Concentrations of various antibiotics in serum and fluids accumulated in diffusion chambers implanted in various sites in rabbits.

Diffusion chambers with Millipore membranes were implanted in soft tissue, kidneys, and peritoneal and pleural cavities of rabbits. Single doses of azlocillin, cefazolin, and gentamicin were injected intramuscularly and ampicillin was administered orally 2--5 weeks after implantation. The concentrations of the respective drugs in simultaneously collected samples of fluid from each diffusion chamber were measured and compared with concentrations found at the same time in serum. All chambers were tolerated well, and the method proved to be effective for collecting data on the distribution of drugs throughout the body.