[Indocyanine Green Reference Standard (Control 901) of National Institute of Hygienic Sciences].

The raw material of indocyanine green was examined for the preparation of the "Indocyanine green Reference Standard (Control 901)". Analytical data obtained were as follows: ultraviolet and visible spectrum, lambda max = 785, 394, 216 nm; absorbance, E1cm(1%) (785 nm) = 3239; infrared spectrum, same as Indocyanine Green USP Reference Standard; sodium iodide, 4.1%; thin-layer chromatography, no impurities were detected until 100 micrograms; high-performance liquid chromatography, 4 impurities were detected; loss on drying, 1.8%; assay, 103.4% against USP Reference Standard. Based on the above results, this raw material was authorized to be the Reference Standard of the National Institute of Hygienic Sciences.