Analysis of conjugated estrogens in a vaginal cream formulation by capillary gas chromatography

A capillary gas-chromatographic method is described for the quantitative analysis of nine equine estrogens in a vaginal cream formulation. The sodium sulfate ethers of the estrogens were selectively extracted from the formulation, subjected to enzyme hydrolysis, and derivatized to their oxime-trimethylsilyl esters. Resolution of the resulting derivatives was achieved on short (15 m) capillary column, wall-coated with cyanopropylmethyl silicon stationary phase.