U.S. patent application number 14/592790 was filed with the patent office on 2015-05-07 for unit dose cartridge and dry powder inhaler.
The applicant listed for this patent is MannKind Corporation. Invention is credited to Michael Crick, Robert Feldstein, Per B. Fog, Roderike Pohl, Trent A. Poole, Solomon S. Steiner.
Application Number | 20150122258 14/592790 |
Document ID | / |
Family ID | 34273452 |
Filed Date | 2015-05-07 |
United States Patent
Application |
20150122258 |
Kind Code |
A1 |
Steiner; Solomon S. ; et
al. |
May 7, 2015 |
UNIT DOSE CARTRIDGE AND DRY POWDER INHALER
Abstract
A dry powder inhaler having improved aerodynamic properties for
diluting, dispersing, and metering drug particles for increasing
the efficiency of pulmonary drug delivery to a patient is
described. The inhaler comprises, in general, a housing having an
air intake, an airflow-control/check-valve, a mixing section and a
mouthpiece. A cartridge loaded with a single dose of medicament can
be installed in the mixing section.
Inventors: |
Steiner; Solomon S.; (Mount
Kisco, NY) ; Poole; Trent A.; (South Amherst, MA)
; Fog; Per B.; (Bedford Hills, NY) ; Pohl;
Roderike; (Sherman, CT) ; Crick; Michael;
(Middlebury, CT) ; Feldstein; Robert; (Yonkers,
NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MannKind Corporation |
Valencia |
CA |
US |
|
|
Family ID: |
34273452 |
Appl. No.: |
14/592790 |
Filed: |
January 8, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13490292 |
Jun 6, 2012 |
8950397 |
|
|
14592790 |
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|
12102625 |
Apr 14, 2008 |
8215300 |
|
|
13490292 |
|
|
|
|
10655153 |
Sep 4, 2003 |
7464706 |
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|
12102625 |
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|
09621092 |
Jul 21, 2000 |
7305986 |
|
|
10655153 |
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60145464 |
Jul 23, 1999 |
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|
60206123 |
May 22, 2000 |
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Current U.S.
Class: |
128/203.15 |
Current CPC
Class: |
A61M 15/0023 20140204;
A61M 2205/43 20130101; A61M 16/0495 20140204; A61M 16/0825
20140204; A61M 2202/064 20130101; A61M 15/0028 20130101; A61M
15/0015 20140204; A61M 15/002 20140204; A61M 15/0086 20130101; A61M
15/0025 20140204 |
Class at
Publication: |
128/203.15 |
International
Class: |
A61M 15/00 20060101
A61M015/00 |
Claims
1. An inhaler comprising: a mixing cavity adapted to mount a
medicament-containing cartridge, wherein airflow exiting the
medicament-containing cartridge during an inhalation is configured
to meet a shearing flow.
2. The inhaler of claim 1, wherein the medicament-containing
cartridge includes a drug powder.
3. The inhaler of claim 1, wherein the shearing flow is from
airflow that does not flow through the medicament-containing
cartridge.
4. The inhaler of claim 1, wherein the shearing flow is from
cartridge bypass airflow.
5. The inhaler of claim 1, further comprising a mouthpiece.
6. The inhaler of claim 5, wherein the mouthpiece includes a
transport conduit with an expansion wall having a divergence angle
configured to create a horizontal discharge path.
7. The inhaler of claim 6, wherein the horizontal discharge path
has a 3:1 aspect ratio.
8. The inhaler of claim 6, wherein the divergence angle is about 3
degrees.
9. The inhaler of claim 5, wherein the mouthpiece is configured to
diverge an air stream of particles when the inhaler is in use.
10. The inhaler of claim 5, wherein the mouthpiece is configured to
converge an air stream of particles when the inhaler is in use.
11. The inhaler of claim 5, wherein the mouthpiece is configured to
converge an air stream of particles to aim the particles when the
inhaler is in use.
12. The inhaler of claim 5, wherein the mouthpiece is connected to
the mixing cavity by a joint.
13. An inhaler comprising: an air pathway configured to generate a
shearing flow, wherein the shearing flow is directed to meet
airflow exiting a medicament-containing cartridge during an
inhalation.
14. The inhaler of claim 13, wherein the medicament-containing
cartridge includes a drug powder.
15. The inhaler of claim 13, wherein the shearing flow is from
airflow that does not flow through the medicament-containing
cartridge.
