US 20080066743 A1
An aerosol medication delivery apparatus includes a holding chamber having an input end and an output end and defining an interior space. The output end comprises an orifice having a cross-sectional area of less than about 60 mm2. In one preferred embodiment, the orifice has a circular cross-section. Preferably, the orifice has a diameter of between about 2.0 mm and about 7.50 mm. In one preferred embodiment, an inhalation and exhalation valve is located at the output end. A method of using the holding chamber is also provided.
28. An aerosol medication delivery apparatus comprising:
a holding chamber having an input end and an output end, said holding chamber defining an interior space between said input and output ends, wherein said output end comprises an orifice having a cross-sectional area of less than about 60 mm2, an inhalation valve disposed downstream of said orifice and an exhalation valve disposed downstream of said orifice.
29. The aerosol medication delivery apparatus of
30. The aerosol medication delivery apparatus of
31. The aerosol medication delivery apparatus of
32. The aerosol medication delivery apparatus of
This application is a continuation of U.S. application Ser. No. 10/979,743, filed Nov. 2, 2004, which is a continuation of International Application PCT/US03/12121, with an international filing date of May 2, 2003, which claims the benefit of U.S. Provisional Application No. 60/377,528, filed May 3, 2002, the entire disclosures of which are hereby incorporated herein by reference.
The present invention relates to an aerosol delivery apparatus, and in particular, to an aerosol medication delivery apparatus having a narrow orifice.
Aerosol medication delivery systems are used, in general, to administer medication in aerosol form to the lungs of a user. For example, some systems use a pressurized metered-dose inhaler (pMDI), which typically includes a container in which the medication particles are stored under pressure, and an actuator used to dispense the medication from the container. In other systems, a holding chamber is connected to one of the container or actuator, as shown for example in U.S. Pat. No. 6,293,279, assigned to Trudell Medical International, and which is hereby incorporated herein by reference. The holding chamber reduces the need for the user to coordinate activation of the pMDI canister with inhalation, helps reduce the delivery of nonrespirable medication particles from the canister, and helps reduce the impaction of medication particles in the user's oropharnyx and upper airway. In some configurations, shown for example in the U.S. Pat. No. 6,293,279 and U.S. Pat. No. 5,881,718, the apparatus can be provided with one or both of an inhalation and exhalation valve(s) at an output end of the chamber. The output end is typically configured with a mouthpiece, which is received in the mouth of the user, or with a mask, which is placed over the mouth and nose of the user.
Users of the aforementioned devices often suffer from various bronchial ailments that can reduce lung capacity and output, which problems can be exacerbated with young children and domestic cats and dogs. Many of these devices, however, are not especially suited for users with low tidal volumes, such as neonatals. In particular, such devices typically have an orifice at the output end of the holding chamber that is greater than 78 mm2. Such relatively large openings may not produce the sweeping force necessary to draw aerosol out of a chamber with low tidal volumes, especially when the device is configured with inhalation/exhalation valves. As used herein, the word “user” includes humans and animals, including domestic cats and dogs.
By way of introduction, various preferred embodiments of an aerosol medication delivery apparatus include a holding chamber having an input end and an output end and defining a chamber housing having an interior space. The length of the chamber housing as measured from the input end to the output end is at least 70 mm and the diameter of the holding chamber is at least 20 mm. In one preferred embodiment, the chamber housing has a length of 120 mm and the diameter of the holding chamber is 40 mm. The output end comprises an orifice having a cross-sectional area of less than about 60 mm2. In one preferred embodiment, the orifice has a circular cross-section. Preferably, the orifice has a diameter of between about 2.0 mm and about 7.5 mm.
In one aspect, one preferred embodiment of the apparatus includes an inhalation and exhalation valve at the output end. In other aspects, methods of using the holding chamber are provided.
The foregoing paragraphs have been provided by way of general introduction, and are not intended to limit the scope of the following claims. The presently preferred embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.
In an alternative embodiment shown in
As shown in
As shown in the embodiment of in
In one preferred embodiment, shown in
A middle portion 36 joins the input and output end. In one preferred embodiment, the middle portion 36 has an inner, central portion 40 that is tapered and follows the contour of an interior channel formed in the adapter. The shape of the middle portion, and in particular the central portion 40, provides indicia to the user about which end to secure to the holding chamber by indicating the flow direction. Additional indicia, besides the shape, such as arrows and words, can also be provided. Preferably, the middle portion includes a plurality of ribs 38 extending radially from the central portion 40 which join the input and output ends 32, 34.
Preferably, the downstream end 46 has a cross-sectional area that is less than the cross-sectional area of the upstream end 44. Preferably, the channel 42 tapers between the upstream and downstream ends. Preferably the ratio of the cross-sectional area of the channel at the upstream end to the downstream end is between about 1.5:1 and about 6:1, and more preferably at a ratio of about 4:1.
For example, in one preferred embodiment, the upstream end 44 has a cross-sectional area of between about 200 mm2 and about 350 mm2, and more preferably about 283 mm2, although greater and lesser areas may be suitable. In one preferred embodiment, the opening at the upstream end 44 is configured as a circular opening having a diameter between about 18 mm and about 20 mm, and more preferably a diameter of about 19 mm. Of course, other non-circular shapes and/or cross-sectional areas are acceptable.
