Abstract:
An inhalation device for administering powdered forms of medication includes a housing with a rotatable dosing ball associated with an opening of a powdered reservoir located inside the housing. The dosing ball may be operated manually and includes a peripheral dosing cavity for receiving a dose of powder. The dosing ball is connected with a torsion spring and further includes a stop piece. In addition, the dosing ball is associated with a pivotable trip flap that has a movable limit stop. The dosing ball is preloaded by turning the dosing ball until the stop piece comes to rest on the movable limit stop of the trip flap. The dosing ball is then released as normal user breathing triggers a swaying of the trip flap. The stop piece is configured to hit against the bottom of the housing which abruptly blocks acceleration of the dosing ball, which in turn causes the medicine to be catapulted out of the dosing cavity and be widely dispersed in the stream of respiratory air so that the medicine may be inhaled completed and in sync with respiration. Overdosing or release of multiple doses is thus prevented by the inhalation device.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a inhalation device for administering powdered forms of medication which includes a housing with a rotatable dosing apparatus that has a circular perimeter area and is associated with defines opening of a powder reservoir located inside the housing that can be operated manually and comprises a peripheral dosing cavity for receiving a portion of powder, and a mouthpiece connected to the housing at the level of the dosing apparatus and opposing air intake holes so as to form an air duct in which the powder dose released by turning the dosing apparatus is catapulted into the user&#39;s stream of respiratory air. 
     DESCRIPTION OF THE PRIOR ART 
     An inhalation device of this type that works without a propellant or additional air has been described, for example, in EP 0 559 663. This powder inhalator comprises a reservoir filled with a powdered form of medication that is located inside a housing, the funnel-shaped opening of which being locked by a dosing drum that can be turned manually. The perimeter of the dosing drum comprises at least one dosing cavity whose size matches the powder dose to be inhaled and which is filled with medicine whenever it is in the opening range of the powder reservoir. A mouthpiece is connected at the level of the dosing apparatus, and air intake holes are located at the opposite side of the housing. When the dosing drum is turned , the powdered form of medicine falls into the air duct of the mouthpiece, either by mere gravitational force or boosted by a vibrating mechanism, and is inhaled with the patient&#39;s stream of inhaled air. The known problem of this device type, i.e. complete discharge of the medicine from the dosing cavity and the mouthpiece which is critical for reliable dispersing and dosing is to be achieved here by a specific air conduction system that causes puff blowing of the dosing chamber and complete inhalation of the powder dose through a short air path. 
     However, the inhalation devices of the type described have a disadvantage in that the medicine is not completely blown out or is not adequately dispersed in the air stream to ensure reliable dosing when the stream of inhaled air is weak only. Dosing reliability is furthermore reduced by the fact that medicine will be fed into the mouthpiece even if inhalation is weak or does not take place when the dosing apparatus is operated manually but will completely or partly remain there, so that any subsequent inhalation process will result in overdosing or multiple dosing. 
     To boost the stream of inhaled air, improve dispersion, and make the intake of the medicine more reliable, powder inhalators have been proposed that are equipped with a pumping device to produce an additional stream of compressed air. 
     For example, a defined dose of a powdered medicinal substance is placed into the flow channel of a mouthpiece located at the side of a propellant-free inhalation device as described in EP 0 549 605l using a plunger that can be moved by pressing a button inside a lateral recess forming a dosing cavity. At the same time, one interior wall of said dosing cavity is in communication with the cylinder of a pump. The preloaded plunger of the pump is released using a switching device operated by inhaling to produce an air stream which places the powdered medicinal substance via a nozzle into the stream of inhaled air and spreads it therein. 
     This inhalation device consists of a multitude of the most various components due to sophisticated mechanisms for dosing and for producing and releasing an additional stream of compressed air. Such inhalators are therefore very expensive as regards manufacture and assembly of their components, and they are susceptible to failure due to their complicated design and the required interaction of various elements, especially when dust, dirt, and breathing moisture can intrude. Moreover, complete- charging of the dosing cavity which forms a lateral recess cannot be guaranteed or can only be ensured by adding more components. As said additional stream of air is produced by the motion of the pump plunger and conducted to the dosing cavity via a sieve bottom, the required blowing pressure to be exerted upon the powdered medicine is either weak or requires a powerful pumping unit. 
     Another decisive disadvantage of this solution is the fact that the powdered form of medication is in the mouthpiece before the stream of compressed air is released in sync with respiration, and that it remains there if it is not inhaled. On the one hand, this may result in double dosage when the medicine is taken at a later point in time, on the other hand the medicinal substance lying bare can be contaminated or get moist, which would impede the operation of the powder inhalator. In addition, the known powder inhalators are not adequately protected against intrusion of dirt and moisture, especially breathing moisture, or unintentional release of the powdered form of medicine. 
