Antiinflammatory steroid e.g. beclomethasone crystal growth inhibition - in chlorofluorinated aerosol propellants by crystallisation from ethyl acetate and micronising of resulting crystals (NL 2.12.80)

摘要

In a new procedure for the conversion of an antiinflammatory steroid which undergoes crystal growth in chlorofluorinated aerosol propellants into a crystalline form which is not susceptible to this crystal growth, the steroid is crystallised from ethyl acetate and the prod. obtd. is micronised. New antiinflammatory steroid aerosol preparations contain a steroid which has been subjected to the above procedure. The new procedure prevents steroid crystal growth to a size (>20 mu) unsuitable for administration by inhalation. The procedure is simple, proceeds in almost 100% yield, and avoids the use of toxic materials (ethyl acetate has a rat LD50 of 11.3 g/kg. p.o., and gives no toxic effects when administered to rats and mice in a dosage of 1 g/kg. for 30 days.