Preclinical pharmacokinetics of radiolabelled hyaluronan

BackgroundHyaluronan (HYA) is a high molecular weight glucosaminoglycan with a great perspective for medical applications.Because HYA is widespread in the body, it is difficult to determine the fate of exogenously administered HYA.MethodsIn this study, HYA of different molecular weights (0.1–1 MDa) was labelled with 99mTc, and the distribution profiles were determined after administrating the HYA to rats.ResultsAfter the intravenous administration of 99mTc-HYA, a rapid decrease in the radioactivity of blood samples was observed, presumably because of 99mTc-HYA uptake by the liver; only minimal signs of liver radioactivity washout were detected. After the oral administration of 99mTc-HYA, no significant absorption to the central compartment was found. A preliminary study using 14C-HYA exhibited a different distribution profile than 99mTc-HYA because of the different administered dose and the fate of the degradation products. Even with 14C-HYA, only traces of radioactivity were absorbed after oral administration.ConclusionsThis paper provides quantitative information regarding the distribution parameters of radiolabelled HYA in preclinical experiments.