Estimation of impurity profiles in drugs and related materials

Abstract

The estimation of impurity profiles in drugs and related materials has been demonstrated using combinations of chromatographic and spectroscopic techniques. Examples chosen to illustrate this approach are: (1) an examination of flumecinol and its impurities using packed column GC—mass spectrometry; (2) the estimation of 17β-ethinyl-17α-hydroxy impurities in 17α-ethinyl-17β-hydroxy steroids using capillary GC; (3) the identification of impurities in hexoestrol using HPLC—linear photodiode array detection (LDA) and off-line mass spectrometry; (4) the estimation of 9(11)-dehydromestranol in mestranol using HPLC—LDA; and (5) the estimation of an l-threo impurity in a d-threo hydroxy acid intermediate using a chiral column containing covalently bonded bovine serum albumin.