     It is therefore the problem of this invention to provide an inhalation device of the type described above that has a simple design, allows safe handling, can be produced at low cost, and guarantees exact dosing and complete inhalation of the powdered form of medicine, thereby reliably excluding overdosing and multiple doses. 
     SUMMARY OF THE INVENTION 
     The inhalation device of the present invention includes a dosing apparatus is that connected with elastic fastening devices and includes a stop piece, and the dosing apparatus can be preloaded until it hits on a movable limit stop while the dosing cavity remains within the range of the powder dispensing hole of the powder reservoir, the limit stop being movable by the user&#39;s breathing air for releasing the preloaded dosing apparatus. The accelerated motion of the dosing apparatus can be blocked suddenly by the stop piece. 
     In other words, the basic concept of this invention is to preload the dosing apparatus before the medicine is taken or before the dosing cavity containing the medicine is placed within the air duct, and that it is held in said preloaded condition to a limit stop that can be moved by inhaling. Inhaling releases and accelerates the dosing apparatus, and its accelerated motion is stopped abruptly when the stop piece of said dosing apparatus hits on the housing or housing bottom. This sudden interruption of the rotation of the dosing apparatus causes the powdered form of medication to be flung out of the dosing cavity at high speed and to be widely dispersed across the air duct. At the same time, the user&#39;s inhalation air which caused the release of the dosing cavity and the medicine is still active so that the finely dispersed powder dose is directly carried over into the stream of the user&#39;s respiratory air and completely taken in by the user&#39;s body via his or her respiratory tract. As the medicine is released by respiration, it has to be inhaled. Subsequent overdosing or multiple dosing due to residual powder in the mouthpiece from a previous inhalation attempt is therefore excluded. 
     In accordance with another aspect of the invention said dosing cavity is designed as a dosing ball. The benefit of this design is that the air stream is swirled in the air duct which improves the dispersion of the powder. 
     In accordance with yet another aspect of the invention, the movable limit stop that keeps the dosing ball in a preloaded condition is attached to a trip flap that shuts the air duct and is pivotably hinged in the air duct. When the user breathes in, a negative pressure is generated that swings the trip flap and limit stop to release the rotation of the preloaded dosing ball. Moreover, said pivotable trip flap prevents the intrusion of moisture into the interior of the housing as may be caused by unintentional exhaling into the mouthpiece 
     An advantageous improvement of the invention comprises an operating lever for turning and preloading the dosing ball that is attached to the external side of the housing and to which a cap for sealing the mouthpiece of the inhalation device is slidably mounted on rails. Thus the cap will always be connected to the device and cannot be lost. Consequently, any risk of contamination or unintentional actuation of the arrested operating lever is either very low or completely excluded. 
     In accordance with another aspect of the design of the invention, a pumping device is provided in the housing whose reservoir of compressed air is in communication with the dosing cavity via a valve unit in such a way that when the preloaded dosing ball is triggered in sync with inhalation, i. e. when the powder dose is released from the powder reservoir, the valve unit will simultaneously release compressed air to the dosing cavity or to the medicine contained therein. This improves the dispersion of the powdered form of medication, especially in the early phase of deagglomeration. It also guarantees complete and reliable intake of the medicine by users with reduced respiratory capacity such as older people or children. 
     Other features, useful designs and benefits of the invention follow from the description of an embodiment of the invention below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     Two embodiments of the invention shall now be explained in more detail with reference to the attached figures, wherein: 
     FIG. 1 shows a lateral sectional view of the inhalation device of the invention in its closed initial position, 
     FIG. 2 shows the inhalation device of FIG. 1 with the cap removed from the mouthpiece and folded downwards; 
     FIG. 3 shows a diagrammatic sectional view of the inhalation device of FIGS. 1 and 2 at the time when the powdered form of medicinal substance is inhaled; 
     FIG. 4 shows a lateral sectional view of an inhalation device according to the invention working without an additional stream of compressed air in its initial closed position; 
     FIG. 5 shows an inhalation device with an integrated nasal adapter in its mouthpiece; and 
     FIG. 6 shows three side views of the powder inhalator with different cap positions. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The powder inhalation device that provides an additional stream of compressed air according to FIGS. 1 through 3 includes an oblong housing  1  with a mouthpiece  2  fitted laterally to its lower end and a transverse wall  3  at its upper end, the latter comprising an air exit hole  4  in communication with a compressed air duct  5  leading to the lower part of the housing along the inner wall of said housing. The lower part of housing  1  comprises a hollow axle end  6  directed towards the interior of the housing and a capped nut (not shown in the figure) running in axial alignment with said axle end but propping up from the outer wall of housing  1 . Said axle end and capped nut are integrally fitted to the wall of the housing at the level of the longitudinal axis of mouthpiece  2 , but in transverse direction to said axis. A first radial axle end hole  7  is located in the walling of said hollow axle end at the end of said mouthpiece  2 . The hollow formed inside axle end  6  is in communication with said compressed air duct  5 . In addition, there are air inlet holes  8  at the rear wall of said housing  1  opposite said mouthpiece  2 , and a curved oblong hole  9  in the side wall of said housing  1 . 
