Quantitative determination of the macrolide antibiotic tulathromycin in plasma and broncho-alveolar cells of foals using tandem mass spectrometry

• Published in: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences Vol. 850; no. 1; pp. 464 - 470
• Main Authors: Scheuch, Eberhard, Spieker, Janina, Venner, Monica, Siegmund, Werner
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-05-2007; Elsevier Science
• Subjects: Analysis; Analytical, structural and metabolic biochemistry; Animals; Anti-Bacterial Agents - analysis; Anti-Bacterial Agents - blood; Anti-Bacterial Agents - pharmacokinetics; Biological and medical sciences; Broncho-alveolar cells; Bronchoalveolar Lavage Fluid - chemistry; Disaccharides - analysis; Disaccharides - blood; Disaccharides - pharmacokinetics; Drug assay; Fundamental and applied biological sciences. Psychology; General pharmacology; Heterocyclic Compounds - analysis; Heterocyclic Compounds - blood; Heterocyclic Compounds - pharmacokinetics; Horses; LC–MS/MS; Medical sciences; Pharmacokinetics; Pharmacology. Drug treatments; Reference Standards; Tandem Mass Spectrometry - methods; Tulathromycin; Broncho-alveolar cells; Pharmacokinetics; LC–MS/MS; Tulathromycin; Drug assay; Drug; Biological fluid; Liquid chromatography; In vitro; Macrolide; Blood plasma; Antibiotic; Mass spectrometry MS/MS; Tulathromycin; Drug assay; Pharmacokinetics; Broncho-alveolar cells; LC-MS/MS; Protein synthesis inhibitor; Antibacterial agent; Quantitative analysis
• ISSN: 1570-0232; 1873-376X
• DOI: 10.1016/j.jchromb.2006.12.034

The long-acting antibiotic tulathromycin is on the marked for treatment of pulmonary infection of cattle, swine and horses. To measure disposition and distribution of tulathromycin in foals, a high throughput method was developed for horse plasma (calibration range: 0.006–0.8
μg/mL) and broncho-alveolar cells (calibration range: 0.1–4.0
μg/10
9
cells) using tandem mass spectrometry. Tulathromycin was extracted from plasma and broncho-alveolar fluid using cation exchange cartridges with acetonitrile/ammonia (95:5, v/v). The chromatography was performed isocratically with a mobile phase consisting of 5
mM ammonium formiate buffer/acetonitrile (30:70, v/v). The mass spectrometer operated in selected ion mode with atmospheric pressure chemical ionization to monitor the respective MH
+ ions
m/
z 577.3 for tulathromycin and
m/
z 679.3 for the internal standard roxithromycin. All quality parameters fulfilled the international criteria for bioanalytical method validation and were successfully applied to the determination of tulathromycin in plasma of foals and broncho-alveolar cells. In foals, tulathromycin after intramuscular administration was rapidly absorbed, widely distributed and slowly eliminated. It cumulated manifold in broncho-alveolar cells.