U.S. patent application number 13/364201 was filed with the patent office on 2012-05-24 for dry powder inhaler with aeroelastic dispersion mechanism.
This patent application is currently assigned to STC.UNM. Invention is credited to Hugh C. Smyth, Charles R. Truman.
Application Number | 20120125331 13/364201 |
Document ID | / |
Family ID | 40532977 |
Filed Date | 2012-05-24 |
United States Patent
Application |
20120125331 |
Kind Code |
A1 |
Smyth; Hugh C. ; et
al. |
May 24, 2012 |
DRY POWDER INHALER WITH AEROELASTIC DISPERSION MECHANISM
Abstract
A dry powder inhaler for delivering medicament to a patient
includes a housing defining a chamber for receiving a dose of
powdered medicament, an inhalation port in fluid communication with
the chamber, at least one airflow inlet providing fluid
communication between the chamber and an exterior of the housing,
and an aeroelastic element in the chamber and associated with a
dose of powdered medicament. A tensioning assembly is configured to
apply a first amount of tension to the aeroelastic element such
that the aeroelastic element is capable of vibrating in response to
airflow through the chamber so as to aerosolize the dose of
powdered medicament.
Inventors: |
Smyth; Hugh C.;
(Albuquerque, NM) ; Truman; Charles R.;
(Albuquerque, NM) |
Assignee: |
STC.UNM
Albuquerque
NM
|
Family ID: |
40532977 |
Appl. No.: |
13/364201 |
Filed: |
February 1, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12246116 |
Oct 6, 2008 |
8127763 |
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13364201 |
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11713180 |
Mar 2, 2007 |
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12246116 |
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60778878 |
Mar 3, 2006 |
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Current U.S.
Class: |
128/203.15 |
Current CPC
Class: |
A61M 15/0055 20140204;
A61M 15/0091 20130101; A61M 15/0035 20140204; A61M 15/0065
20130101; A61M 15/0045 20130101; A61M 15/0005 20140204; A61M
15/0003 20140204; A61M 2202/064 20130101; A61M 2206/14 20130101;
A61M 15/0051 20140204; A61M 15/0028 20130101; A61M 2205/8275
20130101; A61M 2206/16 20130101; A61M 15/0068 20140204; A61M
15/0043 20140204 |
Class at
Publication: |
128/203.15 |
International
Class: |
A61M 15/00 20060101
A61M015/00 |
Claims
1-20. (canceled)
21. A dry powder inhaler for delivering medicament to a patient,
the inhaler comprising: a housing defining a chamber for receiving
a dose of powdered medicament; an inhalation port in fluid
communication with the chamber; at least one airflow inlet
providing fluid communication between the chamber and an exterior
of the housing; and a strip of material having a generally flat top
surface, a generally flat bottom surface, and a plurality of
recesses in the top surface, wherein the recesses are each
configured to hold a metered dosage of a powdered medicament, the
strip of material being positioned between the inhalation port and
the at least one airflow inlet such that a flow of air generated by
a user via the inhalation port is configured to move the medicament
that is released from one of the recesses through the chamber as an
aerosolized dose.
22. An inhaler as in claim 21, wherein the recesses are cup shaped
in geometry.
23. An inhaler as in claim 21, wherein the recesses are serially
aligned along the strip.
24. An inhaler as in claim 21, further comprising an actuator that
is actuatable to make contact with the strip of material to thereby
disperse the medicament from the recess.
25. An inhaler as in claim 24, wherein the actuator is actuatable
by the user inhalation that causes air to act on the actuator.
26. The inhaler of claim 24, wherein the actuator comprises an
aeroelastic element, and further comprising at least one tensioning
member configured to hold the aeroelastic element at a tension that
produces a desired vibrational response to airflow ranges of a
patient.
27. The inhaler of claim 26, wherein the tensioning member is
adjustable to change the desired vibrational response.
28. The inhaler of claim 24, wherein the actuator comprises one of
a membrane, a reed, a sheet, a panel, and a blade.
29. The inhaler of claim 24, wherein the actuator is made of a
material comprising at least one of a polymer, a metal, and a
metal-coated polymer.
30. The inhaler of claim 24, further comprising a powder dose
applicator, the powder dose applicator being configured to dispense
the dose of powdered medicament to the recesses prior to inhalation
by a patient.
31. The inhaler of claim 21, further comprising: a mouthpiece
including the inhalation port; and a nozzle between the chamber and
the inhalation port.
