This invention relates to spacer devices for metered dose inhalers for administering medications.
Metered dose inhalers (MDI) are used for administering medications, such as bronchodilator drugs and corticosteroids, to the lungs.
The canister 12 holds a reservoir 17 of medication and is pressurized with a propellant. A metering valve 13 is located at the bottom of the canister 12 and the medication flows out through a stem 11. The user loads the canister 12 into the boot portion 14 of the actuator 19 such that the stem 11 fits into the spray nozzle 15. When the user presses down on the canister 12, the valve stem 11 presses into the spray nozzle 15, causing it to discharge a preset amount of medication as an aerosolized spray 18 out of the mouthpiece 16 for delivery into the user's lung. When working properly, the user inhales the aerosolized medication 18 through the mouth and into the bronchial passageways of the lungs.
However, MDIs are not very efficient at drug delivery; they deliver only about 10% of the dose to the lungs, with the rest being deposited elsewhere, such as the oropharynx. This is because pressurized MDIs generate an aerosol spray with a velocity that is faster than the patient can inhale. This puts a lot of demand on the users' performance to synchronize their inhalation with the spray actuation in order to release the aerosol spray at the beginning of inhalation. This problem is particularly acute in children and the elderly. With the lack of proper synchronization, instead of being inhaled into the lung, much of the sprayed medication may be deposited onto the back of the mouth or pharynx. In addition to loss of therapeutic effectiveness, this can cause cough, voice hoarseness, fungal infections, and absorption of the medication into the bloodstream.
Because of these difficulties, many patients are advised to use a spacer that is fitted to the mouthpiece of the MDI to overcome some of the problems of poor coordination and oropharyngeal deposition. Spacers work by lengthening the distance between the actuator mouthpiece and the user's mouth, thus giving the user more time to synchronize inhalation and reducing the impaction onto the oropharynx. Also, evaporation of spray solvent would decrease the size of particles, facilitating more deposition in the lungs and better penetration to peripheral airways.
The one-way valve 28 allows the user to inhale the medication through the spacer 20. In case the user exhales, the one-way valve 28 would act to divert the exhaled breath outward rather than entering the chamber 22. Some spacers are also equipped with a whistle as a flow rate indicator, i.e. making a whistling sound if the user is inhaling too quickly.
Yet, there are still problems with existing spacers. There is a tradeoff between size and effectiveness. Spacers can have a compact design, but those are too short and small to be effective. More complex spacer designs, such as the valved holding chambers (VHC), have a wider and longer barrel to improve drug delivery effectiveness, but the problem is that they are too bulky, making them inconvenient to carry around. This is a very serious problem for patients who must carry around their MDIs at all times for acute asthma attacks. Because they are so bulky, MDI users often leave their spacers at home instead of carrying it with them. Thus, there is a need for a spacer device that is compact and easy-to-carry, yet large enough for effective drug delivery.
The present invention provides a compact spacer device for a metered dose inhaler. In one aspect, the present invention is a spacer device for a metered dose inhaler (MDI). The spacer device has a proximal end and a distal end. The proximal/distal designation follows the direction of medication flow from the MDI, through the aerosol chamber, and out to the user. The spacer device may be made as a single unitary structure, or its various segments may be separate parts that are joined together. The spacer device or parts thereof could be made using any suitable type of material, including plastic materials such as polyethylene-vinyl-acetate (PEVA), polyethylene, polypropylene, silicone, etc.
Aerosol Chamber:
The spacer device comprises an aerosol chamber for holding the aerosolized medication sprayed from the MDI. The aerosol chamber could be designed in any suitable way for this purpose. In some embodiments, the aerosol chamber comprises a forward shell, a rear shell, and an extendable barrel in between. For example, the extendable barrel may comprise a flexible plastic sheath that is supported by a coiled wire spring.
In another embodiment, the aerosol chamber comprises a main barrel in the shape of a corrugated tube, which allows the aerosol chamber to have a compressed configuration and an expanded configuration. The main barrel segment could have any suitable cross-sectional shape, such as circular, oblong, oval, rounded square or rectangle, etc. (which may be symmetrical or asymmetrical).
In some embodiments, the aerosol chamber further comprises a one-way valve that permits air flow coming out of the aerosol chamber into the mouthpiece (e.g. when the user inhales), but diverts air flow coming from the mouthpiece away from the interior of the aerosol chamber (e.g. when the user exhales into the spacer).
