To loratadine 
 The main components of this product to desloratadine, the chemical name 8 - chloro -6,11 - dihydro -11 (4 - Asia piperidyl)-5H-benzo - [5,6] heptane [1 ,2-b] pyridine, the chemical structure is as follows: 
 Molecular formula: C19H19CIN2 MW: 310.82 
 This product is a long-term non-sedative tricyclic antihistamine is loratadine, the active metabolite, through selective peripheral H1 receptor antagonist to alleviate allergic rhinitis or chronic idiopathic urticaria related symptoms. In addition, in vitro studies, product can inhibit histamine release from human mast cells. Animal studies suggest that the product is not easy through the blood-brain barrier.