ESCITALOPRAM - IMPURITY H [ n-oxide impurity

Escitalopram Impurity H is an N-oxide derivative arising from oxidation of the piperazine nitrogen in the parent compound. It retains the core 1-(2-pyrimidinyl)-piperazine scaffold of escitalopram but features an oxygenated nitrogen in the piperazine ring, altering its electronic and steric properties. This impurity forms via oxidative degradation pathways during synthesis or storage. Its distinct polarity and chromatographic behavior enable differentiation from the API. Used as an HPLC reference standard for quantifying N-oxide impurity levels in escitalopram formulations.