The invention relates to a spray-dried powder formulation comprising particles that contain the following components i) to iii): i) anticholinergic agents, in particular at least one compound of formula 1, in which X - represents a negatively charged anion, ii) at least one embedding material selected from the group consisting of mono- or disaccharides, oligosaccharides, polymers, sugar alcohols and cholesterol, iii) an organic, physiologically acceptable, sterically demanding acid, selected from the group consisting of ascorbic acid, a monovalent, divalent or trivalent carboxylic acid, with the exception of amino carboxylic acids, preferably fumaric acid, oxalic acid, or diacetic acid, and a fruit acid or culinary acid, preferably citric acid, tartaric acid, malic acid, lactic acid, acetic acid, .alpha.-hydroxycaprylic acid or gluconic acid. The invention also relates to a method for producing said formulation and to the use of an organic, physiologically acceptable, sterically demanding acid from the group consisting of ascorbic acid, a monovalent, divalent or trivalent carboxylic acid, with the exception of amino carboxylic acids, preferably fumaric acid, oxalic acid, or diacetic acid, and a fruit acid or culinary acid, preferably citric acid, tartaric acid, malic acid, lactic acid, acetic acid, .alpha.-hydroxycaprylic acid or gluconic acid, for stabilising a powder formulation produced by spray-drying containing the aforementioned compound of formula 1 according to i) and a suitable embedding material ii).
