Swine dysentery and poultry cholera are very harmful animal diseases which cause great damage. Flumequine and kitasamycin are new and up-to-date preparations for the treatment of these diseases. ++ Imequyl ad us. vet. and ++ Trubin ad us. vet. are the registered medicines. The doses are 7 mg flumequine and 21 mg kitasamycin/body weight kg. The drug technological problem is that flumequine does not dissolve sufficiently in water. It dissolves well at pH = 10, but kitasamycin is unstable at this pH. It was hoped that these two components would together act as agonists, and that kitasamycin would promote the dissolution of flumequine. An injection preparation and a powder mixture for dissolution were developed. Chemical interaction between the components was conformed by IR and NMR measurements.