Multi-dose dry powder inhalation device

A breath-actuated dry powder medicament inhalator device having a housing and a conduit mounted within the housing defining an air passageway therethrough having an aperture in the sidewall thereof. A blister-type strip of sealed containers arranged in a matrix of rows and columns wherein the columns extend generally diagonally to the longitudinal axis of the strip is secured in a two-piece cage adapted for being rotatably mounted around the conduit of the inhalator device. Advancement means are provided for rotatably moving the two-piece cage and blister strip contained thereby in a generally helical pathway relative to the conduit so as to successively advance each of the sealed containers of the blister strip into registration with the conduit aperture. Piercing means are associated with the housing for successively piercing each of the sealed containers of the blister strip when advanced into registration with the conduit aperture by the advancement means in order to introduce the dry powder compound contained therein into the air passageway of the conduit.

Technical Field 
This invention relates to an inhalator device for the inhalation of 
medicament in dry powder form, and more particularly to a multi-dose dry 
powder inhalation device for administering multiple doses of medicament 
from a blister-type strip. 
Related Art 
As is well known to those skilled in the art, there are essentially two 
general classes of inhalation devices currently being offered in the 
marketplace for bronchial administration of a dose of dry powder 
medicament. The first class of device is characterized by using a 
pressurized aerosol propellant for the inhaler which discharges a metered 
dose of a medication suspended in a pharmaceutically inert liquid 
propellant such as fluorocarbon. This class of inhalation device has the 
characteristic of consistently delivering a predetermined dose of 
medication. However, the particles of medication are propelled at a high 
velocity from the metering valve, and there is a propensity for some of 
the medication to be deposited on the back of the mouth and in the throat 
of a user. Accordingly, these devices suffer the disadvantage that while a 
consistent, metered dose leaves the valve of the device, the effective 
dose entering the lungs of a user can vary with the shape and physical 
dimensions of the user's oral cavity and his ability to coordinate his 
breathing with the discharge of the medication. 
The second class of generally known inhalation devices utilize a user's 
inhaled breath as a vehicle to transport a dry powder drug dosage. 
However, these devices also suffer certain shortcomings which are well 
known to one skilled in the art. A significant disadvantage of the second 
class of inhalation devices is a lack of an air flow velocity regulating 
means that can result in excessive inhalation velocity during use of the 
devices. Accordingly, these devices also suffer the disadvantage that the 
excessive inhalation velocity can cause the dry powder drug being inhaled 
to impinge upon the back of the mouth and the throat and to be thwarted 
from completing the desired journey to the lungs of a user. 
Also, and very importantly, the second class of inhalation device suffers 
an additional shortcoming of not providing a large enough number of doses 
if a sealed compartment is utilized to transport the dry powder medicament 
to the site of dispersion. Alternatively, if the dry powder medicament is 
contained in a reservoir in order to provide a high number of doses of 
medicament, it is well known that moisture in most dry powder medicaments 
will tend to cause agglomeration and clumping of the dry powder which act 
to inhibit dispersion of the dry powder when introduced into the airflow 
of an inhalator device during inhalation by a user. Accordingly, the 
reservoir-type of inhalator device suffers from the disadvantage of being 
periodically rendered substantially unusable by becoming clogged by the 
agglomerated dry powder medicament. Thus, there is a long-felt need for a 
high dose dry powder inhalator that is easy to use and does not suffer 
from the problems and shortcomings of inhalators described hereinabove. 
Representative of the reservoir-type of dry powder inhalation device is the 
TURBUHALER.RTM. which is marketed by AB Astra in Europe and the subject 
matter of U.S. Pat. Nos. 4,524,769 and 4,907,583 (assigned to A. B. Draco 
of Sweden). This dry powder medicament inhaler device was developed for 
the delivery of small quantities of pharmacologically active dry powder 
compounds without the necessity for any carrier compound. The 
breath-actuated inhalator comprises a dosing unit constructed as a disk 
(with groups of conical holes for the drug compound) which is positioned 
at the bottom of a drug compound storage unit. The larger diameter bottom 
areas of the truncated cones of the disk oppose the storage unit so as to 
facilitate filling thereof during the loading and emptying of the dosing 
unit at inhalation. 
