Chiral resolution of enantiomeric steroids by high-performance liquid chromatography on amylose tris(3,5-dimethylphenylcarbamate) under reversed-phase conditions

Amylose tris(3,5-dimethylphenylcarbamate) (Chiralpak AD) was used under reversed-phase conditions for the: chiral separation of 26 steroids. It was found that the chiral separation behavior of Chiralpak AD under reversed-phase conditions differs clearly from those under normal-phase conditions thereby extending the range of application of this chiral stationary phase. The substitution of methanol for acetonitrile in the aqueous eluent did not grossly change the chiral separation behavior. The enantioselectivity under reversed-phase conditions is strongly dependent on the water concentration in the eluent up to 10%. The influence of the temperature on the chiral separation is discussed from a practical point of view. A HPLC method for the quantification of the unnatural enantiomer of estradiol in drug substances applying Chiralpak AD under reversed-phase conditions was developed and successfully validated. (C) 1998 Elsevier Science BN. AU rights reserved.