Chiral separation of diltiazem, trimetoquinol and related compounds by micellar electrokinetic chromatography with bile salts.

The separation of optically isomeric diltiazem hydrochloride, trimetoquinol hydrochloride and related compounds by micellar electrokinetic chromatography was investigated employing four bile salts as chiral surfactants. The chiral separation of diltiazem hydrochloride and timetoquinol hydrochloride was successfully achieved by use of sodium taurodeoxycholate under neutral conditions, although enantiomers of carboline derivatives A and B and 2,2'-dihydroxy-1,1'-dinaphthyl were resolved with all the bile salts under conditions from neutral to alkaline. The chiral separation of diltiazem-related compounds was affected by the structure of the samples in addition to the effects of bile salt structures and pH of the buffer solutions. Application to the optical purity testing of trimetoquinol hydrochloride by the area percentage method is described. A possible chiral separation mechanism is briefly mentioned.