Pyridone carboxylic acids such as ofloxacin (OFLX)' are important substances in the field of medical treatment. Related compounds are widely used as chemotherapeutic agents in clinical medicine, and OFLX, for instance, is administered clinically as a racemic mixture2. When the pharmacological properties of enantiomers differ from each other, there is considerable interest in the chromatographic resolution of the enantiomers for analytical and preparative purposes. A variety of approaches have been used for the resolution of enantiomers by high-performance liquid chromatography (HPLC), which is of especial pharmaceutical interest, but no studies on the chromatographic resolution of the enantiomers of pyridone carboxylic acids have yet been reported. A useful method for the analysis of these isomers is required for the determination of optical purity in pharmaceutical preparations and in biological fluids for pharmacokinetic purposes.
Various methods have been reported for the separation of enantiomeric mixtures3. These involves derivatization with chiral reagents4p5, the use of chiral stationary phases6 and of chiral eluents -' 9. Chiral mobile phase methods are particularly simple and can be used with conventional HPLC columns, but their applications have been limited to the separation of amino acids, hydroxy carboxylic acids and their derivative compounds".
In this paper, we describe a new, simple and convenient HPLC method for the resolution of the enantiomers of pyridone carboxylic acids using a chiral mobile phase.
EXPERIMENTAL
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