Quantification of Vancomycin and Clindamycin in Synovial Tissue and Bone Using Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry.

Background: Approximately 1-2% of patients undergoing hip or knee arthroplasty encounter a periprosthetic joint infection (PJI). Currently, the treatment involves revision surgeries and long-term antibiotic therapy. However, too low antibiotic concentrations can lead to treatment failure, whereas excessively high concentrations can lead to adverse events. Although optimal dosing is very important, there remains an insufficient understanding of the relationship between the concentrations of the plasma and antibiotics at the target site. This study aimed to develop and validate a novel ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) technique for quantifying two frequently prescribed antibiotics, vancomycin and clindamycin, in synovial tissue and bone samples.

Methods: Method validation was performed based on the guidelines of the European Medicines Agency (EMA) and US Food and Drug Administration (FDA).

Results: The method was found linear for vancomycin from 0.8 to 25 μg/g and for clindamycin from 0.5 to 25 μg/g in the bone and from 1 to 25 μg/g for both compounds in synovial tissue (r2 > 0.990). The results of the validation of precision, accuracy, and carry-over were all within the acceptable ranges. All clindamycin extracts were stable in the autosampler for the bone and synovial tissue samples for up to 24 hours. Vancomycin extracts were stable in synovial tissue for up to 24 hours but not in bone sample extracts.

Conclusions: A method for quantifying vancomycin and clindamycin in synovial tissue and bone using UHPLC-MS/MS was developed and validated.