The binding of isoxazolyl penicillins to human serum proteins.

The binding of oxacillin, cloxacillin and flucloxacillin to human serum proteins was investigated with ultrafiltration methods and under the conditions of steady-state gel filtration and frontal analysis. In the different experiments very much lower rates of protein binding were found than had been expected according to the data in the literature. Partly the isoxazolyl penicillins are bound to the ultrafiltration membranes. The sources of error are discussed.