Dosing is accomplished by rotating the dosing unit in the storage unit 
toward a pressure plate beneath the dosing unit. Plastic scrapers over the 
dosing units serve to load the holes with the drug compound, and dosing is 
performed by merely twisting the turning grip back and forth. Thus, when a 
user inhales through the inhaler device, the air enters a channel in the 
operating unit and passes through a hole in the pressure plate and through 
the dosing unit for release of the dose loaded in certain conical holes 
exposed to the area of the inhalation channel. Dry powder drug aggregates 
are broken up by the turbulent air flow in the inhalation channel and by 
the inserts in the nozzle mouthpiece. The non-refillable and non-reusable 
TURBUHALER.RTM. inhalator can provide up to 200 doses prior to disposal 
thereof. However, as is well known in the inhalator art, this type of 
multiple dose inhaler suffers from a number of shortcomings including 
potentially significant dosage variability. 
Another inhalator device of interest is disclosed in U.S. Pat. No. 
5,161,524 assigned to Glaxo Inc. The inhalator device disclosed therein is 
a significant advancement in the second class of inhalators since it 
provides for a metered dose dosage inhalator with an automatic regulating 
means to provide a substantially constant predetermined maximum airflow 
velocity therethrough in order to minimize impingement of dry powder 
medicament at the back of the upper throat. The apparatus disclosed and 
claimed in the aforementioned patent is a very advantageous advancement in 
the inhalator art, but utilizes a relatively complex diaphragm mechanism 
to regulate airflow velocity and also is potentially subject to the 
agglomeration tendency of all large reservoir multi-dose dry powder 
inhalator devices. 
The limitations of prior art dry powder medicament inhalator devices have 
now been overcome by the reusable, high dosage inhalator device of the 
present invention. 
Disclosure of the Invention 
Therefore, in accordance with the present invention, applicant provides a 
multi-dose inhalator device for administering a predetermined dose of dry 
powder compound from a blister-strip of sealed containers of dry powder 
compound wherein the portable inhalator device is adapted for reuse. The 
inhalator device comprises a housing having a conduit mounted therein 
which defines an air passageway therethrough, an air inlet end, an air 
exit end and an aperture extending through the side wall of the conduit 
between the ends thereof. A blister strip of sealed containers is provided 
wherein the sealed containers are arranged in a matrix of rows and columns 
and wherein the columns extend generally diagonally to the longitudinal 
axis of the strip. Cage means are provided for rotatably mounting the 
blister-type strip of sealed containers of dry powder compound in a 
cylindrical configuration around the conduit wherein the rows of the 
blister-type strip extend generally parallel to the longitudinal axis of 
the conduit. 
The inhalator device further includes advancement means associated with the 
housing for rotatably moving the cage means in a generally helical pathway 
relative to the conduit so as to successively advance each of the sealed 
containers of the blister-type strip into registration with the aperture 
of the conduit. Finally, piercing means associated with the housing are 
provided for piercing each of the sealed containers of the blister strip 
when advanced into registration with the aperture of the conduit so as to 
introduce the dry powder compound into the air passageway of the conduit. 
Thus, the blister-type strip will be rotatably and axially moved relative 
to the conduit as said sealed containers thereof are advanced along a 
helical pathway and then successively pierced for administration of a 
predetermined amount of the dry powder compound from the inhalator device. 
It is therefore the object of the present invention to provide an improved 
multi-dose dry powder inhalator device. 
It is another object of the present invention to provide an improved 
multi-dose dry powder inhalator device which obviates problems associated 
heretofore with high dosage dry powder inhalator devices. 
It is another object of the present invention to provide an improved dry 
powder inhalator device which utilizes a blister-type strip of sealed 
containers of the dry powder compound wherein the sealed compartments of 
the dry powder compound are successively advanced from the first to the 
last sealed compartment contained within the strip. 
It is yet another object of the present invention to provide an improved 
multi-dose dry powder inhalator device which simply and efficiently 
administers a high number of metered doses of a dry powder compound and 
which may be reused subsequent to exhaustion of the dry powder compound 
doses carried thereby. 
Some of the objects of the invention having been stated hereinabove, other 
objects will become evident as the description proceeds, when taken in 
connection with the accompanying drawings.

