Pidotimod S)-(5-oxo-2-pyrrolidinyl)carbonyl]-thiazolidine-4- carboxyli
c acid PGT/1A, CAS 121808-62-6) is a new synthetic immunostimulant, wh
ich has proved to possess a high activity. This paper describes its ph
ysico-chemical properties, structural identification including polymor
phism, detection of impurities determination of related compounds, sep
aration, quantification and purity assay using high-performance liquid
chromatography (HPLC).