Note: Descriptions are shown in the official language in which they were submitted.
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82589fft
Powder inhaler with capsule chamber for receiving a disposable capsule filled
with an active substance
The invention relates to a powder inhaler operating on the Bernoulli principle
with
replaceable cylindrical disposable capsules as the active substance reservoir.
The
powder inhaler consists essentially of a preferably cylindrical capsule
chamber
provided with means for laterally opening the capsule, an air inlet opening in
the
1o capsule chamber and an air outlet opening and a mouthpiece mounted
downstream
of the air outlet opening. The capsule chamber is constructed so that after
insertion
the reservoir capsule can essentially only move in the longitudinal direction
when an
air stream passes through the capsule chamber, guided substantially parallel
to the
longitudinal axis of the capsule. According to the invention, the inner wall
of the
capsule chamber is uneven in order to achieve a better emptying of the capsule
than
is obtained with a smooth inner surface.
Prior Art
A number of powder inhalers operating by the Bernoulli principle are known in
the
literature. What they all have in common is that the active substance to be
delivered
is stored in a cylindrical capsule and this capsule is inserted in a capsule
chamber of
the inhaler. The capsule chamber is usually cylindrical in shape, being
somewhat
longer and wider than the capsule so that the capsule is able to vibrate
longitudinally,
i.e. in the direction of air flow, and also transversely, i.e. at right angles
to the
direction of flow, but remains aligned substantially parallel to the chamber
axis. The
capsule chamber has an air inlet near one of its two ends and an air outlet
opening in
the region of the other end. The air outlet leads to a mouthpiece. In order to
deliver
the active capsule contents, first of all the capsule is opened, normally at
two places
on its longitudinal casing. As a rule these openings are located close to the
two
longitudinal ends of the capsule. If an air stream is now generated from the
air inlet
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towards the air outlet in the capsule chamber, it runs along the longitudinal
axis of the
capsule and has two effects: on the one hand the capsule is moved mainly along
its
longitudinal axis by the air stream. This movement may also occur
intermittently so
that the capsule vibrates. On the other hand, the air flowing along the two
capsule
openings produces a lower pressure in front of the capsule openings than
inside the
capsule, so that the powder contained in the capsule is picked up by the air
stream
and thereby nebulised.
The capsules normally used for inhalers of this kind consist of two cup-like
1o components which fit telescopically one inside the other. The outer shape
of a
composite capsule of this kind is that of a closed cylinder with hemispherical
ends.
The cylinder has a longitudinal axis and a transverse axis. The longitudinal
axis is
the axis which runs parallel to the generatrix of the cylinder casing. The
longitudinal
axis is longer than the transverse axis with the result that the longitudinal
section of
the capsule has an oval geometry and the cross section has a circular
geometry.
Usually, the capsules for inhalable powders consist of hard gelatine but may
also
consist of a plastic material. In connection with this reference is made to EP
1100474.
DE 3345722 discloses an inhaler of this kind as described at the beginning of
this
section (Prior art) consisting of two housing elements which are radially
moveable
towards each other, with a single capsule chamber. The inner surface of the
hollow
cylindrical capsule chamber is smooth.
WO 91/02558 discloses another inhaler as hereinbefore described wherein
instead of
a single capsule chamber there are a plurality of capsule chambers arranged in
a
similar manner to a revolver magazine. The open ends of this magazine are
delimited by walls, the air inlet or air outlet being located only at one
point in these
walls. This magazine is mounted to be rotatable so that a capsule chamber is
only
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connected to the air inlet, the air outlet and the cutting elements required
to open the
capsule in a certain position.
EP 0911047 discloses an inhaler with a) a cup-shaped lower part open upwardly,
b)
a plate which covers the opening in the lower part and perpendicular to which
is
formed a capsule chamber of the kind described above, whilst on the capsule
chamber is provided a button which is moveable against a spring which has two
sharp spikes for opening the capsule, c) an upper part with a mouth tube which
is
connected to the capsule chamber, and capable of conveying a powder aerosol,
and
1o d) a lid. The elements a), b) c) and d) are joined together by a common
hinge
element so that they can be flipped relative to each other. In addition, this
patent
application describes a capsule holder wherein the capsule holder may be
constructed as a hole in the plate b) and has ribs at the edge. The capsule is
jammed into this capsule holder to hold it in readiness.
FR-A-2 146 202 describes an inhaler with a flat cylindrical chamber in which
only the
capsule can be moved. The capsule opened at the ends rotates during the
inhaling
process, driven by tangentially incoming air, about its transverse axis.
US-A-4 069 819 describes an inhaler wherein the capsule is pierced through the
base of the capsule chamber and during inhalation is set in motion by the air
flowing
in tangentially in the region of the base.
Description of the Invention
Surprisingly, it has now been found that the delivery of the active substance
can be
improved using the powder inhaler described above which is known from the
prior art
and more uniform emptying of the capsules can be guaranteed, if the capsule
chamber is not only of the optimum size, larger than the capsule, but if it
has an inner
surface structure in the form of a relief which is capable of guiding the
capsule during
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vibrations in the capsule chamber. Only capsule chambers with a smooth inner
surface are known from the prior art.
