Enantioselective Extraction of Ofloxacin Enantiomers Using Ester Alcohol L-Tartarate as Chiral Selector

The distribution behavior of ofloxacin enantiomers was examined in the aqueous and organic solvent of a two-phase system containing chiral selector L-tartarate. The effect of extraction equilibrium time, buffer pH, organic solvents and length of alkyl chain of L-tartarate on the partition coefficients and enantioselectivity of racemic ofloxacin were investigated, respectively. The L-tartarate formed more stable complexes with R-ofloxacin than that with S-ofloxacin. The partition coefficients and enantioselectivity of racemic ofloxacin increased with increasing length of alkyl chain of L-tartarate. Solvents showed a large influence on enantioselectivity and partition coefficients. Optimum buffer pH was about 7 for separation of racemic ofloxacin by extraction.