(dye'' en es' trol).
Phenol, 4,4¢-(1,2-diethylidene-1,2-ethanediyl)bis-, (E,E)-.
(E,E)-4,4¢-(Diethylideneethylene)diphenol [84-17-3; 13029-44-2].
» Dienestrol contains not less than 98.0 percent and not more than 100.5 percent of C18H18O2, calculated on the dried basis.
Packaging and storage Preserve in well-closed containers.
USP Reference standards 11
B: Ultraviolet Absorption 197U
Solution: 5 µg per mL.
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).
Melting range 741: between 227 and 234, but the range between beginning and end of melting does not exceed 3.
Loss on drying 731 Dry it at 105 for 2 hours: it loses not more than 0.5% of its weight.
Residue on ignition 281: not more than 0.2%.
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.
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USP35NF30 Page 2891