The measure adopted according to the invention ensures that the capsule
containing
the active substance can basically only move back and forth in the capsule
chamber
by a short distance along its longitudinal axis and has only limited play
along its
transverse axis and is nevertheless uniformly emptied. In addition, the points
of
contact of the capsule with the inner chamber surface are also minimised and
in this
way the vibration is simplified.
It is therefore an aim of the present invention to provide powder inhalers
having
disposable capsules as the active substance reservoir which improve the
delivery of
the active substance.
A further aim of the invention is to modify powder inhalers of this kind so as
to
guarantee uniform emptying of different capsules.
A further objective is to provide a powder inhaler of this kind having a
capsule
chamber in which a reservoir capsule can move freely in the longitudinal
direction.
A further objective is to provide a powder inhaler of this kind having a
capsule
chamber in which a reservoir capsule can move only slightly in the transverse
direction, without interfering with the longitudinal movement of the capsule.
A further aim is to provide powder inhalers having capsule chambers wherein
the
area of contact between the inner surface of the chamber and the capsule
surface is
minimised.
Another aim is to provide powder inhalers having capsule chambers in which a
3o degree of emptying of more than 60% and preferably more than 90% is
regularly
achieved.
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According to one aspect of the present invention, there is provided a capsule
chamber for a powder inhaler in the form of a cavity having an inner cavity,
wherein
the cavity is open on two sides for accommodating a disposable capsule for a
pharmaceutically active inhalable composition with a diameter for the inner
cavity
which is 1.1 to 2.5 times as great as the capsule diameter and a length, the
length of
the inner cavity of the capsule chamber, which is 1.02 to 2 times as great as
the
length of the capsule so that the capsule for use with the inhaler is enabled
to move
or vibrate due to an air flow between an air inlet on one side of the chamber
and an
air outlet on the other side of the chamber, wherein an inner surface of the
capsule
chamber comprises spacers for the capsule in the form of raised elements such
that
the capsule is constrained regarding movement thereof in transverse direction
and
wherein the capsule is essentially only movable back and forth along the
capsule's
longitudinal axis.
According to another aspect of the present invention, there is provided an
assembly
consisting of at least two capsule chambers as described herein.
According to yet another aspect of the present invention, there is provided a
powder
inhaler consisting of a lower housing with an assembly as described herein and
an
upper housing part which has a mouthpiece connected to the air outlet opening
of
one of the capsule chambers of the assembly.
According to still another aspect of the present invention, there is provided
a powder
inhaler consisting of a lower housing part with a capsule chamber as described
herein and an upper housing part which has a mouthpiece connected to the air
outlet
opening of the capsule chamber.
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According to a further aspect of the present invention, there is provided a
combination comprising: (a) a generally cylindrical capsule having an outer
surface, a
longitudinal axis and containing a pharmaceutically active inhalable
medicament, and
(b) a medicinal powder inhaler device comprising, (1) a capsule chamber for
receiving the capsule, said capsule chamber having an inner surface, an inlet
proximate a first end, for admitting air into the chamber and an outlet,
proximate a
second end, which communicates with a mouthpiece, the axis of the chamber
being
the line running between the first and second ends, by means of which
mouthpiece a
patient can draw by inhalation a stream of air which flows from the inlet,
through the
capsule chamber, wherein it admixes with medicament which has been released
from
the capsule that has been received by the chamber, thence through the outlet
and
finally from the mouthpiece from whence the patient may inhale the mixture of
air and
medicament, the inner surface of said capsule chamber and the outer surface of
said
capsule defining clearance along the longitudinal axis and clearance in a
transverse
direction sufficient to enable the capsule to vibrate longitudinally in the
direction of air
flow and also transversely at right angles to the direction of flow while
remaining
aligned substantially parallel to the chamber axis when air is caused to pass
through
the chamber in response to inhalation by the patient, the combination
including raised
elements on either the inner surface of said capsule chamber or the outer
surface of
said capsule, which raised elements align the axis of the capsule with the
longitudinal
axis of the capsule chamber and which extend into the clearance of the
transverse
direction to constrain the capsule such that, when it vibrates within the
capsule
chamber, movement back and forth along its longitudinal axis is permitted with
essentially no transverse movement, and (2) means for piercing a capsule
placed into
the capsule chamber, to thereby release medicament from the capsule into the
capsule chamber.