Mouthpiece:
At the distal end of the aerosol chamber, there is a mouthpiece. In some embodiments, the distal mouthpiece is in the shape of a corrugated tube, which allows the mouthpiece to have a compressed configuration and an expanded configuration. In some embodiments, the mouthpiece comprises a rigid segment at the distal end of the mouthpiece, wherein the rigid segment is more rigid than a more proximally-located segment of the mouthpiece. The spacer device may further comprises a mouthpiece cover that comprises a mouthpiece cap for fitting onto the mouthpiece.
Fastening Means:
The spacer device comprises a fastening means to couple the MDI to the spacer device. The fastening means may have any suitable design. In some embodiments, the fastening means is a mounting bracket to hold the MDI. The mounting bracket could have any suitable design to hold the MDI such that the mouthpiece of the MDI is aligned with the aerosol chamber of the spacer device. In one embodiment, the mounting bracket comprises flexing holder arms for gripping the actuator boot of the MDI. The MDI is held in the mounting bracket such that the mouthpiece of the MDI is mated with the aerosol chamber. In some cases, the mounting bracket has a support wall that is parallel and flush against the aerosol chamber.
Examples of other types of fastening means include anchoring knobs, through-holes for mating, elastic bands, pivoting rods, plastic ties, harnesses, latches, hooks, snaps, Velcro (hook-and-loop fastening), etc. In some embodiments, the fastening means couples the proximal end of the aerosol chamber or the adapter to the spray outlet of the MDI. For example, such a fastening means could be an elastic band. In another example, the collar described below could be considered a fastening means. The spacer device could comprise two or more fastening means.
In some embodiments, the spacer device comprises a second fastening means. In this embodiment, the first fastening means located at a proximal portion of the aerosol chamber. As used herein, the term “proximal portion” in relation to the aerosol chamber means the proximal one-fourth end section of the aerosol chamber. The second fastening means is located above (distal to) the first fastening means. In the embodiment where the spacer device comprises a mouthpiece cover, the mouthpiece cover could comprise the second fastening means for coupling to the MDI. In this design, the second fastening means could couple to the mounting bracket, or actuator boot, or the medication canister of the MDI. In this way, the mouthpiece cover of the spacer device is coupled to the mounting bracket, actuator boot, or the medication canister of the MDI. This coupling is detachable, that is, the mouthpiece may be uncoupled from the MDI so that the mouthpiece is accessible for use by the user.
Adapter:
The aerosol chamber may further comprise an adapter to enable the spacer device to adopt different configurations. The adapter has a hollow interior to give continuity between the MDI and the aerosol chamber. The mouthpiece of the MDI may be inserted into the adapter. Any of various types of adapter configurations could be used. Swivel Adapter: In some embodiments, the adapter is a swivel-type adapter. This type of adapter could have any suitable design. In one embodiment, the adapter comprises an outer case and an inner case, wherein the inner case is within the outer case. The inner case and the outer case are rotatably slidable relative to each other. The inner case and the outer case could be made of a hard plastic material.
Flexible Tube Adapter:
In some embodiments, the adapter is a flexible tube-type adapter. This type of adapter could be in the shape of a tube, which could have any suitable cross-sectional shape, such as circular, oblong, oval, rounded square or rectangle, etc. (which may be symmetrical or asymmetrical). In some embodiments, the adapter is in the shape of a corrugated tube. In this embodiment, the fastening means may be located on the adapter. In some embodiments, the adapter is made to be more flexible than the main barrel. In some embodiments, the adapter is made of a natural or synthetic rubber material, such as silicone rubber, latex rubber, styrene-butadiene rubber, butyl rubber, etc.
Collar:
The proximal end of the aerosol chamber is coupled to the spray outlet of the MDI. Any suitable design could be used for this purpose. In some embodiments, the adapter comprises a collar for receiving the mouthpiece of the MDI and help coupling of the MDI to the space device. The collar could be made of a soft material, such as silicone plastic, to promote a secure fit with the mouthpiece of the MDI. In some embodiments, the spacer device further comprises a cushion positioned against the support wall of the mounting bracket and between the MDI. The cushion mates with the adapter. The cushion may be made of a softer material than the mounting bracket, such as silicone plastic or polyurethane foam. In this embodiment, the cushion comprises the collar for receiving the mouthpiece of the MDI. In some cases, the cushion comprises an outwardly protruding bumper on the side facing towards the MDI. This bumper may be useful to dampen loose rattling of the MDI in the mounting bracket.
