A simple and reproducible quantitative retention-activity relationship (QRAR) model utilizing biopartitioning micellar chromatography was developed for the biological parameter estimation of drugs. The correlation between retention factors of quinolones obtained in physiological conditions (pH, ionic strength) and biological activities was investigated using different second-order polynomial models. The predictive and interpretative ability of the chromatographic models was evaluated in terms of cross-validated data (RMSEC, RMSECV and RMSECVi). The aim was to obtain adequate QRAR models of half-life, clearance, volume of distribution, plasma protein combination rate, area under concentration-time curve and toxicity (LD50) of quinolones, and to elucidate the advantages and limitations of using a single parameter as independent variable for describing and estimating the activities.