4b
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According to still a further aspect of the present invention, there is
provided a
medicinal powder inhaler device comprising, (a) a capsule chamber having an
inner
surface, for receiving a generally cylindrical capsule having an outer
surface, a
longitudinal axis and containing a pharmaceutically active inhalable
medicament, said
capsule chamber having an inlet proximate a first end, for admitting air into
the
chamber and an outlet, proximate a second end, which communicates with a
mouthpiece, the axis of the chamber being the line running between the first
and
second ends, by means of which mouthpiece a patient can draw by inhalation a
stream of air which flows from the inlet, through the capsule chamber, wherein
it
admixes with medicament which has been released from a capsule that has been
received by the chamber, thence through the outlet and finally from the
mouthpiece
from whence the patient may inhale the mixture of air and medicament, the
inner
surface of said capsule chamber and the outer surface of said capsule defining
clearance along the longitudinal axis and clearance in a transverse direction
sufficient
to enable the capsule to vibrate longitudinally in the direction of air flow
and also
transversely at right angles to the direction of flow while remaining aligned
substantially parallel to the chamber axis when air is caused to pass through
the
chamber in response to inhalation by the patient, the combination including
raised
elements on the inner surface of said capsule chamber, which raised elements
align
the axis of the capsule with the longitudinal axis of the capsule chamber and
which
extend into the clearance of the transverse direction to constrain the capsule
such
that, when it vibrates within the capsule chamber, movement back and forth
along its
longitudinal axis is permitted with essentially no transverse movement, and
(b) means
for piercing a capsule placed into the capsule chamber, to thereby release
medicament from the capsule into the capsule chamber.
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Brief Description of the Drawings
Figure 1 shows a cross section through a cylindrical capsule chamber according
to
the invention with 3 longitudinally mounted ribs.
Figure 2 shows a longitudinal section through the wall of the cylindrical
capsule
chamber according to the invention with undulating ribs.
Figure 3 shows the embodiment according to Figure 2 in conjunction with the
embodiment according to Figure 1 as a longitudinal section through the wall of
the
cylindrical capsule chamber according to the invention.
Figure 4 shows a capsule chamber according to the invention with a helically
mounted rib.
Figure 5 shows a capsule chamber according to the invention of square cross
section.
Figure 6 shows an inhaler with the capsule chamber according to the invention.
Figures 7 a to d show a powder inhaler with a revolver magazine which contains
a
plurality of capsule chambers according to the invention.
Figure 8 shows a powder inhaler with an upper part and lower part which are
movable relative to each other.
4d
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p.
Specific description of the Invention
For the powder inhalers according to the invention it is possible to use the
inhalers
described in the prior art section hereinbefore, particularly those described
in DE
3345722, WO 91/02558 or EP 0911047. This means that the features mentioned for
the powder inhalers generally described in the prior art section also refer to
the
powder inhaler according to the invention, with the exception of the features
mentioned regarding the shape of the inner surface of the capsule chamber, and
1o need not therefore be specifically mentioned at this point. The capsules
mentioned
in the same section may be used in the inhaler according to the invention.
The outer shape of the capsule chamber is of no significance for the purposes
of the
present invention. The outer shape is determined by the position of the
capsule
chamber and any movements thereof in the inhaler or the movements of other
parts
of the inhaler around the capsule chamber.
The inner shape of the capsule chamber is designed according to the invention
so
that it comprises a cavity open on two sides for accommodating a disposable
capsule
for pharmaceutically active inhalable substances. Preferably, these two
openings are
provided at opposite ends or immediately adjacent these ends. The inner form
may
for example be a preferably uniform cylinder or cuboid. Preferably the inner
configuration resembles a cylinder.
The dimensions of the capsule chamber are matched to those of the capsule.
As an illustration some examples of typical capsule dimensions will now be
given, indicating the size of the capsule chamber.
Total length of the closed capsule: 26.1 0.3 mm; 23.3 +0.3 mm; 24.2 0.3
mm; 21.7+0.3mm; 19.4+0.3mm; 18.0+0.3mm; 15.9+0.3mm; 14.3+0.3
mm; 11.1 0.3 mm.
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Outer diameter of the capsule body: 9.55 mm; 8.18 mm; 7.36 mm; 7.34 mm;
6.63 mm; 6.07 mm; 5.57 mm; 5.05 mm; 4.68 mm.
External diameter of the capsule caps: 9.91 mm; 8.53 mm; 7.66 mm; 7.64
mm; 6.91 mm; 6.35 mm; 5.83 mm; 5.32 mm; 4.91 mm.
The standard commercial capsules are size 3, which is known at least in
Germany.
In the telescopic capsules described the diameter of the upper part is 5.83
and the
diameter of the lower part is 5.57 mm.
The capsule chamber according to the invention has an inner surface structure
which
defines an inner cavity enclosed thereby. By the inner cavity is meant the
geometric
space which comes into contact with the inner surface of the capsule chamber
without being penetrated by any surface structures provided. Preferably, it is
the
corresponding cylindrical space with the largest diameter which can be fitted
within
the surface structures.
The inner cavity preferably has a diameter which is 1.1 to 2.5 times as great
as the
capsule diameter. Preferably, the diameter is 1.1 to 2.2 times, more
particularly 1.2
to 1.6 times as great as the capsule diameter. The length of the inner cavity
of the
capsule chamber is 1.02 to 2 times the length of the capsule, preferably 1.04
to 1.8,
more particularly 1.1 to 1.6 times the length of the capsule. The diameter of
the
chamber should be less than the length of the capsule, so that the capsule is
held in
the longitudinal direction in the chamber and cannot tilt to one side.