32. The inhaler of claim 21, wherein the inhalation port is at a
first end of the housing and said at least one airflow inlet is at
a second end of the housing substantially opposite the first end of
the housing.
33. A method for delivering medicament to a patient comprising:
providing an inhaler comprising a housing defining a chamber, an
inhalation port in fluid communication with the chamber, and at
least one airflow inlet providing fluid communication between the
chamber and an exterior of the housing; providing a strip of
material having a generally flat top surface, a generally flat
bottom surface, and a plurality of recesses in the top surface,
wherein the recesses each hold a metered dosage of a powdered
medicament, wherein the strip of material is positioned between the
inhalation port and the at least one airflow inlet; and inhaling
from the inhalation port to draw the medicament that is released
from one of the recesses through the chamber as an aerosolized
dose.
34. A method as in claim 33, further comprising contacting the
strip to dispense the medicament from the recess.
35. A method as in claim 34, wherein the inhaler includes an
actuator, and wherein inhaling from the inhalation port actuates
the actuator to contact the strip.
36. A method for metering dosages of a dry powder medicament, the
method comprising: providing a strip of material having a generally
flat top surface, a generally flat bottom surface, and a plurality
of recesses in the top surface, wherein the recesses are each
configured to hold a metered dosage of a powdered medicament, the
strip of material being configured to be positioned within an
inhaler such that a flow of air generated by a user via an
inhalation port of the inhaler is configured to aerosolize the
powdered medicament; and using a powder dose applicator, dispensing
a dose of powdered medicament to the recesses.
37. A method as in claim 36, wherein the powder dose applicator
comprises a dispensing chute having a top end and a bottom end, and
a wheel at the bottom end, and further comprising rotating the
wheel to dispense the powder from the bottom end and into one of
the recesses.
38. A method as in claim 36, wherein the recesses are cup shaped in
geometry.
39. A method as in claim 36, wherein the recesses are serially
aligned along the strip, and further comprising advancing the strip
and dispensing powder into the next recess.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S.
application Ser. No. 11/713,180, entitled "Dry Powder Inhaler with
Aeroelastic Dispersion Mechanism," filed on Mar. 2, 2007, pending,
which claims the benefit of priority of U.S. provisional
application No. 60/778,878, entitled "Dry Powder Inhaler with
Aeroelastic Dispersion Mechanism," filed on Mar. 3, 2006, the
contents of both of which are incorporated herein by reference in
their entirety.
TECHNICAL FIELD
[0002] The present invention is directed generally to inhalers, for
example, dry powder inhalers, and methods of delivering a
medicament to a patient. More particularly, the present invention
is directed to dry powder inhalers having an aeroelastic dispersion
mechanism.
BACKGROUND
[0003] Dry powder inhalers ("DPIs") represent a promising
alternative to pressurized meted dose inhaler ("pMDI") devices for
delivering drug aerosols without using CFC propellants. See
generally, Crowder et al., 2001: an Odyssey in Inhaler Formulation
and Design, Pharmaceutical Technology, pp. 99-113, July 2001; and
Peart et al., New Developments in Dry Powder Inhaler Technology,
American Pharmaceutical Review, Vol. 4, n,3, pp. 37-45 (2001).
Martonen et al. 2005 Respiratory Care, Smyth and Hickey American
Journal of Drug Delivery, 2005.
[0004] Typically, the DPIs are configured to deliver a powdered
drug or drug mixture that includes an excipient and/or other
ingredients. Conventionally, many DPIs have operated passively,
relying on the inspiratory effort of the patient to dispense the
drug provided by the powder. Unfortunately, this passive operation
can lead to poor dosing uniformity since inspiratory capabilities
can vary from patient to patient, and sometimes even use-to-use by
the same patient, particularly if the patient is undergoing an
asthmatic attack or respiratory-type ailment which tends to close
the airway.
[0005] Generally described, known single and multiple dose DPI
devices use: (a) individual pre-measured doses, such as capsules
containing the drug, which can be inserted into the device prior to
dispensing; or (b) bulk powder reservoirs which are configured to
administer successive quantities of the drug to the patient via a
dispensing chamber which dispenses the proper dose. See generally,
Prime et al., Review of Dry Powder Inhaler's, 26 Adv. Drug Delivery
Rev., pp. 51-58 (1997); and Hickey et al., A New Millennium for
Inhaler Technology, 21 Pharm. Tech., n. 6, pp. 116-125 (1997).
