DRY POWDER INHALER DELIVERY SYSTEM

Abstract: A powder storage and delivery system for a drug powder inhaler (20) has a carrier disk (46) with a blister shell (54) sealed by a shear layer (56). A tab (48) is adhered to the shear layer (56), underneath the blister shell (54). The carrier disk (46) is placed into a dry powder inhaler (20). An actuator (80) pushes against the tab (48), causing the shear layer (56) to tear away, releasing the powder drug contents (62) from the blister into the dry powder inhaler (20). A disk carrier (130) has bursting blisters (132) with a brittle blister shell (132) sealed with a foil lid (150), and covered by a plate (136). An actuator (160) moves against the plate (136), causing the plate (136) to buckle and the blister shell (132) to burst open, releasing powdered drug (62) into the dry powder inhaler (20).

Description: DESCRIPTION DRY POWDER INHALER DELIVERY SYSTEM BACKGROUND OF THE INVENTION Field of the Invention The field of the invention is dry powder storage devices and systems for powdered drugs. Various drugs in a dry powder mixture form may be inhaled directly into the lungs, through the mouth or nose. Inhalation allows the drug to bypass the digestive system and may eliminate the need for other more interven- tional drug application techniques, e.g., hypodermic injections, etc. Direct inhalation, can in some cases, allow smaller doses of a drug to be used to achieve the same desired results as the same drug taken orally. In other cases, inhalation can help to avoid undesirable side effects. To provide for direct inhalation of a powdered drug, various dry powder inhalers have been used. These dry- powder inhalers typically deliver dry powder from a bulk reservoir, capsule, or blister package, for inhalation by the patient. For sealing the powdered drug from the environment (to reduce caking, contamination, etc.), individual discrete sealed dose containers, such as blisters are preferred. However, while various blister dry powder storage and delivery devices have been used, various disadvantages remain. For example, the blister must be strong enough to provide a good seal against the environment, but also be able to reliably release the drug powder when used by the patient. In addition, to better provide accurate doses, virtually of the drug powder must be released from the blister into the inhalation device, without, of course, allowing any of the blister or con¬ tainer material mix with or flow out with the drug powder. As inhaled drugs, such as asthma drugs, may be used very frequently, the drug storage and delivery materials and device should advantageously be compact, low cost and easy to manufacture and use. Accordingly, it is an object of the invention to provide an improved dry powder storage and delivery system, for use with an inhaler. SUMMARY OF THE INVENTION To these ends a dry powder storage and delivery device preferably includes a disk having radially spaced apart metal foil blisters containing a drug powder. The blis¬ ters are advantageously sealed onto an underlying metal foil shear layer. In the preferred embodiment, the shear layer is bonded onto a carrier disk. Shear tabs are advantageously bonded onto to the shear layer, underneath each blister, with a gap separating the tabs from the disk. In the preferred use, an actuator pushes on the tab, shearing or tearing out the shear layer from the blister, and releasing the dry powder contents of the blister. The blister may also preferably be formed of a brittle material with a generally centrally located score line, so that the blister will burst open when engaged by an actuator, to release the powder drug contents of the blister. BRIEF DESCRIPTION OF THE DRAWINGS Other objects and features of the present invention will become apparent from the following detailed descrip¬ tion taken together with the accompanying drawings. The drawings, however, are provided for illustration purposes only and are not intended as a limitation on the scope of the invention. In the drawings, wherein similar reference characters denote similar elements throughout the several views: Fig. 1 is a perspective view of a dry powder inhaler; Fig. la is a perspective view of the advance knob of the inhaler of Fig. 1; Fig. lb is a plan view of the inhaler of Fig. l; Fig. lc is a schematically illustrated partial section view of the inhaler of Fig. 1; Fig. 2 is a perspective view of a drug carrier disk, having exterior tabs; Fig. 3 is a perspective view of an alternative carrier disk, having interior disk tabs; Fig. 4 is another disk carrier embodiment having tabs contained within the disk; Fig. 5 is an enlarged partial section view taken along line 5-5 of Fig. 2; Fig. 5A is a top view thereof; Fig. 5B is an exploded section view taken along line 5B-5B of Fig. A; Fig. 5C is a bottom view thereof; Fig. 6 is a side elevation view thereof, just prior to opening the blister; Fig. 7 is a side elevation view thereof, just after the blister has been sheared open; Fig. 8 is a section view of the carrier disk of Fig. 2 installed