Comparative validation of LC-MS, micro-bioassay, and ELISA for lincomycin quantification: application to pharmacokinetic analysis in healthy and co-infected porcine models

This study compared liquid chromatography–mass spectrometry (LC-MS), micro-bioassay (MBa), and enzyme-linked immunosorbent assay (ELISA) for quantification of lincomycin (10 mg/kg BW) in porcine serum and evaluated lincomycin pharmacokinetic (PK) data in healthy piglets also co-infected with Actinobacillus pleuropneumoniae and Pasteurella multocida. All methods satisfied standard bioanalytical validation criteria, including low limits of detection and quantification, acceptable intra-assay imprecision and error, and strong linearity across clinically relevant concentration ranges. Serum concentrations measured by MBa and ELISA showed high correlation with LC-MS in both healthy and infected models (Pearson r ≥ 0.97, low bias on Bland–Altman analysis); they produced comparable PK parameters (Cmax, Tmax, area under the curve [AUC], clearance, and mean residence time), indicating suitability for PK/pharmacodynamic (PD)-based dose optimization. PK analysis demonstrated rapid absorption after intramuscular administration and disease-associated alterations in selected distribution and disposition parameters. AUC and clearance were nearly similar across analytical methods and largely consistent between software platforms (WinNonlin and PKSolver). Thus, lower-cost MBa and ELISA—combined with freely available PKSolver—can generate robust, decision-relevant PK/PD data for lincomycin in swine, providing a practical framework for antimicrobial dose refinement and stewardship in resource-limited veterinary and farm settings.