WO1996023540A1

WO1996023540A1 - Process for producing inhalable particles of active agent

Info

Publication number: WO1996023540A1
Application number: PCT/DE1996/000125
Authority: WO
Inventors: Klaus Frietsch
Original assignee: Hugo Kern Und Liebers Gmbh & Co., Platinen- Und Federnfabrik
Priority date: 1995-02-01
Filing date: 1996-01-24
Publication date: 1996-08-08
Also published as: AU4481996A; DE29501527U1

Abstract

A device for the mechanical production of inhalable active agent particles from a solid supply of active agent (4) annular in shape and inserted in a casing (42), with a grinding wheel (16) like a face mill fitted in the casing (42) and drivable in rotation by a rotary drive (4) especially taking the form of a spring drive which acts on the supply of active agent (14), in which the rotary drive (4) has a drag regulator (38) which reduces the speed of the rotary drive (4) or the rotation speed of the grinding wheel (16).

Description

Device for producing inhalable active substance particles

The invention relates to a device for the mechanical production of inhalable active substance particles according to the preamble of claim 1.

Such a device has become known from the international patent application PCT / EP 93/01157. In the known device, both the supply of active substance in the form of an annular tablet and a mahogany in the form of a face milling cutter are arranged in a housing equipped with a mouthpiece, which bears three milling cutters arranged uniformly to one another and can be driven in rotation by a rotary drive likewise accommodated in the housing. The rotary drive is designed as a spring motor, which can be pulled up by a tensioning wheel and started by means of a release button. Thereby Wirkstoffpar- be removed Tikel and by sucking (breathing) runs out ^¬ wear.

However, this device has a number of disadvantages. It can often be observed that the grinding wheel or the milling knives do not uniformly remove them, but are moved in the form of a rattling or slip movement along the front of the active substance supply. This means that a high proportion of particles does not reach the prescribed size in the range from one to 10 μ. This worsens the effect, since particles that are outside the range mentioned are not respirable, ie do not arrive in the lungs. In addition, there is the danger that sintering processes occur on the surface of the active substance supply, which complicate proper removal of active substance particles and / or change the chemical composition of the active substance.

It should also be noted that the grinding wheel overshoots at the end of the intended grinding process, so that the prescribed discharge angle, which u. a. the removal and thus the dosage is determined, is not exactly adhered to.

Since the milling knives of the grinding wheel come to a standstill in the same angular position after each cycle, radially running furrows can form in the supply of active substance in the course of use, which further complicate the smooth removal or grinding process.

There is also the risk that the spring of the rotary drive is overstressed during the winding process, since the winding path is limited by the spring coils resting against the spring core. Since the spring has a steeply increasing characteristic curve in this area in particular, it is hardly possible in practice to generate a predetermined torque which is necessary for a precisely metered sequence. This is why the rotary drive is often pulled up too much, resulting in an excessive one. Torque. The running speed of the grinding wheel is too high and the problems of rattling and / or Slips appear more and more.

The invention was therefore based on the problem of improving a device of the type mentioned at the outset in such a way that it no longer has the problems described. In particular, it should be able to remove a precisely specified amount of active substance particles in a precisely reproducible manner in the prescribed particle size with each grinding process. The removal should be ensured evenly without rattling or slipping.

This problem is solved with a device having the features of claim 1. Advantageous embodiments are indicated by the features of the subclaims.

The invention is based on the idea of equipping the rotary drive with an escapement regulator, which reduces the running speed of the rotary drive and thus the rotational speed of the grinding wheel. It is hereby achieved that the grinding wheel is operated at a lower speed and thus a constant contact of the milling knives with the active ingredient supply is ensured. At the same time, active ingredient particles are extracted in the desired homogeneity, which result in an optimal active ingredient dosage.

The inhibitor also ensures that the rotational energy of the grinding wheel or the entire drive train is minimized. Overshooting of the drive at the end of the grinding process is thus reliably avoided.

The escapement regulator is preferably designed as a mechanical set of rules or escapement with an armature as a vibration element, which is meshed with the grinding wheel or the rotary drive is coupled. Such mechanical regulations, as they are basically known, for example, from the watch industry, offer the advantage that the rotational movement is very much slowed down or comes to a standstill with each engagement cycle of the armature. As a result, the rotational energy of the grinding wheel becomes zero, so that an overshoot when the intended run-off angle is reached is excluded.

