Dextrans are glucose polymers used in therapeutic as plasma volume expanders for half a century. Recently, these macromolecules were shown to be drug carriers or to be substituted with functional groups. This review gives a summary to pharmacokinetics of neutral and modified dextrans.

Neutral and modified dextrans exhibit a biexponential decline of plasma rate after iv administration with an initial plasmatic fall rate and a secondary linear plasmatic rate decrease. Molecular weight (Mw) influences markedly their pharmacokinetics. Hepatic accumulation and plasma retention time increase with Mw after iv administration, as low Mw dextran are rapidly eliminated by kidney with a short half life. Neutral dextrans are probably taken up by the liver via asialoglyco-receptors present on parenchymal and non parenchymal cells as evidenced by the competition with galactosylated bovine serum albumin, a classical ligand for asialoglycoproteins receptors. Electric charge is a major determinant in the pharmakokinetics of modified dextrans. Weak cationic dextrans, such as diethylaminoethyl, are rapidly taken up, mainly by the liver, after iv administration. Weak anionic dextrans, such as carboxymethyl dextrans, have prolonged plasma retention time due to low electrostatic interactions with negatively charged biological membranes. On the other hand, dextran sulfate (strong anionic dextran) is taken up by the liver via scavenger receptors present in non-parenchymal hepatic cells. This mechanism is Mw independent and non specific.

The pharmacological properties of peptides, proteins, and drugs were also shown to be altered by conjugation with dextran allowing better pharmacological treatments. An appropriate control of the pharmacokinetics is important in order to target the macromolecules to specific organs and to increase their biological efficiency.