Patent Publication Number: US-2009235931-A1

Title: Unit dose dry powder inhaler

Description:
This application is a Continuation of U.S. patent application Ser. No. 11/130,970, filed May 17, 2005, which claims the benefit of U.S. Provisional Application No. 60/575,137 filed May 28, 2004. 
    
    
     BACKGROUND OF INVENTION 
     The field of the invention is dry powder inhalers. 
     Certain medicines may be inhaled in dry powder form directly into the lungs. Inhalation bypasses the digestive system and avoids any potential metabolic inactivation or destruction of the medicine by the digestive system. Inhalation can also provide very rapid onset of the effect of the medicine. Inhalation may also allow smaller doses to be used to achieve the same desired results as orally ingested medicines. In other cases, it provides a delivery technique for medicines that display unacceptable side effects when taken by other methods. In addition, inhalation also avoids the potential risks of injection to both medical caregivers and patients. 
     Various inhaler designs have been proposed, to allow dry powder medicines to be inhaled. Most of these inhalers are metered dose inhalers or multiple dose dry powder inhalers. Metered dose inhalers dispense a suspension of powder particles in a compressed propellant gas. Multiple dose dry powder inhalers generally repeatedly dispense individual doses from a bulk powder reservoir, or from a blister disk or cassette. However, certain medicines, such as certain peptides or proteins, or medicines such as vaccines, antidotes, etc., are generally taken by a patient infrequently or even only one time. Metered dose inhalers and multiple dose dry powder inhalers are not intended or well designed for one-time use, to deliver a single dose. These types of inhalers are typically too bulky, costly, inefficient, or difficult to use, when only a single dose is desired, and where the inhaler can be practically discarded after use, in an environmentally acceptable way. 
     Several unit dose inhalers, intended for one-time use, have been proposed. However, they have not achieved widespread use. Disadvantages remain with unit dose inhalers relating to powder storage, dose uniformity, dispersion performance, ease of use, cost, and other factors. Accordingly, there is a need for an improved inhaler for efficiently providing a single dose of a powdered drug. 
     It is an object of the invention to provide such an improved unit dose dry powder inhaler. 
     SUMMARY OF THE INVENTION 
     A unit dose dry powder inhaler has a chamber housing including a dispersion chamber. An air flow passageway extends through the chamber housing, and through the dispersion chamber. A dose of a dry powder pharmaceutical is contained at a powder location on or in the chamber housing. A cover or cup attached to the chamber housing is pivotable relative to the chamber housing from a first position, where the air flow passageway is closed off from the powder location, to a second position, where the air flow passageway connects through the powder location. The powder is stored directly within the inhaler itself. The powder can be quickly and easily inhaled by twisting or turning the cover, to open up the air flow passageway through the powder location. 
     In a second aspect, the dispersion chamber contains one or more beads, to improve dispersion of the powder. 
     In a third aspect, a ratchet or anti-reverse movement device is provided on the cover or the chamber housing, to help avoid inadvertent attempts to inhale a dose of powder from a used or empty inhaler. 
     Other and further aspects and advantages are also described. The invention resides as well in subcombinations of the components and method steps described and shown. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
       In the drawings, wherein the same reference number indicates the same element, in each of the views: 
         FIG. 1  is a top and front perspective view of a unit dose dry powder inhaler. 
         FIG. 2  is a bottom and rear perspective view of the inhaler shown in  FIG. 1 . 
         FIG. 3  is a perspective view similar to  FIG. 1 , and with the cover or cup removed, for purpose of illustration, to show the chamber housing. 
         FIG. 4  is a perspective view similar to  FIG. 2 , and with the cover or cup removed, for purpose of illustration, to show the chamber housing. 
         FIG. 5  is a bottom perspective view of the top or mouthpiece section shown in  FIGS. 1-4 . 
         FIG. 6  is an inverted perspective view of the top section shown in  FIG. 5 . 
         FIG. 7  is a top perspective view of the base section shown in  FIGS. 3 and 4 . 
         FIG. 8  is a bottom perspective view of the base section shown in  FIG. 8 . 
         FIG. 9  is a top perspective view of the cover element shown in  FIGS. 1 and 2 . 
         FIG. 10  is plan view of the cover element shown in  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Turning now in detail to the drawings, as shown in  FIGS. 1-4 , an inhaler  20  has a top or mouthpiece section  22  rigidly attached to a base  24 , to form a chamber housing  100 . A cup or cover  26  fits over and is pivotably attached to the chamber housing  100 . The inhaler  20  is advantageously provided within a sealed pouch or container  28  as shown in  FIG. 2 . The inhaler  20  is preferably removed from the pouch immediately before use, to better reduce adverse environmental affects on the dose of powder. 
