RESUMO
The binding characteristics of quinolone antibacterial agent, ofloxacin (OFLX) and ciprofloxacin(CPFX) with catalase(CAT) were studied by fluorescence spectroscopy in aqueous solution. It was showed that both OFLX and CPFX had a strong ability to quench the CAT intrinsic fluorescence through a static quenching procedure. The formation constant K and the number of bind ing site n were further calculated according to the fluorescence quenching r esults.
RESUMO
AIM To predict skin permeability of drugs with theoretical parameters. METHODS The semiempirical self-consistent field molecular calculation AM1 method is utilized to obtain the structural parameters of drug molecules. Stepwise multiple regression analysis or BP neural network is then utilized to establish the correlation between skin permeability of drugs and their structural parameters. RESULTS The calculated human skin permeability coefficients (kp) of 22 model drugs in vitro or the R values (R=absorbed/unabsorbed) of 17 drugs in vivo are in good agreement with their observed values. CONCLUSION Theoretical parameters can be used to predict skin permeability of drugs.