Best Mode for Carrying Out the Invention 
As used in the specification of the instant application, the term "dry 
powder medicament" means a dry powder substance used to achieve a 
therapeutic effect in respiratory therapy. The term "multi-dose dry powder 
inhalator" used herein means a device that is capable of delivering 
multiple doses of dry powder medicament without requiring refilling of the 
device. Also, although the dry powder inhalator device of the instant 
invention is shown as a device adapted primarily for oral inhalation, it 
should be appreciated that the invention contemplates inhalator devices 
that may also be adapted for nasal inhalation of dry powder compounds or 
medicaments. 
Referring now more specifically to the drawings, a preferred embodiment of 
a dry powder dosage inhalator device according to the present invention is 
shown in FIGS. 1-9 and generally designated 10. Inhalator device 10 
comprises a housing 12 having an air passageway conduit 14 secured in the 
central portion thereof. Conduit 14 (see FIGS. 1, 6 and 6A) defines an air 
passageway therethrough and most suitably has a venturi 14A in the medial 
portion thereof between the air inlet end 14B and air exit end 14C (which 
is adapted to be inserted into the mouth of a user). Although venturi 14A 
is depicted in the preferred embodiment of inhalator device 10, applicant 
contemplates that inhalator device 10 could also be constructed without 
14A in conduit 14 and still function with an acceptable degree of 
efficacy. 
An aperture 14D is provided in the side wall of the air passageway P so as 
to extend from the outside surface of conduit 14 to the inside venturi 
portion 14A of air passageway P. A swirl chamber 14E is provided between 
aperture 14D and venturi portion 14A for assuring deaggregation of the dry 
powder medicament which is urged into aperture 14D in a manner which will 
be described in detail hereinafter. Most suitably, a ramp 14A' is provided 
within venturi 14A and adjacent the internal end of aperture 14D to 
disrupt air flow so as to create localized mixing of air and the dry 
powder medicament (see FIG. 6A). Conduit 14 also includes a plurality of 
frusto-conical protuberances 14F on the outer surface thereof which are 
arranged in a helix extending generally around the longitudinal axis of 
conduit 14 and which serve a function to also be described in detail 
hereinafter. 
Housing 12 further includes an advancement mechanism generally designated 
16 and a button actuated piercing mechanism generally designated be for 
piercing a sealed compartment of a blister strip in order to introduce the 
dry powder medicament contained therein into the passageway P of conduit 
14. 
A blister strip or pack 20 (see particularly FIGS. 1, 2 and 4) is provided 
which is sufficiently flexible to be rolled from an initially flat 
configuration into a cylindrical configuration. Blister strip 20 most 
suitably is formed from soft aluminum having cold formed cavities 20A 
therein filled with the dry powder medicament and an adhesive-coated 
aluminum lid stock 20B secured to the top thereof. Blister strip 20 may 
also be formed from a polymer such as fluoropolymer which is adaptable to 
thermo-vacuum processing in order to form cavities 20A with the 
adhesive-coated aluminum lid 20B provided thereon. Lid 20B and cavities 
20A of blister strip 20 are of necessity formed so as to be capable of 
being penetrated by button-actuated piercing mechanism 18 to be described 
hereinafter. Also, and very significantly to the instant invention, it can 
be seen with particular reference to FIG. 2 that cavities 20A of blister 
strip 20 are formed in a matrix wherein the rows extend normally to the 
longitudinal axis of the strip and the columns extend parallel to each 
other and diagonally to the longitudinal axis of the strip so as to extend 
helically around the axis of a cylinder formed with the flexible strip. 
Most suitably blister strip 20 contains either 60 or 120 doses of dry 
powder medicament within cavities 20A although other dosage levels are 
within the contemplated scope of the present invention. 
Referring now particularly to FIGS. 1, 2, 3 and 5, a two-piece blister cage 
generally designated 30 is shown which serves to support each 
dose-containing cavity 20A of blister strip 20 in a nesting relationship. 
More specifically, cage 30 is formed from a flexible inner cage 32 
constructed of flat segments 32A, each containing molded receptacles or 
nests 32B therein for receiving a row of cavities 20A of blister strip 20. 
Segments 32A defining nests 32B therein are pivotably formed together with 
a suitable molded hinge 32C between each of segments 32A to allow for 
forming of a cylindrical cage from an initially flat strip of segments 
32A. Nests 32B of inner cage 32 each define an aperture or opening 32B' in 
the bottom thereof. 
