In recent times, Fexofenadine Impurity synthesis was main objective for KarpsChem team. As we knowFexofenadine, α, α-dimethyl-4-[1-hydroxy-4-[4-(hydroxydiphenyl-methyl)-1-piperidinyl] butyl]-benzene acetic acid  is the active carboxylic acid analogue of the antihistamine terfenadine. It shares the histamine H1 receptor antagonist and non-sedative properties of the parent compound. This could be attributed to its capability to exist in zwitter-ionic form so it cannot pass through blood-brain barrier and therefore does not cause sedation. Fexofenadine is a second generation antihistamine drug useful to available treatments of allergic diseases with a wide margin of safety. KarpsChem has succesfully synthesized and supplyed critical impurities of Fexofenadine i.e. Fexofenadine EP Impurity A CAS: 76811-98-8; Fexofenadine EP Impurity C CAS:185066-37-9; Fexofenadine EP Impurity E CAS:115-46-8; Fexofenadine Impurity 1 CAS:154477-54-0 etc. to clients.