Analysis of diethylstilbestrol and its impurities in tablets using reversed-phase high-performance liquid chromatography.

A high-performance liquid chromatographic (HPLC) method is described which is capable of resolving cis- and trans-diethylstilbestrol (DES), DES mono- and dimethyl ethers and 4,4'-dihydroxystilbene. The mobile phase and internal standard used stabilise the cis-trans DES isomer ratio, and the method is capable of quantitating both isomers in dosage forms without derivatisation. Recovery of DES from tablets is quantitative. Results of tablet analyses using this method are compared with those obtained with the official spectrophotometric procedure.