Toxicology

Impurity Ipratropium EP Impurity E
Applications N-Isopropyl Noratropine is a Noratropine derivative, an intermediate in the production of Ipratropium.
References Simms, P., et al.: J. Pharm. Biomed. Anal., 17, 841 (1998),

Applications Labelled 7α-Hydroxy-4-cholesten-3-one (H825130). 7α-Hydroxy-4-cholesten-3-one is a metabolite of Cholesterol (C432501).
References Connor, W., et al.: J, Clin. Invest., 48, 1363 (1969),

Applications A labelled inhibitor of glucose synthesis.
References Garcia-Salguero, L. et al.: Arch. Int. Physiol., Biochim. Biophys., 99, 237, (1991); Martirosyan, A., et al.: Biochem. Pharmacol., 68, 1729 (2004);

Stability Hygroscopic
Applications 3-Sulfoglycolithocholic Acid Disodium Salt is a derivative of Lithocholic acid (L469180). Lithocholic acid (LCA) is a putative tumor promoter,that is shown to be able to inhibit mammalian DNA polymerase β.
References Ogawa, A., et al.: Jap. J. Canc. Res., 89, 1154 (1998)

Impurity Clobetasol Propionate EP Impurity K / Betamethasone Dipropionate EP Impurity C
Applications Betamethasone 21-Propionate (Clobetasol Propionate EP Impurity K) is a degradation product of Betamethasone. Glucocorticoid.
References Andersson, P., et al.: J. Pharm. Pharmacol., 36, 763 (1984), Wurthwein, G., et al.: Biopharm. Drug Dispos., 11, 381 (1990), Samtani, M., et al.: J. Pharm. Sci., 93, 726 (2004), Samtani, M., et al.: Drug Metab. Dispos., 33, 1124 (2005),

Applications Methyltriphenylphosphonium Bromide is a lipophilic molecule with a cation allowing for it to be used to deliver molecules to specific cell components. Also considered an antineoplastic agent.
References Selassie, C.D. et al.: J. Med. Chem., 33, 1914 (1990); Venkatachalam, M.A et al.: Kidney Int., 49, 449 (1996);

Stability Hygroscopic
Applications A metabolite of Equilin (E592800).
References Enmark, E., et al.: J. Clin. Endocrinol. Metab., 82, 4258 (1997), Wang, Z., et al.: J. Med. Chem., 43, 2419 (2000), Jiang, X., et al.: Steroids, 71, 334 (2006),

Stability Hygroscopic
Applications One of the bioactive forms of Riboflavin. Nutritional factor found in milk, eggs, malted barley, liver, kidney, heart, leafy vegetables. Richest natural source is yeast. Minute amounts present in all plant and animal cells. Vitamin (enzyme cofactor).
References Unna, K., et al.: J. Pharmacol. Exp. Ther., 76, 75 (1942), Rivlin, et al.: N. Engl. J. Med., 283, 463 (1970), Al-Shammary, F.J., et al.: Anal. Profiles Drug Subs., 19, 429 (1990),

Applications A new indicator for the determination of organic acid anhydrides by the morpholine method.
References Ruch, J.E., et al.: Anal. Chem., 47, 2057 (1975),

Applications Dabigatran Carboxamide Ethyl Ester is an impurity of Dabigatran Etexilate Mesylate (D100150) which is a nonpeptide, direct thrombin inhibitor.
References Hauel, N., et al.: J. Med. Chem., 45, 1757 (2002); Mungall, D., et al.: Curr. Opin. Invest. Drugs, 3, 095 (2002); Stangier, J., et al.: J. Clin. Pharmacol., 45, 555 (2005)

Applications A metabolite of Nortriptyline (N837000).
References Callaghan, R., et al.: J. Biol. Chem., 268, 16059 (1993), Dagenais, C., et al.: Biochem. Pharmacol., 67, 269 (2004), Doran, A., et al.: Drug Metab. Dispos., 33, 165 (2005),

Impurity Rosuvastatin EP Impurity F
Applications (4R,6S)-6-[(1E)-2-[4-(4-Fluorophenyl)-6-(1-methylethyl)-2-[methyl(methylsulfonyl)amino]-5-pyrimidinyl]ethenyl]-2,2-dimethyl-1,3-dioxane-4-acetic Acid 1,1-Dimethylethyl Ester (Rosuvastatin EP Impurity F) is a Rosuvastatin (R700500) intermediate as HMG-CoA reductase inhibitor.
References Beck, et al.: J. Med. Chem., 33, 52 (1999),

Applications 4-Hydroxy Estradiol 1-N7-Guanine is an estrogen metabolite formed with DNA which can lead to the mutations that initiate breast, prostate, and other types of cancer. Estrogen-DNA depurinating adducts as biomarkers of cancer risk and their use in cancer detection and prevention.
References Chakravarti, D., et al.: Mutat. Res., 456, 17 (2000), Liehr, J., et al.: Endocr. Rev., 21, 4054 (2000), Chakravarti, D., et al.: Oncogene, 20, 7945 (2001), Cavalieri, E., et al.: Chem. Res. Toxicol., 14, 1041 (2002),

Impurity Verapamil EP Impurity J HCl
Applications Nor Verapamil Hydrochloride (Verapamil EP Impurity J HCl) is a metabolite of Verapamil.
References Mutlib, A.E., et al.: The Journal of Pharm. & Exp. Therapeutics, 252, 2, 593 (1989)

Stability Light Sensitive, Temperature Sensitive
Applications A metabolite of all-trans Retinoic acid (R250200).
References Idres, N., et al.: Cancer Res., 61, 700 (2001), Taimi, M., et al.: J. Biol. Chem., 279, 77 (2004), Vermot, J., et al.: Science, 308, 563 (2005),

Applications Atorvastatin impurity. Atorvastatin Methyl Ester
References Graul, A., et al.: Drugs Future, 22, 956 (1997),

Applications A metabolite of Venlafaxine.

