UNIT DOSE CARTRIDGE AND DRY POWDER INHALER
A dry powder inhaler having improved aerodynamic properties for diluting, dispersing, and metering drug particles for increasing the efficiency of pulmonary drug delivery to a patient is described. The inhaler comprises, in general, a housing having an air intake, an airflow-control/check-valve, a mixing section and a mouthpiece. A cartridge loaded with a single dose of medicament can be installed in the mixing section.
This application is a continuation of co-pending U.S. utility patent application Ser. No. 13/490,292, filed Jun. 6, 2012, which is a continuation of U.S. Ser. No. 12/102,625, filed Apr. 14, 2008, now U.S. Pat. No. 8,215,300, which is a continuation of U.S. Ser. No. 10/655,153 filed Sep. 4, 2003, now U.S. Pat. No. 7,464,706, which is a continuation-in-part of U.S. Ser. No. 09/621,092, filed Jul. 21, 2000, now U.S. Pat. No. 7,305,986, which claims priority from U.S. provisional application Ser. No. 60/145,464 filed Jul. 23, 1999, and No. 60/206,123 filed May 22, 2000, all of which are incorporated herein by reference in their entirety.FIELD OF THE INVENTION
The present invention is in the field of drug administration inhalers having improved control over system volumetric airflow rate, medicament particle transport, particle dispersion, particle metered dosimetry and patient compliance.BACKGROUND OF THE INVENTION
In the early 1970's it was found that certain medicines could be administered in dry-powder form directly to the lungs by inhalation through the mouth or inspiration through the nose. This process allows the medicine to bypass the digestive system, and may, in certain cases, allow smaller dosages to be used to achieve the same results as orally ingested or injected medicines. In some cases, it provides a delivery technique that reduces side effects for medicines and interactions with other prescribed medicines, as well as providing a more rapid drug medication uptake.
Inhaler devices typically deliver medicine in a liquid droplet mist or as a dry powder aerosol. Deposition of particulate matter within the human lungs is a very complex and not fully understood phenomenon. People breathe over a relatively broad tidal volume. It is known that lower transport velocities of gas-entrained particles entering the mouth avoid impaction better within the oropharyngeal cavity. This is particularly true of particles greater than one to two microns in diameter.
In order for particles to remain suspended in a gas stream, their superficial transport velocity must be greater than their gravity settling velocity. For example, a 100 micron particle must have a transport gas velocity of approximately 7 ft/sec or greater for the 100 micron particle to remain in a particle/gas entrainment state. The required transport velocity for smaller particles is much less High speed particles have a greater propensity to impact and deposit on the tissue lining of the oropharyngeal cavity, as noted above. Thus, a significant number of particles are lost and will not enter the lungs, if those particles are not transported at the correct velocity.
Another common problem with inhalers is that the particles agglomerate, causing clumping of particles that then adhere to the inhaler or the oral cavity, rather than entering the lungs. Most approaches to this problem have been to include a surfactant in, on or with the particles to decrease the adhesion between particles.
Importantly, it should not be difficult for a patient to load the inhaler with medicine, and to easily and properly use the inhaler so that the correct dosage is actually administered. Many current dry particle inhalers fail in one or more of these important criteria.
It is therefore an object of the present invention to provide inhalers which are easy to properly use, and which deliver drug powders so that the powder enters the lungs instead of adhering to the back of the throat.
It is an object of the invention to provide an inhaler which will operate effectively with dry powder medicaments having particles ranging in size from about 0.5 to about 10 microns, and preferably from about 1 to about 5 microns in size.
It is a further object of the present invention to provide an inhaler that can operate effectively over a broad inhalation tidal volume range of human breath.
It is a still further object of the present invention to provide an inhaler which controls the volume and velocity of airflow so as to provide effective and desirable colimation, de-agglomeration and entrainment of the inhaled drug.
A related object is to provide an inhaler which creates a high-shear airflow field and controlled circulating gas action to break up particle agglomeration during proper inhaler usage.
