Additional outcome variables: Plasma (single dose and steady state): AUC, AUC0-12/24h, Cmax, Tmax, t1/2ß, Cav(ss). Pus and plasma: ratios of AUC and Cav(ss) to MIC, T>MIC The following parameters will be determined if possible: the diameter of the pericapsular space with enrichment of contrast agent, the degree of contrast agent enhancement in this zone and the pus density, rate of drug degradation in pus at body temperature in vitro, pH-value of pus, pus viscosity and specific weight.