16. The inhaler of claim 13, wherein the shearing flow is from
cartridge bypass airflow.
17. The inhaler of claim 13, further comprising a mouthpiece
connected to a mixing section by a joint.
18. The inhaler of claim 17, wherein the mouthpiece is configured
to diverge an air stream of particles when the inhaler is in
use.
19. The inhaler of claim 17, wherein the mouthpiece is configured
to converge an air stream of particles when the inhaler is in
use.
20. The inhaler of claim 13, wherein the inhaler is a dry powder
inhaler.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S.
utility patent application Ser. No. 13/490,292, filed Jun. 6, 2012,
which is a continuation of U.S. Ser. No. 12/102,625, filed Apr. 14,
2008, now U.S. Pat. No. 8,215,300, which is a continuation of U.S.
Ser. No. 10/655,153 filed Sep. 4, 2003, now U.S. Pat. No.
7,464,706, which is a continuation-in-part of U.S. Ser. No.
09/621,092, filed Jul. 21, 2000, now U.S. Pat. No. 7,305,986, which
claims priority from U.S. provisional application Ser. No.
60/145,464 filed Jul. 23, 1999, and No. 60/206,123 filed May 22,
2000, all of which are incorporated herein by reference in their
entirety.
FIELD OF THE INVENTION
[0002] The present invention is in the field of drug administration
inhalers having improved control over system volumetric airflow
rate, medicament particle transport, particle dispersion, particle
metered dosimetry and patient compliance.
BACKGROUND OF THE INVENTION
[0003] In the early 1970's it was found that certain medicines
could be administered in dry-powder form directly to the lungs by
inhalation through the mouth or inspiration through the nose. This
process allows the medicine to bypass the digestive system, and
may, in certain cases, allow smaller dosages to be used to achieve
the same results as orally ingested or injected medicines. In some
cases, it provides a delivery technique that reduces side effects
for medicines and interactions with other prescribed medicines, as
well as providing a more rapid drug medication uptake.
[0004] Inhaler devices typically deliver medicine in a liquid
droplet mist or as a dry powder aerosol. Deposition of particulate
matter within the human lungs is a very complex and not fully
understood phenomenon. People breathe over a relatively broad tidal
volume. It is known that lower transport velocities of
gas-entrained particles entering the mouth avoid impaction better
within the oropharyngeal cavity. This is particularly true of
particles greater than one to two microns in diameter.
[0005] In order for particles to remain suspended in a gas stream,
their superficial transport velocity must be greater than their
gravity settling velocity. For example, a 100 micron particle must
have a transport gas velocity of approximately 7 ft/sec or greater
for the 100 micron particle to remain in a particle/gas entrainment
state. The required transport velocity for smaller particles is
much less High speed particles have a greater propensity to impact
and deposit on the tissue lining of the oropharyngeal cavity, as
noted above. Thus, a significant number of particles are lost and
will not enter the lungs, if those particles are not transported at
the correct velocity.
[0006] Another common problem with inhalers is that the particles
agglomerate, causing clumping of particles that then adhere to the
inhaler or the oral cavity, rather than entering the lungs. Most
approaches to this problem have been to include a surfactant in, on
or with the particles to decrease the adhesion between
particles.
[0007] Importantly, it should not be difficult for a patient to
load the inhaler with medicine, and to easily and properly use the
inhaler so that the correct dosage is actually administered. Many
current dry particle inhalers fail in one or more of these
important criteria.
[0008] It is therefore an object of the present invention to
provide inhalers which are easy to properly use, and which deliver
drug powders so that the powder enters the lungs instead of
adhering to the back of the throat.
[0009] It is an object of the invention to provide an inhaler which
will operate effectively with dry powder medicaments having
particles ranging in size from about 0.5 to about 10 microns, and
preferably from about 1 to about 5 microns in size.
[0010] It is a further object of the present invention to provide
an inhaler that can operate effectively over a broad inhalation
tidal volume range of human breath.
[0011] It is a still further object of the present invention to
provide an inhaler which controls the volume and velocity of
airflow so as to provide effective and desirable colimation,
de-agglomeration and entrainment of the inhaled drug.
[0012] A related object is to provide an inhaler which creates a
high-shear airflow field and controlled circulating gas action to
break up particle agglomeration during proper inhaler usage.