Although other configurations are possible, most suitably inner cage 32 
serving to nest blister pack 20 therein will consist of 15 segments 32A 
containing rows of either four or eight blister cavity nests 32B. Notches 
32C are provided adjacent each end of segments 32A to interlock with outer 
cage or sleeve 34 in a manner to be described hereinbelow. Most suitably 
inner cage element 32 is formed from polypropylene in the flat condition 
but capable of being formed into a cylindrical configuration after 
assembly with blister pack 20 and outer cage 34. 
Outer cage or sleeve 34 is also formed as a flexible strip which can be 
formed into a cylindrical shape as required. Outer cage 34 is formed as an 
integral unit most suitably defining 15 raised portions 34A corresponding 
to the 15 segments 32A of inner cage 32. Raised portions 34A extend 
horizontally across the width of outer cage 34 and most suitably define 
either four or eight apertures 34B therein which are in vertical 
registration with a respective row of cavities 20A of blister strip 20 
which reside in a corresponding row of nests 32B of inner cage 32. Outer 
cage element 34 further defines (most suitably) 15 pairs of ratchet teeth 
34C provided between the raised portions 34A thereof to provide for 
rotational movement of outer cage element 34 by advancement mechanism 16. 
Outer cage element 34 also is formed so that the ends thereof may be 
snapped together by suitable means (not shown) in order to form a joint J 
(see FIG. 5) to hold former flat outer cage element 34 in a cylindrical 
configuration as desired. Outer cage element 34 is provided with apertures 
34D adjacent each end of raised portions 34A to facilitate assembly with 
inner cage 32 by serving to interlockingly receive corresponding notches 
32C of said inner cage 32. Similarly to inner cage 32, outer cage 34 is 
preferably formed from polypropylene, although other materials could be 
used for fabrication thereof. 
Referring now to FIGS. 8 and 9A, 9B, button actuated piercing mechanism be 
will be described in more detail. Mechanism be comprises button LeA which 
is urged into its normally raised position by spring 18B. Secured to 
button 18A and extending vertically downwardly therefrom and through an 
aperture 18C in housing 12 is a hollow needle or cannula 18D. Cannula 18D 
is positioned so as to be in vertical registration with aperture 14D of 
conduit 14 (see FIG. 6). Thus, as advancement mechanism 16 (to be 
described in detail hereinafter) serves to rotate successive dry powder 
medicament-filled cavities 20A of blister strip 20 into vertical 
registration with conduit aperture 14D, cannula 18D is positioned for 
downward vertical actuation in order to: (1) traverse through an aperture 
34B of outer cage element 34; (2) pierce protective lid 20B and cavity 20A 
of blister strip 20 thereunder; and to (3) force the dry powder medicament 
through the bottom of a corresponding nest 32B of inner cage 32 and into 
aperture 14D of conduit 14. 
In order to provide a repeatable dry powder medicament flow from ruptured 
cavity 20A of blister strip 20 through to swirl chamber 14E of conduit 14, 
a good seal must be provided between the bottom of blister strip cavity 
20A and corresponding inner cage nest 32B, as well as between the bottom 
of inner cage nest 32B and aperture 14D leading to swirl chamber 14E of 
conduit 14. This seal is effected through finger pressure which is 
maintained on button 18A so as to press the shoulder 18D' of cannula 18D 
against the inside of blister strip cavity 20A. A molded seal face will be 
provided on exit hole 32B' from nests 32B of inner cage 32 which will have 
sufficient flexibility to seal each nest to aperture 14D of conduit 14 
when the nest is in operative engagement therewith. Most suitably, there 
is also a spherical molded surface around aperture 14D to facilitate a 
positive seal. Thus, as the applicant maintains downward pressure on 
button 18A, air will enter and pass through the central opening of cannula 
bed and through conduit aperture 14B in order to facilitate swirling of 
the dry powder medicament in swirl chamber 14E and introduction thereof 
into venturi portion 14A of air passageway P. Ambient air will be allowed 
to enter cannula 18D through suitable openings (not shown) in the button 
and housing of button-actuated piercing mechanism 18. Most suitably, 
cannula 18D will be formed from steel and press fed into button 18A which 
will be formed from polystyrene. Spring 18B will most suitably be a 
conventional stainless steel compression spring. 