     The top section  22  includes a mouthpiece  32  extending out or up from a finger grip plate  34 . Finger tabs  36  on the finger grip plate  34  provide convenient and secure finger positions for holding the inhaler  20 . As shown in  FIGS. 5 and 6 , a first or top curved chamber wall  42  is formed in the underside of the mouthpiece section  22 , opposite from the mouthpiece  32 . A chamber tube  40  extends from a central area of the chamber wall to or through the mouthpiece  32 . A top chamber inlet groove  46  extends outwardly at an angle from the chamber wall  42 . A snap groove  52  is located along the lower edge of the top section  22 . A top air inlet  38  passes through the lower lip of the snap groove  52 . A raised chamber rim or shoulder  48  surrounds the chamber wall  42 . Attachment holes  50  in the top section  22  are used to attach and align the base  24  onto the top section  22 . 
     Referring now to  FIGS. 7 and 8 , the base  24  has a flange  64  extending radially outwardly from a cylinder section  65 . A dose bowl or recess  74  is formed in the cylinder  65 , and is surrounded by a bowl rim or raised shoulder  76 . As shown in  FIG. 3 , a visual indicator  96 , is provided on the outside of the cylinder, opposite or directly across from the dose bowl  74 . A flange inlet  68  and a flange outlet  63  extend through the flange  64 , on opposite sides of the dose bowl  74 . Horizontal spacer ribs  94  project outwardly from the cylinder  65 , opposite from the dose bowl  74 , and extend across an arc of 60-270, 90-210 or 110-180 degrees. Ratchet teeth or recesses  71  and  73  are located about 90 degrees apart on or in the flange  64 . A stop tooth is similarly located about 90 degrees apart from the tooth  73  on the flange  64 . Attachment pegs  70  extend up or out from the flange  64  for engagement into the holes  50  in the top section  22 . A curved second or bottom chamber wall  60  is formed in the base  24  and is surrounded by a raised bottom chamber rim  61 . A bottom chamber inlet groove  62  extends from the flange outlet  63  to the bottom chamber wall  60 . 
     As shown in  FIGS. 3-8 , the top or mouthpiece section  22  and the base  24  are joined together, with the pegs  70  in the holes  50 . The top or first chamber wall  42  in the mouthpiece section  22  comes together with the second or bottom chamber wall  60  in the base  24  to form a dispersion chamber, generally indicated as  45  in  FIG. 3 . One or more beads  44  may optionally be contained within the dispersion chamber  45 . The raised top chamber rim  48  around the top chamber wall  42  contacts with the raised bottom chamber rim  61  around the bottom chamber wall  60 . The bottom chamber inlet groove  62  aligns with the top chamber inlet groove  46 , to form a chamber inlet passageway  69  connecting the flange outlet  63  with the dispersion chamber  45 . The top or first air inlet  38  in the mouthpiece section  22  is permanently fixed in position or aligned over the flange inlet  68  in the base. The mouthpiece section  22  and the base  24  may be joined via adhesives, welding, pressing, or with other known techniques. The beads  44 , if used, are placed into the dispersion chamber  45  before the mouthpiece section and the base are permanently and irrotatably joined together. When joined together, the mouthpiece section  22 , the base  24 , and the bead or beads  44  (if used), form the chamber housing  100 . 
     Turning to  FIGS. 9 and 10 , a snap ring projection  90  is formed on the inside diameter of a cover flange  80 . A cover inlet slot  82  and a cover outlet slot  84  are formed in the cylindrical sidewall of the cover. The slots  82  and  84  are located on the cover and dimensioned so that they can be aligned respectively with the flange outlet  63  and the flange inlet  68  in the flange  64  of the base  24 . One or more ribs  85  are preferably provided on the outside cylindrical walls of the cover  26 . A ratchet arm  98  is formed on the lip  99  of the cover  26 . A dose loading hole  88  is provided in the cylindrical sidewall of the cover, opposite from the slots  82  and  84 . As shown in  FIG. 2 , the bottom of the cover  26  is flat or has a central concave area, to allow the inhaler  20  to stand upright on a flat surface. 
     Referring to  FIGS. 3 ,  4 ,  9  and  10 , the cover  26  is attached to the mouthpiece section  22  via the snap ring  90  snapping into the groove  52 . The inhaler  20  is then assembled, as shown in  FIGS. 1 and 2 , and is ready for loading with a single dose  92  of a dry powder pharmaceutical. 
     The mouthpiece section  22 , the base  24  and the cover  26  are preferably molded of a plastic material, allowing them to be manufactured inexpensively, using a minimum amount of material. Molding also allows for convenient formation of various of the features described above. However, various other manufacturing techniques, involving forming the mouthpiece section, base and cover as integral components, or involving making them via assembly of discrete sub-components, may of course also be used. 
