GLC assay of conjugated estrogen formulations

A procedure is described for the enzyme hydrolysis and GLC assay of conjugated estrogens in commercial formulations. Resolution of up to nine of the components is achieved on a methyl phenyl cyanopropyl silicone-coated column using a dual-derivatization and dual-injection technique. Replicate results from analyses of a commercial tablet formulation yielded coefficients of variation between 1.0 and 17.2%, depending mainly on the quantity present; a coefficient of variation of 0.4% was obtained for the assay for total conjugated estrogens. Similar results were obtained with other commercial formulations.