Abstract:
A drug powder inhaler has a cover plate pivotably attached to a lid on an inhaler housing. A lever is pivotably attached to the cover plate. A blister pack disk is rotatably mounted on the housing under the cover plate. A powder duct in the housing extends from a staging chamber underneath one end of the lever to an aerosolizing chamber. An actuator in the housing is pressed to shear open a blister on the blister pack disk and thereby deliver the drug dose contents of the blister into the staging chamber. A switch senses pressure in the mouthpiece and switches on a motor spinning an impeller within the aerosolizing chamber, when inhalation is detected.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This application is a continuation of U.S. patent application Ser. No. 09/351,895, filed Jul. 13, 1999, and now pending, which is a continuation-in-part of application Ser. No. 08/428,960, filed Apr. 24, 1995 and now U.S. Pat. No. 5,622,166, and incorporated herein by reference.  
         FIELD OF THE INVENTION  
         [0002]    The field of the invention is inhalers. More specifically, the invention relates to inhalers for delivering drugs in a solid finely divided dry powder or fluid form.  
           [0003]    Inhalers are used to deliver drugs into a patient&#39;s lungs. Typically, an inhaler contains or provides a mixture of drugs and air or propellants. The mixture is delivered via the patient inhaling from a mouthpiece on the inhaler, for treatment of various conditions, for example, bronchial asthma. However, delivery of drugs via inhalation can be used for many other treatments, including those unrelated to lung condition.  
           [0004]    One well known inhaler, the Diskhaler, described in U.S. with each successive dose. However, while the device described in U.S. Pat. No. 4,627,432 has met with varying degrees of success, disadvantages remain in indexing or advancing a blister disk within an inhaler, with opening the blisters to access the drug contents, with reliably providing intended dosages, and in other areas.  
           [0005]    Accordingly, it is an object of the invention to provide an improved inhaler.  
         SUMMARY OF THE INVENTION  
         [0006]    To these ends, the present inhaler preferably includes a cover plate pivotably attached to a lid on an inhaler housing. A blister pack disk is rotatably mounted on the housing under the cover plate, and is movable in a single forward direction. An actuator in the housing is most desirably aligned with a lever on the cover plate. The patient pushes the actuator which shears open a blister on the disk and then causes the lever to crush the blister, to deliver the drug powder contents of the blister into a duct within the housing, for subsequent inhalation by the patient.  
           [0007]    Other and further objects will appear hereinafter. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    In the drawings, wherein similar reference characters denote similar elements throughout the several views:  
         [0009]    [0009]FIG. 1 is perspective view of the present inhaler with the mouthpiece covered by the cover assembly;  
         [0010]    [0010]FIG. 2 is a perspective view thereof with the mouthpiece uncovered;  
         [0011]    [0011]FIG. 3 is a plan view of the inhaler as shown in FIG. 1;  
         [0012]    [0012]FIG. 4 is a plan view of the inhaler as shown in FIG. 2;  
         [0013]    [0013]FIG. 5 is an exploded perspective view of the inhaler of FIGS. 1 and 2;  
         [0014]    [0014]FIG. 6 is an plan view of the inhaler of FIGS. 1 and 2 with the lid open;  
         [0015]    [0015]FIG. 7 is a partial section view taken along line  7 - 7  of FIG. 6;  
         [0016]    [0016]FIG. 8 is an enlarged top and front perspective view of the cover assembly on the inhalers of FIGS. 1 and 2;  
         [0017]    [0017]FIG. 9 is a bottom and rear perspective view of the cover assembly of FIG. 8;  
         [0018]    [0018]FIG. 10 is an enlarged view of features shown in FIG. 9;  
         [0019]    [0019]FIG. 11 is a partial section view taken along line  11 - 11  of FIG. 5;  
         [0020]    [0020]FIG. 12 is similar view showing positions of various components during use of the device;  
         [0021]    [0021]FIG. 13 is a partial section view taken along line  13 - 13  of FIG. 3;  
         [0022]    [0022]FIG. 14 is a partial section view taken along line  14 - 14  of FIG. 4;  
