Pharmacokinetics of monoclonal antibody HAb 18 and its F(ab^)_(2) and fab fragments in mice

The pharmacokinetics of 131I-labelled HAb18 McAb against primary hepatocellular carcinoma (PHC) and its F(ab^2) and Fab fragments following i.v. administration in BALB/c mice was investigated. Dynamic observations showed that the pharmacokinetics of 131I-labelled HAb18 was significantly different from that of the fragments. (1) The pharmacokinetics of HAb 18 conformed to a onecompart-mental open pharmacokinetic model. The clearance rate was relevant to injection doses, and the higher doses produced lower clearance values. (2) The pharmacokinetics of the F(ab^)_(2) was similar to that of the Fab and fitted to a two-compartmental pharmacokinetic model. The clearance process of the fragments was significantly fast than intact HAb18 McAb.