[Cyanocobalamin Reference Standard (Control 871) of National Institute of Hygienic Sciences]

Cyanocobalamin was tested for the preparation of "Cyanocobalamin Reference Standard (Control 871)". Analytical data obtained were as follows: loss on drying, 11.6%; infrared spectrum, same as that of Cyanocobalamin Reference Standard (Control 861); thin-layer chromatography, two contaminants were detected; high-performance liquid chromatography, seven contaminants were detected; assay, 99.9% by JP XI method and 100.2% by HPLC method in terms of J.P. Reference Standard (Control 861), respectively. On the basis of those results, this material was authorized as the Japanese Pharmacopoeia Standard (Control 871).