[0013] A more specific object is to provide an inhaler mouthpiece
which is sized and shaped to develop an airflow which will air
stream entrained medicament particles through the oropharyngeal
cavity.
[0014] Another specific object is to provide a
medicament-containing inhaler cartridge which will supply
medicament for complete air entrainment and proper dispersion into
the air stream.
[0015] Yet another object is to provide an inhaler
airflow-controlling check valve which will straighten the airflow
and limit the airflow volume and velocity to values between
pre-determined maxima and minima so as to properly entrain,
de-agglomerate and deliver medicament particles to the inhaler
user.
[0016] Other objects and advantages of the invention will become
apparent upon reading the following detailed description and upon
reference to the drawings. Throughout the drawings, like reference
numerals refer to like parts.
SUMMARY OF THE INVENTION
[0017] A dry powder inhaler (DPI) includes an air intake and check
valve section; a mixing and cartridge section; and a mouthpiece all
designed to control the volume and velocity of the inhaled air and
aerosolized drug. This inhaler can be operated over a very broad
inhalation tidal volume range of human breath. Several features of
the inhaler provide advantageous properties, most significantly
with respect to using carefully designated aerodynamic forces to
dilute and de-agglomerate the medicament particles, rather than
using broad high pressure forces that would contribute to
relatively great particle losses in the oropharyngeal region.
[0018] The inhaler intake chamber mounts a check valve bulb having
a tapered bulb, bulb travel rod and biasing spring, and one or more
perimeter chutes or venturis on the bulb to modulate and control
the flow of air through the device. The intake further optionally
includes a feedback module (not shown) to generate a tone
indicating to the user when the adequate inhalation airflow rate
has been achieved.
[0019] The inhaler mixing section holds a cartridge containing a
dry powder medicament. The cartridge has two telescopically
assembled halves, and each half has an air inlet hole or
orifice-port and an air outlet hole or orifice-port. When the
halves are twisted so as to align the air holes, the air stream
from the check valve enters the cartridge and then picks up,
fluidizes and de-agglomerates the medicament powder in the
cartridge. The airflow entraining the particles then exits the
cartridge and flows through the mouthpiece to the inhaler user. The
cover on the mixing section can open only when the mouthpiece is at
an appropriate pre-determined angle to the intake conduit. The
mixing section helps to impart a cyclonic flow to air passing
through the mixing chamber and cartridge.
[0020] An important feature of the inhaler is the mouthpiece. The
mouthpiece is integrated to the swivel joint of the mixing section,
and can be rotated back into the inhaler intake section and then
enclosed by a cover for storage. A mouthpiece transport conduit has
the ability to expand the cross-section of the airflow, which in
turn reduces the velocity of approach of the drug powder into the
oral cavity. As shown in FIGS. 10, 18, 19, 21 and 23, the
mouthpiece is offset with respect to the centerline of the mixing
cavity and mounted cartridge, and the airflow inlet from the check
valve mechanism into the mixing chamber and cartridge is also
offset. These tangential offsets encourage a helical airflow around
the cartridge, as explained in further detail below. Initially, the
tangential mouthpiece exit tube increases the velocity of the
transport gas, which in turn inducts the discharged particles into
the exit tube. The mouthpiece exit tube then expands in one
dimension and the transport gas slows while the particle
concentration per unit volume becomes more dilute. Flow is expanded
to create a secondary shear flow, which helps to further
de-agglomerate particles. This also creates a horizontal aspect
ratio and therefore aerosol discharge path that is more effective
in negotiating and streaming the aerosol through the convoluted
pathway of the oral pharynx.
[0021] The mouthpiece expansion wall divergence angle is important
for stable particle transport conditions to exist. An optimum
divergence angle is between 14 and 16 degrees. However, a slightly
larger 17 degree divergence angle can be used to achieve a
horizontal aerosol discharge path with a 3:1 aspect ratio closely
approximating the aspect ratio at the rear of the human throat.
Once the expansion divergence has reached a specified limit, the
continuing slot discharge tube maintains the proper collimation of
the particles for controlled particle injection speed and direction
of the path of the particles into the oral cavity. The mouthpiece
includes a tongue depressor, and a tactile protrusion to contact
the lips of the user to tell the user that the Dry Powder Inhaler
(DPI) is in the correct position.
