[The Progesterone Reference Standard (Control 931) of the National Institute of Health Sciences].

Raw progesterone material was tested for preparation of the "Progesterone Reference Standard (Control 931)". Analytical data obtained were as follows: melting point, 131.6 degrees C; infrared spectrum, the same as that of the JP Progesterone Reference Standard; optical rotation, [alpha]D20 = +181.1 degrees; thin-layer chromatography, no impurity was detected; high-performance liquid chromatography (HPLC), trace amounts of two impurities were detected; loss on drying, 0.23%; assay results, 99.4% by UV spectrophotometry in the JP XII and 100.5% by HPLC. Based on the above findings, the raw material was authorized as the JP Progesterone Reference Standard (Control 931).