Dry powder inhaler with aeroelastic dispersion mechanism

Abstract

The present invention comprises a dry powder inhaler (DPI) that uses a patient's inhalation flow to concentrate energy in an aeroelastic element for deaggregation and dispersion of a powder dose. The result is a DPI that delivers a dose independent of inspiratory abilities of the patient, solving a major problem of conventional DPIs. Increased tension on the aeroelastic element causes higher frequency vibrations and improved powder dispersion. The tension of the aeroelastic element can be modified prior to dispensing the DPI to the patient, allowing for individualization for single patients or groups of patients. In addition, the DPI has features that increase the turbulence of the airflow as it passes through the device, further increasing the dispersion and deaggregation of the powder. The DPI can hold a single dose or multiple doses. The powder doses can be dispensed directly onto the aeroelastic element, or may be in adjacent blister packaging.

Description

DESCRIPTION OF THE DRAWINGS

FIG. 1: is the airflow at velocity V passing over an aeroelastic membrane (1) under tension, resulting in flutter or vibration of the aeroelastic membrane (in cross-section). The vibration is represented by vertical arrows, and the airflow is represented by horizontal arrows.

FIG. 2: is a configuration to create vortex-induced vibration in an aeroelastic membrane due to airflow over a triangular-shaped rod (2) (in cross-section). The rod causes opposing vortices as airflow passes over and under the rod.

FIG. 3: is a schematic representation of a cross-sectional view of the inhaler of the invention with representations of the major elements of the invention.

FIG. 4: is a schematic representation of the first and second rollers (10) loaded with the aeroelastic membrane with axles in the center of the rollers (15).

FIG. 5: is representation of the preferred embodiment of the dosing applicator.

FIG. 6: is an alternate embodiment of the dosing applicator.

FIG. 7: is a representation of the aeroelastic membrane and its relation to the base clamps (19), upper clamps (20) and tension rods (5). FIG. 7a represents the action that occurs when the advancement means is activated, wherein the upper clamps and tension rods are lifted from the aeroelastic membrane, allowing it to move freely and bring a powder dose (18) in to the center dispensing region. An arrow (21) shows the direction of membrane travel. FIG. 7b shows the powder dose in the center dispensing region and the upper clamps lowered into their resting position. FIG. 7c depicts the final step wherein the tensioner rods return to their resting position, tensioning the aeroelastic membrane at a pre-determined level of tension.

FIG. 8: is a representation of the dispensing mechanism of an alternative embodiment of the invention, wherein a blister strip (22) comprising a series of individual dosing cup (23) filled with a powder dose replaces the aeroelastic membrane and a tensioned aeroelastic element (1) is immediately adjacent to the blister strip. The large arrows depict the direction of airflow across the blister strip and aeroelastic element. The small vertical arrows depict the vibrational motion of the aeroelastic element.

FIG. 9: is a representation of the dispensing mechanism of an alternative embodiment of the invention, wherein a blister strip with multiple dosing cups (24) for different medicaments replaces the aeroelastic membrane and a tensioned aeroelastic element is immediately adjacent to the blister strip.

FIG. 10: is a representation of the dispensing mechanism of an alternative embodiment of the invention, wherein the aeroelastic element is an aeroelastic and deformable membrane (25) with deformable dosing cups (26) that contain the powder dose. As the membrane is stretched by the tensioning rods, the dosing cup deforms and raises the powder dose to the level of the surrounding membrane, where it is easily dispersed upon inhalation by the patient. The horizontal arrows represent the tensioning of the aeroelastic, deformable membrane.