The anchor is preferably designed as a bracket, so that the inhibitor can be made extremely space-saving.

The anchor is particularly preferably designed as a closed ring, which has the advantage over the above-described bow shape that the annular space available within the housing can be optimally used in order to maximize the volume and distance the anchor center of gravity from the Realize axis of rotation for the vibration element. A large volume and the greatest possible distance from the center of gravity is required to set the desired inertia behavior of the anchor. The ring shape makes it possible to realize the anchor as an inexpensive and stable plastic injection-molded part, since, due to the large volume, a sufficient mass can be achieved despite the low specific density.

Instead of an armature designed as a bracket or ring with an associated armature wheel, the escapement regulator can also be designed as a centrifugal force regulator or even in the form of an eddy current brake.

An advantageous embodiment of the invention provides that the rotary drive with a first stop to fix the End position is provided, when the drive torque of the rotary drive assumes the value zero, that is to say that the rotary drive comes to a standstill when this stop is reached.

At the same time, because of the slowing down of the drive speed of the rotary drive caused by the escapement regulator, it is ensured that the grinding wheel, which is preferably rigidly coupled to the rotary drive, comes to a standstill immediately and does not oscillate. This, in turn, is important for the correct production of active substance particles, since this ensures that the same particle size is always maintained and not accidentally larger or smaller chunks outside the desired size as a result of uneven loading by the milling cutters be knocked out of the solidified active substance body.

According to a further advantageous embodiment of the device according to the invention, a second stop is provided which serves to limit the maximum elevator angle and which interacts with the tensioning wheel of the rotary drive. This prevents over-tensioning of the spring used in the rotary drive and ensures a constant drive speed and a constant torque of the rotary drive with great repeatability. Since the spring is always only tensioned up to a defined load point, fatigue or damage to the drive spring is practically impossible.

It also proves to be advantageous that the design of the stops enables the selection of a specific characteristic range of the springs used in the rotary drive. If necessary, the device according to the invention can be different active ingredient preparations can be adjusted with correspondingly different ablation rates.

A further preferred embodiment of the device according to the invention provides that the stops are designed as a drag stop which changes the location of the grinding wheel at a standstill after each actuation. This advantageously has the consequence that the end point always changes continuously after each actuation of the rotary drive, and thus the position of the grinding wheel. Digging in of the milling knives by standstill at an identical angular position no longer occurs.

The drag stop is preferably designed as a sliding block which is arranged in a groove provided on the circumference of a driver for the grinding wheel. The groove can in this case be formed almost completely circumferential, with a web limiting the circumferential angle of the sliding block. Thus, drain angles of more than 360 °, ie. H. up to almost two full rotations possible. On the one hand, the grinding wheel comes to rest at a different angular position each time it is actuated, on the other hand, this configuration allows a high removal rate, since the drain angle can be almost doubled compared to the previously known solution.

In order to further improve the handling of the device according to the invention, it can additionally be provided with a trigger with an integrated pawl with which the rotary drive can be locked at any angle of rotation. In this way, multiple, short actuations of the grinding wheel can be achieved without additional tensioning of the rotary drive.

Based on an embodiment shown in the schematic drawing, the invention, as well as special Advantages of the invention are explained and described in more detail. Show it:

FIG. 1 shows a longitudinal section through a device according to the invention,

FIG. 2 shows a cross section through the device according to FIG. 1 along the section line A-A with a bow-shaped anchor,

FIG. 3 shows a cross section through the device according to FIG. 1 along the section line A-A with an annular armature,

FIG. 4 shows a cross section through the device according to FIG. 1 along the section line B-B with the end mill in the initial position,

Figure 5 shows a cross section through the device of Figure 1 along the section line B-B with the end mill in the end position and

Figure 6 shows a cross section through the device of Figure 1 along the section line C-C.

