Studies on hydroxyethyl starch. Part II: Changes of the molecular weight distribution for hydroxyethyl starch types 450/0.7, 450/0.5, 450/0.3, 300/0.4, 200/0.7, 200/0.5, 200/0.3 and 200/0.1 after infusion in serum and urine of volunteers.

32 volunteers, none of whom showed any symptoms for kidney, liver or pancreas disease, were given by infusion 500 ml of various type of hydroxyethyl starch (HES) at a concentration of 6% (450/0.7, 450/0.5, 450/0.3, 300/0.4) as well as of 10% (200/0.7, 200/0.5, 200/0.3, 200/0.1) over a period of 30 min. After infusion both the Mw and the Mn diminished. The rate of elimination of HES from serum entirely depended on molar substitution and not on Mw. The quotient Mw/Mn decreased considerably over the entire test period. The lower molecular weight limit in serum remained relatively the same at 60,000 Daltons. Maximum molecular weight limit of urine, too, was 60,000 Daltons.