Action and use
Estrogen.
Definition
Ethinylestradiol Tablets contain Ethinylestradiol.
The tablets comply with the requirements stated under Tablets and with the following requirements.
Content of ethinylestradiol, C20H24O2
90.0 to 110.0% of the stated amount.
Identification
(1) Shake a quantity of the powdered tablets containing 0.25 mg of Ethinylestradiol with four 20-mL quantities of
acetone, filter each extract in turn, evaporate the combined filtrates to dryness on a water bath in a current of
nitrogen and dissolve the residue in 0.25 mL of
acetone.
(2) 0.1% w/v of
ethinylestradiol BPCRS in
acetone.
chromatographic conditions
(b) Use the mobile phase as described below.
(c) Apply 20 µL of each solution.
(d) Develop the plate to 15 cm.
mobile phase
10 volumes of ethanol (96%) and 90 volumes of toluene.
confirmation
By each method of visualisation the principal spot in the chromatogram obtained with solution (1) corresponds in position and colour to that in the chromatogram obtained with solution (2).
B. Triturate a quantity of the powdered tablets containing 0.1 mg of Ethinylestradiol with 0.5 mL of 0.1
m sodium hydroxide and 5 mL of
water, allow to stand for 5 minutes, filter, acidify the filtrate with 0.15 mL of
sulfuric acid, add 3 mL of
ether, shake and allow to separate. Evaporate the ether layer to dryness and heat the residue on a water bath for 5 minutes with 0.2 mL of
glacial acetic acid and 2 mL of
orthophosphoric acid. A pink colour with an intense orange fluorescence is produced.
Tests
Uniformity of content
Tablets containing less than 2 mg and/or less than 2% w/w of Ethinylestradiol comply with the requirements stated under Tablets using the following method of analysis. Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
(1) Add 2 mL of the mobile phase to one tablet, allow to stand for 5 minutes, mix with the aid of ultrasound for 5 minutes and centrifuge. Dilute the supernatant liquid with the mobile phase, if necessary, to produce a solution expected to contain 0.0005% w/v of Ethinylestradiol.
(2) 0.0005% w/v of ethinylestradiol BPCRS in the mobile phase.
chromatographic conditions
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 1.5 mL per minute.
(d) Use an ambient column temperature.
(e) Use a detection wavelength of 280 nm.
(f) Inject 20 µL of each solution.
mobile phase
40 volumes of water and 60 volumes of acetonitrile.
determination of content
Calculate the content of C20H24O2 in each tablet using the declared content of C20H24O2 in ethinylestradiol BPCRS.
Assay
Use the average of the individual results determined in the test for Uniformity of content.
Storage
Ethinylestradiol tablets should be protected from light.