FIG. 1 shows a longitudinal section through a device 2 for the mechanical production of inhalable active substance particles, which has a housing 42 in which a solidified active substance supply 14 is located. The end face of the housing 42 shown on the left in FIG. 1 is provided with a mouthpiece 10, in which the active substance supply 14 acted upon by a compression spring 12 is accommodated. The active substance supply 14 is in the form of an annular tablet which is held in a hollow cylindrical tablet receptacle. me 44 is arranged and is pressed against a grinding wheel 16, which is designed in the manner of an end mill, which in turn is set in rotation by a leg spring 24 of a rotary drive 4. In the area of the housing 42 in which the active substance supply 14 engages with the grinding wheel, there is an air gap 18 embedded in the wall of the housing 42, which is only interrupted by 4 pillars or webs through which the incoming air, absorbs the particles removed from the active substance supply 14 during engagement with the grinding wheel 16 as an aerosol and supplies them to the user (not shown here) through the mouthpiece 10 or tablet holder 44.

The rotary drive 4 driving the grinding wheel 16 has, in addition to the leg spring 24 already mentioned, a driver 40 for the leg spring 24 and a driver 36 for the grinding wheel 16. The driver 40 for the leg spring 24 works together with a stop 20, which is preferably a drag stop is designed and serves on the one hand to define a specific characteristic range of the leg spring 24 for the rotary drive 4 and on the other hand to ensure that the grinding wheel 16 does not come to a standstill but always reaches a different end point.

An inhibitor is integrated in order to allow the rotary movement of the rotary drive 4 to run in a controlled manner and to slow it down. For this purpose, an armature 38 serves as a vibration element of the escapement regulator, which is supported in an armature bearing 22 and is coupled via a toothing 52 to the driver 36 for the grinding wheel 16.

A tensioning wheel 30, which is arranged on the front side of the housing 42 opposite the mouthpiece 10, is used to tension the leg spring 24, which is connected to a freewheel 32 on a Flange 34 is mounted. On the one hand, the freewheel 32 enables the elevator movement for the rotary drive 4, on the other hand prevents the tensioning wheel 30 from returning.

The flange 34 also receives a trigger 26 with a pawl 27 which is held in the rest position by a compression spring 28. The trigger 26 serves to hold the driver 36, which is acted upon by the tensioned leg spring 24, for the grinding wheel 16. For this purpose, the driver has ratchet teeth 54 in the engagement area of the pawl 27 (FIG. 6). By pressing the trigger 26 against the restoring force of the compression spring 28, the driver 36 is released, so that the grinding wheel 16 is set in rotation.

FIG. 2 shows a cross section through the device according to FIG. 1 along the section line A-A, i. H. through the armature 38, which here is bow-shaped with a slight curvature and has an eccentric fulcrum in the form of the armature bearing 22, around which the armature 38 swings when the trigger 26 is actuated, and thus the sequence of the driver 36 in engagement with it for the Grinding wheel 16 slows down.

In Figure 3 is the same representation as shown in Figure 2 with the difference that the anchor 38 is designed here as a ring anchor. This configuration allows the inexpensive manufacture of the armature 38 as a plastic injection molded part, because due to the ring shape, the moving mass of the armature 38 can be made sufficiently large so that it has the required inertia and the resulting slowdown of the rotational movement is ensured.

Another cross section is shown in FIGS. 4 and 5 reproduced by the device 2 according to FIG. 1 along the section line BB, FIG. 4 showing the initial position of the rotary drive 4 and FIG. 5 the end position thereof.

In the initial position shown in FIG. 4, the rotary drive 4 is fully pulled up. A sliding block 20 serves as a stop for the elevator movement and is displaceably mounted in a groove 46 provided on the circumference of the driver 40. The groove 46 is almost completely circumferential with the formation of a web 48, so that the sliding block 20 can in principle be moved between the starting position shown in FIG. 4 and the end position indicated in FIG. 5. Depending on the width of the web 48, a displacement path can be realized which, in the limit case, corresponds to a brief full revolution. In the exemplary embodiment shown, the web 48 is designed such that the sliding block 20 can sweep over an angular sector of approximately 340 °.

Furthermore, a driver pin 50 is formed on the driver 40 for the leg spring 24, which cooperates with the sliding block 20. In the position shown in FIG. 4, the driver nose is brought into contact with the sliding block 20, which in turn rests on the web 48. The position shown thus represents the (second) stop, which limits the elevator movement of the rotary drive 4.