A more specific object is to provide an inhaler mouthpiece which is sized and shaped to develop an airflow which will air stream entrained medicament particles through the oropharyngeal cavity.
Another specific object is to provide a medicament-containing inhaler cartridge which will supply medicament for complete air entrainment and proper dispersion into the air stream.
Yet another object is to provide an inhaler airflow-controlling check valve which will straighten the airflow and limit the airflow volume and velocity to values between pre-determined maxima and minima so as to properly entrain, de-agglomerate and deliver medicament particles to the inhaler user.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals refer to like parts.SUMMARY OF THE INVENTION
A dry powder inhaler (DPI) includes an air intake and check valve section; a mixing and cartridge section; and a mouthpiece all designed to control the volume and velocity of the inhaled air and aerosolized drug. This inhaler can be operated over a very broad inhalation tidal volume range of human breath. Several features of the inhaler provide advantageous properties, most significantly with respect to using carefully designated aerodynamic forces to dilute and de-agglomerate the medicament particles, rather than using broad high pressure forces that would contribute to relatively great particle losses in the oropharyngeal region.
The inhaler intake chamber mounts a check valve bulb having a tapered bulb, bulb travel rod and biasing spring, and one or more perimeter chutes or venturis on the bulb to modulate and control the flow of air through the device. The intake further optionally includes a feedback module (not shown) to generate a tone indicating to the user when the adequate inhalation airflow rate has been achieved.
The inhaler mixing section holds a cartridge containing a dry powder medicament. The cartridge has two telescopically assembled halves, and each half has an air inlet hole or orifice-port and an air outlet hole or orifice-port. When the halves are twisted so as to align the air holes, the air stream from the check valve enters the cartridge and then picks up, fluidizes and de-agglomerates the medicament powder in the cartridge. The airflow entraining the particles then exits the cartridge and flows through the mouthpiece to the inhaler user. The cover on the mixing section can open only when the mouthpiece is at an appropriate pre-determined angle to the intake conduit. The mixing section helps to impart a cyclonic flow to air passing through the mixing chamber and cartridge.
An important feature of the inhaler is the mouthpiece. The mouthpiece is integrated to the swivel joint of the mixing section, and can be rotated back into the inhaler intake section and then enclosed by a cover for storage. A mouthpiece transport conduit has the ability to expand the cross-section of the airflow, which in turn reduces the velocity of approach of the drug powder into the oral cavity. As shown in
The mouthpiece expansion wall divergence angle is important for stable particle transport conditions to exist. An optimum divergence angle is between 14 and 16 degrees. However, a slightly larger 17 degree divergence angle can be used to achieve a horizontal aerosol discharge path with a 3:1 aspect ratio closely approximating the aspect ratio at the rear of the human throat. Once the expansion divergence has reached a specified limit, the continuing slot discharge tube maintains the proper collimation of the particles for controlled particle injection speed and direction of the path of the particles into the oral cavity. The mouthpiece includes a tongue depressor, and a tactile protrusion to contact the lips of the user to tell the user that the Dry Powder Inhaler (DPI) is in the correct position.
The cartridge halves can be twisted into and out of positions in which the air inlet holes and the air outlet holes are respectively aligned. The cartridge can only be inserted into the mixing chamber when a cartridge alignment boss is aligned with a receiving recess at the bottom of the mixing chamber, and a cartridge collar and engages a mating mixing chamber collar (
While the invention will be described in connection with several preferred embodiments and procedures, it will be understood that it is not intended to limit the invention to these embodiments and procedures. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.DETAILED DESCRIPTION OF THE INVENTION
An improved inhaler has been developed which has several novel features optimizing performance. Medicament particles can be delivered/administered over a broad range of inhalation velocity and tidal volume of human breath. An inhaler mouthpiece exit tube dilutes, expands, and collimates the particle dispersoid so that the particles do not re-agglomerate during delivery. This inhaler provides the means to effect a process whereby particles are fluidized, suspended, then scavenged from the walls by re-circulating scrubbing air, as well as higher speed-flow-through air, followed by a high-shear flow field discharge into an expanded, slower-moving mass of air that disperses and meters the particle concentration expelled from the unit dose cartridge upper outlet port.
