9.4. Steroids

Publisher Summary This chapter presents the evaluation of impurities in hormonal steroids and mainly their synthetic analogues is dealt with. Other non-hormonal synthetic derivatives (e.g. quaternary ammonium derivatives) and pharmaceutically less important groups of natural steroids such as sterols and bile acids are only briefly mentioned. These are very advantageous features from the points of view of their determination by UV spectrophotometry in various matrices and the detectability in the course of the TLC or HPLC analysis but are of little importance when the analytical task is the direct determination of impurities/degradation products in bulk drugs and their formulations. Several spectrophotometric methods based on (colour) reactions are also available but the importance of their application to the determination of impurities in steroid drugs has been surpassed by modem chromatographic methods.