fexofenadine and its Impurities
Fexofenadine used to relieve allergy symptoms such as watery eyes, runny nose, itching eyes/nose, sneezing, hives, and itching. It is sold under the trade name Allegra & FX 24. Reference standards of Fexofenadine API,and its pharmacopeial, non pharmacopeial impurities, and stable isotopes are listed below.

![4-[4-[4-(Hydroxydiphenylmethyl)-1-piperidinyl]-1-b PA 06 17040](https://www.pharmaffiliates.com/pimages/PA0617040.jpg)
4-[4-[4-(Hydroxydiphenylmethyl)-1-piperidinyl]-1-butyn-1-yl]-α,α-dimethyl-benzeneacetic Acid
4-[4-[4-(Hydroxydiphenylmethyl)-1-piperidinyl]-1-butyn-1-yl]-α,α-dimethyl-benzeneacetic Acid
Catalogue No.:PA 06 17040
CAS :
832088-68-3
Molecular Formula : C32H35NO3
Molecular Weight : 481.63


Methyl 2-(3-(4-(4-(hydroxydiphenylmethyl)piperidin-1-yl)butanoyl)phenyl)-2-methylpropanoate
Methyl 2-(3-(4-(4-(hydroxydiphenylmethyl)piperidin-1-yl)butanoyl)phenyl)-2-methylpropanoate
Catalogue No.:PAI 06 002010
CAS :
937009-94-4
Molecular Formula : C33H39NO4
Molecular Weight : 513.67


2-(3-(1-Hydroxy-4-(4-(hydroxydiphenylmethyl)piperidin-1-yl)butyl)phenyl)-2-methylpropanoic Acid
2-(3-(1-Hydroxy-4-(4-(hydroxydiphenylmethyl)piperidin-1-yl)butyl)phenyl)-2-methylpropanoic Acid
Catalogue No.:PAI 06 002030
CAS :
479035-75-1
Molecular Formula : C32H39NO4
Molecular Weight : 501.66


2-(3-(4-(4-(Hydroxydiphenylmethyl)piperidin-1-yl)but-1-en-1-yl)phenyl)-2-methylpropanoic Acid Hydrochloride
2-(3-(4-(4-(Hydroxydiphenylmethyl)piperidin-1-yl)but-1-en-1-yl)phenyl)-2-methylpropanoic Acid Hydrochloride
Catalogue No.:PA 06 17630
CAS :
NA
Molecular Formula : C32H38ClNO3
Molecular Weight : 520.11


Fexofenadine Related Compound A (4-[1-oxy-4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]butyl]-alpha,a (1270388)
Fexofenadine Related Compound A (4-[1-oxy-4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]butyl]-alpha,a (1270388)
Catalogue No.:PA USP1270388
CAS :
76811-98-8
Molecular Formula : NA
Molecular Weight : NA


Fexofenadine Related Compound B (3-[1-hydroxy-4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]butyl]-alp (1270399)
Fexofenadine Related Compound B (3-[1-hydroxy-4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]butyl]-alp (1270399)
Catalogue No.:PA USP1270399
CAS :
NA
Molecular Formula : NA
Molecular Weight : NA


Fexofenadine Related Compound C ((+/-)-4-[1-hydroxy-4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]-but (1270446)
Fexofenadine Related Compound C ((+/-)-4-[1-hydroxy-4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]-but (1270446)
Catalogue No.:PA USP1270446
CAS :
NA
Molecular Formula : NA
Molecular Weight : NA

![(Z)-4-[4-[4-(Hydroxydiphenylmethyl)-1-piperidinyl] PA 06 17640](https://www.pharmaffiliates.com/pimages/PA0617640.jpg)
(Z)-4-[4-[4-(Hydroxydiphenylmethyl)-1-piperidinyl]-1-buten-1-yl]-α,α-dimethyl-benzeneacetic Acid
(Z)-4-[4-[4-(Hydroxydiphenylmethyl)-1-piperidinyl]-1-buten-1-yl]-α,α-dimethyl-benzeneacetic Acid
Catalogue No.:PA 06 17640
CAS :
NA
Molecular Formula : C32H37NO3
Molecular Weight : 483.65


Methyl 2-(3-(1-hydroxy-4-(4-(hydroxydiphenylmethyl)piperidin-1-yl)butyl)phenyl)-2-methylpropanoate
Methyl 2-(3-(1-hydroxy-4-(4-(hydroxydiphenylmethyl)piperidin-1-yl)butyl)phenyl)-2-methylpropanoate
Catalogue No.:PAI 06 002070
CAS :
1187954-56-8
Molecular Formula : C33H41NO4
Molecular Weight : 515.69


2-(4-(4-(4-(Diphenylmethylene)piperidin-1-yl)butanoyl)phenyl)-2-methylpropanoic Acid Methyl Ester
2-(4-(4-(4-(Diphenylmethylene)piperidin-1-yl)butanoyl)phenyl)-2-methylpropanoic Acid Methyl Ester
Catalogue No.:PA 06 0171003
CAS :
1025909-08-3
Molecular Formula : C33H37NO3
Molecular Weight : 495.66


Ethyl 2-(4-(1-hydroxy-4-(4-(hydroxydiphenylmethyl)piperidin-1-yl)butyl)phenyl)-2-methylpropanoate
Ethyl 2-(4-(1-hydroxy-4-(4-(hydroxydiphenylmethyl)piperidin-1-yl)butyl)phenyl)-2-methylpropanoate
Catalogue No.:PA 06 0171006
CAS :
174483-06-8
Molecular Formula : C34H43NO4
Molecular Weight : 529.72


(E)-2-(4-(4-(4-(Diphenylmethylene)piperidin-1-yl)but-1-en-1-yl)phenyl)-2-methylpropanoic Acid;
(E)-2-(4-(4-(4-(Diphenylmethylene)piperidin-1-yl)but-1-en-1-yl)phenyl)-2-methylpropanoic Acid;
Catalogue No.:PA 06 0171008
CAS :
1026338-29-3
Molecular Formula : C32H35NO2
Molecular Weight : 465.64