Note: Descriptions are shown in the official language in which they were submitted.
- ~4~88g
BACKGROUND OF THE INVENTION
It is well known to administer powdered medicament
to the lung bronchioles of a patient by means of inhalation
devices having mouthpieces which enable the medicament to be
inhaled through the mouth of the patient. The medicament is
supplied in capsules which are inserted in the device and
- pierced prior to use after which inhalation through the mouth-
piece will cause the powdered medicament to be released from
the capsule and to pass to the patient. An object of the
10 present inventlon is to provide an improved such inhalation
device which has a low resistance to air flow and an ability
to discharge the contents of the capsule which makes it par-
ticularly suitable for use in the treatment of asthmatic patients.
BRIEF SUNMARY OF THE INVENTION
- According to the present invention, there is provided
an inhalation device comprising a body with a dispersion
" chamber therein and a capsule-retain~n pocket formed in
the wall of said body and open to the exterior, a rotor which
iS rotatable in the-chamber by passage of air therethrough,
one or more air inlet apertures in the body, the said aperture
~ or apertures opening, around the periphery of the rotor, into
-, the chamber and at such an angle that air entering the chamber
- through the aperture or apertures will cause the rotor to
rotate, a mouthpiece through which air from the chamber can
be inhaled, the said capsule-retaining pocket being arranged
` to receive and retain a pierced capsule, said pocket opening
- into the chamber whereby inhalation of air through the
.-:
mouthpiece will draw air through said aperture or apertures
and through the pocket whereby to draw medicament from the
capsule into the chamber and out through the mouthpiece at
the same time rotating the rotor.
Preferably, the rotor is arranged to brush the end
of a capsule in the capsule-retaining pocket as the rotor
' - : .
1048884
rotates. This causes the capsule to vibrate. Such vibration
of the capsule makes it possible to empty capsules containing
cohesive powders and to dispense theM satisfactorily, but is
not necessary with capsules charged with easily dispersible
powders.
BRIEF DESCRIPTION OF ACCOMPANYING_DRAWIN~S
Figure 1 is a longitudinal sectional view of an
inhalation device according to a preferred embodiment of the
invention,
Figure 2 is an end elevation,
Figure 3 is an elevation of the opposite end,
Figure 4 is a transverse section on line X-X of
Figure 1, and
Figure 5 is a detail view of a rotor.
DESCRIPTION OF PREFFERED EMBODIMENT
In the illustrated embodiment of the invention, an
inhalation device comprises a cylindrical body 1 with a
cylindrical dispersion chamber 2 therein. The chamber 2 is
closed at one end by an end wall 3 and a mouthpiece 4 is
20 fitted to the body at the other end of the chamber. A rotor
5 is arranged inside the dispersion chamber 2. This rotor
5 is a free-running multi-bladed wheel mounted on a central
spindle 6 running axially of the cylindrical chamber. The
rotor illustrated has two blades extending radially outwards
from the central spindle sleeve 7. Any number of blades can
be used, though two to four blades are preferred. The blades
can be set at any desired angle andtor can be curved. The
rotor must be light in weight and is, for example, of plastics
material.
104~B84
The spindle sleeve 7 must be a close fit on the spindle 6
and the rotor is rotatable about the spindle.
. One end of the spindle 6 is mounted in a cross-
bar 8 extending across the mouthpiece 4. The rotor is
located at the opposite end by means of an end stop plug 9
which is firmly fixed in the spindle sleeve 7. A pointed end
of the spindle 6 bears against the internal end of the plug 9.
This arrangement prevents axial displacement of the rotor 5.
Powder cannot enter the spindle sleeve 7.
One or more air inlet apertures 10 extend through
, .
the cylindrical body 1 and open into the dispersion chamber 2.
These apertures 10 are in the form of slots which run lengthwise
, of the body and are disposed at an angle which is conveniently
. tangential to the rotor.
; The body is also provided with a capsule-retaining
pocket 11. This pocket 11 is arranged at or near the closed
end 3 of the dispersion chamber and has an opening leading
lnto a recess 12 in the end wall 3 of the dispersion chamber.
r~ The pocket is arranged to receive a hard gelatine- capsule 13
containing a powdered medicament.
The rotor 5 is so positioned with respect to its
spindle 6 and the end wall 3 that it brushes lightly against
, the end of the capsule 13 protruding from the recess 12. The
rotation of the rotor therefore causes the capsule 13 to
vibrate and this assists in the emptying of cohesive powders
from the capsule and the dispersion of such powders. If the
device is intended for use with only capsules containing easily
dispensible powders it is not necessary to arrange for the
rotor to brush the capsules.
The body is provided at one end with a piercing
needle 14 for piercing the ends of the capsule 13. This
- 1~48~384
needle 14 is located in a capsule piercing pocket 15 in the
end wall 3 of the body. The capsule 13 can then be inserted
into the pocket 15 and pressed against the pointed end of the
needle 14, to pierce the capsule and can then be placed in the
capsule-retaining pocket 11. A stirrup 16 is hingedly mounted
on the body 1 and can, as shown in Figure 1 be swung to and
from a position in which it extends across the open end of the
capsule and retaining pocket 11 to prevent egress of the capsule.
It has been found that powder dispersion is improved
by providing one of the blades of the rotor with a cut away 17.
The end of the rotor which brushes the capsule is preferably
provided with a bevel 18.
The device is, except for the spindle 6 and needle
~.
14 made of plastics material, preferably one which has a high
resistance to the build up of static electricity.
In use, a capsule 13 is pierced at both ends by
means of needle 14 and is then fitted in the pocket 11. The
patient then applies the mouthpiece 4 to the mouth and draws
in air through the mouthpiece. The greater part of the inhaled
air will enter the chamber 2 through the tangential slots 10
and this will cause the rotor 5 to rotate rapidly. However,
a portion of the inhaled air is drawn into the chamber 2 through ~-
the capsule 13 and thls causes the rapid emptying of the powdered
medicament into the dispersion chamber 2. The rotation of the
rotor 5 and the turbulent air flow within the dispersion
chamber 2 will cause the efficient dispersion of the powdered
medicament into the air being inhaled by the patient.
With this device there is provided an excellent
deep lung and upper lung penetration of the drug. The
resistance to air flow can be low, for example at 2.5 cm.
water gauge at 601/min air flow. The vibration set up by the
:, :
-- 5
, :;
1048884
brushing of the rotor against the capsule assists in the
;. dispersion of the powder prior to the emptying of the capsule.
; If a freerer flowing powder is used the brushing arrangement
- may be dispensed with and an unbalanced rotor would then assist
in the emptying of the capsule.
.
~,.
.~
r~-
~'
,;
; :
i
~,
... .
.... . .
;,,
,....
.,
...
;~1 ,
, .,..
,.:
~ .
-- 6 ~
i~
, . . .
;;, . . . . .
' '
