Metered-dose valve for pharmaceutical aerosol

摘要

A medicinal aerosol product having a blockage resistant metered-dose valve with a metal valve stem, particularly for use with CFC-free solution formulations using hydrogen-containing propellants, such as 134a and/or 227, and ethanol. The valve stem (10) has a reduced internal volume (40) and a constant internal diameter as compared to conventional deep drawn stems. The valve stems are preferably composed of stainless steel containing at least 11.5 % chromium and are preferably fabricated by machining the outside of the stem and drilling the central outlet and side port. The stems are preferably bright annealed and/or treated with nitric or citric acid.