     A cap  10  that can be shifted along guide rails (not shown) on mouthpiece  2  is telescopically connected with an operating lever  11  (FIG. 2) whose free end is pivoted at the above capped nut (not shown). The operating lever  11  also comprises an extension that starts from a pivoted part at its swivelling axis (not shown) , the free end of which is in linkage with an angle lever  23  located in the interior of housing via the curved oblong hole  9  and a tappet  24 . The telescopic connection of cap  10  to operating lever  11  hinged to housing  1  allows removal of said cap from mouthpiece  2  while its connection to the inhalation device is retained so that it cannot be lost. 
     A powder reservoir  12  with a powder discharge hole  12   a  that points towards said axle end  6  is located above said axle end  6  inside said housing  1 . There is an inspection glass  13  for level checking at the wall of housing  1  that faces said powder reservoir  12 . The powder reservoir  12  consists of a transparent material. A disk  10   a  is fitted to cap  10  to cover the inspection glass  13  for protecting the medicine from sunlight when cap  10  is pushed open. 
     The interior space of housing  1  is closed towards the opening of mouthpiece  2  by a hinged trip flap  14  that can be swung upwards and outwards. A limit stop  14   a  is mounted to the side of trip flap  14  that points towards the interior of the housing. 
     The powder discharge hole  12   a  is sealed by dosing ball  15  that tightly fits to its rim and extended rim areas. The dosing ball  15  comprises an axial bore of the bearing  15   a in which it is pivoted on axle end  6 . Furthermore, a torsion spring  16  with a short fixed leg  16   a  and a long movable leg  16   b  rests on axle end  6 , said short leg  16   a  being fixed by said dosing ball  15 . 
     The dosing ball  15  comprises a hemispherical dosing cavity  17  at its peripheral surface that points towards said powder reservoir  12  for receiving the powdered form of medication when said cavity is in the range of said powder discharge hole  12   a.    
     Said dosing ball  15  further comprises a radial valve hole  18  located in the same sectional level as said first radial axle end hole  7 . A blowpipe  19  is connected to the opening of valve hole  18  at the perimeter of dosing ball  15  the open side of which is directed towards said dosing cavity  17 . Finally, the peripheral surface of dosing ball  15  comprises a stop piece  20  to arrest said dosing ball  15  either on limit stop  14   a  or at the bottom of housing  1 . 
     A bellows  21  comprising a hole that is connected to the air exit hole  4  is located below said transverse wall  3 . At its opposite end, said bellows  21  rests on a support plate  22  that is connected to the above-mentioned angle lever  23  that acts as compression bar. The free end of angle lever  23  that is connected with the extension not shown) of the operating lever  11  outside housing  1  via the oblong hole  9  comprises a protruding rectangular tappet  24  that is in linkage with the long leg  16   b  of torsion spring  16 . 
     The function of the embodiment described above in static condition of a powder inhalator with compressed air reinforcement shall be described next. 
     When the powder inhalator is in unused condition, cap  10  is slid onto mouthpiece  2  (FIG. 1) in such a way that intrusion of foreign particles is prevented. It is therefore impossible for a user to remove or lose cap  10  unintentionally or to trigger the administration of the medicine unintentionally when carrying the inhalator in a case, jacket pocket, etc. 
     The inspection glass  13  is covered by disk  10   a  and protects the powdered form of medicine in the transparent powder reservoir  12  against sunlight. The trip flap  14  is in its vertical position in which it seals mouthpiece  2 . The bellows  21  and torsion spring  16  are in unstressed condition as at the lower position of angle lever  23 , and the dosing cavity  17  of the dosing ball rests in the powdered substance, i. e. to the right of the funnel-shaped powder discharge hole  12   a  as shown in the figure. The powder reservoir  12  is designed to hold a single fill of about 200 doses. 
     To discharge one dose of the powdered form of medication determined by the size of the dosing cavity  17 , the cap  10  is removed from mouthpiece  2  but remains inseparably connected to the operating lever  11  and thus with the device as a whole. When the operating lever  11  is moved downwards, the tappet  24  is swung along the curved oblong hole  9  into its upper position, and the angle lever connected to the operating lever  11  is pressed upwards to compress the bellows  21 , thereby compressing the air therein, and to turn the dosing ball  15  with the help of torsion spring  16  first until it its stop piece  20  touches upon limit stop  14 a of the trip flap  14  and—from that moment on—to load torsion spring  16  and thus to preload the dosing ball  15 . The dosing cavity  17  is located in preloaded condition of the dosing ball  15  at the left edge of powder discharge hole  12   a  in the figure. 
     When the user inhales via the mouthpiece  2 , the negative pressure that is generated swings the trip flap  14  upwards and releases the dosing ball that is held in place by limit stop  14   a , said dosing ball being turned by the force of torsion spring  16  until the stop piece  20  audibly hits onto the bottom of housing  1 . At the same time, the radial valve hole  18  in said dosing ball  15  is brought into alignment with the first radial axle end hole  7  of the hollow axle end  6  so that the air compressed in the bellows  21  is impulsively blown via air exit hole  4 , compressed air duct  5 , the hollow of axle end  6 , the radial axle end hole  7 , the valve hole  18 , and the blowpipe  19  into the dosing cavity  17  which is accurately filled with the powdered medicine and placed outside the range of the powder reservoir  12 . 
