Impurity Standard List

Amlodipine besylate

S.NO Impurity Name Monograph Chemical Name Structure CAS NUMBER
1 AmlodipineImpurityA/Related compound D EP/USP 3-ethyl 5-methyl (4RS)-4-(2-Chlorophenyl)-2-[[2-(1,3-dioxo-1,3-dihydro-2H-isoindole-2-yl) ethoxy] methyl]-6-methyl-1,4-dihydropyridine-3,5-dicarboxylate 88150-62-3
2 AmlodipineImpurityB EP 3-ethyl 5-methyl (4RS)-4-(2-Chlorophenyl)-6-methyl-2- [[2- [[2- (methyl carbamoyl) benzoyl] amino] ethoxy] methyl]-1,4-dihydropyridine-3,5-dicarboxylate 721958-72-1
3 AmlodipineImpurityD/ Related compound-A (Dehydro Amlodipine) EP/USP 3-ethyl 5-methyl 2-[(2-aminoethoxy) -methyl]-4-(2-chlorophenyl)-6-methyl pyridine-3,5-dicarboxylate  113994-41-5
4 AmlodipineImpurityE/ Related compound E (Amlodipine diethyl ester)/ EP/USP diethyl(4RS)-2-[(2-aminoethoxy) methyl] -4-(2-chlorophenyl)-6-methyl-l, 4-dihydropyridine-3,5-dicarboxylate 140171-65-9
5 AmlodipineImpurityF/Related compound-F (Dimethoxyimpurity) EP/USP dimethyl(4RS)-2-[(2-aminoethoxy) methyl]-4-(2-chlorophenyl)-6-methyl-l,4-dihydropyridine-3,5-dicarboxylate 140171-66-0
6 AmlodipineImpurityG EP dimethyl-4-(2-chlorophenyl)-2,6-dimethyl-l, 4-dihydropyridine-3,5-dicarboxylate 43067-01-2
7 AmlodipineForPeak Identification  
8 Des chloroImpurityof Amlodipine besilate In house 3-ethyl 5-methyl 2-((2-aminoethoxy) methyl)-6-methyl-4-phenyl-1, 4-dihydropyridine-3,5-dicarboxylate benzenesulfonate NA
9 R (+) Amlodipine Impurity In house (R)-3-Ethyl 5-methyl 2-((2-aminoethoxy) methyl)-4-(2-chlorophenyl)-6-methyl-1,4-dihydropyridine-3,5-dicarboxylate Benzenesulfonate 828247-64-9
10 Des chloro Impurity of Amlodipine(St-IV) In house 3-ethyl 5-methyl 2-((2-(1,3-dioxoisoindolin -2-yl) ethoxy) methyl)-6-methyl-4-phenyl-1,4-dihydropyridine-3,5-dicarboxylate NA
11 Dimethoxy Impurity of Amlodipine(St-IVB) In house dimethyl 4-(2-chlorophenyl)-2-((2-(1,3-dioxoisoindolin-2-yl)ethoxy)methyl)- 6-methyl-1,4-dihydropyridine-3,5- dicarboxylate NA 
12 Dimethoxy Impurity of Amlodipine(St-II) In house ethyl 4-(2-(1,3-dioxoisoindolin-2-yl) ethoxy)-3-oxobutanoate 88150-75-8
13 Aspartate impurity of Amlodipine EP 4-(2-chlorophenyl)-2-[[2-[(1,2-dicarboxyethyl) amino] ethoxy] methyl]-1,4-dihydro-6-methyl-3,5-Pyridinedicarboxylic acid 3-ethyl 5-methyl ester 400602-35-9
14 Amlodipine Impurity-F Maleate (As per USP) USP Dimethyl(4RS)-2-((2-aminoethoxy) methyl))-4-(2-chlorophenyl)-6-methyl-1,4-dihydropyridine-3,5-Dicarboxylate.maleate -

