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.