omeprazole and its Impurities
A selective and irreversible proton pump inhibitor, Omeprazole is used in the treatment of gastroesophageal reflux disease (GERD) and peptic ulcers.Omeprazole exists as a racemic mixture of R and S enantiomers.Reference standards of Omeprazole API,and its pharmacopeial, non pharmacopeial impurities, and stable isotopes are listed below.


1-(5-Methoxy-1H-benzimidazol-2-yl)-3,5-dimethyl-4-oxo-1,4-dihydro-2-pyridinecarboxylic Acid
1-(5-Methoxy-1H-benzimidazol-2-yl)-3,5-dimethyl-4-oxo-1,4-dihydro-2-pyridinecarboxylic Acid
Catalogue No.:PA 15 05580
CAS :
1227380-90-6
Molecular Formula : C16H15N3O4
Molecular Weight : 313.31


8(9)-Methoxy-1,3-dimethyl-12-thioxopyrido[1',2':3,4]imidazo[1,2-a]benzimidazol-2-(12H)-one (Mixture of Regioisomers)
8(9)-Methoxy-1,3-dimethyl-12-thioxopyrido[1',2':3,4]imidazo[1,2-a]benzimidazol-2-(12H)-one (Mixture of Regioisomers)
Catalogue No.:PA 15 05620
CAS :
NA
Molecular Formula : C16H13N3O2S
Molecular Weight : 311.36


5-Methoxy-1-((4-methoxy-3,5-dimethylpyridin-2-yl)methyl)-2-(((4-methoxy-3,5-dimethylpyridin-2-yl)methyl)sulfinyl)-1h-benzo[d]imidazole
5-Methoxy-1-((4-methoxy-3,5-dimethylpyridin-2-yl)methyl)-2-(((4-methoxy-3,5-dimethylpyridin-2-yl)methyl)sulfinyl)-1h-benzo[d]imidazole
Catalogue No.:PA 15 05650
CAS :
1346599-85-6
Molecular Formula : C26H30N4O4S
Molecular Weight : 494.61


2,2'-(((4-Methoxy-3,5-dimethylpyridine-2,6-diyl)bis(methylene))bis(sulfanediyl))bis(5-methoxy-1H-benzo[d]imidazole)
2,2'-(((4-Methoxy-3,5-dimethylpyridine-2,6-diyl)bis(methylene))bis(sulfanediyl))bis(5-methoxy-1H-benzo[d]imidazole)
Catalogue No.:PA 15 05730
CAS :
NA
Molecular Formula : C26H27N5O3S2
Molecular Weight : 521.65


R-Omeprazole (5-Methoxy-2-[(R)-[(4-methoxy-3,5-dimethyl-2-pyridyl)methyl]sulfinyl]-1H-benzimidazole (1478479)
R-Omeprazole (5-Methoxy-2-[(R)-[(4-methoxy-3,5-dimethyl-2-pyridyl)methyl]sulfinyl]-1H-benzimidazole (1478479)
Catalogue No.:PA USP1478479
CAS :
161796-77-6
Molecular Formula : NA
Molecular Weight : NA


Omeprazole Related Compound A (5-methoxy-2-[[(4-methoxy-3,5-dimethylpyridin-2-yl)methyl]sulfonyl]-1 (1478516)
Omeprazole Related Compound A (5-methoxy-2-[[(4-methoxy-3,5-dimethylpyridin-2-yl)methyl]sulfonyl]-1 (1478516)
Catalogue No.:PA USP1478516
CAS :
88546-55-8
Molecular Formula : NA
Molecular Weight : NA


Omeprazole Related Compound E (4-Methoxy-2-[[(RS)-(5-methoxy-1H-benzimidazol-2-yl)sulfinyl]methyl]- (1478527)
Omeprazole Related Compound E (4-Methoxy-2-[[(RS)-(5-methoxy-1H-benzimidazol-2-yl)sulfinyl]methyl]- (1478527)
Catalogue No.:PA USP1478527
CAS :
176219-04-8
Molecular Formula : NA
Molecular Weight : NA


Omeprazole Related Compound I (4-Methoxy-2-[[(5-methoxy-1H-benzimidazol-2-yl)sulfonyl]methyl]-3,5-d (1478561)
Omeprazole Related Compound I (4-Methoxy-2-[[(5-methoxy-1H-benzimidazol-2-yl)sulfonyl]methyl]-3,5-d (1478561)
Catalogue No.:PA USP1478561
CAS :
158812-85-2
Molecular Formula : NA
Molecular Weight : NA


2-(((4-((tert-Butyldimethylsilyl)oxy)-3,5-dimethylpyridin-2-yl)methyl)thio)-6-methoxy-1H-benzo[d]imidazole
2-(((4-((tert-Butyldimethylsilyl)oxy)-3,5-dimethylpyridin-2-yl)methyl)thio)-6-methoxy-1H-benzo[d]imidazole
Catalogue No.:PAI 15 009020
CAS :
NA
Molecular Formula : C22H31N3O2SSi
Molecular Weight : 429.65


2-(((4-((tert-Butyldimethylsilyl)oxy)-3,5-dimethylpyridin-2-yl)methyl)sulfinyl)-6-methoxy-1H-benzo[d]imidazole
2-(((4-((tert-Butyldimethylsilyl)oxy)-3,5-dimethylpyridin-2-yl)methyl)sulfinyl)-6-methoxy-1H-benzo[d]imidazole
Catalogue No.:PAI 15 009030
CAS :
NA
Molecular Formula : C22H31N3O3SSi
Molecular Weight : 445.65

![4-Methoxy-2-(((5-methoxy-1H-benzo[d]imidazol-2-yl) PAI 15 009031](https://www.pharmaffiliates.com/pimages/PAI15009031.jpg)
4-Methoxy-2-(((5-methoxy-1H-benzo[d]imidazol-2-yl)thio)methyl)-3,5-dimethylpyridine 1-oxide
4-Methoxy-2-(((5-methoxy-1H-benzo[d]imidazol-2-yl)thio)methyl)-3,5-dimethylpyridine 1-oxide
Catalogue No.:PAI 15 009031
CAS :
142885-92-5
Molecular Formula : C17H19N3O3S
Molecular Weight : 345.42

![1-(5-Methoxy-1-(1-(5-methoxy-1H-benzo[d]imidazol-2 PA 15 0051006](https://www.pharmaffiliates.com/pimages/PA150051006.jpg)
1-(5-Methoxy-1-(1-(5-methoxy-1H-benzo[d]imidazol-2-yl)-3,5-dimethyl-4-oxo-1,4-dihydropyridine-2-carbonyl)-1H-benzo[d]imidazol-2-yl)-3,5-dimethyl-4-oxo-1,4-dihydropyridine-2-carboxylic Acid
1-(5-Methoxy-1-(1-(5-methoxy-1H-benzo[d]imidazol-2-yl)-3,5-dimethyl-4-oxo-1,4-dihydropyridine-2-carbonyl)-1H-benzo[d]imidazol-2-yl)-3,5-dimethyl-4-oxo-1,4-dihydropyridine-2-carboxylic Acid
Catalogue No.:PA 15 0051006
CAS :
2819805-13-3
Molecular Formula : C32H28N6O7
Molecular Weight : 608.61