     The powdered form of medication is swirled with the stream of the user&#39;s inhaled air by the blown in compressed air and the abrupt blocking of the rotation of dosing ball  15  as well as by centrifugal and gravitational forces and carried in fine dispersion into the user&#39;s air passages. At the same time, the stream of compressed air boosts the atomization of the powder to guarantee safe inhalation of the powdered medicament even at an inhalation volume below the average value of 11/s, e. g. with children and older people. The trip flap  14  falls back into its initial vertical position immediately after inhalation, thus protecting the dosing ball  15  and the powdered substance against moist respiratory air when the patient unintentionally exhales into the mouthpiece  2 . Resetting of said trip flap to its initial vertical position is also ensured by a butt that is located in the cap and acts on the trip flap when the cap is closed (not shown). 
     When the operating lever  11  is moved into the closing position of cap  10 , the angle lever  23 , the bellows  21  and dosing ball  15  as well as torsion spring  16  are set back to their initial position as shown in FIG. 1, the feed valve for compressed air formed by the axle end hole  7  and the valve hole  18  or the lateral area of the centric bore of the bearing  15   a  of dosing ball  15  being closed again. A second radial axle end hole  25  also referred to herein as an additional radial axle end hole, is located in the hollow axle end  6  to let air into the bellows  21 . When the dosing ball  15  is in its initial position, said second radial axle end hole  25  is in alignment with the valve hole  18  (or another hole not shown here) to allow air to flow into the bellows  21  for another compression process. 
     The powder inhalator can only be activated again when the cap has been removed and the operating lever been moved again. It is only then that another dose of the medicament can get into the user&#39;s respiratory tract, this time carried in the stream of inhaled air only. If the user does not inhale and/or seal the mouthpiece  2  again, the powdered medicament remains in the dosing cavity  17  within the powder reservoir  12 . Unintentional double or multiple dosing is excluded. In addition, a noise is produced when the stop piece  20  of the dosing ball  15  hits on the housing bottom and foreign air is blown out of the blowpipe  19  with a hiss, said noise indicating to the user that the powdered medicament really was administered. 
     Thus the inhalation device can be handled safely and easily even by less skilled users. As its few components are mainly made of injection moulded parts, it can be assembled conveniently and inexpensively in a two-piece housing. 
     FIG. 4 shows a simplified embodiment of the inhalation device according to the invention, i. e. without the means for generating an additional stream of compressed air. This embodiment is characterized by a simple design and uncomplicated manufacture; it guarantees excellent dispersion of the powdered medicine and reliable intake by the patient even without extra air. The dosing ball  15  is in its relaxed position with the connected torsion spring  16  unloaded in the initial position shown in FIG. 1 when the mouthpiece  2  is sealed by cap  10 . The tappet  24  of the operating lever  11  that is linked to the long leg  16   b  of the torsion spring  16  is at its lower position in oblong hole  9 . When the cap  10  is removed from the mouthpiece  2  and the operating lever  11  moved to the position shown in FIG. 2, the dosing ball  15  turns simultaneously with the motion of the tappet  24  until the stop piece  20  of said dosing ball  15  hits on limit stop  14   a . When the operating lever  11  is moved on until its tappet  24  hits on the other, upper end of the oblong hole  9 , the torsion spring  16  is bent, and the dosing ball  15  whose dosing cavity  17  is placed immediately at the rim of the powder reservoir  12  is preloaded. When the patient inhales and the negative pressure thereby generated in the mouthpiece results in flinging up the trip flap  14 , the dosing ball is suddenly released. Its accelerated movement due to preloading is abruptly blocked when the stop piece  20  hits on the bottom of mouthpiece  2 . 
     Sudden acceleration and blocking of the motion of the powdered form of medication contained in the dosing cavity  17  and centrifugal forces result in complete detachment of the medicine from the dosing cavity  17  and its dispersion and swirling across a large area in their duct of the mouthpiece  2 . Complete intake of the powder dose by the patient is guaranteed without an additional stream of compressed air by simultaneous and, due to the negative pressure, intermittent feed of inhalation air. 
     FIG. 5 shows an embodiment of said powder inhalator with an integrated monorhinal adapter  26  inserted into the mouthpiece  2 . Said nasal adapter  26  can be mounted fixedly or detachably and may be inseparably inserted into the mouthpiece at a later point in time. Said nasal adapter  26  has a unique design to fit to a specific inhalation device only. 
     FIG. 6 shows the inhalation device with its cap  10  completely slid onto the mouthpiece  2 , with its cap  10  removed from the mouthpiece  2 , and with its cap  10  removed and the operating lever  11  that activates the inhalator moved downwards. FIG. 5 clearly shows that the cap  10  is guided on a rail profile  11   a  along said operating lever; it extends the operating lever telescopically but always stays connected to it. 
     All powdered forms of medication can be administered using the inhalation device according to the invention. It has proved to be particularly advantageous for treating asthmatic diseases and the like. 
     Active ingredients to be administered can be, for example, beta-sympathomimetics and corticoids. It is particularly suited for the following substances and combinations/mixtures thereof: salbutamol, cromolyn sodium, budesonide, beclometason, reproterol, fenoterol. 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 1 
                 housing 
               