As already emphasised, the capsule chamber has two openings, an inlet for
incoming air and an air outlet. The air inlet is smaller in cross section than
the
capsule chamber so that in this region of the capsule chamber the flow
velocity of the
air is relatively high and a powder in the capsule is delivered by the
Bernoulli effect.
The air inlet opening is conveniently arranged centrally in the base of the
chamber.
On the air outlet side there may be a perforated plate or other device such as
projecting components to prevent a capsule moving in the capsule chamber from
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blocking the air outlet or any capsule fragments formed from being sucked into
thd'
mouthpiece.
The perforated plate may for example be part of a funnel-shaped connecting
member
which can be fitted on to the start of the inhalation channel leading to the
mouthpiece
in such a way that the edge of the funnel with the perforated plate engages in
a plate-
shaped insert which forms the base of the mouthpiece. The perforated plate
may,
however, also be replaceably fixed by jamming it between the funnel edge of
the
connecting member and a stop of the plate-shaped insert.
A plurality of openings may also be provided as the outlet opening. The cross
section available for the air to flow out of the capsule chamber is
conveniently greater
at every point than the air inlet opening so that the air charged with the
pharmaceutical composition can flow out unimpeded as far as possible. The air
outlet opening is expediently arranged centrally in the top of the chamber but
may
also be arranged to one side in the top region.
The provision of the two openings is intended to guide an air stream axially
through
the capsule chamber.
The capsule chamber has at at least one point along its longitudinal axis (in
relation
to the interior of the capsule chamber) an opening for or a connection to a
cutting
device which is provided with at least two sharp spikes or cutters for
piercing or
cutting open a capsule located in the capsule chamber. Preferably there are at
least
two such places, with a cutter or spike being able to act on the capsule
through each
of these places. The cutting device is moveable into the interior of the
chamber
counter to the pressure of the spring and is operated by means of a spring
mounted
actuating button.
3o The points or cutting edges of the cutting device are preferably arranged
so that they
can penetrate into the upper or lower region of the capsule. As the length of
the
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capsule chamber is adapted to the length of the pharmaceutical capsules, the
cutters
are preferably located close to the top or bottom end of the capsule chamber.
The
side wall of the capsule chamber may have radial bores or oblong slots in the
region
of its top and bottom end which face the spikes or cutting edges and serve to
allow
the spikes or cutters to pass through. The dimensions of these bores/slots are
matched to the cross section of the spikes or cutting edges.
In a preferred embodiment the guide for the spikes of the cutting device
comprises a
sealing plate. In this way the seal between the capsule chamber in the
inhaling
1o position and the cutting device is improved. For the spring mounting of the
sealing
plate it is possible to use the spring which resets the actuating button for
the cutting
device.
Finally, in another embodiment, a lever system is provided for actuating the
cutting
device. This lever system is preferably actuated by an actuating button
mounted on
the base or side of the housing of the inhaler. The lever system may consist
of a
rocker and a toggle lever, while the actuating button acts on one end of the
rocker
and the other end of the rocker presses on one end of the toggle lever, the
other end
of the toggle lever secured to the cutting device pushing the cutting device
forward.
The rocker and toggle lever are preferably mounted to be pivotable about axes
in
holders secured to the housing.
The capsule is supposed to be opened close to both its ends for the inhalation
process. The hemispherical caps of the capsule should not be damaged in their
central region. This is important because the capsule or caps of the capsule
act as a
sort of valve. Because of the pressure conditions the capsule is pulled
towards the
inlet opening counter to the inflowing air and closes it off. As the user
continues to
suck on the mouthpiece, suction is produced in the capsule chamber by which
the
capsule is carried towards the air outlet with the inflowing air. The suction
now
formed at the air inlet ensures that the capsule is pulled towards the inlet
opening
again. The entire process is repeated in rapid succession as long as the
patient
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contiues to inhale through the mouthpiece and sets the capsule vibrating
stronglyin
the axial direction.
The capsule chambers for powder inhalers known from the prior art have a
contour-
free inner surface. According to the invention, the structure of the inner
surface of
the capsule chamber is different from a smooth surface.
This is achieved by forming spacers from the capsule, in the form of raised
elements,
on the inner surface of the capsule chamber, which is also referred to simply
as the
surface of the capsule chamber, for the purposes of the present invention.
The spacers are such that their points which are furthest from the surface
align the
capsule axially and promote axial movement of the capsule in the chamber. At
the
same time the spacers should not jam the capsule laterally, but should allow
slight
lateral movement of the capsule.
The height of the spacers (i.e. the spacing between the base and the apex) is
preferably from 0.1 mm to 5 mm, more preferably from 0.5 mm to 2 mm.
The raised elements are preferably at equal spacings from the capsule in the
capsule
chamber. These spacings are preferably 0.1 to 1 mm, more preferably 0.2 to 0.5
mm.
