Medicinal aerosol formulation products with improved chemical stability

摘要

The present invention relates to a medicinal aerosol formulation product with improved chemical stability. The product is a pressurized metered dose inhaler including an aerosol canister equipped with a metering valve provided with sealing rings and/or gaskets made of a vulcanisate of an elastomeric composition of a butyl rubber, a cross-linking agent for the butyl rubber, and an accelerator for the cross-linking agent. The accelerator includes a polysulphide compound derived from a substituted dithiocarbonic acid or derivative thereof. The pressurized metered dose inhaler contains in the aerosol canister a medicinal aerosol formulation containing a long acting beta2 agonist, a hydrofluorocarbon propellant, a co-solvent, and a mineral acid as a stabilizer for the active ingredient.