Surgery – Respiratory method or device – Means for mixing treating agent with respiratory gas
Reexamination Certificate
2001-01-31
2004-04-06
Lewis, Aaron J. (Department: 3761)
Surgery
Respiratory method or device
Means for mixing treating agent with respiratory gas
C128S203120, C604S058000
Reexamination Certificate
active
06715486
ABSTRACT:
The field of the invention is inhalers.
BACKGROUND OF THE INVENTION
Inhalers are used to deliver drugs into a patient's lungs. Typically, an inhaler contains or provides a mixture of drug particles and air or propellant gas. The mixture is delivered via the patient inhaling from a mouthpiece on the inhaler with the air or propellant gas carrying the drug particles into the patient's lungs.
In dry powder inhalers, the drug particles, in the form of a fine dry powder, are entrained into an airflow, and inhaled by the patient, for treatment for various conditions, for example, bronchial asthma. Drugs delivered via a dry powder inhaler can be used to treat many conditions, including those unrelated to lung conditions, via the systemic absorption of the drug into the bloodstream, via the lung.
For effective dose delivery using a dry powder inhaler, the powder particles must first be dispersed to form a powder/air aerosol. Various techniques for forming powder aerosols have been proposed. Some of these techniques use the airflow from the patient's inspiration alone to disperse the powder. Other techniques involve forming a powder aerosol by spinning a propeller within a chamber; generating a fast moving flow of air over or through the powder; and shaking, vibrating, or impacting a powder laden string, tape, or mesh, using mechanical devices or ultrasonics. In addition, various other techniques for generating powder aerosols have been proposed or used, with varying degrees of success. Challenges remain in achieving a dry powder inhaler which can effectively create a dry powder aerosol for inhalation, while also having advantages in other areas, such as effectiveness in creating an aerosol, reliability, complexity of design, costs, ergonomics, dose consistency, etc.
Accordingly, it is an object of the invention to provide an improved dry powder inhaler.
SUMMARY OF THE INVENTION
To these ends, in a first aspect, a dry powder inhaler has a dispersion chamber including a bead race. A nosepiece or mouthpiece has at least one outlet opening connecting or entering into the dispersion chamber. One or more inlets also connect into the dispersion chamber. The dispersion chamber contains one or more beads which can move about in the bead race. A powder formulation containing smaller active pharmaceutical particles, and optionally also containing larger inert carrier particles, is placed into or adjacent to the chamber.
When a patient inhales on the mouthpiece, air and powder are drawn into, or flow about within, the dispersion chamber. The beads collide with the interior chamber surfaces, and/or each other, and the powder particles on the chamber surfaces or on the beads. The movement of the beads separate the smaller active drug particles from each other and/or the larger inert carrier particles, if any. In addition to these mechanical forces, other causes of dispersion may include fluid shear between the beads, the powder particles, and the chamber walls. Larger carrier particles, if included in the powder formulation, can further enhance dispersion via enhanced impact energy and abrasion. The active particles are entrained into the airflow through the dispersion chamber, for inhalation by the patient. The larger inert or excipient carrier particles may or may not be entrained and inhaled. The carrier particles are advantageously provided to scour the powder path clean of the fine active particles, so that a more uniform dose may be delivered.
In second and separate aspect of the invention, the beads within the dispersion chamber are induced to move chaotically, so that most or all of the interior surfaces of the dispersion chamber, and the surfaces of the beads are contacted. As a result, less of the powder may be held up within the dispersion chamber, and a more uniform dose may be delivered. Flow rate performance may also be improved.
In a third and separate aspect of the invention, the flow resistance of a dry powder inhaler is reduced by providing one or more beads into the air flow path of the inhaler. As a result, improved dispersion of powder is achieved, with no additional inspiratory effort by the patient.
A dispersion chamber is a chamber or confined area wherein dry powder is dispersed and/or mixed with air. The dispersion chamber may be the only location where powder is dispersed, or it may be one of two or more such locations or powder dispersing or deagglomerizing features. A bead is a loose component not physically attached to any other component or surface of the inhaler, so that it is free to move within the inhaler, with at least one degree of freedom. A bead race is a surface, which a bead contacts, continuously or intermittently. A bead race may be a well-defined or consistent path in or on which beads uniformly move about, or it may be a surface not part of such a path.
The invention resides as well in subcombinations of the components, features, and steps described. While the drawings and written description may disclose features and components in connection with a specific embodiment, the features and components described below may be used, along or in combinations, with any embodiment.
REFERENCES:
patent: 2470296 (1949-05-01), Fields
patent: 2470297 (1949-05-01), Fields
patent: 2534636 (1950-12-01), Stirn
patent: 2816549 (1957-12-01), Webster
patent: 3362405 (1968-01-01), Hazel
patent: 3809084 (1974-05-01), Hansen
patent: 3861210 (1975-01-01), Giverus
patent: 4452239 (1984-06-01), Malem
patent: 4509515 (1985-04-01), Altounyan et al.
patent: 4790305 (1988-12-01), Zoltan et al.
patent: 4841964 (1989-06-01), Hurka et al.
patent: 4860740 (1989-08-01), Kirk et al.
patent: 5042472 (1991-08-01), Bunin
patent: 5048514 (1991-09-01), Ramella
patent: 5492112 (1996-02-01), Mecikalski et al.
patent: 5522383 (1996-06-01), Calvert et al.
patent: 5596982 (1997-01-01), Blaha-Schnabel
patent: 5619984 (1997-04-01), Hodson et al.
patent: 5642727 (1997-07-01), Datta et al.
patent: 5714007 (1998-02-01), Pletcher et al.
patent: 5797391 (1998-08-01), Cook et al.
patent: 6007630 (1999-12-01), Pletcher et al.
patent: 6063194 (2000-05-01), Poliniak et al.
patent: 6073629 (2000-06-01), Hardy et al.
patent: 6074688 (2000-06-01), Pletcher et al.
patent: 6089227 (2000-07-01), Nilsson
patent: 6096368 (2000-08-01), Sun
patent: 6125998 (2000-10-01), Batista
patent: 6230707 (2001-05-01), Horlin
patent: 6418926 (2002-07-01), Chawla
patent: 0 407 028 (1990-05-01), None
patent: 0 407 028 (1990-05-01), None
patent: 0 504 459 (1992-09-01), None
patent: 2 352 556 (1977-12-01), None
patent: 654860 (1951-07-01), None
patent: 2 179 260 (1987-03-01), None
patent: 7509342-7 (1983-07-01), None
patent: WO 90/15635 (1990-12-01), None
patent: WO 95/03846 (1995-02-01), None
Chen Jeffrey
Ganem Charles
Gieschen Andrew W.
Greenspan Bernard
Ligotke Michael
Lewis Aaron J.
Patel Mital
Perkins Coie LLP
Quadrant Technologies Limited
LandOfFree
Dry powder inhaler does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dry powder inhaler, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dry powder inhaler will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3241537