[0006] In operation, DPI devices desire to administer a uniform
aerosol dispersion amount in a desired physical form (such as a
particulate size) of the dry powder into a patient's airway and
direct it to a desired deposit site. If the patient is unable to
provide sufficient respiratory effort, the extent of drug
penetration, especially to the lower portion of the airway, may be
impeded. This may result in premature deposit of the powder in the
patient's mouth or throat.
[0007] A number of obstacles can undesirably impact the performance
of the DPI. For example, the small size of the inhalable particles
in the dry powder drug mixture can subject them to forces of
agglomeration and/or cohesion (i.e., certain types of dry powders
are susceptible to agglomeration, which is typically caused by
particles of the drug adhering together), which can result in poor
flow and non-uniform dispersion. In addition, as noted above, many
dry powder formulations employ larger excipient particles to
promote flow properties of the drug. However, separation of the
drug from the excipient, as well as the presence of agglomeration,
can require additional inspiratory effort, which, again, can impact
the stable dispersion of the powder within the air stream of the
patient. Unstable dispersions may inhibit the drug from reaching
its preferred deposit/destination site and can prematurely deposit
undue amounts of the drug elsewhere.
[0008] A number of different inhalation devices have been designed
to attempt to resolve problems attendant with conventional passive
inhalers. For example, U.S. Pat. No. 5,655,523 discloses and claims
a dry powder inhalation device which has a
deagglomeration-aerosolization plunger rod or biased hammer and
solenoid. U.S. Pat. No. 3,948,264 discloses the use of a
battery-powered solenoid buzzer to vibrate the capsule to
effectuate the efficient release of the powder contained therein.
Those devices are based on the proposition that the release of the
dry powder can be effectively facilitated by the use of energy
input independent of patient respiratory effort.
[0009] U.S. Pat. No. 5,533,502 to Piper discloses and claims a
powder inhaler using patient inspiratory efforts for generating a
respirable aerosol. The Piper invention also includes a cartridge
capable of rotating, holding the depressed wells or blisters
defining the medicament holding receptacles. A spring-loaded
carriage compresses the blister against conduits with sharp edges
that puncture the blister to release the medication that is then
entrained in air drawn in from the air inlet conduit so that
aerosolized medication is emitted from the aerosol outlet
conduit.
[0010] Crowder et al. describe a dry powder inhaler in U.S. Pat.
No. 6,889,690 comprising a piezoelectric polymer packaging in which
the powder for aerosolization is simulated using non-linear signals
determined a priori for specific powders.
[0011] In recent years, dry powder inhalers (DPIs) have gained
widespread use, particularly in the United States. Currently, the
DPI market is estimated to be worth in excess of $4 billion. Dry
powder inhalers have the added advantages of a wide range of doses
that can be delivered, excellent stability of drugs in powder form
(no refrigeration), ease of maintaining sterility, non-ozone
depletion, and they require no press-and-breathe coordination.
[0012] There is great potential for delivering a number of
therapeutic compounds via the lungs (see, for example, Martonen T.,
Smyth H D C, Isaccs K., Burton R., "Issues in Drug Delivery: Dry
Powder Inhaler Performance and Lung Deposition": Respiratory Care.
2005, 50(9); and Smyth H D C, Hickey, A J, "Carriers in Drug Powder
Delivery: Implications for Inhalation System Design," American
Journal of Drug Delivery, 2005, 3(2),117-132). In the search for
non-invasive delivery of biologics (which currently must be
injected), it was realized that the large highly absorptive surface
area of the lung with low metabolic drug degradation, could be used
for systemic delivery of proteins such as insulin. The
administration of small molecular weight drugs previously
administered by injection is currently under investigation via the
inhalation route either to provide non-invasive rapid onset of
action, or to improve the therapeutic ratio for drugs acting in the
lung (e.g. lung cancer).
[0013] Gene therapy of pulmonary disease is still in its infancy
but could provide valuable solutions to currently unmet medical
needs. The recognition that the airways may provide a real
opportunity for delivering biotech therapeutics in a non-invasive
way was recently achieved with Exubera.TM., an inhaled insulin
product. This product has obtained a recommendation for approval by
US Food and Drug Administration and will lead to expanded
opportunities for other biologics to be administered via the
airways.