Cetirizine Di Hydrochloride

S.NO Impurity Name Monograph Chemical Name Structure CAS NUMBER
15 Cetirizine Impurity A/ CBHP EP/USP (RS)-1-[(4-Chloropheny) phenylmethyl] piperazine 303-26-4
16 Cetirizine Impurity B/ Cetirizine acetic acidg EP/USP (RS)-2-[4-[(4-Chloropheny) phenylmethyl] piperazin-1-yl] acetic acid 113740-61-7
17 Cetirizine Impurity C/ 2-Chloro cetirizine EP/USP (RS)-2-[2-[4[(2-chlorophenyl) phenylmethyl] piperazin-1-yl] ethoxy] acetic acid 83881-59-8
18 Cetirizine Impurity D/ Cetirizine dimer EP/USP 1,4-bis[(4-Chloropheny) phenylmethyl] piperazine 346451-15-8
19 Cetirizine impurity E EP (RS)-2-[2-[2-[4-[(4-chlorophenyl) phenylmethyl] piperazin-1-yl] ethoxy] ethoxy] acetic acid 682323-77-9
20 Cetirizine Impurity F/Deschlorocetirizinea EP/USP 2-[2-[4-(diphenylmethyl) piperazin-1-yl] ethoxy] acetic acid 83881-53-2
21 Cetirizine Impurity G/ Cetirizine ethanol EP/USP (RS)-2-[4-[(4-chlorophenyl) phenylmethyl] piperazin-1-yl] ethan-1-ol 164726-80-1
22 METHYL ESTER OF CETIRIZINE (IMPURITY – E, As per USP) USP Methyl 2-[2-[4-[(4-chlorophenyl) phenyl methyl]-1-piperazinyl] ethoxy] acetate 83881-46-3
23 3- CHLORO IMPURITY OF CETIRZINE (IMPURITY – F, As per USP) USP 2-[2-[4-[(3-Chlorophenyl) phenyl methyl] piperazin-1-yl] ethoxy] acetic acid 1232460-29-5
24 PARACHLORO BENZHYDROL (IMPURITY – I, As per USP) USP 4-chloro benzhydrol 119-56-2
25 Para Chloro Benzo Phenone (IMPURITY – J, As per USP) USP (4-chlor phenyl) phenyl methanone 134-85-0
26 Cetirizine N-Oxide (IMPURITY – H, As per USP) USP 2-(2-{4-[(4-chlorophenyl) (phenyl) methyl] piperazin-1-yl} ethoxy) acetic acid N-oxide 1076199-80-8
27 Chloro pheniramine maleate
28 Cetirizine for peak identification
29 4-CBP Nitroso Impurity - 1-((4-Chlorophenyl) (phenyl)methyl)-4-nitrosopiperrazine 2005-04-1

Telmisartan

S.NO Impurity Name Monograph Chemical Name Structure CAS NUMBER
30 Telmisartan Impurity-C E.P

1,1-dimethylethyl 4’-[[4-methyl-6-
(1-methyl-1H-benzimidazol-2-yl)-2-propyl-1H-benzimidazole-1yl] methyl]biphenyl-2-carboxilate

 144702-26-1
31 Telmisartan Impurity-E E.P

1-((2'-Carboxy-[1,1'-biphenyl]-4-yl)methyl)-4-
methyl-2-propyl-1H-benzo[d]imidazole-6-carboxylic cid

 884330-12-5
32 Hydroxyzine hydrochloride EP working standard EP/USP

4-[[4-Methyl-6-(1-methyl-1H-benzimidazol-2-yl)-2-
propyl-1H-benzimidazol-1-yl]methyl][1,1-biphenyl]-2-carboxamide

 915124-86-6
33 Telmisartan Impurity-H EP

4-[[4-Methyl-6-(1-methyl-1H-benzimidazol-2-yl)-2-
propyl-1H-benzimidazol-1-yl]methyl][1,1-biphenyl]-2-carboxamide

