Diethylstilbestrol Tablets

General Notices

Action and use

Estrogen.

Definition

Diethylstilbestrol Tablets contain Diethylstilbestrol.

The tablets comply with the requirements stated under Tablets and with the following requirements.

Content of diethylstilbestrol, C18H20O2

90.0 to 110.0% of the stated amount.

Identification

Extract a quantity of the powdered tablets containing 3 mg of Diethylstilbestrol with ether, filter and evaporate the filtrate to dryness. The residue complies with the following tests.

A. The light absorption, Appendix II B, in the range 230 to 350 nm of a 0.002% w/v solution in absolute ethanol exhibits a maximum only at 241 nm.
B. The light absorption, Appendix II B, in the range 230 to 450 nm of the irradiated solution prepared as directed in the Assay exhibits two maxima, at 292 nm and 418 nm.
C. Dissolve 0.5 mg in 0.2 mL of glacial acetic acid, add 1 mL of orthophosphoric acid and heat in a water bath for 3 minutes. A deep yellow colour is produced which almost disappears on dilution with 3 mL of glacial acetic acid (distinction from dienoestrol).

Assay

Weigh and powder 20 tablets. To a quantity of the powder containing 5 mg of Diethylstilbestrol add 50 mL of absolute ethanol, shake for 15 minutes, add sufficient absolute ethanol to produce 100 mL and centrifuge. Dilute 20 mL of the clear supernatant liquid to 50 mL with absolute ethanol and to 25 mL of the resulting solution add 25 mL of a solution prepared by dissolving 1 g of dipotassium hydrogen orthophosphate in 55 mL of water. Transfer a portion of the mixture to a 1 cm, closed quartz cell, place the cell 10 cm from a 15-watt, short-wave, ultraviolet lamp and irradiate for 10 minutes. Measure the absorbance of the irradiated solution at the maximum at 418 nm, Appendix II B, and calculate the content of C18H20O2 from the absorbance obtained by repeating the operation using diethylstilbestrol BPCRS in place of the powdered tablets.

Storage

Diethylstilbestrol Tablets should be protected from light.