An air passage 50 (
Aerosolized powder is drawn from the cartridge 301 and mixing section 30 through the mouthpiece 40 to the users' oropharangeal cavity via the mouthpiece 40. As air and powder travel through the mouthpiece, the velocity of the travel slows, thus preparing the powder for effective delivery to the inhaler user's broncheal tract and lungs.
So that writing or identifying indicia on medicament-containing cartridge 301 can be read easily, the mixing section 30 has a cap 352 which may be configured as a transparent magnifying lens. An arrow 460 (
Air is caused to enter the inhaler by an inhalation effort which the inhaler user exerts on and in the mouthpiece 40. As shown particularly in
When the inhaler user draws air through the mouthpiece 40, air flows to and around the bulb 184, and the imbalance of air pressure forces acting upon the reciprocating bulb 184 pushes the bulb in a downstream direction along the rod 182 into positions which inhibits airflow. Because the bulb 184 is mounted to the tension spring 185, increasing amounts of force are required to draw the bulb 184 into increasingly airflow-restricting positions. Additional bulb movement control can be provided, if desired, by an opposing second spring (not shown) forming a high-sensitivity push-pull system.
This bulb and spring mechanism allow the inhaler user to generate a slight partial vacuum in his lungs before the bulb is drawn away from the seating arrangement. Thus, by the time significant vacuum is generated, a slight velocity increase of airflow through the inhaler assists in drawing the medicament from the cartridge (FIGS. 1 and 17-19), through the inhaler and into the bronchial region and lungs of the user.
As suggested particularly in
When air is being drawn through the inhaler 10 and the bulb 184 is drawn along the rod 182 so as to impact the conical head 181, a clicking sound is produced. In accordance with one aspect of the invention, this clicking sound indicates to the inhaler user that he or she is drawing properly upon the mouthpiece and operating the inhaler correctly. If desired, a vibratory mechanical reed (not shown) can be mounted in the airflow path to produce an audible signal to the user. Alternatively, an electronic flow or pressure sensor can trigger an audible or visual signal indicator to tell the user that proper airflow has been established.
This airflow-control/check-valve system 180 serves to deliver air at a predetermined volume and velocity to downstream inhaler parts. The airflow, at this predetermined volume and velocity, acts to pick-up, fluidize, de-agglomerate and deliver entrained medicament particles to the inhaler user in a dispersed form and at a proper location to enter the user's bronchial system.
Venturi and Mixing Section
As suggested particularly in
In general, the mixing section 30 is provided with shapes on its interior surface to encourage airflow acceleration so as to suspend medicament particles in the airflow and to de-agglomerate them. Within the cup 32 a medicament-containing cartridge 301 can be mounted. As more fully described below, the cartridge 301 is provided with air inlet and outlet holes (
As suggested in
Alternatively, a chamber which includes internal protrusions or spiral shapes can be provided. The interior surfaces of the mixing chamber can be shaped to provide one or more helical flows of air around and within the cartridge, if desired.
The cartridge 301 is shown in further detail in
The upper cartridge half 302 defines an air inlet hole 306 and an outlet hole 307, and the cartridge lower half defines a corresponding air inlet hole 308 and an air outlet hole 309. This upper half can be made of a clear very low water absorbent nylon. As shown particularly in
As suggested particularly in
This cartridge 301 is approximately one-quarter inch in diameter and its body is approximately 1 inch in axial length, and so to facilitate easy installation and extraction from the inhaler 10, a handle or manipulator structure 314 is provided atop the cartridge 301. Here, the handle structure 314 comprises four web extensions 315 which extend from the cartridge body to a finger disk 316 which may have a coined or serrated periphery. A pointer or dial indicator 317 is formed atop the disk 316 and is further discussed below.
