Gentamicin and tobramycin binding to human serum in vitro

The binding of gentamicin and tobramycin to human serum was studied in vitro using equilibrium dialysis of pooled human serum supplemented to various concentrations of either drug. Only minimal and variable non-specific binding was noted for each drug: gentamicin, less than 15% and tobramycin, less than 30%. Conventional Scatchard analysis conducted over an array of drug concentrations failed to identify any specific binding proteins.