[0014] Key to all inhalation dosage forms is the need to maximize
the "respirable dose" (particles with aerodynamic diameters<5.0
.mu.m that deposit in the lung) of a therapeutic agent. However,
both propellant-based inhalers and current DPI systems only achieve
lung deposition efficiencies of less than 20% of the delivered
dose. The primary reason why powder systems have limited efficiency
is the difficult balancing of particle size (particles under 5
.mu.m diameter) and strong inter-particulate forces that prevent
deaggregation of powders (strong cohesive forces begin to dominate
at particle sizes<10 .mu.m) (Smyth H D C., Hickey, A J.,
"Carriers in Drug Powder Delivery: Implications for inhalation
System Design," American Journal of Drug Delivery, 2005, 3(2),
117-132). Thus, DPIs require considerable inspiratory effort to
draw the powder formulation from the device to generate aerosols
for efficient lung deposition (see FIG. 1 for an illustration of
typical mechanism of powder dispersion for DPIs). Many patients,
particularly asthmatic patients, children, and elderly patients,
which are important patient groups for respiratory disease, are not
capable of such effort. In most DPIs, approximately 60 L/min of
airflow is required to effectively deaggregate the fine cohesive
powder. All currently available DPIs suffer from this potential
drawback.
[0015] Multiple studies have shown that the dose emitted from dry
powder inhalers (DPI) is dependent on air flow rates (see Martonen
T., Smyth H D C, Isaccs K., Burton R., "Issues in Drug Delivery:
Dry Powder Inhaler Performance and Lung Deposition": Respiratory
Care. 2005, 50(9)). Increasing air-flow increases drug dispersion
due to increases in drag forces of the fluid acting on the particle
located in the flow. The Turbuhaler.RTM. device (a common DPI), is
not suitable for children because of the low flow achieved by this
patient group (see Martonen T., Smyth H D C, Isaccs K., Burton R.,
"Issues in Drug Delivery: Dry Powder Inhaler Performance and Lung
Deposition": Respiratory Care. 2005, 50(9)).
[0016] Considerable intra-patient variability of inhalation rates
has been found when patients inhale through two leading DPI
devices. That inherent variability has prompted several companies
to evaluate ways of providing energy in the inhaler (i.e. "active"
DPIs). Currently, there is no active DPI commercially available.
The active inhalers under investigation include technologies that
use compressed air, piezoelectric actuators, and electric motors.
The designs of those inhalers are very complex and utilize many
moving parts and components. The complexity of those devices
presents several major drawbacks including high cost, component
failure risk, complex manufacturing procedures, expensive quality
control, and difficulty in meeting specifications for regulatory
approval and release (Food and Drug Administration).
[0017] Alternatively, powder technology provides potential
solutions for flow rate dependence of DPIs. For example, hollow
porous microparticles having a geometric size of 5-30 .mu.m, but
aerodynamic sizes of 1-5 .mu.m require less power for dispersion
than small particles of the same mass. This may lead to flow
independent drug dispersion but is likely to be limited to a few
types of drugs with relevant physicochemical properties.
[0018] Thus there are several problems associated with current dry
powder inhaler systems including the most problematic issue: the
dose a patient receives is highly dependent on the flow rate the
patient can draw through the passive-dispersion device. Several
patents describing potential solutions to this problem employ an
external energy source to assist in the dispersion of powders and
remove this dosing dependence on patient inhalation
characteristics. Only one of these devices has made it to market or
been approved by regulatory agencies such as the US Food and Drug
Administration. Even upon approval, it is likely that these complex
devices will have significant costs of manufacture and quality
control, which could have a significant impact on the costs of
drugs to patients.
[0019] The present disclosure describes exemplary dry powder
inhalers and associated single or multi-dose packaging, which holds
the compound to be delivered for inhalation as a dry powder. These
dry powder inhalers bridge the gap between passive devices and
active devices. The inhalers are passive devices that operate using
the energy generated by the patient inspiratory flow inhalation
maneuver. However, the energy generated by airflow within the
devices is focused on the powder by using oscillations induced by
airflow across an aeroelastic element. In this way the inhalers can
be "tuned" to disperse the powder most efficiently by adjusting the
resonance frequencies of the elastic element to match the
physicochemical properties of the powder. In addition, the airflow
rate required to generate the appropriate oscillations within the
device is minimized because some of the energy used to create the
vibrations in the elastic element is pre-stored in the element in
the form of elastic tension (potential energy). Inhaler performance
may be tailored to the lung function of individual patients by
modulating the elastic tension. Thus, even patients with poor lung
function and those who have minimal capacity to generate airflow
during inspiration will able to attain the flow rate required to
induce oscillations in the elastic element.
