In vivo and real time determination of ornidazole and tinidazole and pharmacokinetic study by capillary electrophoresis with microdialysis.

The aim of this study was to develop a rapid and sensitive method for in vivo and real time monitoring unbound ornidazole (ONZ) and tinidazole (TNZ) in rabbit blood using capillary electrophoresis coupled with microdialysis. The UV wavelength was set at 214 nm and all separations were performed in 20 mM Tris-H3PO4 (pH 1.5) buffer. Microdialysis probes were perfused at 4 microl/min resulting in relative recoveries of 33.1+/-3.6% and 34.8+/-3.3% (n=3) for ONZ and TNZ, respectively. The linearity was studied in the concentration range of 1.0-412 microg/ml for ONZ and 1.0-520 microg/ml for TNZ. The detection limits were 0.7 microg/ml for ONZ and 0.6 microg/ml for TNZ (S/N=3). All separation could be achieved within 15 min. This method has been successfully applied to the pharmacokinetic study of ONZ and TNZ in rabbit blood.