[0022] The cartridge halves can be twisted into and out of
positions in which the air inlet holes and the air outlet holes are
respectively aligned. The cartridge can only be inserted into the
mixing chamber when a cartridge alignment boss is aligned with a
receiving recess at the bottom of the mixing chamber, and a
cartridge collar and engages a mating mixing chamber collar (FIG.
2). Each cartridge has a unique key on each half that fits only
with a particular part of the inhaler, thereby insuring that the
proper cartridge containing the proper medicament is preselected,
and further insuring that the cartridge is installed properly in
the inhaler.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is an isometric view of the inhaler embodying the
invention.
[0024] FIG. 2 is an exploded view of the inhaler shown in FIG.
1.
[0025] FIG. 3, including FIGS. 3a, 3b and 3c, is a front isometric
view of the medicament containing cartridge used with the inhaler,
showing cartridge outlet hole or orifice port alignments.
[0026] FIG. 4, including FIGS. 4a, 4b and 4c, is a rear isometric
view of the medicament-containing cartridge used with the inhaler
shown in FIG. 3, showing inlet hole or orifice port alignments.
[0027] FIG. 5 is a front elevational view of the cartridge shown in
FIGS. 3 and 4.
[0028] FIG. 6 is a rear elevational view of the cartridge shown in
FIGS. 3, 4 and 5.
[0029] FIG. 7 is a sectional view taken substantially in the plane
of line 7-7 in FIG. 5.
[0030] FIG. 8 is a sectional view taken substantially in the plane
of line 8-8 in FIG. 7.
[0031] FIG. 9 is a sectional view taken substantially in the plane
of line 9-9 in FIG. 7.
[0032] FIG. 10 is a top plan view of the inhaler shown in FIGS. 1
and 2.
[0033] FIG. 11 is a sectional view taken substantially in the plane
of line 11-11 in FIG. 10.
[0034] FIG. 12 is a sectional view taken substantially in the plane
of line 12-12 in FIG. 10.
[0035] FIG. 13 is an isometric view of the inhaler shown in FIGS. 1
and 2 but configured for the insertion or removal of a
medicament-containing cartridge.
[0036] FIG. 14 is an isometric view similar to FIG. 13 but
configured as it appears when a medicament-containing cartridge has
been inserted in the inhaler.
[0037] FIG. 15 is a sectional view taken substantially in the plane
of line 15-15 in FIG. 13.
[0038] FIG. 16 is a sectional view taken substantially in the plane
of line 16-16 in FIG. 14.
[0039] FIGS. 16a, 16b and 16c are fragmentary sectional views taken
substantially in the plain of line 16a-16c in FIG. 16.
[0040] FIG. 17 is an isometric view showing the inhaler of FIGS. 1
and 2, parts being broken away to permit the diagramming of airflow
through the inhaler.
[0041] FIG. 18 is an isometric view similar to FIG. 17 diagramming
airflow through and around the inhaler check valve, mixing section,
cartridge and mouthpiece.
[0042] FIG. 19 is an isometric view similar to FIG. 18 diagramming
airflow through and around the inhaler check valve, inside the
cartridge, and through the mouthpiece.
[0043] FIG. 20 is an isometric view similar to FIGS. 1, 2, 17, 18
and 19 showing the inhaler, the inhaler flow-control/check-valve,
and the flow-control/check-valve sub-housing.
[0044] FIG. 21 is a top plan view of the inhaler shown in FIG.
20.
[0045] FIG. 22 is a sectional view taken substantially in the plane
of line 22-22 in FIG. 21.
[0046] FIG. 23 is a top plan view substantially similar to FIG.
21.
[0047] FIG. 24 is a sectional view taken substantially in the plane
of line 24-24 in FIG. 23.
[0048] FIG. 25 is an isometric view of the flow-control/check-valve
and sub-housing shown on FIGS. 17, 18, 19, 20, 22 and 24.
[0049] While the invention will be described in connection with
several preferred embodiments and procedures, it will be understood
that it is not intended to limit the invention to these embodiments
and procedures. On the contrary, it is intended to cover all
alternatives, modifications and equivalents as may be included
within the spirit and scope of the invention as defined by the
appended claims.
