Tetrazolium salts in pharmaceutical analysis II: direct assay of diethylstilbestrol and diethylstilbestrol dipropionate.

A convenient spectrophotometric determination of diethylstilbestrol and diethylstilbestrol dipropionate was developed involving their interaction with triphenyltetrazolium chloride at 50 degrees for 45 min and subsequent measurement of the formazan formed. The significance of extended conjugation within t,e 4,4'-stilbenediol molecule to induce the color reaction is documented. Ideal adherence of color absorption to Beer's law permitted accurate and precise determination of diethylstilbestrol and diethylstilbestrol dipropionate pure forms over the range of 2-22 microgram of diethylstilbestrol/ml. Application of the tetrazolium color reaction to the analysis of diethylstilbestrol dipropionate dosage forms was achieved without prior hydrolysis or extraction.