SUMMARY OF THE INVENTION
[0020] An exemplary embodiment of the invention comprises a dry
powder inhaler with an integrated assisted dispersion system that
is adjustable according to the patients' inspiratory capabilities
and the adhesive/cohesive nature of the powder. The inhaler
comprises an aeroelastic element that flutters or oscillates in
response to airflow through the inhaler. The aeroelastic element
provides concentrated energy of the airflow driven by the patient
into the powder to be dispersed. The aeroelastic element is
preferably a thin elastic membrane held under tension that reaches
optimal vibrational response at low flow rates drawn through the
inhaler by the patient. The aeroelastic element is preferably
adjustable according to the patient's inspiratory capabilities and
the adhesive/cohesive forces within the powder for dispersal.
[0021] According to various aspects of the disclosure, a dry powder
inhaler for delivering medicament to a patient includes a housing
defining a chamber for receiving a dose of powdered medicament, an
inhalation port in fluid communication with the chamber, at least
one airflow inlet providing fluid communication between the chamber
and an exterior of the housing, and an aeroelastic element in the
chamber and associated with a dose of powdered medicament. A
tensioning assembly is configured to apply a first amount of
tension to the aeroelastic element such that the aeroelastic
element is capable of vibrating in response to airflow through the
chamber so as to aerosolize the dose of powdered medicament.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 illustrates airflow across an aeroelastic element in
accordance with various aspects of the disclosure.
[0023] FIG. 2 illustrates airflow past an airflow modifier and
across an aeroelastic element in accordance with various aspects of
the disclosure.
[0024] FIG. 3A is a schematic representation of a top
cross-sectional view of an exemplary inhaler in accordance with
various aspects of the disclosure.
[0025] FIG. 3B is a schematic representation of an end
cross-sectional view of an exemplary inhaler in accordance with
various aspects of the disclosure.
[0026] FIG. 4 is a schematic representation of first and second
rollers loaded with the aeroelastic membrane with axles in the
center of the rollers in accordance with various aspects of the
disclosure.
[0027] FIG. 5 is representation of an exemplary dosing applicator
in accordance with various aspects of the disclosure.
[0028] FIG. 6 is a representation of another exemplary dosing
applicator in accordance with various aspects of the
disclosure.
[0029] FIGS. 7A-7C are representations of an exemplary aeroelastic
membrane and its relation to exemplary base clamps, upper clamps,
and tensioning rods in accordance with various aspects of the
disclosure.
[0030] FIG. 8 is a representation of an exemplary dispensing
mechanism in accordance with various aspects of the disclosure.
[0031] FIG. 9 is a representation of an alternative exemplary
dispensing mechanism in accordance with various aspects of the
disclosure.
[0032] FIG. 10 is a representation of an alternative exemplary
dispensing mechanism in accordance with various aspects of the
disclosure.
DETAILED DESCRIPTION
[0033] An exemplary embodiment of a dry powder inhaler 100 is
illustrated in FIGS. 3A and 3B. According to various aspects of the
disclosure, the dry powder inhaler 100 may comprise a casing 102
having an outer wall 104 and two inner walls 106, 108. The inner
walls 106, 108 may extend in a first direction from a first inner
surface 112 of the outer wall 104 toward a second inner surface 114
of the outer wall 104. The inner walls 106, 108 may also extend in
a second direction from a proximal end 116 of the casing 102 to a
distal end 118 of the casing 102. Thus, according to various
aspects, the outer wall 104 and inner walls 106, 108 may cooperate
to define three chambers in the casing 102.
[0034] According to some aspects, the three chambers may include a
middle chamber 122 and two side chambers 124, 126 located on
opposite sides of the middle chamber 122 relative to one another.
The side chambers may comprise a first side chamber 124 located to
a first side of the middle chamber 122 and a second side chamber
126 located to a second side of the middle chamber 122.
[0035] In accordance with various aspects, the distal end 118 of
the casing 102 may include one or more airflow inlets 128 providing
fluid communication between the middle chamber 122 and ambient air
outside the casing 102. The proximal end 116 of the casing 102 may
include a mouthpiece 130. The mouthpiece 130 may a separate
structure affixed to the outer wall 104 of the casing 102, or the
mouthpiece 130 and casing 102 may comprise a single piece of
unitary construction. The mouthpiece 130 may include an opening 132
providing fluid communication between the middle chamber 122 and
the outside of the casing 102. The opening 132 may be shaped as an
oval, a circle, a triangle, or any other desired shape. The
mouthpiece 130 may have a shape that facilitates pursing of a
patient's lips over the mouthpiece 130 and creating a seal between
the lips and the mouthpiece 130.
