Separation-based bioanalysis of teicoplanin for therapeutic drug monitoring: Chromatographic selectivity,...

Teicoplanin is a highly protein-bound glycopeptide supplied as a mixture of structurally related components. Its therapeutic drug monitoring (TDM) result therefore depends on component coverage, calibrator composition, biological matrix, sample preparation, chromatography, and detector response. This critical review maps separation-based teicoplanin methods in human matrices, with emphasis on chromatographic selectivity and biomedical fitness. PubMed/MEDLINE was searched from January 2009 through 18 August 2026 and supplemented by citation searching. Twenty-six eligible primary method publications and three contextual comparison or interlaboratory studies were identified by the present search strategy; these counts do not imply exhaustive coverage. Plasma was the principal matrix in 16 primary methods, serum in seven, dried blood spots (DBS) in two, and urine in one. Twenty methods incorporated mass-spectrometric detection and nine were multiplex assays. HPLC-UV and micellar electrokinetic chromatography made component resolution visible but often required longer analysis or enrichment. Targeted LC-MS/MS supported low-volume and multiplex TDM, although retention, component summation, calibrators, and internal standards differed. High-resolution MS expanded analogue identification, while paired total/unbound assays addressed variable protein binding. A study-level matrix showed inconsistent reporting of matrix effect, carry-over, stability, dilution integrity, and patient-sample comparison. Interlaboratory evidence demonstrates variability but does not isolate calibrator, component-coverage, or internal-standard differences as proven causes. Analytical validity, method agreement, and clinical utility should therefore be evaluated separately. Serum or plasma remains the best-supported reference matrix for routine dose adjustment; DBS requires formal paired agreement and independent validation of any conversion equation. High-resolution MS is valuable for component identification but is not necessary for routine TDM once a targeted measurand and method are validated. Future assays should define the measurand before the platform, document component summation and calibrator traceability, and report matrix-appropriate validation and auditable resource use.