The raised elements may be in the form of ribs with sharp edges, with soft
undulating
transitions or in the form of pins. Combinations thereof are also possible.
The tips or edges of these raised elements preferably have a minimal surface
area.
In the case of ribs, these may be arranged axially, i.e. parallel to the
longitudinal axis
of the capsule in the chamber, transversely, i.e. perpendicularly to the
longitudinal
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axis of the capsule or askew with respect to the longitudinal axis of the
capsule. The
term "askew" also includes helically arranged ribs.
If the ribs are arranged axially, the capsule chamber expediently has at least
three or
more such ribs. Preferably it has no more than nine, most preferably not more
than
six ribs of this kind. The length of the ribs is selected so that they guide
the capsule
as it moves axially without blocking this movement. Preferably, the ribs
extend over
the full height of the chamber. In this case the ribs preferably have a
triangular cross
section, one point of the triangle pointing away from the inner surface of the
capsule
lo chamber. This embodiment has the advantage that the capsule can be guided
in the
capsule chamber without any great frictional losses during its axial movement.
Other
geometric shapes for the ribs are also possible, e.g. ribs with a semicircular
or
rectangular cross section, etc.
To prevent the capsule from becoming jammed in the axially arranged ribs,
these ribs
may be arranged so that the arrangement does not appear rotationally
symmetrical in
cross section. In other words, where there are three ribs, for example, two of
the ribs
are closer to one another than to the third rib.
If the ribs are arranged tangentially, all the edges pointing towards the
capsule
should describe the shape of a uniform cylinder. In the case of ribs running
around
the periphery of the casing of the capsule chamber it is essential that the
spacings
between the ribs be designed so that the axially moving capsule cannot be
impeded
in its movement by a rib of this kind. In this case, at least two ribs are
preferred. In
cross section they preferably have soft transitions, i.e. an undulating
surface. This
construction has the advantage that the cross section of the capsule chamber
along
the longitudinal axis varies constantly, so that when air flows axially along
the
longitudinal axis of the capsule chamber there may be slight pressure
differences
which promote the emptying of the capsule.
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A further embodiment of the capsule chamber comprises an inner surface with
an"
undulating transverse pattern as described above, with ribs formed axially on
this
surface, i.e. perpendicularly to the undulations. These ribs are in turn
designed so
that the outer edges of the ribs are equidistant to the central longitudinal
axis of the
capsule chamber and therefore the outer edges of the ribs do not have an
undulating
surface but a surface which is not curved (parallel to the longitudinal axis).
In the case of pin-shaped raised elements these may either be arranged in
linear
manner and optionally replace the ribs or they may be randomly arranged. The
pins
lo will in any case be aligned so that the axial movement of the capsule
cannot be
disrupted but on the contrary the capsule is guided in its movement.
The present invention also relates to an assembly of at least two capsule
chambers
which are structurally joined together. Such an assembly may be for example a
magazine or revolver magazine with 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17,
18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more capsule chambers.
These
may be arranged in a circle, helix or spiral with one another, the top ends of
the
capsule chambers all pointing in the same direction. By the top end is meant
the end
close to which or on which is found the air outlet opening and on which the
top of the
capsule abuts (the narrow end of the capsule). Preferably, in a revolver
magazine of
this kind, the capsule chambers are arranged in a circular or spiral pattern.
The capsule chamber according to the invention may be incorporated in suitable
powder inhalers. The powder inhalers thus modified by the capsule chamber
according to the invention, which in the simplest case consist of the capsule
chamber, an air inlet opening, an air outlet opening connected for air flow to
a
mouthpiece and optionally a device for opening the capsules, are also a
subject of
the present invention.
3o The air mixed with the pharmaceutical substance in the chamber is passed
through
the mouthpiece to the mouth of the user. The mouthpiece, which is generally
tubular
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and optionally somewhat flattened, may be arranged axially or at an angle to
the axis
of the chamber or offset laterally from the axis of the chamber.
The mouthpiece of the inhaler may be constructed in the form of a cap which is
fitted
on to the underlying component (lower part) of the inhaler which contains the
capsule
chamber. This cap may be hinged to the edge of the inhaler housing so as to be
pivotable about an axis extending perpendicularly to the longitudinal axis of
the
inhaler. The mouthpiece and the lower part of the inhaler housing may,
however,
also be fixed to one another by a conventional push-fit connection. In any
case,
lo access generally, to the capsule chamber and to the cutting device in the
lower
housing part, on the one hand, and to the inner components such as the
perforated
plate and the upper housing part (of the mouthpiece-cap) is made substantially
easier by the removability or pivotability of the two components.
In order to replace used capsules with fresh ones, in an embodiment of this
kind the
mouthpiece is flipped upwards or the push-fit connection between the
mouthpiece
and the lower housing part is undone. The capsule chamber is then freely
accessible, so that the emptied capsule can be removed and a full one
inserted. The
device is then flipped shut or pushed shut.
