CA1048884A - Inhalation devices - Google Patents

Abstract

A B S T R A C T

An inhalation device comprises a body with a dispersion chamber. A rotor is arranged in the chamber and is caused to rotate by passage of air through the chamber. One or more air inlet apertures open into the chamber around the rotor. A mouthpiece communicates with the chamber and air from the chamber can be inhaled through this mouthpiece. A capsule-retaining pocket is arranged to receive a pierced capsule and opens into the chamber. Inhalation of air through the mouthpiece will draw medicament from the capsule through the chamber and out through the mouthpiece and will at the same time rotate the rotor.

Description

- ~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 ' - : .

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 :, :

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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.
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Claims (5)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An inhalation device comprising a body with a dispersion chamber therein and a capsule-retaining 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 aper-ture 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.

2. A device as claimed in claim 1, wherein the body has a capsule-piercing pocket in which a capsule can be removably inserted and pressed against a point in the pocket thereby to pierce the capsule.

3. A device as claimed in claim 1, wherein the rotor is mounted on a spindle carried by a cross-bar extending across the mouthpiece.

4. A device as claimed in claim 1, 2 or 3, wherein the capsule-retaining pocket is arranged so that one end of a capsule located therein extends into the dispersion chamber and the rotor is so positioned as to brush against the protruding end of the capsule as it rotates.

5. A device as claimed in claim 1, 2 or 3 wherein the rotor includes two blades extending radially and oppositely outwards from a spindle sleeve, one of said blades having a cut-away portion.