OBJECTIVE: To establish the internal quality control evaluation method for therapeutic drug monitoring of vancomycin based on Levey-Jennings quality control chart combined with Westgard multi-rule theory

so as to provide references for rational clinical drug use. METHODS: Vancomycin standard was dissolved and blank serum was added to prepare quality control plasma with mass concentrations of 10 μg/mL

25 μg/mL and 50 μg/mL

respectively

and methodological studies were carried out to assess the feasibility. Totally 30 vancomycin quality control samples in the hospital from Jun. to Aug. 2020 were monitored

and Levey-Jennings quality control chart and Z-score quality control chart were drawn. Combined with Westgard multi-rule theory

internal quality control was evaluated and statistically analyzed. RESULTS: Vancomycin showed good linear relationship within the range of 2.5 μg/mL to 100 μg/mL. The intra-day and inter-day precision RSD and recoveries of the low

medium and high concentrations of the quality control samples met the requirements of the Pharmacopoeia of the People’s Republic of China: Ⅳ（2020 Edition） for the determination of biological samples. The internal quality control evaluation showed one loss of control of vancomycin. After analysis

there was no out of control after removing error factors. CONCLUSIONS: The establishment of internal quality control system for therapeutic drug monitoring of vancomycin can effectively improve the accuracy of blood drug concentration monitoring

and provide more accurate individualized pharmaceutical services for clinical practice.