Dimensions:
There are a range of dimensions suitable for design of the spacer device and its various components. As an example, the full length of the aerosol chamber may be in the range of 3-18 or 3-9 cm in its compressed configuration and 9-22 or 9-30 cm in its expanded configuration. As an example, the length of the main barrel may be in the range of 3-7 cm or 3-9 cm in its compressed configuration, and 8-20 or 8-26 cm in its expanded configuration. As an example, the outer diameter of the main barrel may be in the range of 2-7 cm wide. As an example, the volume of the aerosol chamber in expanded configuration may be in the range 50-800 cm2; and in some cases, at least 125 cm2. In embodiments where the mouthpiece has a compressed/extended configuration, as an example, the length of the mouthpiece may be in the range of 1-3 cm in its compressed configuration and 2-6 cm in its extended configuration. As an example, the outer diameter of the mouthpiece may be in the range of 1-2.5 cm.
Medical Inhaler Assembly:
In another aspect, the present invention is a medical inhaler assembly. The assembly comprises a MDI and a spacer device of the present invention. The spacer device is coupled to the MDI such that the aerosol chamber or the main barrel of the aerosol chamber is aligned substantially parallel to the actuator boot of the MDI. This coupling may be detachable or permanent. The actuator boot of the MDI and the spacer device could be combined as a single unitary device (with the medication canister being replaceable). In some embodiments, the proximal end of the aerosol chamber or the adapter is coupled to the spray outlet of the MDI in the manner already described above. This coupling may be detachable or permanent.
Regardless of how the coupling between the spacer device and the MDI is done, the inhaler assembly is put into a compact configuration in which the aerosol chamber or the main barrel of the aerosol chamber is aligned substantially parallel to the actuator boot of the MDI. In some embodiments, the aerosol chamber is positioned flush to the MDI, i.e. the gap between the aerosol chamber of the spacer device and the actuator boot of the inhaler is less than 2 cm; and in some cases, less than 1 cm. In some embodiments, the main barrel of the aerosol chamber is positioned flush to the MDI, i.e. the gap between the main barrel of the aerosol chamber and the actuator boot of the inhaler is less than 2 cm; and in some cases, less than 1 cm.
Method of Combining:
In another aspect, the present invention is a method of combining a MDI with a spacer device. The method comprises having a MDI and a spacer device of the present invention. The spacer device is coupled to the MDI by the one or more fastening means as described above. In embodiments where the spacer device comprises a mounting bracket, the method comprises positioning the MDI on the mounting bracket. In embodiments where the coupling includes a second fastening means on a mouthpiece cover, the method comprises placing the mouthpiece cap on the mouthpiece of the spacer device, or attaching the second fastening means to the mounting bracket, or actuator boot, or the medication canister of the MDI.
The spacer device is coupled to the MDI such that the aerosol chamber or the main barrel of the aerosol chamber is aligned substantially parallel to the actuator boot of the MDI. In some embodiments, the aerosol chamber is positioned flush to the MDI, i.e. the gap between the aerosol chamber of the spacer device and the actuator boot of the inhaler is less than 2 cm; and in some cases, less than 1 cm. In some embodiments, the main barrel of the aerosol chamber is positioned flush to the MDI, i.e. the gap between the main barrel of the aerosol chamber and the actuator boot of the inhaler is less than 2 cm; and in some cases, less than 1 cm.
Method of Use:
In another aspect, the present invention is a method of using a MDI with a spacer device of the present invention. To prepare for use, the aerosol chamber is folded downward away from the MDI. As an example, the angle of folding could be in the range of 60-150° or 75-135°. In embodiments where the spacer device comprises a swivel adapter, this involves the step of swiveling the aerosol chamber downward. In embodiments where the spacer device comprises a second fastening means on a mouthpiece cover, this step involves removing the mouthpiece cap off the mouthpiece of the spacer device.
With the aerosol chamber folded downward into open position, the aerosol chamber is then expanded in a distal direction along its main longitudinal axis. In embodiments where the aerosol chamber comprises a forward shell, a rear shell, and an extendable barrel, this involves the step of separating the forward shell from the rear shell. The barrel may self-extend outward under spring action, or by the user pulling on the forward shell, or a combination of both. In embodiments where the mouthpiece of the spacer device comprises a rigid segment at its distal end, and the user grasps the rigid segment to pull the aerosol chamber and mouthpiece out in the distal direction.
The user may insert the mouthpiece of the spacer device into their mouth and actuate the MDI. In some embodiments, the method further comprises, after use, compressing the aerosol chamber back into its compressed configuration. The aerosol chamber is folded back upward to put the spacer device back into its compact configuration. In embodiments where the spacer device comprises a second fastening means on a mouthpiece cover, this step involves placing the mouthpiece cap back on the mouthpiece of the spacer device.
To assist in understanding the invention, reference is made to the accompanying drawings to show by way of illustration specific embodiments in which the invention may be practiced. The drawings herein are not necessarily made to scale or actual proportions. For example, lengths and widths of the components may be adjusted to accommodate the page size.