Starting from this position, the grinding process is now started after the trigger 26 has been actuated. The driver 36 for the grinding wheel 16 describes, according to the view in FIG. 4, a clockwise rotary movement, the driver lug 50 first detaching from the sliding block 20 and coming into contact with the sliding block 20 opposite after a rotary movement of approximately 320 °. In the course of the further rotary movement, the sliding block 20 is removed from the driving nose 50 - left

entrained and dragged along in the groove 46 until it comes to rest against the web 48 and reaches the end position shown in FIG. A further rotary movement is no longer possible and the grinding process is complete. Here, the driver 36, and thus the grinding wheel 16, has completed almost two full rotations, the grinding wheel 16 coming to rest in an angular position which differs from FIG.

A renewed elevator movement is now made possible by actuating the tensioning wheel 30, whereby the driver 40 for the leg spring 24 is rotated further together with the sliding block 20 until the latter is locked on the driver 36 for the grinding wheel 16 or whose driver nose 50 rests. In the course of the further rotational movement of the driver 40, the groove 46 slides under the sliding block 20 held on the driving lug 50 until the web 48 comes into contact with the sliding block 20 and thus prevents a further elevator movement. Compared to the starting position shown in FIG. 4, the position now reached is offset by approximately 90 ° counterclockwise, so that the grinding wheel 16 is angularly offset with respect to the active substance supply 14. A renewed actuation of the release button 26 allows the grinding process to proceed in the manner described above. Different rest positions are gradually achieved here, since each grinding process contains somewhat less than two full revolutions, for example 640 ° discharge angle.

FIGURE LEGEND

Rotary drive device

Mouthpiece Pressure spring Active ingredient supply (tablet) Grinding wheel Air inlet

sliding block

Anchor bearing

Leg spring

trigger

Pawl

Pressure eder

Tensioning wheel

Freewheel

flange

Driver for grinding wheel anchor

Driver for leg spring housing tablet holder groove web

Driving lug toothing Latching toothing

Claims

PATENT CLAIMS

1. Device for the mechanical production of inhalable active substance particles from a solidified active substance supply (14), which is designed in the form of a ring and is accommodated in a housing (42), with a rotary drive arranged in the housing (42) and designed in particular as a spring motor (4) rotationally drivable grinding wheel (16) in the manner of an end mill which engages the active substance supply (14), characterized in that the rotary drive (4) has an inhibitor (38) which controls the running speed of the rotary drive (4) or the Rotation speed of the grinding wheel (16) reduced.

2. Apparatus according to claim 1, characterized in that the escapement regulator is designed as a mechanical control unit (escapement) with an armature (38) as a vibration element, which via a toothing (52) with the rotary drive (4) or the grinding wheel (16) is coupled.

3. Apparatus according to claim 2, characterized in that the armature (38) is designed as a bracket.

4. The device according to claim 2, characterized in that the armature (38) is designed as a closed ring.

5. Device according to one of claims 2 to 4, characterized in that the armature (38) is designed as a plastic injection molded part.

6. The device according to claim 1, characterized in that the inhibitor controller is designed as a centrifugal controller or eddy current brake.

7. Device according to one of the preceding claims, characterized in that the rotary drive (4) is provided with a first stop (20, 46, 50) which serves to limit the maximum run-off angle and at the Errei¬ chen the drive torque of the rotary drive ( 4) assumes at least approximately the value zero.

8. The device according to claim 7, characterized in that the stop as a trailing stop (20, 46, 50) is ausgebil¬ det, so that the location (angular position) of the standstill of the grinding wheel (16) is changed after each actuation.

9. Device according to one of the preceding claims, characterized in that a second stop (20, 46, 50) is provided which serves to limit the maximum lift angle and over-tensioning a spring (24) used in the rotary drive (4) ) prevented.

10. The device according to claim 8 or 9, characterized gekennzeich¬ net that the drag stop is formed as a sliding block (20) which is guided in a on the periphery of a driver (40) for the Mahirad (16) groove (46) and cooperates with a driver nose (50) of a driver (36) for the rotary drive (4) or the spring (24).

11. The device according to claim 10, characterized in that the groove (46) is formed almost completely circumferential to form a web (48).

12. Device according to one of the preceding claims, characterized in that a trigger (26) is provided which is in engagement with the rotary drive (4) in such a way that it can be locked at any outlet angle before reaching the end position.