 915124-86-6
34

Telmisartan Impurity-I

(Telmisartan methyl ester)		 EP

2-(4-{[4-Methyl-6-(1-methyl-1H-1,3-benzodiazol-2-yl)-2-propyl-1H-1,3-benzodiazol-1-yl]methyl}phenyl)benzoic acid methyl ester

 528560-93-2

Raloxifene HCl

S.NO Impurity Name Monograph Chemical Name Structure CAS NUMBER
35 Raloxifene (Dimethoxy Impurity) USP (6-methoxy-2-(4-methoxyphenyl) benzo[b] thiophen-3-yl) (4-(2-(piperidin-1-yl) ethoxy) phenyl) methanone 84541-38-8
36 Raloxifene Impurity-C (N-Oxide) USP 1-(2-(4-(6-hydroxy-2-(4-hydroxyphenyl) benzo[b] thiophene-3-carbonyl) phenoxy) ethyl) piperidine 1-oxide 195454-31-0
37 4-Methoxy-2-(4-Methoxy phenyl) benzo[b] Thiophene Impurity of Raloxifine In house 4-Methoxy-2-(4-Methoxy phenyl) benzo[b] thiophene 90433-54-8
38 Raloxifene Impurity-H USP 4-(2-(piperidin-1-yl) ethoxy) benzoic acid hydrochloride 84449-80-9
39 Methyl 4-(2-(piperidin-1-yl)ethoxy)benzoate In house Methyl 4-(2-(piperidin-1-yl)ethoxy)benzoate 89407-97-6

Clopidogrel bisulfate

S.NO Impurity Name Monograph Chemical Name Structure CAS NUMBER
40 Impurity-A EP/USP (2S)-2-(2-chlorophenyl)-2- [6,7-dihydrothieno [3,2-c] pyridin-5(4H)-yl] acid 144457-28-3
41 Impurity-B EP/USP Methyl (2S)- (o-chlorophenyl) [4,5-dihydrothieno[2,3-c] pyridine-6 (7H)-yl] acetate 1396841-05-6
42 Impurity-C EP/USP Clopidogrel Bisulfate R-Isomer; Methyl (-) -(R) -(o-chlorophenyl) [6,7-dihydrothieno [3,2-c] pyridine-5(4H)-yl] acetate hydrogen sulfate 120202-71-3

