Mass transfer of antibiotics adsorbed by human serum albumin in hemodialyzers.

The removal rate of a drug by a hemodialyzer is very important to determine the dosage of the drug to a patient without kidney function. Mass transfer of a drug in a hemodialyzer and a patient's body is more complicated than that of ordinary solutes because most drugs are adsorbed by serum albumin. In this paper, we reveal the adsorption characteristics of five clinical antibiotics onto human serum albumin (HSA) with new experimental methods and discuss the influence of adsorption characteristics on removal of antibiotics by hemodialyzers using mathematical models. The adsorption equilibrium of the antibiotics with HSA followed the Langmuir isotherm. Adsorption rates of the antibiotics onto HSA were measured using a constant-flow stirred tank reactor with an ultrafiltration module. A kinetic model for antibiotic transfer in a hemodialyzer and a patient's body was derived with the parameters obtained by the above experiments. Validity of the model was confirmed by dialysis experiments using hemodialyzers and antibiotic solutions including HSA. Removal estimation of a drug by hemodialysis therapy is feasible by the model with the parameters of the Langmuir isotherm for the drug.