     With the inhaler  20  initially assembled, the dose loading hole  88  is aligned over the dose bowl  74 , and the inhaler  20  is laying on its side, with the dose bowl facing up. A dose of a dry powder pharmaceutical powder  92  is placed into the bowl, through the hole  88 , preferably using an automated powder loading system. The cover  26  is then turned or rotated by about 90 degrees. This moves the bowl  74  containing the powder  92  to a midpoint between the loading hole  88  and the slots  82  and  84 . The inhaler  20  is thus in the storage position, and may be sealed into the pouch or package  28  and sealed. In the storage position, the flange inlet  68  and the flange outlet  63  to the bowl  74  are closed off by the cover flange  80 . 
     The smooth cylindrical inside surface of the bowl  74  slides over the bowl rim  76 . The bowl rim  76  helps to contain the powder within the bowl. The spacer ribs  94  space the inside cylindrical walls of the cover apart from the outside cylindrical walls of the cylinder  65  on the base  24 . Consequently, the bowl makes sliding contact only with the bowl rim  76  and the spacer ribs  94 . The bowl therefore remains aligned on the cylinder  65 , and rotates only when a desired amount of turning force or torque is applied. This prevents inadvertent turning of the bowl during packaging, shipment and handling. However, it also allows the bowl to turn when nominal force is applied, so that users with low hand and finger strength or dexterity are able to use the inhaler. 
     In use, the inhaler  20  is removed from the package  28 . The user grasps the finger tabs  36  with one hand and rotates the cover by about ¼ turn or 90 degrees, to an open position. The ratchet arm  98  allows the cover to be rotated only in the forward direction (counterclockwise in  FIG. 2 ). The ratchet arm may also provide an audible and/or tactile click or pop when the open position is reached. A detent or an open position stop pin or boss may also be provided, to help insure that the cover is correctly and fully moved into the open position. The visual indicator  96  is aligned in the dose loading opening  88 , providing a visual indication to the user that the inhaler is in the open or ready to use position. 
     The pivoting movement of the cover  26  opens the air flow passageways in the inhaler  20 . A first air flow path is formed via the top or first inlet  38  and the flange inlet  68 , which are permanently open. A second air flow path is formed by the flange outlet  63 , the chamber inlet  69 , the dispersion chamber  45 , and the chamber tube  40 . With the inhaler in the storage position, the first airflow path is closed off from the second air flow path by the lip  99  of the cover  26 , as the slots  80  and  82  are not aligned with the openings  63  and  68  in the flange  64 . When the cover  26  is turned further into the open or ready position, as described below, the first and second air flow paths are connected through the bowl  74  and the slots  82  and  84  in the sidewall of the cover  26 . 
     In the open position, the flange inlet  68  and outlet  63  to the bowl  74  are now open, as they are aligned with the slots  82  and  84  in the cover  26  Thus, in the open position, there is an unobstructed continuous air flow path through the inhaler. The user inhales on the mouthpiece  32 . Air flows in the top inlet  38 , through the flange outlet  63 , into the cover inlet slot  82 , through the bowl  74 , and then out of the bowl through the cover outlet slot  84 , the flange inlet  68 , and into the dispersion chamber  45  via the chamber inlet passageway  69 . As air flows through or over the bowl  92 , powder is entrained in the air. The inlet and outlet slots  82  and  84  connect tangentially into the bowl  74 . This provides a swirling air movement, to enhance entrainment of the powder into the flowing air. 
     The air/powder mixture flows into the dispersion chamber, where the powder is more effectively dispersed, to provide better inhalation performance. Dispersion in the chamber  45  occurs via rapid circular movement of the powder and air. In embodiments containing beads in the chamber, the beads assist in dispersion, as described in U.S. Pat. No. 6,427,688 and U.S. Published Patent Application No. 200110027790A1, both incorporated herein by reference. 
     Air and dispersed powder flow out of the dispersion chamber  45  through the chamber tube  40  and mouthpiece  32 , and are inhaled by the user. Sheath air channels  54  may be provided around the chamber tube, to surround the powder-laden stream of inhaled air with ambient air. Use of sheath air reduces deposition of powder in the mouth and throat, so that more of the powder is delivered into the lungs of the user. 
     After use, the cover  26  is optionally rotated an additional ¼ turn, into a used or discard position. The stop boss or pin  75  engages with the ratchet arm  98 , to prevent the cover from turning in either direction. Accordingly, in the used position, the cover is locked and cannot turn, and the visual indicator  96  is not visible. This indicates to the user that the inhaler is used and should be discarded. Hence, turning the cover into the used position helps to prevent attempts to inhale a dose from a used inhaler. 
     The specific size, shape and arrangement of various of the features shown  FIGS. 1 and 2 , including the finger plate  34  and tabs  36 , mouthpiece  32 , ribs  85 , and the cover  26 , is arbitrary. The appearance of these features is a matter of design preference from a large array of options. These features may be selected or changed to create any desired ornamental external appearance of the inhaler  20 . 
     Thus, a novel unit dose dry powder inhaler has been shown and described. Many changes, substitutions and uses of equivalents may of course be made without departing from the spirit and scope of the invention. The invention, therefore, should not be limited, except by the following claims and their equivalents.