Analysis of steroids. XXXVIII. The use of high-performance liquid chromatography with diode-array UV detection for estimating impurity profiles of steroid drugs.

High-performance liquid chromatography (HPLC) diode-array UV-spectrophotometric detection is used for estimating impurity profiles of steroid drugs. It is shown to be a very useful first screening method for the identification of UV-active impurities and degradation products, giving a rapid answer to many questions or at least providing important initial information to complement the results obtained by other spectroscopic techniques. In this paper the estimation of the impurity profiles of ethynyloestradiol, norgestrel, and norethisterone, and of the degradation product of RGH-1113 (3-chloro-, 6,9-difluoro-11 beta,16 alpha,17 alpha,21-tetrahydroxy-1,3,5-pregnatrien-20-one 16,17-acetonide 21-acetate) will be discussed.