Hydroxyethyl starch (HES) 200/0.5 APIs, formed by acid-hydrolyzed and hydroxyethylized
high-branched chain amylopectin starch, is a medium MW and low molar substitution
ratio HES. Its chemical formula is poly (O-2-hydroxyethyl) starch, and the
common name is HES200/0.5 (penta starch).

HES solution has quick effect and strong volume expansion properties; it can maintain
four hours' middle strength expansion; it can be cleared away from kidney;
less accumulation in plasma and tissue, least effect on coagulation; it can improve
microcirculation. HES 200/0.5 solution is the most frequently used plasma substitute
in Europe, and is the preferred remedy in curing and defending hypovolemia
and shock.

Pharmacology:
Hydroxyethyl starch 200/0.5 can expand plasma volume, consequently improve the cardiac
output and oxygen transport of low plasma volume and shock patient, reduce
the pack of red cell and viscosity of blood plasma. Meanwhile, HES 200/0.5 has
its particular pharmacology in decreasing plasma leakage and dropsy of injured capillary
tube, which will benefit the critically-ill patient who will be or was
in organ failure

Pharmacokinetics:
The smaller the molar substitution ratio of HES is, the quicker it metabolize, but
high C2/C6 ratio will slower the metaboly in body, accordingly decrease the effect
of substitution. After the HES solution was given by intravenous infusion,
the initial polymer can be separated into fractions of different molar masses. The
average molecular weight in the plasma will be declined to 70-80kd rapidly, and
then kept the value above the kidney threshold during therapy. The other larger
molar masses will be metabolized by alpha-amylase, and then eliminated by renal
excretion

Toxicology:
There is no one dead case among all the cured beastie, even under the maximum dosage.
No teratogenicity was found in the teratogenicity research on rats and rabbits,
no teratogenicity and embryotoxicity was inspected under the dosage of 20ml/kg,
no indication of anti-procreate and immunity-toxicity in experiment on Guinea
pig. Meanwhile the experiments also proved that no mutagenicity, no carcinogenicity,
no local toxicity of HES200/0.5

Clinical usage:
HES 200/0.5 solution is the mostly common used plasma substitute at present. It can
improve the cardiac output and oxygen transport of low plasma volume and shock
patient, reduce the pack of red cell and viscosity of blood plasma. Lots of clinical
experiments have improved that it has beneficial effect in cardiac output,
oxygen support, oxygen consume and organ function of low plasma volume and shock
patient