Electrophoresis, Vol.23, No.11, 1702-1708, 2002
Enantioseparation of novel COX-2 antiinflammatory drugs by capillary electrophoresis using single and dual cyclodextrin systems
A capillary electrophoresis method was developed for the enantioseparation of three novel cyclooxygenase-2 (COX-2) inhibitor drugs (E-6259, E-6036 and E-6087) with anti-inflammatory and analgesic activities using sulfobutyl ether-beta-cyclodextrin (SBE-CD) as a chiral selector. The use of 50 mm sodium tetraborate at pH 9.2 with 30% v/v methanol, containing 7.1 mm SBE-beta-CD, as a background electrolyte (BGE) allowed the complete enantioseparation of the three neutral racemic mixtures (resolution = 2.4, 3.0 and 8.7, respectively) and their corresponding metabolites (oxidation products) in a single run. Migration times were shortened with some loss of enantioresolution by adding 1.75 mm dimethyl-beta-cyclodextrin (DM-beta-CD) to the previous BGE (dual CD system). The reversal of the migration order of E-6259 enantiomers in the dual CD system was also studied. Furthermore, the addition of DM-beta-CD to the BGE introduced a new chemoselectivity in the system that allowed E-6259 to be separated from the structurally similar compound E-6036.
Keywords:capillary electrophoresis;charged cyclodextrins;COX-2 anti-inflammatory drugs;dual cyclodextrin systems;enantiomer separation