[0036] The inhaler 100 may include a nozzle 134 between the middle
chamber 122 and the opening 132. According to various aspects, the
nozzle 134 may extend from the opening 132, through the mouthpiece
130, and into the middle chamber 122. In some aspects, the nozzle
134 may comprise at least one helical tube 136 through which air
and powder can be inhaled. The tube 136 can be configured to
increase the turbulence in the air that flows through the nozzle
134.
[0037] An aeroelastic element 140 may extend across a center region
142 of the middle chamber 122 between the inner walls 106, 108. The
aeroelastic element 140 may include one or more doses of a
medicament 141, for example, doses of powdered medicament, and the
center region 142 may comprise a region for dispensing a dose of
medicament into airflow through the inhaler 100. According to some
aspects, the aeroelastic element 140 may comprise a membrane 144,
for example, a thin elastic membrane, wound between two spools 146,
148. An unused end of the membrane 144 may be wound on a first
spool 146, and a used end of the membrane 144 may be wound on a
second spool 148. The first spool 146 may be disposed about a first
axle 147, and the second spool 148 may be disposed about a second
axle 149. The first spool 146 may be in the first side chamber 124,
and the second spool 148 may be in the second side chamber 126. In
such an embodiment, the membrane 144 extends through a slot 150 in
the inner wall 106, across the center region 142, and through a
slot 152 in the inner wall 108. In accordance with some aspects,
the aeroelastic element 140 may comprise a membrane, a film, a
reed, a sheet, a panel, or a blade. The aeroelastic element may be
manufactured of materials comprising polymers, thin metals,
polymer-coated metals, and/or metal-coated polymers.
[0038] According to various aspects, the inhaler 100 may include
two base clamps 154, 156 fixedly attached to a first inner surface
112 of the casing 102. According to some aspects, the base clamps
154, 156 may be in the middle chamber 122. A first of the base
clamps 154 may be between the center region 142 and the first inner
wall 106, and the second of the base clamps 156 may be between the
center region 142 and the second inner wall 108. The aeroelastic
element 140 may rest on the base clamps 154, 156. The inhaler 100
may include two upper clamps 158, 160 in the middle chamber 122
associated with the two base clamps 154, 156. For example, a first
upper clamp 158 may be on an opposite side of the aeroelastic
element 140 relative to the first base clamp 154 and configured to
descend atop the first base clamp 154 to sandwich the aeroelastic
element therebetween. Similarly, the second upper clamp 160 may be
on an opposite side of the aeroelastic element 140 relative to the
second base clamp 156 and configured to descend atop the second
base clamp 156 to sandwich the aeroelastic element therebetween.
The upper clamps 158, 160 and base clamps 154, 156 may hold the
aeroelastic element 140 in place across the center region 142 with
a desired amount of tension. The desired amount of tension may be
determined based on a user's inhalation strength. It should be
appreciated that in some aspects, the upper clamps may be fixedly
attached to the second inner surface 114 of the casing 102, and the
base clamps may be configured to ascend toward the upper clamps to
sandwich the aeroelastic element therebetween.
[0039] In an alternative embodiment (not shown), a first of the
base clamps 154 may be in the first side chamber 124 between the
first spool 146 and the first wall 106, and the second of the base
clamps 156 may be in the second side chamber 126 between the second
spool 148 and the second wall 108.
[0040] The inhaler 100 may include an advancement member 162
extending outward of the casing 102. The advancement member 162 may
comprise, for example, a lever, a dial, or the like. The
advancement member 162 may be mechanically coupled to the first and
second upper clamps 158, 160 via, for example, a crank 164 or other
known linkage. The advancement member 162 and crank 164 are
structured and arranged such that when the advancement member 162
is actuated by a user, the crank 164 is caused to move the upper
clamps 158, 160 in a direction away from the base clamps 154, 156.
Actuation of the advancement member 162 may also cause the second
axle 149 to turn in a manner that increases the used end of the
aeroelastic element 140 wound thereon.
[0041] According to some exemplary aspects, as shown in FIGS.