FIG. 9A illustrates button-actuated piercing mechanism 18 in its 
inoperative raised position and FIG. 9B illustrates button-actuated 
piercing mechanism 18 in its operative depressed position wherein cannula 
18D has pierced a blister strip cavity 20A and introduced the dry powder 
medicament contained therein into venturi portion 14A of passageway P 
within conduit 14. 
Finally, with particular reference to FIGS. 8 and 9A, 9B, the advancement 
mechanism 16 of inhalator device 10 will be described in detail. 
Advancement mechanism 16 consists of a reciprocatingly mounted button 16A 
which is adapted to engage four pairs of ratchet teeth 34C of outer cage 
element 34 with four pairs of corresponding teeth 16B and to rotate the 
cage assembly consisting of inner cage 32, blister strip 20 and outer cage 
34 one row over (counterclockwise) with respect to hollow piercing cannula 
18D of button-actuated piercing mechanism 18 and conduit aperture 14D. A 
fixed stop will prevent reverse rotation and a spring (not shown) will 
serve to reset advancement mechanism 16 to its original position. 
Advancement mechanism 16 may be of any suitable design to engage outer 
cage element 34, rotate same one row, and disengage outer cage element 34 
and reset for another indexing movement as desired by a user. Although 
other materials may be utilized, advance mechanism 16 is preferably 
fabricated from nylon for extended wear resistance and the return spring 
(not shown) formed from a suitable urethane. 
Thus, it can be appreciated that due to the unique matrix of blister strip 
cavities 20A and the cooperative engagement of the undersides of nests 32B 
of inner cage 32 with the helically arranged protuberances 14F on the 
outer surface of conduit 14, blister strip cavities 20A will move in a 
helical pathway around conduit 14 and be successively presented from first 
to last cavity 20A to piercing cannula 18D and conduit aperture 14D 
therebeneath during the course of multi-dosing of a dry powder medicament 
by a user. 
For better understanding, FIG. 7A depicts inhalator device 10 with blister 
strip 20 in its unused position and FIG. 7B depicts inhalator device 10 
subsequent to exhaustion of the entire 60 doses of dry powder medicament 
contained in blister strip cavities 20A. As can be appreciated, the 
assembly of inner cage 32, blister strip 20 and outer cage 34 has 
helically advanced from within housing 12 to a position substantially 
outside of housing 12 during the course of multiple dosing with inhalator 
device 10 of the instant invention. To reiterate, blister strip 20 is 
caused to helically advance around conduit 14 by the interaction of 
protuberances 14F on the outer surface of conduit 14 with the undersides 
of nests 32B of inner cage 32 (the columns of which define four helical 
pathways to movably contact protuberances 14F of conduit 14). 
In use, applicant contemplates that inner cage 32, blister strip 20 and 
outer cage 34 would be obtained from a pharmacy or the like and be a 
disposable part of reusable inhalator device 10. The aforementioned 
elements would be procured in a flat state for ease of packaging, etc. and 
assembled according to the description provided hereinabove. The assembly 
of inner cage 32, blister strip 20 and outer cage 34 would then be formed 
into a cylindrical disposable cartridge which would be inserted into 
inhalator device 10 by squeezing housing 12 into a slightly oval shape to 
prevent engagement by advancement mechanism 16 as the assembly is screwed 
fully into position over conduit 14. Thereafter, advancement mechanism 16 
would be utilized to successively advance the individual cavities 20A of 
blister strip 20 into a properly indexed position with button-actuated 
piercing mechanism 18 to facilitate dosing by a user. Once all of the 
doses in the blister strip have been administered (preferably either a 60 
dose or a 120 dose blister strip), the spent disposable assembly would be 
merely rotated several more turns in the indexing direction 
(counter-clockwise) in order to remove the assembly from inhalator device 
10 for disposal thereof. 
It will thus be seen that there has been described a novel multi-dose dry 
powder inhalator device which is designed to easily and simply provide a 
high number of dry powder medicament doses from a blister strip package 
without the disadvantages suffered by presently known dry powder 
medicament inhalator devices. 
It will be understood that various details of the invention may be changed 
without departing from the scope of the invention. Furthermore, the 
foregoing description is for the purpose of illustration only, and not for 
the purpose of limitation--the invention being defined by the claims.