Chromatographic Separation and Purification of Mitotane Racemate in a Varicol Multicolumn Continuous Process

The multicolumn continuous chromatographic separation process that increases throughput, purity, and yield compared to batch chromatography is considered as an important preparative technique to purify pharmaceutical drugs. Mitotane is a chiral drug marketed in the racemic form but pharmacological effects due to molecule chirality indicate that one of the enantiomers is more potent. Preparative separation of the mitotane enantiomers was performed by a continuous Varicol unit operated on a scale of 30 g/day. Amylose tris(3,5-dimethylphenylcarbamate) functioned as the stationary phase and acetonitrile-isopropanol mixtures as mobile phases. The enantiomeric purities obtained were 97.0 % for S-(–)-mitotane and 96.8 % for R-(+)-mitotane in the raffinate and extract streams, respectively. The unit provided productivities of 1.14 kg raffinate per day and kg adsorbent and 0.68 kg extract per day and kg adsorbent.