7A-7C, the inhaler 100 may include one or more tensioning rods 166,
168 configured to increase the tension of the aeroelastic element
140 beyond the tension applied by the base clamps 154, 156 and
upper clamps 158, 160. The tensioning rods 166, 168 are between the
first and second upper clamps 158, 160. The tensioning rods 166,
168 may be mechanically coupled to the crank 164 such that
actuation of the advancement member 162 causes the tensioning rods
166, 168 to move in a direction away from the aeroelastic element
140. When the advancement member 162 is released or unactuated, the
tensioning rods 166, 168 return to a position that applies a
desired amount of tension to the aeroelastic element 140. It should
be appreciated that in some aspects, one or more tension
controllers 157, 159 (FIG. 4) may be attached to one or both of the
spool axles 147, 149, thus allowing the tension of the aeroelastic
element 140 to be manually fixed and maintained across the spool
axles 147, 149 and obviating the need for tensioning rods. In any
design, the amount tension applied by the clamps, tensioning rods,
and/or tension controllers can be determined based on inhalation
strength of a user.
[0042] Referring again to FIG. 3B, in various aspects, the second
axle 149 associated with the second spool 148 may comprise a
concentric spring 170, which is mechanically coupled to the
advancement member 162 so that actuation of the advancement member
162 results in the aeroelastic element 140 being transferred from
the first spool 138 to the second spool 148 as the spring-loaded
axle 149 is activated. The inhaler 100 may include a roller 172
(FIG. 5) adjacent to the first spool 146 and engaging the
aeroelastic element 140, thereby resulting in additional tension in
the aeroelastic element.
[0043] According to some aspects, for example, inhalers having an
aeroelastic element with multiple doses of medicament, a dose
counter 174 may be mechanically coupled to the advancement member
162 in such a way that the dose counter 174 changes numbers by one
each time the advancement member 162 is actuated. In some aspects,
the dose counter 174 may be at an exterior surface of the casing
102 so as to be visible to a user. In some aspects, the dose
counter 174 may be inside the casing 102, but visible to a user via
a transparent or translucent window (not shown), as would be
understood by persons skilled in the art.
[0044] According to various aspects, as shown in FIG. 5, the
inhaler 100 may include a powder dose applicator 176 located
between the first spool 146 and the first base clamp 154. In some
aspects, the powder dose applicator 176 may include a dispensing
chute 178 filled with at least one dose of powder 180. The
dispensing chute 178 may include a top end 182 and a bottom end
184. A wheel 186 may be at the bottom end of the dispensing chute
178. The wheel 186 may be rotatable about an axle 188. The axle 188
may be mechanically coupled to the advancement member 162 such that
the wheel 186 rotates an amount sufficient to dispense one dose of
powdered medicament to the aeroelastic element. For example, the
wheel 186 may include one or more notches 190 in its periphery,
with the volume of each notch being sized for one dose of powdered
medicament.
[0045] According to some aspects, the wheel shown in FIG. 5 may be
replaced with a dispensing disk 686, as shown in FIG. 6. For
example, the dispensing chute 178 above the aeroelastic element 140
is filled with at least one dose of powdered medicament. The
dispensing disk 686 may be located between the aeroelastic element
140 and the dispensing chute 178 and may be in contact with the
bottom end 184 of the chute 178. The disk 686 may further include
multiple dispensing openings 690 clustered in one section of the
disk 686, for example, a periphery of the disk 686. The dispensing
openings 690 correspond to an accurate amount of powdered
medicament to be dispensed as a dose. The dispensing disk 686
rotates about an axle 688 as the advancement member 162 is
actuated, thereby resulting in an accurate amount of powdered
medicament falling through the dispensing openings 690 and to the
aeroelastic element 140. For example, the disk 686 may make one
complete 360.degree. rotation each time the advancement member 162
is actuated.
[0046] In various aspects, the inhaler 100 may include blister
strip packaging attached to the two spools in place of the powder
dose applicators discussed above. For example, as shown in FIG. 8,
the blister strip packaging 801 may include at least one individual
dosing cup 803. Each cup 803 may be filled with a dose of powdered
medicament and covered by a peelable top layer. The dosing cups 803
may be arranged serially along the length of the packaging strip
801. An aeroelastic element 840 may be stretched across the center
region 142 and fixedly coupled to, for example, the inner walls or
any other structure capable of maintaining the element 840 fixedly
stretched across the center region 142. The strip 801 may be in
proximity to the aeroelastic element 840 in the center region 142
such that the aeroelastic element 840 may act as an actuator,
making contact with the blister packaging and dispersing the powder
dose when the aeroelastic element begins to vibrate during
inhalation by a patient. A powder dose opener 805 may be configured
to remove the top peelable layer from the blister strip packaging
801 for one dose when the blister strip 801 is advanced from the
first spool to the second spool. The powder dose opener may
alternatively be a simple puncturing device, such as a needle, that
inserts small holes in the blister strip blister cavity, making the
dose ready for inhalation.