Claims

1. A dry powder inhaler apparatus for delivering pharmaceuticals to a patient, comprising: a. a casing, comprising an outer surface and two inner walls, the inner walls forming an open center chamber through which air can flow within the casing and two enclosed chambers, a right chamber located to the right of the open center chamber and a left chamber located to the left of the open center chamber, the center chamber, further comprising a front end, a back end, a left wall, a right wall and a center dispensing region, the back end of the center chamber further comprising airflow modifiers anterior to the airflow inlets, the airflow modifiers further comprising multiple triangular rods extending from the left wall to the right wall, resulting in vortices which allow air to pass above and below the triangular rodsb. multiple airflow inlets extending from the back of the center chamber through the outer surface of the casing;c. an aeroelastic element spanning the center dispensing region, comprising: i. an aeroelastic membrane with a powder dose, the membrane having a used end and an unused end, the membrane being wound between two spools, a first spool and a second spool, the first spool comprising the unused end being located in the left chamber and the second spool attaching to the used end being located in the right chamber, resulting in the aeroelastic membrane running through the slot in the left wall across the center dispensing region and through the slot in the right wall onto the second spool;ii. two axles running through the center of the spools, the axle for the second spool comprising a concentric spring, resulting in the aeroelastic membrane being transferred from the first spool to the second spool as the spring-loaded axle is activated; andiii. a roller engaging the aeroelastic membrane immediately adjacent to the first spool, resulting in additional tension in the aeroelastic membrane;d. two base clamps fixedly attached to the floor of the chambers, one in the right chamber and one in the left chamber, upon which the aeroelastic element rests, the clamps being located between the spools and the left and right walls;e. two upper clamps located above the base clamps, the upper clamps descending atop the base clamps to hold the aeroelastic element in place across the center dispensing region;f. a crank movably attached to the two upper clamps, said crank causing the upper clamps to raise when the advancing means is activated and the crank moves;g. two tensioner rods located between the upper clamps and the left and right walls and movably attached to a crank, the tensioner rods descending to a pre-determined level to further tension the aeroelastic element, releasing when the advancing means is activated and the crank moves;h. a powder dose applicator located between the first spool and the base clamp in the left chamber, the powder dose applicator comprising: i. a dispensing chute filled with at least one dose of powder, the dispensing chute comprising a top end and a bottom end;ii. a wheel at the bottom end of the dispensing chute, the wheel comprising a multitude of notches around its circumference, the notches filling with powder from the dispensing chute and emptying onto the aeroelastic membrane as the wheel turns; andiii. two flattening rollers, one above and one below the aeroelastic membrane between the dispensing chute and the base clamp, the rollers turning as the aeroelastic membrane moves from the first spool to the second spool, fully engaging the powder with the aeroelastic membrane and breaking up clumps in the powder;i. a turbulent airflow nozzle, comprising an inner end and an outer end, the inner end engaging the front of the chamber, extending through the outer surface of the casing and the outer end extending through the mouth piece, the nozzle further comprising at least one tube through which air and powder can be inhaled, extending from the inner end to the outer end in a helical fashion, thereby increasing the turbulence in the air that flows through the nozzle;j. a mouthpiece affixed to the outer wall of the casing, comprising a cylindrical opening that engages the outer end of the nozzle, allowing the air and powder to leave the dry powder inhaler and enter the patient's respiratory system upon inhalation, and having an appropriate shape for pursing the patient's lips over the mouthpiece and creating a seal between the lips and the mouthpiece;k. a dose counter on the outer wall engaged to an advancement means in such a way that the dose counter changes numbers by one when the advancement means is activated; andl. an advancement means capable of turning the crank to release the upper clamps and tensioner rods, advancing the dose counter, turning the wheel in the dispensing chute, advancing the spring-loaded axle in the second spool by one position to advance the aeroelastic element a predetermined distance from the first spool to the second spool, and moving a powder dose into the center dispensing region.

2. A dry powder inhaler apparatus for delivering pharmaceuticals to a patient according to claim 1, wherein the aeroelastic element is selected from a group comprising: a membrane, film, reed, sheet, panel or blade.

3. A dry powder inhaler apparatus for delivering pharmaceuticals to a patient according to claim 1, wherein the material from which the aeroelastic element is manufactured is selected from a group, comprising polymers, thin metals, and metal-coated polymers.

4. A dry powder inhaler apparatus for delivering pharmaceuticals to a patient according to claim 1, wherein tension controllers are attached to the spool axle, allowing the tension of the aeroelastic membrane to be manually fixed and maintained across the spool axles, obviating the need for tension rods.

5. A dry powder inhaler apparatus for delivering pharmaceuticals to a patient according to claim 1, wherein the powder dose applicator comprises: a. a dispensing chute above the aeroelastic membrane filled with at least one powder dose; andb. a dispensing disk that rotates as the advancing means is activated, located between the aeroelastic membrane and the dispensing chute and being in contact with the bottom end of dispensing chute, the dispensing disk further comprising multiple dispensing openings clustered in one section of the dispensing disk, resulting in an accurate amount of powder falling through the dispensing openings as the disk rotates past the dispensing chute.

6. A dry powder inhaler apparatus for delivering pharmaceuticals to a patient according to claim 1, further comprising: a. blister strip packaging attached to the two spools in place of the aeroelastic element of claim 1, the blister strip packaging comprising at least one individual dosing cup, each filled with a powder dose and covered by a peelable top layer, the dosing cups arranged serially along the length of the strip;b. an aeroelastic element fixedly stretched across the center dispensing region, the aeroelastic element being parallel to the blister strip packaging in the center dispensing region in such proximity that the aeroelastic element acts as an actuator, making contact with the blister packaging and dispersing the powder dose when the aeroelastic element begins to vibrate during inhalation by the patient; andc. a powder dose opener replacing the a powder dose applicator, the powder dose opener being capable of removing the top layer from the blister strip packaging for one dose when the blister strip is advanced between the first and second spools;

7. A dry powder inhaler apparatus for delivering pharmaceuticals to a patient according to claim 3, wherein the blister strip packaging comprises clusters pf multiple small dosing cups for simultaneous multiple drug dosing, the clusters arranged serially along the length of the blister strip.

8. A dry powder inhaler apparatus for delivering pharmaceuticals to a patient according to claim 1, wherein the aeroelastic element is an aeroelastic and deformable membrane, comprising at least one individual dosing cup filled with a powder dose in the same form as blister strip packaging, wherein the dosing cup deforms and raises the powder dose to the level of the surrounding membrane.

9. A dry powder inhaler apparatus for delivering pharmaceuticals to a patient according to claim 1, wherein the inhaler comprises a single powder dose.

10. A method for dispensing powder by inhalation using the dry powder inhaler apparatus claimed in claim 1, comprising the steps of: a. activating the advancement means;b. having the patient purse the patient's lips around the mouthpiece; andc. having the patient inhale so the dry powder inhaler delivers a dose of the powder into the patient's respiratory system.