Methoxy Nafcillin sodium salt

Methoxy Nafcillin sodium salt is a structurally modified derivative of Nafcillin Sodium, characterized by the substitution of a hydroxyl group with a methoxy (-OCH3) moiety at the side chain adjacent to the beta-lactam core. This substitution alters the electronic and steric properties of the parent antibiotic, rendering it a non-active impurity formed during synthetic oxidation processes. The compound retains the thiazolidine-2-one ring and sodium counterion critical to the parent drug's pharmacophore but exhibits reduced antimicrobial activity due to methoxy group steric hindrance. It serves as a key HPLC reference standard for quantifying process-related impurities in Nafcillin Sodium formulations.