The preparation of an improved galenic delivery form of valnemulin, which is notable for its good tolerance and stability in storage, is described. The new delivery form in question is a non-aqueous or oily injection formulation, which is obtainable by means of in-situ preparation and subsequent stabilisation of the free, relatively unstable base of the active ingredient. A further aspect of the present invention concerns the usage of such an injection formulation in a method of treating infectious diseases in productive livestock or domestic animals.
