|Title:||Device in powder inhalators|
|Abstract:||Device in a previously known powder inhalator intended for inhalation of an air flow which contains pharmacologically active compound in micronized form. The powder inhalator comprises a nozzle unit (2) with a nozzle aperture (2a) as well as a container unit (3) with a releasing or dosing unit (6) for delivering the active compound. The air flow generated by inhalation is at least partly aspirated through an air conduit (7) located in the container unit (3), which conduit extends from an air inlet (8), communicating with the environment, via said releasing or dosing unit (6), up to said nozzle unit (2). According to the invention, deflector devices are stationarily arranged in the container unit (3) and/or in the nozzle unit (2), said deflector devices, for example in the shape of a helical channel portion (13), being arranged to create a powerful deflecting movement for the purpose of disrupting said powder particles into the respirable particle size distribution (less than 5 .mu.m).|
|Inventor(s):||Wetterlin; Kjell I. L. (S Sandby, SE), Virtanen; Risto (Nurmijarvi, FI), Andersson; Jan A. R. (S Sandby, SE)|
|Assignee:||Aktiebolaget Draco (Lund, SE)|
1. In a powder inhalator for inhalation of an air flow generated at inhalation having a container containing a pharmacologically active compound in atomized or micronized form, a
conduit extending through the container and having an air inlet, means for delivering a dose of the compound to the conduit, an outlet from the conduit for outflow of the compound in an air flow admitted at least partly through the air inlet, and a
nozzle having a nozzle aperture and communicating with the conduit outlet, the conduit and nozzle together forming a channel for delivery of the compound upon inhalation, the improvement comprising deflector means in the channel for imparting a strong
deflecting and accelerating movement to the flow of air and compound through the channel relative to the axis of the channel, wherein the deflector means are stationarily affixed in the channel along at least one section thereof between the dose delivery
means and the nozzle aperture, the deflector means having at least a substantial radial extent towards the axis of the channel such that the radial extent of any open space along the axis of the channel adjacent the deflector means is small compared to
the radial extents of the deflector means, the deflector means thereby acting to promote disintegration of powder aggregations into particles within the respirable range by causing collisions of such aggregations with the deflector means and with each
2. The improvement according to claim 1, wherein the deflector means comprise deflector elements shaped and positioned to deflect the flow of air and compound rotationally with respect to the axis of the channel.
3. The improvement according to claim 2 wherein there is an open space along the axis of the channel adjacent the deflector means to lower the resistance to the flow of the air and compound.
4. The improvement according to claim 3 wherein the ratio of the radial extent of the open space to the radial extent of the deflector means is not greater than one to two.
5. The improvement according to claim 2 wherein the deflector means are shaped to define at least one helical portion along said section of the channel.
6. The improvement according to claim 5 wherein said section is in the nozzle adjacent the nozzle aperture.
7. The improvement according to claim 6 wherein a portion of the nozzle upstream from said section, relative to the direction of flow of air and compound through the channel, has a continuous diminishing cross-sectional area so as to increase the velocity of the flow of air and compound.
8. The improvement according to claim 5 wherein said section is located in the conduit between the dose delivery means and the conduit outlet.
9. The improvement according to claim 5 wherein the cross-sectional area of the helical portion is between five square millimeters and fifty square millimeters and the length of said portion is between five millimeters and fifty millimeters.
10. The improvement according to claim 4 wherein there is at least one air inlet to the channel between the dose delivery means and the nozzle for aspiration of dilution air into the flow of air and compound.