Identification
B:
Ultraviolet Absorption 197U
Solution:
5 µg per mL.
Medium:
alcohol.
Absorptivities at 228 nm, calculated on the dried basis, do not differ by more than 3.0%.
C:
To a solution of about 10 mg in 0.5 mL of alcohol add 1 mL of hydrochloric acid and about 50 mg of vanillin: a blue color is produced immediately, and it persists on dilution with water but disappears on the addition of alkali (distinction from diethylstilbestrol, which produces no color).
Assay
Mobile phase, Internal standard solution, and Standard preparation
Prepare as directed in the
Assay under
Dienestrol Cream.
Assay preparation
Transfer about 25 mg of Dienestrol, accurately weighed, to a 100-mL volumetric flask. Add methanol to volume, and mix. Pipet 2 mL of this solution, 5 mL of Internal standard solution, and 5 mL of water into a 50-mL volumetric flask. Dilute with methanol to volume, and mix.
Procedure
Proceed as directed for
Procedure in the
Assay under
Dienestrol Cream. Calculate the quantity, in mg, of C
18H
18O
2 in the portion of Dienestrol taken by the formula:
2.5C(RU / RS).