Baytril(R) IER 2.5% - A new formulation for the oral application on swine - Antibacterial activity, pharmacokinetic and bioavailability

A total of 621 bacterial strains (E. coli, Past. multocida, A. pleuropneumoniae, Bord. bronchiseptica Salmonella spp., Strept. suis, Staph, hyicus, Staph. aureus, M. hyopneumoniae, M. hyosynoviae, M. hyorhinis, Psdm. aeruginosa, Klebs, pneumoniae and Proteus spp.) isolated in 1994/1995 from swine was checked for Minimal Inhibitory Concentration (MIG) of enrofloxacin and other antiinfectives. From all drugs tested, enrofloxacin exhibited the highest antibacterial activity. Baytril(R) I.E.R. 2.5% (premix) is being marketed in Germany for the following indications: pneumonia, respiratory diseases, diarrhoea, septicaemia and edema disease. MIC(90) for etiologically responsible bacterial species are: M. hyopneumoniae: 0.25 mu g/ml; Past. multocida: 0.015 mu g/ml; A. pleuropneumoniae. 0.03 mu g/ml; E. coli: 0.125 mu g/ml and Salmonella spp.: 0.06 mu g/ml. Susceptibility data (MIC(50)/MIC(90)) were put into relation to enrofloxacin serum and organ levels determined by pharmacokinetic studies after food intake of Baytril(R) I.E.R. 2.5% (premix) in concentrations of 50 and 150 ppm. Two to four hours after intake of medicated food, serum and organ/tissue levels of enrofloxacin were clearly above the MIC(90) of the bacterial species mentioned. Since the current registration of Baytril(R) I.E.R. 2.5% (premix) a highly potent antiinfective for oral, individual, or stock treatment in swine is available.