DETAILED DESCRIPTION OF THE INVENTION
[0050] An improved inhaler has been developed which has several
novel features optimizing performance. Medicament particles can be
delivered/administered over a broad range of inhalation velocity
and tidal volume of human breath. An inhaler mouthpiece exit tube
dilutes, expands, and collimates the particle dispersoid so that
the particles do not re-agglomerate during delivery. This inhaler
provides the means to effect a process whereby particles are
fluidized, suspended, then scavenged from the walls by
re-circulating scrubbing air, as well as higher speed-flow-through
air, followed by a high-shear flow field discharge into an
expanded, slower-moving mass of air that disperses and meters the
particle concentration expelled from the unit dose cartridge upper
outlet port.
[0051] Inhaler Overview
[0052] FIG. 1 shows an embodiment of a dry powder inhaler 10
described and claimed herein. In broad conceptual terms, an inhaler
housing 15 includes an intake section 20, a mixing section 30 and a
mouthpiece 40. In the preferred embodiment, this inhaler housing 15
is approximately 93 mm long, 38 mm high, and 22 mm thick. The other
parts illustrated and described here are of proportionate size. The
mouthpiece 40 can be swiveled from a stored position within the
housing 15 to a cartridge installation position in which the
mouthpiece 40 is oriented at 90 degrees to the long dimension of
the housing. When a cap 352 is closed, the mouthpiece can then be
further rotated into an operating position in which the mouthpiece
is located at a 180 degree position to the long dimension of the
housing. When the mouthpiece 40 is stored within the inhaler 15, a
sliding dirt shield cover 16 slidably mounted stored on the housing
can be slid upwardly to protect the mouthpiece 40 and the air
intake conduit entrance of the inhaler. The housing 15 can be
formed of a gamma radiation-proof polycarbonate plastic for the
rapid sterilization of the inhaler in mass production, as well as
in clinical-hospital use.
[0053] An air passage 50 (FIG. 17) extends through the intake
section 20, the mixing section 30 and the mouthpiece 40. A swivel
joint 80 (FIGS. 2 and 17) connects the mouthpiece 40 to the mixing
section 30. In the preferred embodiment, the mouthpiece and mixing
section are one unit, and are connected by a swivel joint to the
main housing. The cap 352 is pivotally attached to the mixing
section 30, and an interlock mechanism 355 prevents the mouthpiece
40 from being swung into an operating position unless the cartridge
301 is properly seated and installed. A cartridge 301 shown in
FIGS. 3, 4 and 5 contains a medicament powder, and it can be
installed in and removed from the mixing chamber 30.
[0054] Aerosolized powder is drawn from the cartridge 301 and
mixing section 30 through the mouthpiece 40 to the users'
oropharangeal cavity via the mouthpiece 40. As air and powder
travel through the mouthpiece, the velocity of the travel slows,
thus preparing the powder for effective delivery to the inhaler
user's broncheal tract and lungs.
[0055] So that writing or identifying indicia on
medicament-containing cartridge 301 can be read easily, the mixing
section 30 has a cap 352 which may be configured as a transparent
magnifying lens. An arrow 460 (FIG. 17) shows the direction of
aerosolized medicament powder discharge from the cartridge and
through the mouthpiece.
[0056] Air is caused to enter the inhaler by an inhalation effort
which the inhaler user exerts on and in the mouthpiece 40. As shown
particularly in FIG. 17 and as suggested by the airflow arrows 460
in FIGS. 17 and 18, ambient air enters the air control system 171
through air intake ports 172 and is directed to an
airflow-control/check-valve 180. As shown in FIGS. 17, 18, and 25,
this check valve system 180 includes a conical head 181 mounted
upon a bulb rod 182. A bulb 184 is slidably mounted upon the rod
182 for reciprocation between a stagnant airflow position and a
dynamic airflow-inhibiting position. The bulb 184 is drawn into a
normal relatively downstream airflow position, by the force of
airflow acting to overcome the bulb reactive force of a conical
tension spring 185 as suggested particularly in FIG. 19. This
spring is preferably formed of medical grade stainless steel.
Chute-like recesses 186 in the surface 187 of the bulb 184 control
and direct the flow of air over the bulb 184. Airflow straightening
vanes 189 mounted on the conical head 181 engage a confronting
conical venturi formation or seat 191 (FIG. 22). Air flowing
between the head 181 and seat 191 is accelerated and the airflow
straightened, in accordance with known characteristics of gaseous
airflow.
[0057] When the inhaler user draws air through the mouthpiece 40,
air flows to and around the bulb 184, and the imbalance of air
pressure forces acting upon the reciprocating bulb 184 pushes the
bulb in a downstream direction along the rod 182 into positions
which inhibits airflow. Because the bulb 184 is mounted to the
tension spring 185, increasing amounts of force are required to
draw the bulb 184 into increasingly airflow-restricting positions.