The inhaler according to the invention allows the pharmaceutical composition
to be delivered more reliably with a lower standard deviation compared with
the devices known from the prior art. Compared with many devices it also
has the additional advantage of better breaking up of any clumps. In fact, the
micronised pharmaceutical compositions in the capsules have a tendency to
form clumps. These clumps are therapeutically undesirable as it is important
for the pharmaceutical composition to be distributed as finely as possible.
When the inhaler according to the invention is used the clumps are
substantially destroyed.
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Preferred inhalers are those described hereinbefore as embodiments of DE
3345722,
WO 91/02558 or EP 0911047. Reference is hereby made once again to the features
mentioned in this section. The inhaler as described hereinbefore in connection
with
EP 0911047 is particularly preferred.
In inhalers of this kind there can only be one capsule chambers according to
the
invention, in accordance with the remarks on DE 3345722 or EP 0911047.
However, the capsule chamber may also be part of a capsule chamber magazine as
described in WO 91/02558.
An inhaler of this kind has a revolver magazine with a plurality of usually
tubular
chambers each loaded with one capsule. The magazine is covered at each of its
two
open ends by a plate, one plate containing the air inlet opening and axially
thereto
the other plate containing the air outlet opening. As the magazine is
rotatably
mounted within these plates, one of the chambers can be pivoted into place
between
the two openings and thus form part of the continuous channel for the inhaled
air.
After an inhalation process has ended the revolver magazine is further rotated
until
the next chamber enters the air throughflow channel. One of the two plates may
be
separated from the magazine, for example, in order to remove used capsules
from
the chambers, or else the entire magazine can be removed for refilling, for
example.
According to this feature of the invention the revolver magazine is releasably
mounted in the inhaler housing. After the capsules in the revolver magazine
have
been used the entire revolver magazine can be replaced or refilled with
capsules.
The inhaler housing may have an eccentrically mounted pin on to which the
revolver
magazine can be fitted.
In order to fix the position of the revolver magazine it may be provided with
recesses
associated with the capsule chambers for a spring-mounted locking bolt
arranged in
the inhaler housing. The recesses are arranged so that the locking bolt only
engages
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therein when one of the capsule chambers is located precisely between the air
inlet
and outlet.
In this way it is possible to ensure that the revolver magazine does not move
during
the inhalation. The spring mounting of the locking bolt should be selected
with
regard to the spring constant so that accidental rotation of the revolver
magazine is
prevented by the locking but on the other hand if greater force is applied the
revolver
magazine can be rotated out of its locked position. Conical shapes for the
free end
of the locking bolt and suitably shaped recesses have a supporting effect.
The locking bolt is preferably arranged coaxially with the air throughflow
channel
underneath the capsule chamber and has a through-bore which simultaneously
forms the air inlet in the base. Preferably, the locking bolt is centrally
mounted in the
inhaler housing. According to another embodiment of the invention the locking
bolt is
acted upon by a spring the other end of which abuts on a stopper releasably
fixed in
the inhaler housing, which also has a central through-bore which is part of
the air
throughflow channel.
In a preferred embodiment the recesses for engagement of the locking bolt in
the
base are arranged in the base plate of the magazine, concentrically with the
air inlet
bores of the capsule chambers and like the casing constructed in the form of a
flat
truncated cone with its base facing outwards. Thus, these recesses are conical
or
funnel-shaped widenings of the air inlet bores, the widened area facing the
locking
bolt. The slopes produced by the widening correspond approximately to the
chamfers
on the top of the locking bolt.
In a preferred embodiment these recesses have an encircling stop edge on the
base
of the casing of the truncated cone, but also in the base plate, which acts as
a
rotation preventer or stop for the head of the locking bolt when the latter
has engaged
in the corresponding recess. Because of this stop edge the magazine cannot be
turned any further once the locking bolt has engaged.
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p.
According to another feature of this embodiment the said stop edge takes up
only
part or half of the periphery of the conical recess, i.e. the funnel-shaped
widening,
and is arranged so that when the locking bolt is engaged it prevents rotation
of the
magazine in one direction but allows it in the other direction, as the sloping
wall of the
funnel-shaped widening merges smoothly into the exterior of the base plate.
In another preferred embodiment only one of the recesses has a stop edge which
takes up the entire circumference of the recess so that when the locking pin
is
1o engaged it is impossible for the magazine to rotate in this recess. This
position is
then regarded as the end position of a magazine in which all the capsules have
been
used. In this embodiment, all the other recesses only have a rotation
preventer on
one side, i.e. effective in one direction, so that the magazine can only ever
be rotated
in the direction in which a capsule chamber containing an unused capsule is
brought
into play, until the end position described above in which locking is complete
is
reached. The user then knows that the magazine has to be loaded with fresh
capsules once this last capsule has been used.
In another preferred embodiment a tongue may be fixed to the locking bolt
which
extends as far as a stop on the inside of the operating button of the cutting
device
when the locking bolt assumes its upper stop position with the revolver
magazine
removed. In this position the said tongue acts as a barrier for the cutting
device.
When the magazine is inserted the locking bolt is pressed down again and in
this
way the barrier for the cutting device is removed.