         [0023]    [0023]FIGS. 15, 16 and  17  are partial section view fragments illustrating movement of components within the device;  
         [0024]    [0024]FIG. 18 is a section view taken along line  18 - 18  of FIG. 5;  
         [0025]    [0025]FIG. 19 is a similar view thereof with various components omitted for drawing clarity, and showing positions of components during use;  
         [0026]    [0026]FIG. 20 is an exploded perspective view of a blister disk for use with the inhaler shown in FIGS. 1 and 2;  
         [0027]    [0027]FIG. 21 is a partial plan view thereof; and  
         [0028]    [0028]FIG. 22 is a section view taken along line  22 - 22  of FIG. 21. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]    Turning now in detail to the drawings, as shown in FIGS.  1 - 4 , a dry powder inhaler includes a housing  32  having a lid  38  attached to the housing with a hinge  36 . The lid  38  is preferably a transparent material, e.g., clear plastic. A removable mouthpiece  34  is provided on one side of the housing  32 . A sliding cover assembly  40  may be pivoted on the lid  38  from a closed position covering the mouthpiece  34 , as shown in FIGS. 1 and 3, to an opened position exposing the mouthpiece  34 , as shown in FIGS. 2 and 4. As best shown in FIGS. 3 and 4 (looking down through the transparent lid  38 ), a disk  42  having a plurality of radially spaced apart blisters  44  is generally centered on top of the housing  32  on a center post  140  extending upwardly from the housing  32 . A lid stop  46  on the housing  32  limits sliding movement of the cover assembly  40  in the opened position.  
         [0030]    Turning momentarily to FIGS. 8 and 9, the sliding cover assembly  40  includes an enclosure  48  having a front curved wall  54 , a side wall  56 , a top wall  58  and a bottom wall  60 . A rim  62  extends upwardly and radially inwardly on the top wall  58 .  
         [0031]    Referring now to FIG. 9, a glide block  64  and an outside retainer  66  extend downwardly and inwardly on the underside of the top wall  58 . A generally flat cover plate  50  is preferably integrally formed with the enclosure  48 , with the cover plate  50  and enclosure comprising the cover assembly  40 . An inside retainer  68  on the cover plate  50  extends radially outwardly. A lever  74  is pivotably supported on a lever pin  76  held in place by lever blocks  72  on the underside of the cover plate  50 . The lever  74  can pivot through a lever opening  78  in the cover plate  50 , as best shown in FIG. 8. A ramp  80  and a guide wall  82  project downwardly from the cover plate  50 , adjacent to the lever  74 , as shown in FIG. 9. The entire cover assembly  40 , which includes the enclosure  48  and cover plate  50  is pivotably attached to the lid  38 , with the lid post  52  extending through a center hub  84  on the cover plate  50 . Clearance holes  70  through the cover plate  50  on either side of the lever opening  78  allow the cover plate to sit on top of the blister disk, as shown in FIG. 18, without excessive vertical interference.  
         [0032]    Referring to FIGS. 8, 9 and  10 , a spring arm  86  having a downwardly projecting end tab  88  is attached to or integral with the cover plate  50 . As shown in FIG. 13, the spring arm  86  includes an arm wedge  96  at its free end, alongside the tab  88 . As shown in FIG. 10, an arm lifter  102  extends downwardly from the lid  38 . An outer slot  94  through the cover plate  50  overlies the spring arm  86 . An inner slot  92  adjoining the outer slot  94  through the cover plate  50  provides clearance for the arm lifter  102 , and allows the cover assembly  40  to rotate (preferably about 90°). The arm lifter  102  includes an internal ramp, and is dimensioned to engage the arm wedge  96 , and lift the arm  86  up towards the lid  38 , as the arm wedge  96  moves into full engagement with the lifter  102 .  
         [0033]    Turning now to FIG. 5, the housing  32  includes a mixing chamber  120 , and a staging chamber  124  connected to the mixing chamber  120  via a duct  122 . Referring now also to FIGS. 6 and 7, an inlet duct  126  extends from one side of the housing  32  to the staging chamber  124  via a duct recess  130 . A crescent barrier  128  around the top of the staging chamber  124  creates an indirect air flow path from outside of the housing, through the inlet duct  126  and into the staging chamber  124 .  
