Determination of macrolides in biological matrices by high-performance liquid chromatography with electrochemical...

A liquid chromatographic method for the determination of macrolide antibiotics is described using a cyanopropyl column which proved to be as efficient or superior to the normally used apolar reversed-phase columns. The recovery of the macrolides from water and plasma was 80-90%. Using 0.5 ml of plasma, 30 ng/ml of clarithromycin, 50 ng/ml of roxithromycin and 10 ng/ml of azithromycin could be determined with acceptable precision and accuracy. The method has been employed in pharmacokinetic studies in humans for the determination of roxithromycin, clarithromycin and azithromycin in plasma, serum and other biological matrices. The particular selectivity of the cyanopropyl phase may also allow the simultaneous determination of erythromycin and its prodrug esters.