6-Hydroxy Chlorzoxazone

6-Hydroxy Chlorzoxazone is a structurally modified derivative of Chlorzoxazone, featuring an additional hydroxy group at the 6-position of the benzene ring. This substitution introduces a polar hydroxyl functionality, altering the compound's solubility and stability profile compared to the parent drug. The oxazone core retains its characteristic lactam structure, while the chloro substituent at C-5 remains intact. This impurity arises via oxidative degradation pathways, specifically hydroxylation of the aromatic ring. It serves as a critical HPLC reference standard for quantifying oxidative degradation in Chlorzoxazone formulations.