Additional bulb movement control can be provided, if desired, by an
opposing second spring (not shown) forming a high-sensitivity
push-pull system.
[0058] This bulb and spring mechanism allow the inhaler user to
generate a slight partial vacuum in his lungs before the bulb is
drawn away from the seating arrangement. Thus, by the time
significant vacuum is generated, a slight velocity increase of
airflow through the inhaler assists in drawing the medicament from
the cartridge (FIGS. 1 and 17-19), through the inhaler and into the
bronchial region and lungs of the user.
[0059] As suggested particularly in FIG. 20, the check valve
arrangement 180 can be mounted in a sub-housing 200 of intake
section 20, and both components 20 and 180 can be removed from the
inhaler housing 50 for cleaning, repair or replacement. A lock
device 196 of known design can be used to secure the sub-housing
200 of intake section 20 and contained components within the
inhaler housing 15.
[0060] When air is being drawn through the inhaler 10 and the bulb
184 is drawn along the rod 182 so as to impact the conical head
181, a clicking sound is produced. In accordance with one aspect of
the invention, this clicking sound indicates to the inhaler user
that he or she is drawing properly upon the mouthpiece and
operating the inhaler correctly. If desired, a vibratory mechanical
reed (not shown) can be mounted in the airflow path to produce an
audible signal to the user. Alternatively, an electronic flow or
pressure sensor can trigger an audible or visual signal indicator
to tell the user that proper airflow has been established.
[0061] This airflow-control/check-valve system 180 serves to
deliver air at a predetermined volume and velocity to downstream
inhaler parts. The airflow, at this predetermined volume and
velocity, acts to pick-up, fluidize, de-agglomerate and deliver
entrained medicament particles to the inhaler user in a dispersed
form and at a proper location to enter the user's bronchial
system.
[0062] Venturi and Mixing Section
[0063] As suggested particularly in FIGS. 12, 17 and 18, the
airflow is then drawn through a venturi passage 201 of restricted
size, thus increasing the velocity of that airflow, and into the
inhaler mixing section 30. As shown in FIGS. 10-17, this mixing
section 30 here comprises a fixed support 31 upon which is
journaled a cup 32. It will be noted that the mouthpiece 40 is
attached to the swivel cup 32 and can thus act as a handle for
pivoting the cup member 32 and mouthpiece to the configurations
shown in FIGS. 1, 14 and elsewhere and as more fully described
below.
[0064] In general, the mixing section 30 is provided with shapes on
its interior surface to encourage airflow acceleration so as to
suspend medicament particles in the airflow and to de-agglomerate
them. Within the cup 32 a medicament-containing cartridge 301 can
be mounted. As more fully described below, the cartridge 301 is
provided with air inlet and outlet holes (FIGS. 5-9), the cup 32 is
sized and shaped so as to direct air into the cartridge through the
lower inlet hole. The air then generally flows up through the
cartridge in an upward direction while producing a dual
counter-rotating helical motion, and out of the cartridge and down
the mouthpiece as particularly suggested in FIG. 19. As suggested
in FIG. 18, excess volume of air can flow around the outside of the
cartridge but within the mixing chamber to again mate with the
emerging medicament-laden air discharged from the cartridge and
flowing into the mouthpiece. Thus, air flowing into the mixing
chamber feeds the cartridge inlet holes, helps to extract air
flowing out from the cartridge discharge holes, dilutes the
medicament-laden airflow, and provides controlled, even
concentrations of medicament particles into the mouthpiece airflow.
The particle entrainment and dilution in the mouthpiece are
provided primarily by the cartridge bypass air.
[0065] As suggested in FIGS. 11, 12, 15 and 16, the mixing chamber
inlet port 33 provides vortex shedding which, aided by the top and
bottom internal mixing chamber internal swirl toroids 34 and 35,
fluidizes, suspends and scrubs the powder in the cartridge. The
upper semi-toroid shape 35 changes airflow direction from
dispersion chamber to mouthpiece, thus aiding further
de-agglomeration of the medicament particles in the entrained
powder stream. To reduce powder cohesion, a modest gas expansion
velocity with subsequent air shearing forces (and flow resistance)
act to support a fully dispersed flow through the mouthpiece
40.