[0047] In some embodiments, as shown in FIG. 9, blister strip
packaging 901 may include clusters 905 of multiple small dosing
cups 903 for simultaneous multiple drug dosing, the clusters 905
may be arranged serially along the length of the blister strip 901.
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. In various
embodiments, as shown in FIG. 10, the inhaler may include an
aeroelastic element 1040 that may comprise, for example, an
aeroelastic and deformable membrane. The element 1040 may include
at least one individual dosing cup 1003 filled with a dose of
powdered medicament in the form of blister strip packaging 1001.
The dosing cup 1003 may be configured to deform and raise the
powder dose to the level of the surrounding element 1040.
[0048] It should be appreciated that the inhaler may comprise a
single powder dose such that the inhaler may be disposed of after a
single use.
[0049] Referring again to FIG. 5, in some aspects, the inhaler 100
may include two rollers 192, one above and one below the
aeroelastic element 140. The rollers 192 may be between the powder
dose applicator 176 and the first base clamp 154 or between the
powder dose applicator 176 and the inner wall 106. The rollers 192
turn as the aeroelastic element 140 moves from the first spool 146
to the second spool 148 due to the frictional force applied by the
aeroelastic element 140 as it is urged past the pinching rollers
192. The rollers 192 fully engage the aeroelastic element 140 and
flatten the powder deposited onto the aeroelastic element 140 and
break up clumps in the powder.
[0050] Thus, the advancement member 162 may be 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/or moving a
dose of powder medicament into the center region 142.
[0051] Referring again to FIGS. 3A and 3B, according to various
aspects, the inhaler 100 may include one or more airflow modifiers
198 proximal of the one or more airflow inlets 128 and at a distal
end of the center region 142. It should be appreciated that the one
or more airflow modifiers 198 may be distal of the center region
142 and/or at a distal portion within the center region 142. In
some aspects, the one or more airflow modifiers 198 may comprise
multiple triangular rods extending from the first inner wall 106 to
the second inner wall 108. As air flows through the one or more
airflow inlets 128 and toward the center region 142, the one or
more airflow modifiers 198 may cause vortices that allow air to
pass above and below the modifiers.
[0052] Referring now to FIG. 1, airflow at velocity V over an
aeroelastic element under tension is illustrated. As shown, the
airflow may result in flutter or vibration of the aeroelastic
element 140. The vibration is represented by vertical arrows, and
the airflow is represented by horizontal arrows. FIG. 2 illustrates
the airflow at velocity V past an airflow modifier prior to
encountering an aeroelastic element 140. As shown, the airflow
modifier introduces turbulence into the airflow, thus increasing
the vibration or flutter of the aeroelastic element for a given
inhalation strength.
[0053] In operation, a method for dispensing powder by inhalation
using any of the aforementioned exemplary dry powder inhaler
apparatuses may begin with a patient actuating the advancement
member. The patient may purse his/her lips around the mouthpiece
and inhales. As the patient inhales, air is sucked into the inhaler
through one or more airflow inlets at the distal end of the
inhaler. The inhaled air flows over the airflow modifiers. The
airflow then encounters the aeroelastic element, causing the
element to vibrate or flutter and disperse a dose of powdered
medicament from the element into the airflow. The combined flow of
air and powder then flow into the distal end of the airflow nozzle
and the mouthpiece. The combined flow of air and powder leave the
mouthpiece and enter the patient's mouth and respiratory tract. The
airflow modifiers and/or the helical shape of the nozzle may
increase the turbulence of the airflow to better aerosolize and
break up the powdered dose of medicament into smaller particles,
thus maximizing the dose received by the patient and allowing the
smaller particles to pass further into the respiratory tract.
[0054] It will be apparent to those skilled in the art that various
modifications and variations can be made in the inhalers and
methods of the present disclosure without departing from the scope
of the invention. Other embodiments of the invention will be
apparent to those skilled in the art from consideration of the
specification and practice of the invention disclosed herein. It is
intended that the specification and examples be considered as
exemplary only.
* * * * *