title: High-performance liquid chromatographic method for simple and rapid determination of linezolid in human plasma.
abstract: A simple high-performance liquid chromatographic (HPLC) method was developed and validated for rapid quantification of linezolid in human plasma. Protein precipitation using a mixture of 5% trichloroacetic acid and methanol (3:1, v/v) provided a straightforward method of sample preparation and the internal standard eperezolid was employed. A concentration range from 0.20 to 40.0 mg/L was utilized to construct calibration curves, and analysis of low- (0.40 mg/L), medium- (7.50 mg/L) and high-quality (25.0 mg/L) control samples revealed excellent reproducibility (<or=3.88%) and accuracy (<or=4.20%). The recovery of both linezolid and eperezolid was approximately 100%. No interference was observed at the retention times of linezolid and eperezolid from blank plasma or eight commonly used antibiotics. Tests confirmed the stability of linezolid in plasma during three freeze-thaw cycles, on the bench during 24 h and during long-term storage of frozen plasma for up to 12 weeks; in extracts it was stable in the HPLC autosampler over 12 h. Overall, this assay offers a highly simplistic approach to quantifying linezolid in plasma, and would be well suited to clinical pharmacokinetic, pharmacodynamic and toxicodynamic analyses.
authors.affiliation: Facility for Anti-infective Drug Development and Innovation, Department of Pharmacy Practice, Victorian College of Pharmacy, Monash University, Parkville, Victoria 3052, Australia.
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Boak
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Roger L
authors.initials: RL
authors.lastname: Nation
authors.forename: Craig R
authors.initials: CR
authors.lastname: Rayner
mesh_terms: D000081:Acetamides / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D006801:Humans; D000069349:Linezolid; D023303:Oxazolidinones / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000081:Acetamides; D023303:Oxazolidinones; C098011:eperezolid; D000069349:Linezolid