[0066] Alternatively, a chamber which includes internal protrusions
or spiral shapes can be provided. The interior surfaces of the
mixing chamber can be shaped to provide one or more helical flows
of air around and within the cartridge, if desired.
[0067] Cartridge
[0068] The cartridge 301 is shown in further detail in FIGS. 3-9.
In the illustrated embodiment, the cartridge 301 comprises an upper
half 302 and a lower half 303, each preferably formed of
transparent plastic material. To encourage medicament particle
dispersion, the preferable plastic material is provided with ultra
smooth surfaces, is capable of being molded into the cartridge
components which have and which maintain great dimensional
accuracy, does not absorb or otherwise interact with water or
moisture, and has electrostatically neutral characteristics such
that the medicament powder in the cartridge 301 is not retained by
cartridge static charge, and does not adhere to the cartridge
halves 302, 303. One such material which can be used for the lower
half 303 is the Topaz brand of cyclicolephin co-polymer plastic
offered by Ticonia Corporation.
[0069] The upper cartridge half 302 defines an air inlet hole 306
and an outlet hole 307, and the cartridge lower half defines a
corresponding air inlet hole 308 and an air outlet hole 309. This
upper half can be made of a clear very low water absorbent nylon.
As shown particularly in FIG. 7, and as suggested in FIG. 3a, the
halves 302 and 303 interengage through a telescopic fit. A
circumferential ring and groove arrangement 310 retain the halves
302 and 303 in their assembled configuration.
[0070] As suggested particularly in FIGS. 5, 6, 8, and 9, the inlet
holes 306 and 308 formed at the lower portion of the cartridge are
beveled, and the outlet holes 307, 309 are likewise beveled at an
angle of substantially 60 degrees so as to encourage air ingress
and egress but to discourage electrostatic adhesion and agglomerate
deposition of 10 or larger micron-sized medicament particles on the
plastic defining the hole edges. To enable airflow and particle
pickup action, the inlet holes 306 and 308 are arranged to overlap
or register with one another when the cartridge halves are twisted
(as suggested by the arrow A in FIG. 4c) into the appropriate
cartridge open position, and the holes 306, 308 are elongated in a
vertical direction. Similarly, the outlet holes 307, 309 are
arranged to overlap and provide free air egress when the cartridge
halves are appropriately aligned, and the holes are elongated in a
horizontal direction so as to orient the air outflow for delivery
to the horizontally elongated channel in the mouthpiece 40.
[0071] This cartridge 301 is approximately one-quarter inch in
diameter and its body is approximately 1 inch in axial length, and
so to facilitate easy installation and extraction from the inhaler
10, a handle or manipulator structure 314 is provided atop the
cartridge 301. Here, the handle structure 314 comprises four web
extensions 315 which extend from the cartridge body to a finger
disk 316 which may have a coined or serrated periphery. A pointer
or dial indicator 317 is formed atop the disk 316 and is further
discussed below.
[0072] At the bottom of the cartridge 301, a cartridge installation
check boss 319 is formed. In accordance with another aspect of the
invention, this check boss can have a unique, non-circular shape of
any desired form such as those shown in FIGS. 16a, 16b and 16c.
These unique embossments are designed to fit within a closely
mating relief 39 formed in the fixed support 31 of the mixing
section. These unique embossed shapes will be uniquely associated
with particular medicaments, so that a cartridge containing an
incorrect medicament cannot be installed in a particular patient's
inhaler.
[0073] Cartridge Mounting Mechanism
[0074] To properly mount the cartridge 301 in the inhaler 10, a
mounting mechanism 350 is provided as especially shown in FIGS. 1,
2, 13-16 and 17. This mounting mechanism 350 takes the form of a
cap 352 formed of clear plastic, pivotally mounted so as to cover
the mixing section cup 32. See especially FIG. 16. A pivot pin 353
interconnects the cap 352 with an extension 354 of the mount 31. To
facilitate reading indicia marked upon the top of the cartridge
pointer 317, the top of this cap 352 is curved so as to act as a
magnifying lens. This dome shape also provides strength to the
cover structure.
