Levocetirizine (dihydrochloride) (Standard) is the analytical standard of Levocetirizine (dihydrochloride). This product is intended for research and analytical applications. Levocetirizine dihydrochloride ((R)-Cetirizine dihydrochloride) is a third-generation peripheral H1-receptor antagonist. Levocetirizine dihydrochloride is an antihistaminic agent which is the R-enantiomer of Cetirizine. Levocetirizine dihydrochloride has a higher affinity for the histamine H1-receptor than (S)-Cetirizine and can effectively treat allergic rhinitis and chronic idiopathic urticaria^[1].