Hydroxyzine D4 is a deuterium-labeled variation of Hydroxyzine, a chemical compound known for its anticholinergic, anxiolytic, and analgesic properties. It is classified as a heterocyclic histamine H1-receptor antagonist.
Cetirizine Impurity C is an impurity of Cetirizine. Cetirizine is a second-generation antihistamine and the carboxylated metabolite of hydroxyzine. It acts as a specific, orally active, and long-acting antagonist of the histamine H1-receptor[1][2].