[0075] The cartridge can be installed and the cap 352 secured in
place when the mouthpiece 40 and cartridge are pivoted into their
operating positions. To this end, a radially outwardly biased lock
pin 356 (FIG. 2) depending from the cap mount 331 pushes the cap
352 upwardly and into an open position when the mouthpiece 40 and
cap mount 331 are swiveled into a position so that the mouthpiece
is located at approximately 90 degrees to the long or greater
dimension of the inhaler body 15. In this configuration, the lock
pin 356 is pushed radially outwardly and the cap 352 is rotated
upwardly when the lock pin 356 is pushed into a relief defined in a
skirt 360 of the cover 358 (FIG. 2). This arrangement acts as a
safety and user prompting feature.
[0076] After the cartridge is inserted into the inhaler and the cap
is closed, the mouthpiece 40 can be pivoted out of its cartridge
installation and cap release position as shown in FIGS. 13-16 and
into the user medication inhalation configuration shown in FIGS. 1,
17 and 20-24. This mouthpiece pivoting motion can occur only when
the cap skirt 360 is pushed down into its closed position and the
lock pin 356 is radially depressed so as to permit mouthpiece 40
swiveling action. Thus, when the inhaler user moves the mouthpiece
from its stored position within the housing 15 to the cap unlocked
position, the cap springs open as shown in FIGS. 13 and 15, and
thereby indicates to the inhaler user that he or she should inspect
and, if necessary, replace or insert a new cartridge 301.
[0077] Mouthpiece
[0078] As suggested above, the mouthpiece 40 discharges
particle-laden air to the oropharyngeal cavity of the user. In
addition, the mouthpiece diverges the air and particle stream to
slow down the particles, and then converges the particle stream to
collimate and aim the particles at the rear of the user's mouth.
The mouthpiece is long enough so that it extends approximately
midway into most users' mouths. To encourage correct inhaler and
mouthpiece usage, the inhaler mouthpiece is oriented so as to
extend diagonally upwardly at approximately a 3 degree angle X as
suggested in FIGS. 22 and 24. As suggested in FIGS. 21 and 23, the
horizontally spaced walls of the mouthpiece diverge at an angle Y
of approximately 5 to 8 degrees. As suggested by a comparison of
FIGS. 21 and 22, the ratio of the height H of the mouthpiece air
passage page to the width W of the air passage is approximately
3:1. If desired, a tooth and lip placement embossment 411 can be
provided to depend from the distal end 412 of the mouthpiece 40.
The mouthpiece is preferably made of Delrin or Celcon co-polymer
acetyl plastic so as to provide proper strength, swivel bearing
self-lubricity, and smooth internal and external finish.
[0079] In use, the inhaler employs a regulated flow of air to
fluidize and aerosolize medicament particles and transport them to
the desired rear region of the orophalangeal cavity. To accomplish
this, air is first drawn into the interior of the inhaler housing
15 and through the intake ports 172 as suggested in FIGS. 17 and
18, to a predetermined volumetric airflow which is controlled by
the flow-control/check-valve mechanism 180. The airstream then
enters into the cartridge interior through the vertically elongated
and aligned inlet ports 306. The air entering the cartridge
interior immediately impinges upon the opposite cylindrical
cartridge wall. The impacted air jet then redistributes itself into
several portions. One of the portions flows downwardly into the
medicament powder bed, and strips the powder from the cartridge
surface and begins to fluidize it into an airborne dust cloud.
Another portion of the impingement jet is directed laterally in
both directions, which creates dual counter-rotating vertical
spinning helical columns. The majority of the fluidized medicament
powder is retained in these two columns, where the first
deagglomeration action is achieved. Yet another portion of the
impingement jet is directed vertically, which creates a vertical
high-speed air jet along the cartridge wall into the cartridge
discharge port or holes 306, 309. Particles in the helical
aerosolized columns are scavenged into the jetstream and then
discharged from the cartridge. This scavenging effect results in
particles being metered out or discharged from the cartridge at a
relatively steady particle distribution rate. Particle
agglomerations are further broken down by the discharge process.
Large agglomerates impinge upon the opposing mixing chamber wall,
and are further reduced into smaller agglomerates. Single particles
and smaller agglomerates are carried forward through the mixing
chamber and into the mouthpiece discharge tube. The remaining
agglomerates are pulled apart in the high-shear and shock flow
field produced by the mouthpiece tangential entry port. Thus a
steady flow of a individual medicament particles emerge from the
mouthpiece and into the users oropharyngeal airway. These airstream
flows and the sub-stream flows thus result in complete air
entrainment of all medicament particles in the cartridge, and
delivery of a complete, closely metered medicament dose to the
patient.
* * * * *