Surgery – Respiratory method or device – Means for mixing treating agent with respiratory gas
Reexamination Certificate
1998-07-24
2001-10-23
Weiss, John G. (Department: 3761)
Surgery
Respiratory method or device
Means for mixing treating agent with respiratory gas
C128S200140, C128S200230
Reexamination Certificate
active
06305371
ABSTRACT:
The present invention relates to an inhaler for administering medicament by inhalation and a method of manufacturing a housing of the same.
BACKGROUND OF THE INVENTION
Various kinds of inhaler are known for delivering metered doses of medicament for inhalation. Typically, pressurized liquid systems and dry powder systems are used to deliver medicament to a patient. In one pressurized liquid system a liquid containing medicament is stored in a pressurized container and a metered dose is delivered as an aerosol by a pressurized metered dose inhaler. In dry powder systems powder containing medicament is stored in individual blisters, on tape or in bulk in a chamber and a metered dose is provided by a dry powder inhaler.
All such inhalers include parts which come into contact with medicament and parts, some in common with the parts which come into contact with medicament, which come into contact with the mouth or nose of a user. It will be appreciated that it is important to ensure that those parts do not have any adverse effect on either the medicament or the user.
It is an aim of the present invention to provide an improved inhaler and a method of manufacturing a housing of the same in view of this requirement.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides an inhaler for administering medicament by inhalation, including a housing formed as a single-piece molding having a first portion which, in normal use, comes into contact with medicament and the mouth or nose of a user through which medicament is inhaled and a second portion which defines at least part of the outer surface of the housing and, in normal use, does not come into contact with medicament or the mouth or nose of a user through which medicament is inhaled, wherein the material constitution of at least part of the second portion defining at least part of the outer surface of the housing is different to the material constitution of the first portion.
The at least part of the second portion can have many different material constitutions, for instance in including a coloring pigment for identifying the medicament to be administered and/or being formed of a rubberized material to provide for improved grip.
In this way, a range of housings having a single basic design can be developed for use with different medicaments. This approach has the particular advantage that, because the second portion of each of the housings does not come into contact with medicament or the mouth or nose of a user and the first portion of each of the housings is formed of the same material, in many countries throughout the world it is only be necessary to obtain regulatory approval for one housing in the entire range.
Preferably, other than a coloring pigment in the at least part of the second portion, the first and second portions have generally the same material constitution. Where the first and second portions are formed of polymeric materials, those portions are in a preferred embodiment formed of the same polymeric material even if of a different grade. In this way, the molding of the housing is simplified, since the first and second portions of the housing will bond together more readily and the problems associated with using materials having different thermal expansion characteristics are avoided. In practice, the coloring pigment in the at least part of the second portion is conveniently provided from a master batch which includes pigment, a polymer base or carrier (which may be different to the basic polymeric material of the first and second portions) and processing aids such as lubricants and dispersion agents.
Preferably, the first portion has a relatively simple material constitution, in particular without a coloring pigment. In this way, the risk of chemical leaching from the first portion is minimized.
The present invention also provides a method of manufacturing a housing of an inhaler for administering medicament by inhalation having a first portion which, in normal use, comes into contact with medicament and the mouth or nose of a user through which medicament is inhaled and a second protion which defines at least part of the outer surface of the housing and, in normal use, does not come into contact with medicament or the mouth or nose of a user through which medicament is inhaled, the method comprising the step of molding the first and second portions as a single piece, wherein at least part of the second portion defining at least part of the outer surface of the housing is formed of a material of different constitution to that of the first portion.
Preferably, the material for the at least part of the second portion is successively introduced into a mold with respect to the material for the first portion and the remainder of the second portion.
Alternatively, the housing may be moulded by insert molding. That is, material is introduced into a first mold to form part of the housing and then that part is transferred to another mold into which another material is introduced to complete the housing. In this way, the first portion of the housing which comes into contact both with medicament and the mouth or nose of a user is formed of a material suited for the medical purpose and for which regulatory approval has already been obtained, whilst the at least part of the second portion is formed from another material of different constitution.
By providing the housing as a single-piece molding the housing is more robust than a housing formed of separate components. Moreover, it is impossible for a user to tamper with the housing. If the first and second portions of the housing were to be provided by separate components it would be open to a user to interchange parts from one housing for use with one medicament with parts from another housing for use with another medicament which would lead to cross-contamination. Furthermore, the housing is less expensive to manufacture as a single-piece molding than as separate moldings which would have to be assembled.
The present invention recognises for the first time that multi-part molding techniques may be applied in this field with particular advantages, specifically relating to the conflicting demands of material contact with medicament and the mouth or nose of a user in some parts of the housing and desired variation in other parts of the housing.
It will be appreciated that the method of manufacture of the present invention is not limited to two-stage molding and the housing may have many parts formed integrally from different material constitutions.
In a preferred embodiment the inhaler is a pressurized metered dose inhaler and the housing is the actuator of the pressurized metered dose inhaler.
REFERENCES:
patent: 3636949 (1972-01-01), Kropp
patent: 4765348 (1988-08-01), Honeycutt
patent: 5135141 (1992-08-01), Harmer et al.
patent: 5460171 (1995-10-01), Pesenti et al.
patent: 5533498 (1996-07-01), Sioutas
patent: 5544647 (1996-08-01), Jewett et al.
patent: 5704344 (1998-01-01), Cole
patent: 5785216 (1998-07-01), Gouldson et al.
patent: 5797392 (1998-08-01), Keldmann et al.
patent: 5814252 (1998-09-01), Gouldson et al.
patent: 5839429 (1998-11-01), Marnfeldt et al.
patent: 5941241 (1999-08-01), Weinstein et al.
patent: 5975127 (1999-11-01), Dray
patent: 6085950 (2000-07-01), Gouldson et al.
patent: 0 360 463 (1990-03-01), None
patent: 91/19524 (1991-12-01), None
patent: 96/26755 (1996-09-01), None
Frid Per
Jansen Robert
Wright Paul
Astrazeneca AB
Nixon & Vanderhye
Weiss John G.
Weiss, Jr. Joseph F.
LandOfFree
Inhalation for administering medicament by inhalation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Inhalation for administering medicament by inhalation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Inhalation for administering medicament by inhalation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2577219