[Dexamethasone Sodium Phosphate Reference Standard (Control 891) of National Institute of Hygienic Sciences]

The raw material of dexamethasone sodium phosphate was examined for preparation of the "Dexamethasone Sodium Phosphate Reference Standard". Analytical results were as follows: UV spectrum indicates absorption maxima at 242 nm and absorptivity at 242 nm is E1%1cm 304; optical rotation +79.0%; pH 7.7; ethanol 5.2%; water 6.0%; HPLC analysis indicates small amounts of three impurities and the purity was assumed to be 99.8%; assay by HPLC indicated 100.9% against the USP Reference Standard of "Dexamethasone Phosphate". Based on the results, the present raw material was authorized to be the Reference Standard of the National Institute of Hygienic Sciences.