Working Standard’s

S.NO Impurity Name Monograph Chemical Name Structure CAS NUMBER
43 Amlodipine Besilate EP EP 3-ethyl 5-methyl(4RS)- 2-[(2-aminoethoxy) methyl]-4-(2-chlorophenyl)-6- methyl-1,4-dihydropyridine-3,5-dicarboxylate benzenesulfonate 111470-99-6
44 Amlodipine Besilate USP USP 3,5-pyridinecarboxylic acid 2-[(2-aminoethoxy) methyl]-4-(2-chlorophenyl) -1,4-dihydro-6-methyl-3-ethyl 5-methyl ester,(+)mono benzenesulfonate 111470-99-6
45 Amlodipine Besilate IP IP 3-ethyl 5-methyl(4RS)- 2-[(2-aminoethoxy) methyl]-4-(2-chlorophenyl)-6-methyl-1,4- dihydropyridine-3,5-dicarboxylate benzenesulfonate 111470-99-6
46 Amlodipine Besilate JP JP 3-ethyl 5-methyl(4RS)- 2-[(2-aminoethoxy) methyl]-4-(2-chlorophenyl)-6-methyl-1,4- dihydropyridine-3,5-dicarboxylate benzenesulfonate 111470-99-6
47 Amlodipine Maleate - 3-ethyl 5-methyl 2-((2-aminoethoxy) methyl) -4-(2-chlorophenyl)-6-methyl-1,4- dihydropyridine-3,5-dicarboxylate maleate 88150-47-4
48 S (-) Amlodipine Besilate IP (4S)-2-[(2-Aminoethoxy) methyl]-4- (2-chlorophenyl)-1, 4-dihydro-6-methyl-3, 5-pyridinedicarboxylic Acid 3-Ethyl 5-Methyl Ester benzene sulfonate 150566-71-5
49 Cetirizine Di Hydrochloride (EP) EP 2-(2-(4-((4-chlorophenyl) (phenyl) methyl) piperazin-1-yl) ethoxy) acetic acid 83881-52-1
50 Cetirizine Di Hydrochloride (USP) USP 2-(2-(4-((4-chlorophenyl) (phenyl) methyl) piperazin-1-yl) ethoxy) acetic acid 83881-52-1
51 Amlodipine Besilate St-I (Phthalimido Ethanol) In house 2-(2-hydroxyethyl) isoindoline-1,3-dione 3891-07-4
52 Amlodipine Besilate St-II In house ethyl 4-(2-(1,3-dioxoisoindolin-2-yl) ethoxy) -3-oxobutanoate 88150-75-8
53 Amlodipine Besilate St-III In house (E)-ethyl 2-(2-chlorobenzylidene)-4-(2-(1,3-dioxoisoindolin-2-yl) ethoxy)-3-oxobutanoate NA
54 Amlodipine Besilate St-IV(A) In house 3-ethyl 5-methyl 4-(2-chlorophenyl)-2-((2- (1,3-dioxoisoindolin-2-yl) ethoxy) methyl) -6-methyl-1,4-dihydropyridine-3,5- dicarboxylate 88150-62-3
55 Amlodipine Besilate St-IV(B) In house 3-ethyl 5-methyl 4-(2-chlorophenyl)-2-((2- (1,3-dioxoisoindolin-2-yl) ethoxy) methyl)- 6-methyl-1,4-dihydropyridine-3,5- dicarboxylate 88150-62-3
56 Amlodipine Besilate St-V Primary reference standard In house 3-ethyl 5-methyl 2-((2-aminoethoxy) methyl) -4-(2-chlorophenyl)-6-methyl-1,4- dihydropyridine-3,5-dicarboxylate 88150-42-9
57 Amlodipine Besilate St-V (Hanimi) In house 3-ethyl 5-methyl 2-((2-aminoethoxy) methyl) -4-(2-chlorophenyl)-6-methyl-1,4- dihydropyridine-3,5-dicarboxylate 88150-42-9
58 Hydroxyzine hydrochloride EP working standard EP 2-(2-(4-((4-chlorophenyl) (phenyl)methyl) piperazin- 1-yl) ethoxy) ethanol dihydrochloride 2192-20-3
59 Hydroxyzine hydrochloride USP working standard USP 2-(2-(4-((4-chlorophenyl) (phenyl)methyl) piperazin- 1-yl) ethoxy) ethanol dihydrochloride 2192-20-3
60 Levocetirizine di HCl IH/USP USP (R)-2-(2-(4-((4-chlorophenyl) (phenyl)methyl)  piperazin-1-yl) ethoxy) acetic acid dihydro chloride 130018-87-0
61 Telmisartan St-1 working. standard In house   4’-((1,7’-dimethyl-2’-propyle-1H,3’H-[2,5’-dibenzo[d]imidazole]-3’-yl) methyl)- [1,1’-biphenyl]-2-carbonitrile 1338830-39-9
62 Telmisartan EP working. standard EP 2-[4-[[4-methyl-6-(1-methyl benzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]benzoic acid, 144701-48-4
63 Telmisartan USP working. standard USP 2-[4-[[4-methyl-6-(1-methyl benzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]benzoic acid, 144701-48-4
64 Raloxifene -st-II working. standard In house 6-Methoxy-2-(4-methoxy phenyl) benzo(b)thiophene 63675-74-1
65 Raloxifene -st-III working. standard In house 4-(2-(1-piperdine)ethoxy benzoic acid hydrochloride 84449-80-9