Validated Multi-site GLP-compliant Analysis of Solithromycin (SOLI) in Monkey Plasma Samples Following Filtration to Remove Potentially Active Anthrax Spores


A highly sensitive method was developed and validated to allow monkey plasma samples, potentially containing Bacillus anthracis (B. anthracis) spores, to be sterilized and shipped from the collection sites to the bioanalytical laboratory for analysis of Solithromycin (SOLI), a novel fluoroketolide antibiotic, and two of its metabolites. In the presence of plasma, the compounds were found to bind to the filtration devices typically used to remove B. anthracis spores and were unstable in the acetonitrile used for precipitating samples. A stabilizing solution was developed to both inhibit nonspecific binding to the filter and preserve SOLI and its two metabolites during sample processing, storage and shipment. B. anthracis free samples can then be shipped to a bioanalytical laboratory for further processing. The entire process was validated between the sites to ensure accurate and precise bioanalytical data and safety from anthrax.