GB1295081A - A method and device for dispensing particulate medicament material from a container - Google Patents

Abstract

1295081 Dispersing medicaments FISONS PHARMAOEUTICALS Ltd 18 Dec 1969 [8 Jan 1969 16 May 1969] 1206/69 and 25069/69 Heading AST [Also in Division B2] A method for dispensing a particulate medicament from a container having one or more outlets comprises pneumatically rotating the container about an axis thereof which axis is caused to precess, points on the wall of the container undergoing repeated changes in radial acceleration with respect to the axis of precession causing the medicament particles to migrate to and through the outlet(s). The motion of a point on the container wall is a trochoidal path consisting of cusps joined by nodes. The number of nodes occurring per rotation of the container axis about the precession axis is preferably 2 to 25, in particular 3 to 10. The rotational axis describes a path contained within a cone or frusto-cone having an included angle which is preferably 0.5� to 60�, particularly 1� to 5�. A Dispensing Device for use in performing the above method comprises a housing having two snap-fit parts 1, 2 and enclosing a perforated capsule-type powder container 9 supported on a rotary member rotated by flow of air past one or more vanes 8. The container may alternatively be continuously fed with powder from a reservoir. The air may be supplied by a squeeze bulb via opening 4 for depositing antibiotic powders on a wound or skin infection, for example, or by inhalation via opening 3 by a person using the device as an inhaler. The rotary member may comprise a shaft 7 in a stationary bearing 5 having a greater internal diameter adjacent opening 3 than near vane 8 so that the axes of shaft 7 and bearing 5 are inclined. Alternative forms of bearing assembly for the rotary member comprise for example:- a tapered rotary shaft in a blind cylindrical bore of a stationary bearing, Fig. 2 (not shown); a stationary tapered bearing pin engaging in a blind cylindrical bore in a rotary shaft, Fig. 3 (not shown); a cylindrical rotary shaft engaging in a bearing having a frusto-conical bearing surface, the end of the shaft remote from the container engaging the wider end of the bearing surface, Fig. 4 (not shown); a shaft in two parts (17), (19), Figs. 5, 6 (not shown), joined by a universal joint (18), part (19) supporting the container and vane and having an annular part with a bearing surface engaging the internal surface, Fig. 5, or external surface, Fig. 6, of a stationary annular bearing, shaft (17) being a relatively tight fit in a ball race (16); or a flexible rotary shaft, which may have a polygonal cross section, replacing shafts (17), (19) of the last two embodiments. All forms of rotary member and bearing assembly have a region where the rotary member is a relatively loose fit in the bearing assembly and preferably makes a frictional rolling contact thereat, and a region of relatively tight fit which may be a sliding contact between the rotary member and bearing. To prevent the driving air flow passing directly over container 9 the latter may be enclosed in a shroud, or the vane or vanes may be located in a part of the housing separated from a part enclosing the container.