Quantitative bioanalytical validation of fosfomycin in human whole blood with volumetric absorptive microsampling

Background: Fosfomycin is an antibiotic of considerable interest for the treatment of infection by multidrug-resistant bacteria. Translating microsampling techniques into clinical PK studies may provide effective dosing information to improve patient outcomes and minimize the potential development of resistance. Results: Accuracy and precision results were within +/- 15%; the method was validated across the range of 5-2000 mu g/ml of fosfomycin using volumetric absorptive microsampling (VAMS) devices. Conclusion: The VAMS techniques provide acceptable validation data as assessed for lower limit of quantification, linearity, intra- and interday precision and accuracy, selectivity and matrix effects. Results from the recovery and stability studies suggest challenges remain for the analysis of fosfomycin in whole blood using VAMS.