The present invention relates to a method of forming a concentrated solution of first and second pharmacologically active ingredients which involves: providing a solid eutectic composition of the first and second pharmacologically active ingredients providing a first solvent and dissolving the eutectic composition in the first solvent wherein the first and second pharmacologically active ingredients are independently selected from β2 agonists, muscarinic antagonists, anticholinergics, corticosteroids, methylxanthine compounds and salts, esters, polymorphs, hydrates or solvates thereof. A solution obtainable by this method is also described, along with an ampoule for a nebuliser and a pressurised metered dose inhaler comprising the solution. The solution is useful in the treatment of respiratory diseases.
