Liquid chromatographic resolution of the isomers of tipredane and phenylthioproline using urea-solubilized beta-cyclodextrin in the mobile phase.
Two LC assays were developed using urea-solubilized beta-cyclodextrin (beta-CD) as a mobile phase additive in combination with reversed-phase columns. A methylsilane column gave optimal resolution of the steroid tipredane from its epimer. An investigation of the effects of beta-CD concentration, column temperature, column type, and addition of ethanol on the chromatographic separation is detailed. The enantiomer and diastereoisomers of L-cis-phenylthioproline were best resolved by urea-solubilized beta-cyclodextrin and a trimethylsilane column. The elution order of L-cis-phenylthioproline relative to its stereoisomers was reversed after adding ethanol to the beta-CD containing mobile phase or by changing from a beta-CD to an acetylated beta-CD column. The resolution factors for these separations obtained using the beta-CD mobile phase were larger than those obtained using beta-CD columns. Mobile phases containing up to 0.15 M beta-CD and 8 M urea were investigated. The separation of these isomers are dramatically affected by column polarity.
Noroski
J
J
Bristol-Myers Squibb Pharmaceutical Research Institute, New Brunswick, NJ 08903-0191.
Mayo
D
D
Kirschbaum
J J
JJ
D000287:Administration, Topical; D000730:Androstadienes / Q000032:analysis*; D000893:Anti-Inflammatory Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003505:Cyclodextrins; D007536:Isomerism; D011392:Proline / Q000031:analogs & derivatives; D047392:beta-Cyclodextrins
D000730:Androstadienes; D000893:Anti-Inflammatory Agents; D003505:Cyclodextrins; D047392:beta-Cyclodextrins; C051756:tipredane; D011392:Proline; C031215:betadex