Determination of ethinylestradiol in tablets by quantitative TLC method.

A new quantitative TLC method was developed for the determination of ethinylestradiol in tablets. The possible adsorption of ethinylestradiol on the starch can be avoided by enzymatic degradation, which enabled the easy extraction of the active ingredients from the tablet powder. The quantitative evaluation of the separated compounds was performed by densitometry at a wavelength of 280 nm. The relative standard deviation of the method was found to be better than +/- 2.6% in every case except Ambosex tablet where this value was +/- 4.7%. On the basis of the results obtained the method can be proposed for the routine analysis of tablets containing small amount of ethinylestradiol.