         [0034]    In a first embodiment of the present invention, referring once again to FIG. 5, a pressure port or opening  132  in the housing  32  alongside the mixing chamber  120  connects to a pressure switch  170  via a tube  172 . The pressure port aligns with a mouthpiece port  135  leading into the central opening of the mouthpiece. This provides a continuous duct from the mouthpiece opening to the pressure switch. The mouthpiece  34  or an alternative embodiment mouthpiece  136  is secured to the housing  32  with a hook  134 . The mouthpiece is removable by twisting or rotating the mouthpiece, to disengage the hook  134 , and then by pulling it off. Rachet posts  142  having angled top surfaces project slightly above the flat top surface  138  of the housing  32 . An actuation button  146  has a post  148  extending entirely through a post opening  144  in the housing  32 .  
         [0035]    Referring momentarily to FIG. 18, a detent  145  on the housing engages and holds the post  148  in the up position (driving the lever to crush a blister), until the disk is advanced to the next blister. At the front of the housing, behind the mixing chamber  120 , is an inwardly projecting housing inner rim  150 , and an outwardly projecting housing outer rim  152 . The outer rim  152  is engaged by the outside retainer  66 , and the inner rim is engaged by the inside retainer  68 , as the cover assembly  40  is moved between opened and closed positions. The interaction of the inner rim  150  and inside retainer  68  and outer rim  152  and outside retainer  66 , holds the cover assembly and lid down on top of the housing  32 .  
         [0036]    Referring still to FIG. 5, a bottom cover  158  attached to the housing  32  has a button recess  164  around the actuation button  146 , so that the actuation button  146  does not project beyond the bottom surface of the cover  158 . An impeller  162  within the mixing chamber  120  is supported on the shaft of an electric motor  160  behind the mixing chamber  120  in the housing  32 . The motor  160  is wired to batteries  168  and the pressure switch  170 . A battery indicator LED  174  and a status indicator LED  176  are positioned in the housing  32 , above the pressure switch  170 .  
         [0037]    Turning now to FIGS.  20 - 22 , the disk  42  includes a blister foil ring  190 , preferably a metal or aluminum foil having generally conical blisters formed in it. The blister foil ring  190  and a foil seal ring  192  are adhered or bonded onto a carrier disk  194 . As shown in FIG. 21, the carrier disk  194  has tabs  196  suspended within tab slots  198  by bridges  200 . Each blister  44  on the blister foil ring  190  is aligned over a tab  196 . The bridges  200  hold the tabs  196  in position, but allow the tab to pivot about the bridges, with nominal torque. As shown in FIG.  22 , powdered drug  202  is sealed within the blisters  44 . The carrier disk  194  is preferably plastic. The tab supports  200  are small enough to support the tabs  196 , but also to allow the tab to pivot under force of the post of the actuation button.  
         [0038]    In use, a disk  42  is first loaded into the inhaler  30  by sliding the cover assembly  40  from the closed position shown in FIG. 1 to the open position shown in FIG. 2. In this position, the lid  38  and cover assembly  40  are still held down on top of the housing  32  by the interaction of the outside retainer  66  and inside retainer  68  on the housing outer rim  152  and inner rim  150 . The side wall  56  of the enclosure  48  is lifted slightly away from the housing  32 , to a allow it to pass over the lid stop  46 . As this occurs, the retainers  66  and  68  move off of and release from the inner and outer rims  150  and  152 . The cover assembly  40  and lid  38  are then pivoted upwardly about the hinge  36 , to open up the inhaler  30 , as shown in FIG. 6, for placement or replacement of a disk  42 .  
         [0039]    A disk  42  is placed over the center post  140  over the housing top surface  138  with the blisters  44  on top. The lid  38  and cover assembly  40  are pivoted back about the hinge  36 , from the position shown in FIG. 6, to the position shown in FIG. 2. The inhaler  30  is then ready for use.  
         [0040]    The rachet posts  142  on the housing top surface  138  project slightly into the open ends  203  of the tab slots  198 . The disk  42  is accordingly oriented so that a blister  44  will be aligned over the staging chamber  124 . The rachet posts  142  also prevent the disk  42  from moving in reverse (i.e., clockwise in FIG. 6).  
         [0041]    With the lid  38  closed, but with the cover assembly  40  opened (as shown in FIG. 2), the inner end of the lever  74  is aligned over the top of the post  148 . The outer end of the lever  74  is aligned over the top of a blister  44 , and over the staging chamber  124 .  