Also in one exemplary preferred embodiment, the downstream end 46, and the orifice 47 formed at the end thereof, has a cross-sectional area of between about 3 mm2 and about 201 mm2, more preferably between about 7 mm2 and about 78.5 mm2, more preferably less than about 60 mm2, even more preferably less than about 25 mm2, and in one embodiment, preferably about 19.6 mm2. In one preferred embodiment, the opening 47 at the downstream end 46 configured is a circular opening having a diameter between about 2 mm and about 16 mm, more preferably between about 3 mm and about 10 mm, more preferably less than about 7 mm, and more preferably about 5 mm. Of course, other non-circular shapes and/or cross-sectional areas are acceptable. Also, it should be understood that the channel may have a uniform cross-sectional area between the upstream and downstream end, preferably in the dimensions and ranges described above with respect to the downstream end.
In one preferred embodiment, an initial length 48 of the channel at the upstream end, for example about 4 mm, has a uniform cross-sectional area.
Thereafter, the channel preferably tapers. For example, in one preferred embodiment, the channel includes a transitional region 50 having a concave shape, for example with a radius of about 20 mm, a frusto-conical portion 52, and a lower transitional region 54 having a convex shape, for example with a radius of about 20 mm. A final length 56 of the channel at the downstream end, for example about 2.92 mm, preferably again is configured with a uniform cross-sectional area. Preferably, the angle of the sidewalls of the conical portion is about 22° from the central axis 58, forming an angle A of about 44°. Of course, it should be understood that the curved transitional regions can be eliminated, or provided with different radii of curvature. Likewise, the lengths of the initial and final lengths of the channel can be omitted, and also the linear portion between the curved transition areas, such the entire cross-sectional area is tapered or changes along the length of the channel. Alternatively, the channel may be stepped down from a first cross-sectional area to a lesser second cross-sectional area, without any taper.
Referring to another preferred embodiment of the adapter, shown in
In yet another preferred embodiment of the adapter, shown in
It should be understood that the adapter could be molded as a one-piece unit with the valve being in-molded with the adapter, or inserted as a separate component. In addition, it should be understood that the valve can be configured in different shapes and can include a valve that has a central opening with a peripheral portion of the valve being seated on a valve seat, for example a baffle member secured in or adjacent to the channel. In such a configuration, the central portion moves away from the valve seat during inhalation, while an outer peripheral edge of the valve moves away from a valve seat formed on the output piece during exhalation. It should also be understood that the device can be configured with separate inhalation and exhalation valves.
It should be understood that the channel 42, with its downstream and upstream ends 46, 44 can be formed integrally in the output end of the chamber housing, for example by molding, without the need for an adapter. Likewise, the output end of the adapter, defining the mouthpiece, can be formed integrally as part of the chamber housing downstream of the channel. Alternatively, the output end of the adapter can be formed as a separate piece that is mounted to the chamber housing, having a channel, with a valve disposed therebetween as explained above with respect to
Preferably, the adapter 30 and the chamber housing 14 are made of a hard plastic, such as polypropylene. The valve member 110 is preferably made of a flexible material, including for example and without limitation a silicone, a thermoplastic elastomer, rubber, Ethylene-Propylene-Diene-Monomer (EPDM) or Berfluodelaastomers (FFKN).
In operation, the user actuates the dispenser 2, or other device, so as to discharge a medication, preferably in aerosol form, through the input end 6 into the interior space of the holding chamber 4, or chamber housing. The user thereafter inhales through the output end of the adapter 34, 102 and holding chamber. As the user inhales, the medicament, which is preferably in aerosol form, is drawn through the channel 42 from the upstream to the downstream ends 44, 46 thereof. The medicament is then expelled into the exhaust chamber 60 and through the user's mouth via an ET tube where it is deposited in their lungs.
In one preferred embodiment, which includes an inhalation and exhalation valve 110, the edges of the flat sidewalls 128 of the duck bill move away from each other at the slit formed at the apex 130 upon inhalation due to a pressure differential applied to the upstream side of the duckbill, so as to allow the medicament to move through the opening formed thereby. At the same time, the pressure is applied to the upstream side 118 of the base portion so as to seal the downstream side 120 against the valve seat formed by the rib portion 122.
Upon exhalation, a pressure is exerted on the downstream side of the sidewalls 128 causing the duck bill to close. The exhalation pressure, however, is also exerted on the downstream side 120 of the base portion 116, causing the base portion 116 to move away from the valve seat 122 as the hinge flexes 114. As the base portion 116 is unseated, the exhaust air from the user escapes through the channel 124 and openings 132 to the ambient environment. In this way, exhalation by the user does not force air, or any contaminants, back into the holding chamber 4.
The narrow orifice 47 formed in the output end 14, whether integrally or by way of an adapter, is ideally suited for administering medication to users or patients with low tidal volumes in the range of between about 5 ml to about 100 ml, and more preferably between about 5 ml and about 20 ml. The term “tidal volume” as used herein means the average volume inhaled and exhaled during periodic breathing, and generally needed to satisfy metabolic requirements. In particular, the narrow orifice 47, alone and in conjunction with the tapered channel 42, maximizes the emitted dose and respirable fraction of the aerosol. In particular, the velocity of the particles is increased and, is particularly concentrated along the axis or centerline of the channel 42. The increased velocity may increase the number of respirable particles from the population of larger particles, as well as help carry the particles through the system.
The holding chamber with its narrow orifice, whether integrally molded or formed in an adapter portion thereof, is suitable for both spontaneously breathing patients as well as those requiring assisted ventilation.
Although the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. As such, it is intended that the foregoing detailed description be regarded as illustrative rather than limiting and that it is the appended claims, including all equivalents thereof, which are intended to define the scope of the invention.