Metering valves used with pressurised dispensing containers

Abstract

The present invention relates to an improve in metering valves for pressurised dispensing containers. A metering valve for use with a pressurised dispensing container, the metering valve comprising a valve stem assembly co-axially slidable within an annular metering chamber defined between the valve stem assembly and a substantially cylindrical chamber body, the metering valve further comprising an outer seal extending between the valve stem assembly and the chamber body to seal off an outer duct of the valve stem assembly from the metering chamber when the valve stem assembly is in a non-dispensing position and an inner seal extending between the valve stem assembly and the chamber body. The valve stem assembly comprising a straight, central passage extending from an open inner end of the valve stem assembly to a mid-point of the valve stem assembly located longitudinally within the metering chamber. The valve stem assembly further comprises at least two elongated openings in a wall of the valve stem assembly to allow radially-directed flow between an exterior of the valve stem assembly and the central passage, the elongated openings being located to extend either side of the inner seal when the valve stem assembly is in the non-dispensing position.

Description

Metering valves for use with pressurized dispensing containers technical field This invention relates to improvements in metering valves for pressurized dispensing containers. Background technique Pressurized dispensing containers are used to dispense a wide variety of products from runny liquid products to viscous liquid products, powdered products, etc. A liquid propellant is used to propel the product through the valve. These pressurized dispensing containers are typically used to dispense medications. Conventional valves used with pressurized dispensing containers are typically metered valves comprising a valve stem coaxially slidable within a cavity defining an annular metering chamber. An "inner" ring seal and an "outer" ring seal respectively proximal and distal to the storage volume of the pressurized dispensing container are operable between the valve stem and the cavity to seal the metering chamber therebetween. The valve stem is generally movable against the...

AI Technical Summary

Problems solved by technology

Firstly, due to insufficient filling of the metering chamber 13', the initial dose dispensed from the metering valve when inverted may be inconsistent and deviate significantly from the prescribed dose

Second, insufficient discharge from the metering chamber may lead to uneven dose absorption by the metering chamber on the next actuation, as product from a previous actuation may remain in the chamber

This is especially a problem where two valve actuations are performed in close succession as required by many drug delivery modalities

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