Levocetirizine

• CAT Number: R011040
• CAS Number: 130018-77-8
• Molecular Formula: C21H25ClN2O3
• Molecular Weight: 388.89
• Purity: ≥95%
• Synonyms: 2-[2-[4-[(R)-(4-chlorophenyl)-phenylmethyl]piperazin-1-yl]ethoxy]acetic acid
• InChI: InChI=1S/C21H25ClN2O3/c22-19-8-6-18(7-9-19)21(17-4-2-1-3-5-17)24-12-10-23(11-13-24)14-15-27-16-20(25)26/h1-9,21H,10-16H2,(H,25,26)/t21-/m1/s1
• InChIKey: ZKLPARSLTMPFCP-OAQYLSRUSA-N
• SMILES: C1CN(CCN1CCOCC(=O)O)[C@H](C2=CC=CC=C2)C3=CC=C(C=C3)Cl

Levocetirizine（Cat No.:R011040）is a third-generation antihistamine, the active enantiomer of cetirizine, widely prescribed for allergic conditions such as allergic rhinitis, chronic idiopathic urticaria, and seasonal allergies. It selectively blocks peripheral H1-receptors, reducing histamine-mediated symptoms including sneezing, itching, watery eyes, and nasal congestion. Compared with earlier antihistamines, levocetirizine has a rapid onset of action, high potency, and minimal sedative effects due to limited blood–brain barrier penetration. Its once-daily dosing enhances patient compliance, making it effective for long-term allergy management with a favorable safety and tolerability profile across diverse age groups.