within a first embodiment of a dry powder inhaler; Fig. 9 is a section view of the disk carrier of Fig. 2 installed within a second embodiment dry powder inhaler; Fig. 10 is a perspective view of an alternative disk carrier having bursting circumferentially scored blisters on angled plates; Fig. 11 is an alternative disk carrier embodiment having radially scored bursting blisters on flat plates; Fig. 11a a perspective view of the underside of the disk carrier of Fig. 11; Fig. 12 is yet another disk carrier embodiment having circumferentially scored bursting blisters on flat plates; Fig. 13 is a section view fragment taken along line 13-13 of the Fig. 10; Fig. 14 is a side elevation view of the blister of Fig. 13, just prior to opening; Fig. 15 is a side elevation view thereof, showing the blister immediately after opening; and Fig. 16 is a perspective view of a straight strip carrier. DETAILED DESCRIPTION OF THE DRAWINGS Turning now in detail to the drawings, as shown in Fig. 1, a dry powder inhaler 20 has a mouthpiece 22 which is covered by a cap 24 when not in use. A knob 26 on top of the inhaler 20 may be used to advance individual drug doses for delivery through the mouthpiece 22. Referring to Figs. 1, lb, and lc, a blister opening mechanism 38 includes a center button 28 positioned over a spring 44 on a rocker arm 40. The rocker arm 40 has a lever end 42 for pushing up on an interior tab 32 on a carrier disk 34 to shear or tear open a blister 36. The carrier disk 34 and blister 36 are further illus¬ trated in Figs. 2-5. Fig. 2 shows a carrier disk 46 have exterior tabs 48 extending from radially spaced apart blisters 36 supported on a carrier disk 60. Fig. 3 better illustrates the carrier disk 34 shown in Fig. lc, which has interior tabs 32. Fig. 4 shows another alternative carrier disk embodiment having tabs contained within the profile of the disk 50. Shear pin holes 52 extend through the disk 50, and in use, pins in an inhaler device extend through the holes 52 to push against a tab contained within the disk 50, to shear open the blisters 36. The carrier disks 34, 46 and 50 may include an indexing/drive notch 72. Turning to Fig. 5 which illustrates an exterior tab carrier disk design, a blister shell 54 is positioned over a shear layer 56. The perimeter of the blister shell 54 is advantageously heat sealed to the shear layer 56 as shown at 58 in Figs. 5 and 5a. Drug powder 62 is con¬ tained between the blister shell 54 and the shear layer 56. A tab 48 underlies the shear layer 56, below the blister shell 54. The tab 48 is separated from the disk carrier 60 by a gap 64 all around, except for at the hinge line 68 (Fig. 7) . The hinge line 68 may optionally be provided as an indented area. A stress concentrator 70, can similarly be included as an option by providing a point or tooth on the disk carrier 60 at the innermost location of the gap 64, just inside of where the blister shell and shear layer join. The stress concentrator can help start the shearing/tearing action of the shear layer. The blister shell 54 and shear layer 56 are preferably metal, e.g., aluminum, foils. The disk carrier 60 and tab 48 are preferably injection molded or die cut plastic. The shear layer 56 is adhered to the disk carrier 60 and tab 48 with an adhesive 49, and spans across the gap 64, as shown in Figs. 5B and 5C. Figs. 6 and 7 illustrate operation of the disk carrier 60 within an inhaler. As shown in Fig. 6, the disk 60 rests on a support 84 positioned just inside of the gap 64. The blister 36 is positioned over a guide wall 86. As shown in Figs. 6 and 7, an actuator 80 pushes up on the tab 48, which, acting as a lever, causes the shear layer 56 (which forms the bottom surface of the blister 36) to shear and tear away from the blister shell 54, thereby opening the blister. The powder 62 contained within the blister 36 falls free of the blister 36 and disk 60, into a chute in the inhaler. The tab 48 pivots about the hinge point 68. As this occurs, the heat seal 58 remains intact, with the opening of the blister 36 provided by the tearing of the shear layer 56. Referring to Fig. 8, a dry powder inhaler 100 has a housing 102, a mouthpiece 104 and an impeller 108 within a mixing chamber 106. A motor 110 powered by batteries 112 spins the impeller 104. As the blister 36 is sheared open, as shown in Figs. 6 and 7, the powder from the blister 36 falls into the mixing chamber 106, is mixed with air, and can be drawn out and inhaled by the patient. Fig. 9 shows an alternative inhaler embodiment having a centrally located mouthpiece 104. Figs. 10-16 illustrate blisters which are burst open, rather than torn or sheared open. As shown in Fig. 10, a bursting blister carrier disk 130 has a plurality of bursting blisters 132 on angled plates 136. The plates 136 and blisters 132 have a circumferential score 134. Fig. 12 shows a similar embodiment, but with the plates flat in the plane of the disk rather than angled. Fig. 11 shows an alternative embodiment having flat plates 144, with a radial score 142 on the plates 140 