               
                   
                 2 
                 mouthpiece 
               
               
                   
                 3 
                 transverse wall 
               
               
                   
                 4 
                 air exit hole 
               
               
                   
                 5 
                 compressed air duct 
               
               
                   
                 6 
                 hollow axle end 
               
               
                   
                 7 
                 first radial axle end hole (air outlet) 
               
               
                   
                 8 
                 air inlet holes 
               
               
                   
                 9 
                 curved oblong hole 
               
               
                   
                 10 
                 cap 
               
               
                   
                 10a 
                 disk 
               
               
                   
                 11 
                 operating lever 
               
               
                   
                 11a 
                 rail profile 
               
               
                   
                 12 
                 powder reservoir 
               
               
                   
                 12a 
                 powder discharge hole 
               
               
                   
                 13 
                 inspection glass 
               
               
                   
                 14 
                 trip flap 
               
               
                   
                 14a 
                 limit stop 
               
               
                   
                 15 
                 dosing ball 
               
               
                   
                 15a 
                 bore of bearing 
               
               
                   
                 16 
                 torsion spring 
               
               
                   
                 16a 
                 short leg of 16 
               
               
                   
                 16b 
                 long leg of 16 
               
               
                   
                 17 
                 dosing cavity 
               
               
                   
                 18 
                 valve hole in 15 
               
               
                   
                 19 
                 blowpipe 
               
               
                   
                 20 
                 stop piece of 15 
               
               
                   
                 21 
                 bellows 
               
               
                   
                 22 
                 support plate 
               
               
                   
                 23 
                 angle lever 
               
               
                   
                 24 
                 tappet 
               
               
                   
                 25 
                 second radial axle end hole (air inlet) 
               
               
                   
                 26 
                 nasal adapter 
               
               
                   
                 27 
                 air duct