A new HPLC-DAD method for contemporary quantification of 10 antibiotics for therapeutic drug monitoring of critically ill pediatric patients

The common practice of Therapeutic Drug Monitoring (TDM) involves the quantification of drug plasma concentrations at a specific time in a dosing window. Although TDM for antibiotics is not considered mandatory, it may represent a valid tool for clinicians in order to limit antibiotic resistance and avoid therapeutic failures. The aim of our study was to develop and validate High Performance Liquid Chromatography associated to Diode Array Detection (HPLC-DAD) method for contemporary quantification of ten antibiotics in plasma. This method is endowed with a fast analytical procedure that uses the same chromatographic conditions to quantify ceftazidime, ceftriaxone, meropenem, ertapenem, ciprofloxacin, tigecycline, ampicillin, levofloxacin and piperacillin, plus the beta-lactamase inhibitor tazobactam. Method validation was ensured testing selectivity, accuracy, precision, limits of detection and quantification, recovery and stability. The calibration ranges, established accordingly to the expected plasma concentration in patients, showed a coefficient of determination > 0.996 for all compounds. Within and between-days precisions reported a coefficient of variation less than 15 %. Similarly, the accuracy evaluation reported a relative standard deviation < 10 % for each antibiotic. The recovery ranged between 97 and 103 % for all compounds. This method could represent a useful tool for TDM platform of antibiotics.