and blisters. Fig. 11a better illustrates the radial scored blisters 148 on the flat radially scored plates 144. The score or weakened section of the plates 144 and the blisters 142 are preferably centrally located on each blister 148. As shown in Fig. 13, a bursting blister carrier disk 130 has a brittle blister shell 132 attached by a heat seal 58, at the blister shell perimeter, to a lid stock 150. The lid stock 150 in turn is bonded onto a plate 136. The blister shell 132 has a score or weak point 134 at its center. Correspondingly, the plate 136 has a score aligned with the score 134 on the blister shell 132. The blister shell 132 is advantageously made from a brittle plastic or metal material. The lid stock 150 is preferably a metal (e.g., aluminum foil), while the plate 136 is preferably a hard injection molded or die cut plastic, as is the carrier disk center section. In use, as shown in Figs. 14 and 15, a plunger or actuator 160, having a broad flat blade shape with an angled point 166 is driven down onto the score 134 on the plate 136 which is supported at its sides by supports 164 (part of the inhaler) . As the actuator is driven into the blister, the blister cracks or bursts open, as shown in Fig. 15, releasing the powder 62. The blisters shown in Figs. 5 and 13 may also be provided in a strip form, rather than a disk form, as shown in Fig. 16. Thus, while several embodiments have been shown and described, it should be appreciated that many more modifi¬ cations may be made, without departing from the spirit and scope of the present invention.

Claims: WE CLAIM; 1. A powder storage and delivery system for a dry powder inhaler, comprising: a carrier; a blister shell on the carrier; a shear layer attached around the perimeter of the blister shell; and a tab attached to the shear layer. 2. The system of claim 1 wherein the carrier is a disk. 3. The system of claim 1 wherein the carrier is a strip. 4. The system of claim 1 wherein the shear layer comprises a metal foil. 5. The system of claim 1 wherein the blister shell comprises a metal foil. 6. The system of claim 1 wherein the shear layer is attached to the carrier and to the tab. 7. The system of claim 1 wherein the blister shell extends over the carrier. 8. A powdered drug storage and delivery system comprising: a carrier disk; a tab; a shear layer attached to and connecting the carrier disc to the tab; a blister attached to the shear layer, on the tab. 9. The system of claim 8 wherein a gap separates the carrier disk and the tab. 10. A dry powder delivery system for an inhaler, comprising: a carrier; a plate on the carrier; a blister shell attached to the plate around the perimeter of the blister shell; a score line centrally located on the blister shell; and a dose a powdered drug within the blister shell. 11. The system of claim 10 wherein the blister shell comprises a brittle material. 12. A powdered drug storage and delivery system comprising: a round carrier disk having a central opening; a plurality of shear tabs radially projecting from the central opening, each shear tab having a circumferential edge spaced apart from the carrier disk across a gap, and with each shear tab pi-vota- bly connected to the carrier disk at a hinge line along one side of the tab; a shear layer overlying, attached to, and con¬ necting the carrier disc and the shear tabs; and a blister layer overlying and attached to the shear layer, the blister layer including a plurality of blister shells forming a powder containing space in between the shear layer and the blister shells, and with one blister shell formed on substantially each tab. 13. The powder drug storage and delivery system of claim 12 further comprising a stress concentrator at the circumferential edge of the tab, opposite from the hinge line. 14. The powder drug storage and delivery system of claim 12 further comprising a heat seal around a perimeter of substantially each blister shell, attaching the blister layer to the shear layer. 15. The dry powder delivery system of claim 10 wherein the carrier has a central opening and the score line extends radially outwardly from the central opening. 16. The dry powder delivery system of claim 10 wherein the carrier comprises a disc and the score line extends generally parallel to the perimeter of the disc. 17. The dry powder delivery system of claim 10 wherein the carrier comprises a strip. 18. The dry powder delivery system of claim 10 wherein the plate is co-planer with the disc. 19. The dry powder delivery system of claim 10 further comprising a score line on the plate aligned with the score line on the blister shell. 20. The dry powder delivery system of claim 10 further comprising a lidstock bonded on to the plate and a heat seal joining the blister shell to the lidstock.

Inventors: CAMERON ALLAN, EISELE ROBERT F, PORCHE LEONARD, TITZLER DAVID, CAMERON, ALLAN, EISELE, ROBERT, F., PORCHE, LEONARD, TITZLER, DAVID
Applicants: DURA PHARMA INC, DURA PHARMACEUTICALS, INC.
Application year: 1996
Main classification: A61M15
IPC codes: A61M15, A61M16