Metered-dose inhalers, I: Drug content and particle size distribution of beclomethasone dipropionate.

Four commercially available beclomethasone metered dose inhalers were analyzed for both spray content uniformity and particle size. The drug contents of primed and unprimed sprays collected at the beginning of the lifetime of the canister were not significantly different from those collected throughout the experiment. Particle size analysis of the four products using the Andersen Cascade Impactor Mark II showed that the distribution profiles were not identical. An existing HPLC method was modified to quantitate single sprays for content uniformity and to measure the amount on an impactor stage for particle sizing.