         [0042]    With the inhaler  30  preferably held upright, the actuation button  146  is pushed up. As shown in FIGS. 11, 12 and  19 , the upward movement of the post  148  on the actuation button  146  first pivots the tab  196  on the blister  44  over the staging chamber  124 . The tab pivots on the bridges  200 . As this occurs, the foil seal ring  192  sealing the blister  44  on the bottom shears away opening the blister and allowing the powdered drug  202  to fall into the staging chamber  124 .  
         [0043]    As upward movement of the post  148  continues, the post pivots the lever  74  causing the outer end of the lever to crush the blister  44  down, to release any residual powder into the staging chamber  124 .  
         [0044]    With one dose of the powdered drug now delivered from a sealed blister  44  into the staging chamber  124 , the patient places the mouthpiece  34  into the mouth and inhales. The inhalation draws air from outside of the housing through the inlet duct  126 , around and under the crescent barrier  128  and into the staging chamber  124 . Air and powdered drug  202  move through the duct  122  and into the mixing chamber  120 . At the same time, upon inhalation, the reduced air pressure at the mouthpiece  136  is detected by the pressure switch  170  via the tube  172  extending to the pressure port  132 . The switch  170  turns on the motor  160 , spinning the impeller  162  within the mixing chamber  120 . The air and drug is mixed in the mixing chamber  120 , as further described in U.S. Pat. Nos. 5,327,883, and 5,577,497, incorporated herein by reference. As the impeller is already spinning at high speed when the drug enters the mixing chamber, the air/drug mixing and deagglomeration are enhanced.  
         [0045]    The patient inhales on the mouthpiece drawing in the air/drug mixture from the mixing chamber  120  via holes  125  in the rear wall of the mouthpiece  34  (which rear wall also forms the front wall of the mixing chamber  120 ).  
         [0046]    To prepare for delivery of the next dose, the cover assembly  40  is moved from the position shown in FIG. 2, to the position shown in FIG. 1, to cover the mouthpiece  34 . As this closing movement of the cover assembly  40  occurs, the arm wedge  96  on the spring arm  86  is released from the lifter  102 . This allows the spring arm  86  to flex downwardly with the tab  88  engaging into the opened end  202  of a tab slot  198 , approximately at position A as shown in FIGS. 3 and 6. With the continued closing motion of the cover assembly  40  to the position shown in FIG. 3, the tab  88  on the spring arm  86  advances the disk  42  to the next blister  44  (moving the disk  42  counter-clockwise in FIG. 3). For a disk having 16 blisters, the advancing movement, from engagement of the tab  88  to the disk  42 , until the end of movement, is about 22°. As the disk  42  is advanced by the spring arm  86  on the closing cover assembly  40 , the disk  42  rides up and over the angled top surfaces of the rachet posts  142  and then settles back down onto the housing surface  138  with the rachet posts  142  engaged into the next set of opened ends  203  of the tab slots  198 . In this manner, the next blister  44  on the disk  42  is positioned for delivery and inhalation, as described above. When the cover assembly  40  is reopened, to the position shown in FIG. 4, the disk  42  does not move, as the spring arm  86  is lifted up and out from engagement with the disk by the interaction of the lifter  102  on the lid  38  and the arm wedge  96  on the spring arm  86 . Through this repeated motion of opening and closing the cover assembly  40 , each blister  44  on the disk  42  can be sequentially accessed, until all of the blisters are used.  
         [0047]    As the cover assembly  40  is closed, the ramp  80  on the cover plate  50  rides over the top of the post  148 , the push it down, resetting the actuation button  146  for the next dose, as shown in FIGS.  15 - 17 . Simultaneously, the guide wall  82 , which ramps upwardly from the lever  74 , pushes down on the pivoted tab  196  from the blister delivered. The tab  196  is accordingly pushed back down into the plane of the disk  42 , so that the disk can be advanced without interference. The rachet posts  142  prevent the disk  42  from moving in reverse (clockwise in FIG. 3) at anytime.  
         [0048]    Accordingly, a novel inhaler is described and shown with various advantages over the prior art design. The above-described inhaler may contain various changes and modifications, including various substitutions and equivalents, without departing from the spirit and scope of the present invention.