Analysis of LK-157 in Plasma by LC-MS-MS: Application to Studies of Pharmacokinetics and Degradation Pathways in Rats and Dogs

Multiple-species plasma-stability testing and pharmacokinetic studies in rats and dogs were performed on LK-157, a novel 10-ethylidene tricyclic carbapenem and potent inactivator of β-lactamases of classes A, C, and D. An LC-MS-MS method was developed and validated for analysis of LK-157 in rat and dog plasma. Separation was achieved on a C₁₈ column by gradient elution. The lower limit of quantification for LK-157 in plasma was 50 ng mL⁻¹. Intra-day and inter-day precision were