The tissue cage model in the distribution of antibacterial agents.

Developments in the measurement of interstitial tissue fluid using the tissue cage model are described. The design and physical characteristics of tissue cages are examined and evidence is presented to show that the fluid contained within these cages is representative of interstitial tissue fluid. The distribution of a variety of antibacterial agents into tissue cage fluid is examined and shows that this technique is a reliable experimental model for the study of drug distribution. The results also show that some antibacterial agents may never, normally, distribute into the tissue fluid and that the use of tissue homogenates, especially the kidney, is unreliable as a guide to the tissue concentration of a drug.