for dispensing powdery medicaments, which inhalator has a medicament container (3) for storing the medicament to be dispensed, an air duct (6), to which the dosages are brought for transfer by means of air flowing in the air duct (6) to the respiratory organs, and a dispenser for dispensing the dosage and transferring it from the medicament container (3) to the air duct (6), the dispenser having a dispensing part (5a), which has preferably conical dispensing openings (5c) leading through it and expanding in the flow direction of air and which is movable to the medicament container (3) and, correspondingly, to the air duct (6) in such a manner that the dispensing openings (5c) open toward the medicament container (3) and can, when at the medicament container (3), be filled with a powdery medicament, and, correspondingly, when at the air duct (6), open essentially upward in the normal operating position of the inhalator so that air flowing through the dispensing openings (5c) transports the powdery medicament onward along the air duct (6), c h a r a c t e r i z e d in that when the dispensing openings (5c) are at the air duct (6) and when the inhalator is essentially in its operating position, there is below the openings a space (9), on whose collecting surface (9a), which is formed by the bottom of the space, the medicament dispensed through the dispensing openings (5c) falls, and that during inhalation, air flows to the air duct (6) through said space (9) so that the air flowing through the space (9) takes the medicament that has fallen on the collecting surface (9a) along through the dispensing openings (5c) and on to the respiratory organs. 2. An inhalator as claimed in claim 1 , c h a r a c t e r i z e d in that the collecting surface (9a) is located in the air duct (6)^' below the dispensing part (5a) of the dispenser so that an air flow substantially parallel to the dispensing part (5a) of the dispenser and, thus, transverse to the axes of the dispensing openings (5c) of the dispenser is formed on it, which then turns to flow through the dispensing openings (5c) of the dispenser (5). 3. An inhalator as claimed in claim 2, c h a r a c t e r i z e d in that the cross-section of the space (9) between the dispensing part (5a) of the dispenser and the collecting surface (9a) is smaller than the cross-section of the air duct (6) above the dispenser (5). 4. An inhalator as claimed in any one of the preceding claims, c h a r a c t e r i z e d in that the dispenser is in relation to the normal operating position of the inhalator mounted rotatably around a vertical axis. 5. An inhalator as claimed in claim 4, characterized in that the dispenser (5) has several separate groups of dispensing openings (5c) and between the groups areas of solid material, whereby the dispenser (5) rotates in relation to said vertical axis continuously in the same direction so that each group of dispensing openings (5c) arrives alternately at the medicament container (3) and after it, at the air duct (6). 6. An inhalator as claimed in claim 4, characterized in that the dispenser (5) has one group of dispensing openings (5c), and the dispenser (5) rotates around the vertical axis in a reciprocating movement so that the group of dispensing openings (5c) is in turn at the medicament container (3) and correspondingly at the air duct (6). 7. An inhalator as claimed in any one of claims 1 to 4, characterized in that the dispenser (5) is reciprocating and has one group of dispensing openings (5c) that according to the movement of the dispenser is in turn at the medicament container (3) and correspondingly at the air duct (6). 8. An inhalator as claimed in any one of the preceding claims, characterized in that the dispensing part (5a) of the dispenser (5) is plate-like.