Surgery – Respiratory method or device – Means for mixing treating agent with respiratory gas
Reexamination Certificate
1999-07-07
2001-11-27
Weiss, John G. (Department: 3761)
Surgery
Respiratory method or device
Means for mixing treating agent with respiratory gas
C128S203190, C222S499000
Reexamination Certificate
active
06321747
ABSTRACT:
This invention relates to an inhalation device by means of which metered doses of medicament in the form of a powder can be dispersed to a user. In particular it relates to a device of the type in which the medicament powder is held in bulk in a reservoir with which the device is provided, and is metered to the user from the reservoir.
International Patent Application Publication No. WO 96/08284 describes an inhalation device of the type just described, comprising a body defining a reservoir for medicaments in powder form, an outlet through which a user can inhale and a dosing member with at least one metering recess formed therein. The dosing member is moveable between a first position in which the metering recess communicates with the reservoir to receive a dose of powder therefrom and a second position in which the metering recess communicates with the outlet to permit the user to inhale the dose. The metering recess is formed in a smooth flat face of the dosing member which is mounted in contact against a similar flat face of the body at the lower end of the reservoir. The contacting flat faces are made of a hard material having highly polished smooth surfaces which form an effective dynamic seal between the dosing member and body to prevent both loss of powder from and ingression of moisture into the reservoir through the interface between the base and dosing member.
In order to provide the desired sealing characteristics both contacting surfaces must be lapped and polished to ensure very closely matching contours and a high degree of smoothness. Any slight undulation of contour or roughness of finish in either of the contacting surfaces would impair the sealing characteristics. Thus, the precision of finish required on these surfaces demands accurate lapping and polishing operations which add considerably to manufacturing costs.
It is an object to provide a device of the type just described employing an effective dynamic seal which is cheaper and easier to produce.
According to the present invention there is provided an inhalation device comprising a body defining a reservoir for medicament in the form of a powder, an outlet through which a user can inhale, and a dosing member with at least one metering recess formed therein, the dosing member being moveable between a first position in which the at least one metering recess communicates with the reservoir to receive a dose of powder therefrom and a second position in which the at least one metering recess communicates with the outlet to permit the user to inhale the dose, the at least one metering recess being formed in a face of the dosing member, the face being urged into contact against a similar mating face of the body at the lower end of the reservoir to form a dynamic seal, characterised in that at least one of the faces is made of a flexible material having a hardness of less than 80 Shore A. The term ‘dynamic seal’ in this context means a seal that allows and can withstand relative movement of the two faces.
By having at least one of the sealing faces made of a flexible material it is not necessary for either of the faces to have a precision finish to ensure very closely matching contours since the flexible material will compensate for any undulations to maintain an effective seal.
Preferably the flexible material has a coefficient of friction of 0.4 or less. By use of a material having a low coefficient of friction the faces will move smoothly and easily over each other so aiding smooth operation of the device.
Suitably the faces are flat.
Suitably the mating face of the body is made of a flexible material. Preferably the mating face of the body comprises a rubber insert. Suitably, the rubber insert has a hardness between 40 and 60 Shore A.
Preferably the rubber insert comprises chlorinated butyl or butyl laminated with a contacting face made of a layer of PTFE, polypropylene or polyethylene.
Suitably the face of the dosing member is of unitary construction with the dosing member.
REFERENCES:
patent: 3662915 (1972-05-01), Destler, Jr.
patent: 4762248 (1988-08-01), Uhlig
patent: 5331953 (1994-07-01), Andersson et al.
patent: 5394868 (1995-03-01), Ambrosio et al.
patent: 5421482 (1995-06-01), Garby et al.
patent: 5524613 (1996-06-01), Haber et al.
patent: 5611444 (1997-03-01), Garby et al.
patent: 5687710 (1997-11-01), Ambrosio et al.
patent: 5718355 (1998-02-01), Garby et al.
patent: 5740792 (1998-04-01), Ashley et al.
patent: 5799651 (1998-09-01), Garby et al.
patent: 5829434 (1998-11-01), Ambrosio et al.
patent: 6065471 (2000-05-01), Schaeffer et al.
patent: FR 1 587 657 A (1970-03-01), None
patent: WO94 11044 A (1994-05-01), None
patent: WO96 08284 A (1996-03-01), None
Brand Peter John
Buday-Goldberger David
Dmitrovic Bosko
Rand Paul Kenneth
Seguelas Etienne
Riek James P.
SmithKline Beecham Corporation
Weiss John G.
Weiss, Jr. Joseph F.
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