LC-MS for Simultaneous Determination of Vancomycin and Teicoplanin in Patient Plasma and its Application to Therapeutic Drug Monitoring

Background: Therapeutic drug monitoring is recommended for patients taking vancomycin and teicoplanin to ensure pharmaceutical efficacy and prevent toxicity. Only few studies were reported regarding the simultaneous determination of vancomycin and teicoplanin in human plasma. Objective: The study aimed at developing and validating a Liquid Chromatography-Mass Spectrometry (LC-MS) method for simultaneous determination and therapeutic drug monitoring of vancomycin and teicoplanin in patients with severe infection. Method: Plasma was processed by protein precipitation extraction. The analytes were separated on a C18 column by gradient elution with 0.1% formic acid and acetonitrile as mobile phase and measured by electrospray ionization source in positive selective ion monitoring mode at m/z 724.7 (vancomycin), 940.7 (teicoplanin) and 329.0 (bergenin). The plasma samples (104) were obtained from patients who were taking vancomycin or teicoplanin for further analysis. Results: The calibration curves were linear within the range of 0.25–40 μg/mL for vancomycin, and 0.5-40 μg/mL for teicoplanin. Either inter- or intra-day precision was less than 10.01 %. The extraction recoveries ranged from 89.99 to 94.29% for vancomycin and from 39.83 to 40.16 % for teicoplanin. Vancomycin and teicoplanin in plasma were stable at various storage conditions. The measured mean trough concentrations were 12.313 μg/mL for vancomycin and 8.765 μg/mL for teicoplanin. Conclusion: This method was successfully applied to therapeutic drug monitoring of vancomycin and teicoplanin in patients. It is with great clinic value for monitoring and predicting the individual response of patients under treatment.