Proximal to the main barrel segment 32, there is a flexible adapter segment 36 that fits onto the mouthpiece of the inhaler. The adapter segment 36 is made as a pleated tube of silicone rubber with high flexibility. The hollow interior of the adapter segment 36 is continuous with that of the main barrel segment 32. A collar 38 on the adapter segment 36 is designed to fit snugly onto the mouthpiece of an inhaler. The functional purpose of the highly flexible adapter segment 36 is explained below with respect to
At the distal end of the aerosol chamber 31 is a flange 35 where the mouthpiece segment 34 connects. Mouthpiece segment 34 is also made as a corrugated tube. The mouthpiece segment 34 has a smaller diameter than the aerosol chamber 31. The distal tip of the mouthpiece segment 34 is a sturdy rim 37 for grasping when extending the mouthpiece segment outward. The sturdy rim 27 also helps to avoid flattening or crushing of the mouthpiece segment 34 when inside the user's mouth. The rim 37 could be made stiff by any suitable means, such as choice of harder materials, thicker wall, double wall, reinforcement (e.g. wire coils), or any other suitable manner.
Affixed to the adapter segment 36 is an elastic strap 40 for wrapping around the actuator 19 of the inhaler 10. Accompanying the spacer 30 as an accessory part is a mouthpiece cover 50, which comprises an elastic ring 52, leash 56, and a cap 54. The elastic ring 52 fits around the canister 12 of the inhaler 10 and the cap 54 fits over the mouthpiece 34 of spacer 30. There is further information below about the function of elastic strap 40 and mouthpiece cover 50.
The mouthpiece cover 50 is used to secure the mouthpiece 34 end of the spacer 30 to the inhaler 10. The elastic ring 52 is encircled around the canister 12. At the other end, the cap 54 is seated onto the mouthpiece 34 of the spacer 30. With these attachments, the spacer 30 is held in a compact configuration alongside inhaler 10. The pleats on the main barrel segment 32 and mouthpiece 34 are compressed to minimize the length of spacer 30. The adapter segment 36 is made to bend so that the main barrel segment 32 is aligned parallel and flush to the actuator 19. The gap “G” separating the main barrel segment 32 from the actuator 19 is about 0.2 cm.
As shown in
The narrow and extended length design of mouthpiece segment 34 adds flow resistance inside the hollow channel, thus slowing the inhalation flow rate. This helps to improve drug delivery to the lungs. Also, by reaching further into the user's mouth, the extended length design of mouthpiece segment 34 brings the distal end closer to the lungs, thereby improving the efficiency of drug delivery into the lung and reducing the deposition of aerosolized particles on the oropharynx 72 and upper airways.
There are a range of dimensions suitable for design of the spacer and its various segments.
The spacer and the metered dose inhaler may be provided in combination as an assembly, with the spacer as either a detachable component or a permanent attachment.
As seen in
As shown in
The inhaler 210 comprises a medication canister 212 held within an actuator body 219. The spacer device 230 further comprises a mounting bracket 296 and holder arms 294. The inhaler 210 is mounted onto the mounting bracket 296 and gripped in place by flexing holder arms 294. As seen in
A leash 256 is affixed to the forward shell 270 of the aerosol chamber 231. (Alternatively, the leash 256 could be affixed to mounting bracket 296.) The leash 256 holds the mouthpiece cap 254 that fits over the mouthpiece (not shown) of the spacer device 230. At the distal end of the aerosol chamber 231 is a mouthpiece (not shown) that is covered by a mouthpiece cap 254. Referring back to
The cut-away view of
The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Each of the disclosed aspects and embodiments of the invention may be considered individually or in combination with other aspects, embodiments, and variations of the invention. In addition, unless otherwise specified, the steps of the methods of the invention are not confined to any particular order of performance. Modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, and such modifications are within the scope of the invention.
Any use of the word “or” herein is intended to be inclusive and is equivalent to the expression “and/or,” unless the context clearly dictates otherwise. As such, for example, the expression “A or B” means A, or B, or both A and B. Similarly, for example, the expression “A, B, or C” means A, or B, or C, or any combination thereof.
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Entry |
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Search Report by the USPTO dated Aug. 18, 2020 for application PCT/US20/34428. |
Written Opinion by the USPTO dated Aug. 18, 2020 for application PCT/US20/34428. |
Number | Date | Country | |
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62852792 | May 2019 | US |
Number | Date | Country | |
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Parent | 16882449 | May 2020 | US |
Child | 16902367 | US |