The actuation of the cutting device may also be coupled to the rotary movement
of
the capsule magazine, so that at the press of a button first a capsule chamber
is
brought into the correct position and then the cutting device is engaged.
If the revolver magazine and the part of the inhaler housing adjacent thereto
are
constructed with n angles, where n is a whole number indicating the number of
CA 02509521 2011-08-24
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capsule chambers, the side surfaces of the inhaler housing part and of the
revolver
magazine may advantageously be aligned when the magazine is in the correct
position. It is then possible to determine immediately from outside whether
the
chamber is located in the air channel defined by the air inlet and the air
outlet.
As an alternative to the construction of the inner surface of the capsule
chamber according to the invention, the outer surface of the capsule may
also have a surface structure of this kind. In other words, the invention also
encompasses capsules for inhalation having a surface structure which
corresponds in its function to the surface structure of the capsule chamber.
Thus, for example, the capsules may have axial ribs, raised elements,
annular rings and the like. The surface structure described with regard to the
construction of the surface of the inner wall of the capsule chamber is in
this
case "projected" onto the outer surface of the capsule. Where axial ribs were
described for the capsule chamber, for example, with a triangular cross
section, with one of the sides arranged on the surface to form the base and
the apex facing the capsule, the capsule may instead have axially arranged
ribs on its exterior, which face towards the walls of the capsule chamber. The
same applies to other embodiments of the surfaces.
In the inhalation systems according to the invention consisting of a capsule
and inhaler, preferably only one of the two elements, i.e. the capsule
chamber or the capsule, preferably the capsule chamber, has the structured
surface.
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The invention will now be described in more detail with reference to the
Figures.
Figure 1 shows a cross section through a cylindrical capsule chamber (1)
according
to the invention with 3 longitudinally arranged ribs (3). In the capsule
chamber
(1) is a disposable capsule for inhalation (2).
Figure 2 shows a longitudinal section through the wall of the cylindrical
capsule
chamber (1) according to the invention with undulating ribs (4). Only one side
of the
wall is shown.
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Figure 3 shows the embodiment according to Figure 2 in longitudinal section,
showing additional ribs (3) in the longitudinal direction according to Figure
1,
which are perpendicular to the undulating ribs (4).
Figure 4 shows a capsule chamber (1) according to the invention with
helically arranged ribs (3).
Figure 5 shows a capsule chamber (1) according to the invention with a
square cross section and 4 longitudinal ribs (3).
Figure 6 shows how an inhaler may be constructed in which a capsule
chamber according to the invention is integrated. Located in a lower part (5)
optionally with two windows (6) is a plate (7) connected to the capsule
chamber (1). The capsules in the capsule chamber (1) are opened by means
of a button (8) provided with two specially sharpened spikes which is pressed
in counter to the pressure of the spring (9) and thereby cuts open or pierces
the capsule in the chamber in two places. As the user inhales through the
device using the mouthpiece (10) which is connected to the upper part (11),
the air enters the lower part (5) and from there goes into the capsule
chamber (1) according to the invention at the lower end. The device is closed
off by a lid (12), which is hinged to the lower part (5), the plate (7) and
the
upper part (11), so that when the lid is closed dust cannot enter the device.
In
the plate (7) there may optionally be capsule holders in the form of blind
bores. Advantageously, there is a perforated plate (34), which is fixed to the
lower end of the mouth tube (10) or of the inhalation channel leading to the
opening of the mouthpiece and, when the inhaler is in the closed position,
covers the air outlet opening of the capsule chamber (1). The drawings do
not show optional snap-fit hooks on the side of the mouth tube (10) or of the
upper part (11) which is oriented towards the plate (7), which are capable of
3o engaging in the plate (7). In this case the plate (7) has suitably
complementary devices (depressions or holes). Projections or snap fit hooks
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may also be provided laterally on the plate (7), for example to enable the
plate (7) to engage in the lower part. The above mentioned devices for
engaging the mouthpiece (10) or upper part (11) in the plate (7) or the plate
(7) in the lower part (5) are such that the individual elements can easily be
separated from one another again. In addition, a lug may be formed on the
point on the lid (12) which is located above the button (8) in the closed
position so that this lug engages in a depression on the top of the button (8)
and blocks the button (8), so that the button (8) cannot be pressed in the
closed position. This prevents the capsule from being accidentally perforated
lo prematurely once it has been inserted in the capsule chamber.
Figure 7: As can be seen from Figs. 7a, 7b and 7c, an inhaler with a revolver
magazine consists essentially of an inhaler housing (5) with a mouthpiece (10)
which
is hinged laterally to the upper edge of the inhaler housing (11) so as to be
pivotable
about an axis (13), and a revolver magazine (14) with the chambers (1)
according to
the invention for accommodating the capsules. The revolver magazine (14) can
be
fitted on to a pin (15) eccentrically mounted in the inhaler housing (5).
