Abstract
Disposition characteristics of uricase-polyethylene glycol cojugate (PEG-UC) in mice was compared with those of UC-carboxymethyl-dextran conjugate (UC-CMD). Native UC showed moderate elimination from plasma and significant accumulation in the liver, spleen, and kidney after intravenous injection. PEG modification resulted in a prolonged plasma circulation and a restricted tissue distributuion to a great extent, The effect of CMD modification was inferior to PEG modification. Thus PEG was revealed to be a excellent material for the chemical modification of peptide drugs to escape from the recognition of reticuloendithelial system. The present study also suggested that the modyfying material should be selected based on the elimination mechanism and purpose of delivery of aimed peptide.