At the bottom of the cartridge 301, a cartridge installation check boss 319 is formed. In accordance with another aspect of the invention, this check boss can have a unique, non-circular shape of any desired form such as those shown in
Cartridge Mounting Mechanism
To properly mount the cartridge 301 in the inhaler 10, a mounting mechanism 350 is provided as especially shown in
The cartridge can be installed and the cap 352 secured in place when the mouthpiece 40 and cartridge are pivoted into their operating positions. To this end, a radially outwardly biased lock pin 356 (
After the cartridge is inserted into the inhaler and the cap is closed, the mouthpiece 40 can be pivoted out of its cartridge installation and cap release position as shown in
As suggested above, the mouthpiece 40 discharges particle-laden air to the oropharyngeal cavity of the user. In addition, the mouthpiece diverges the air and particle stream to slow down the particles, and then converges the particle stream to collimate and aim the particles at the rear of the user's mouth. The mouthpiece is long enough so that it extends approximately midway into most users' mouths. To encourage correct inhaler and mouthpiece usage, the inhaler mouthpiece is oriented so as to extend diagonally upwardly at approximately a 3 degree angle X as suggested in
In use, the inhaler employs a regulated flow of air to fluidize and aerosolize medicament particles and transport them to the desired rear region of the orophalangeal cavity. To accomplish this, air is first drawn into the interior of the inhaler housing 15 and through the intake ports 172 as suggested in
1. An inhaler comprising:
- a mixing cavity adapted to mount a medicament-containing cartridge, wherein airflow exiting the medicament-containing cartridge during an inhalation is configured to meet a shearing flow.
2. The inhaler of claim 1, wherein the medicament-containing cartridge includes a drug powder.
3. The inhaler of claim 1, wherein the shearing flow is from airflow that does not flow through the medicament-containing cartridge.
4. The inhaler of claim 1, wherein the shearing flow is from cartridge bypass airflow.
5. The inhaler of claim 1, further comprising a mouthpiece.
6. The inhaler of claim 5, wherein the mouthpiece includes a transport conduit with an expansion wall having a divergence angle configured to create a horizontal discharge path.
7. The inhaler of claim 6, wherein the horizontal discharge path has a 3:1 aspect ratio.
8. The inhaler of claim 6, wherein the divergence angle is about 3 degrees.
9. The inhaler of claim 5, wherein the mouthpiece is configured to diverge an air stream of particles when the inhaler is in use.
10. The inhaler of claim 5, wherein the mouthpiece is configured to converge an air stream of particles when the inhaler is in use.
11. The inhaler of claim 5, wherein the mouthpiece is configured to converge an air stream of particles to aim the particles when the inhaler is in use.
12. The inhaler of claim 5, wherein the mouthpiece is connected to the mixing cavity by a joint.
13. An inhaler comprising:
- an air pathway configured to generate a shearing flow, wherein the shearing flow is directed to meet airflow exiting a medicament-containing cartridge during an inhalation.
14. The inhaler of claim 13, wherein the medicament-containing cartridge includes a drug powder.
15. The inhaler of claim 13, wherein the shearing flow is from airflow that does not flow through the medicament-containing cartridge.
16. The inhaler of claim 13, wherein the shearing flow is from cartridge bypass airflow.
17. The inhaler of claim 13, further comprising a mouthpiece connected to a mixing section by a joint.
18. The inhaler of claim 17, wherein the mouthpiece is configured to diverge an air stream of particles when the inhaler is in use.
19. The inhaler of claim 17, wherein the mouthpiece is configured to converge an air stream of particles when the inhaler is in use.
20. The inhaler of claim 13, wherein the inhaler is a dry powder inhaler.
Filed: Jan 8, 2015
Publication Date: May 7, 2015
Inventors: Solomon S. Steiner (Mount Kisco, NY), Trent A. Poole (South Amherst, MA), Per B. Fog (Bedford Hills, NY), Roderike Pohl (Sherman, CT), Michael Crick (Middlebury, CT), Robert Feldstein (Yonkers, NY)
Application Number: 14/592,790
International Classification: A61M 15/00 (20060101);