After the
revolver magazine (14) has been pushed on the mouthpiece (10) is moved into
its
normal position - as a cap on the housing; the inhaler is ready for use. A
capsule
(not shown) can now be perforated by pressing the button (8). As can be seen
from
Figure 7c, the revolver magazine (14) in this case has 6 chambers (1) for
accommodating the capsules (not shown). The base of each chamber (1) has an
air
inlet bore (16). In addition, the revolver magazine (14) has an axial guide
(17) for the
pin (15).
As may be seen from Figure 7d, the inhaler has, adjacent to the chamber (1)
mounted underneath the inhalation channel (18), the cutting device (19) which
is
operated by means of the button (8). This cutting device (19) has two spikes
(20)
which can be radially inserted into the upper and lower part, respectively, of
said
chamber (1), the outer wall of the revolver magazine having weakened or
frangible
regions (21) at suitable points to assist the insertion of the spikes (2). The
spikes
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(20) serve to open the capsule located in the chamber (1) close to the upper
and
lower ends thereof. The revolver magazine (14) also has, underneath the bore
(22),
conical recesses (23) in which a locking bolt (24) can engage as soon as the
corresponding chamber (1) is coaxial with the air inlet or inhalation channel
(18) of
the inhaler housing. The locking bolt is also conically formed at its end
engaging in
the recess (23). At the opposite end it is acted upon by a spring (26) which
bears on
a stopper (27) releasably fixed in the inhaler housing. This stopper, like the
locking
bolt, has a central through-bore which acts as an air inlet (25).
lo In order to prepare the inhaler, with the revolver magazine (14) in place,
this
magazine is rotated so that one of the chambers (1) is brought into a position
in
which the bore (22) in the base or the conical recess (23) is aligned
coaxially with the
air inlet opening (25). The positioning of the chamber (1) is made easier by
the
engagement of the locking bolt (24) in the recess (23). After the bolt has
engaged,
the air inlet opening (25) and the base opening (22) in the chamber (1) are in
alignment. The cap of the capsule is positioned on the base opening (22) and
closes
it off. By actuation of the button (18) counter to the force of a spring (9)
the cutting
edges (20) are moved radially towards the chamber (1), first piercing the
weakened
regions (21) or entering corresponding openings in the side wall of the
revolver
magazine and finally opening the capsule at the top and bottom close to its
ends.
The hemispherical caps of the capsules should not be destroyed.
When air is then sucked through the mouthpiece (10), the air flowing into the
chamber from the base openings (28) in the housing (5) and the air inlet (25)
sets the
capsule vibrating violently, produces turbulence in the powder in the capsule,
mixes
with it and is finally inhaled. The mouthpiece (10) is generally tubular in
construction
but may also be adapted to the shape of the mouth and flattened. Similarly, as
an
alternative to the embodiment shown, the mouthpiece may be arranged axially or
at
an angle to the axis of the chamber or laterally offset from the axis of the
chamber.
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At the base, the mouthpiece (10) may be provided with a plate-shaped insert
(29)"
which is essentially solid. This plate-shaped insert (29) may also have
perforations.
Moreover, the start of the inhalation channel (18) may be covered with a
screen
which prevents the capsule or capsule fragments from being inhaled into the
inhalation chamber (18) in the mouthpiece. Alternatively, projections may be
provided on the wall at this point to hold the capsule back. The perforated
plate is
then preferably arranged in the centre of the plate-shaped insert (29),
advantageously clamped between a stop (30) on the plate (29) surrounding the
air
throughflow and the edge of a funnel-shaped connecting member (31), which is
fitted
on to the beginning (32) of the inhalation channel (19) in such a way that the
edge of
the funnel faces the plate-shaped insert (29) and engages therewith. The
alternatively provided projections may also be arranged at this point.
The embodiment of the inhaler according to the invention as shown in Figure 8
consists of the lower part (5) and the mouthpiece (10), which are fitted
together. The
lower part contains the air inlet channel (25) which is connected to the air
inlet into
the capsule chamber (1). The cutting device (19) is held in its normal
position by a
spring element (9). The mouthpiece (10) contains the capsule chamber (1). The
inner surface structure thereof according to the invention is not shown, nor
in Figures
6 and 7. Projections (33) which limit the play of the capsule project into the
extension
of the capsule chamber. A perforated plate (34) delimits the capsule chamber
and
prevents fragments of capsule from being inhaled, for example. The inhaler may
be
axially compressed counter to the pressure of a spring element (35), the upper
edge
of the lower part reaching the position (36). In this position the blades or
points (20)
of the cutting device (19) may penetrate through the opening (21) into the
capsule
chamber (1) and open the capsules secured therein.
In order to use the inhaler according to Fig. 8 the lower part (5) and
mouthpiece (10)
are pulled apart, the capsule is inserted and the two parts of the inhaler are
fitted
together. After being pressed back into position (36) counter to the spring
element
(35) the cutting device (19) is actuated and released again. Under the
pressure of
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the spring element (35) the inhaler returns to the initial position shown in
Figure 8.
The active substance formulation from the capsule (not shown) can now be
inhaled
by breathing in through the mouthpiece (10).
22