Applications A novel bile acid, an analogue of Cholic acid (C432600).
References Yamaga, N., et al.: J. Biochem., 116, 1123 (1994),

Applications A new Sildenafil (S435000) analogue.
References Balayssac, S., et al.: J. Pharm. Biomed. Anal., 50, 602 (2009),

Impurity Beclomethasone Dipropionate EP Impurity D
Applications 9-Deschloro-9-bromo Beclomethasone Dipropionate (Beclomethasone Dipropionate EP Impurity D) is an impurity of Beclomethasone Dipropionate (B131030).
References Shou, M. et al.: J. Pharmac. Biomed. Anal., 50, 356 (2009); Johnston, S. et al.: J. Chrom. Sci., 48, 733 (2010);

Stability Very Hygroscopic
Applications Mixed conjugate of dietary phytoestrogen.
References Adlercreutz, H;., et al.: J. Steroid Mol. Biol., 52, 97 (1995), Kinjo, J., et al.: Biol. Pharm. Bull., 27, 185 (2004),

Stability Hygroscopic
Applications The optically active isomer of Carvedilol (C184625), a nonselective ß-adrenergic blocker with a1-blocking activity. An antihypertensive used in the treatment of congestive heart failure.
Not a dangerous good if item is equal to or less than 1g/ml and there is less than 100g/ml in the package
References Hirohashi, M., et al.: Arzneim.-Forsch., 40, 735 (1990),

Impurity Clobetasol Propionate EP Impurity A / Betamethasone Dipropionate EP Impurity B
Applications Betamethasone 17-Propionate (Clobetasol Propionate EP Impurity A) is a degradation product of Betamethasone. Glucocorticoid.
References Andersson, P., et al.: J. Pharm. Pharmacol., 36, 763 (1984), Wurthwein, G., et al.: Biopharm. Drug Dispos., 11, 381 (1990), Samtani, M., et al.: J. Pharm. Sci., 93, 726 (2004), Samtani, M., et al.: Drug Metab. Dispos., 33, 1124 (2005),

Applications Testosterone Cypionate is an anabolic steroid with androgenic properties. Testosterone Cypionate is used for testosterone therapy in males with hypogonadism.Controlled Substance.
References Rabkin, J. G., et al.: J. Clin. Psychopharmacol., 19, 19 (1999); Hajjar, R., et al.: J. Clin. Endocrinol. Metab., 82, 3793 (1997); Rhoden, E., et al.: J. Sex Med., 7, 277 (2010);

Applications A major metabolite of Methylphenidate.
References Redalieu, E., et al.: Drug Metab. Dispos., 10, 708 (1982), Brewer, E., et al.: J. Pharm. Sci., 87, 395 (1998), Shah, V., et al.: Pharm. Res., 17, 1551 (2000), Tanaka, N., et al.: Anal. Chem., 73, 420 (2001),

Impurity Valproic Acid USP Related Compound B
Applications A constitutional isomer of Valproic acid; a potent anticonvulsant. Sodium valproate impurity C. Valproic Acid USP Related Compound B.
References Levy, R., et al.: Pharm. Res., 8, 551 (1991), Barton, M., et al.: Epilepsy Res., 47, 217 (2001), Fox, A., et al.: Pain, 105, 355 (2003), Archer, D., et al.: Anesth. Analg., 104, 180 (2007),

Applications Labelled Androgen. It has been used as an androgenic agent. Controlled substance (anabolic steroid).
References Bichet, N., et al.: Toxicol. Appl. Pharmacol., 106, 509 (1990), Gustafson, D., et al.: Toxicol. Sci., 53, 245 (2000), Copple, B., et al.: Toxicol. Sci., 77, 172 (2004), Takashima, K., et al.: Life Sci., 78, 2787 (2006),

Applications Norepinephrine Sulfonic Acid is a derivative of DL-Norepinephrine Hydrochloride (N674500), antagonist of dibutyryl cyclic-AMP in the regulation of narcosis. Norepinephrine modulates human dendritic cell activation by altering cytokine release.
Not a dangerous good if item is equal to or less than 1g/ml and there is less than 100g/ml in the package
References Piguet, P., et al.: J. Exp. Med., 173, 673 (1991), Hosoi, J., et al.: Nature, 363, 159 (1993), Elenkov, I., et al.: Pharmacol. Rev., 52, 595 (2000), Kaplan, D., et al.: Immunity, 23, 611 (2005),

Stability Light Sensitive
Applications 3-Methyl-4-nitroimino-tetrahydro-1,3,5-oxadiazine is a useful synthetic intermediate in the synthesis of Thiamethoxam (T344180); a neonicotinoid insecticide.
References Maienfisch, P., et al.: Z. Naturforsch. B., 61, 353 (2006); Fan, W., et al.: Shanghai Huagong, 27, 25 (2002); Maienfisch, P., et al.: Chimia, 57, 710 (2003); Oliver, J., et al.: J. Environ. Horticult., 28, 135 (2010); Ghosh, A., et al.: J. Entomol. Res., 34, 35 (2010)

Applications Iprovalicarb-d8 is the deuterated form of Iprovalicarb (I747500), which is a systematic fungicide. Iprovalicarb is used for the control of pathogenic fungi from the oomycetes class in grapes, potatoes, tomatoes and other crops.
References Stubler, D., et al.: Pflanzensch.-Nach. Bay., 52, 33 (1999); Stenzel, K., et al.: Bright. Crop Prot. Conf. Pests Dis., 2, 367 (1998);

Stability Hygroscopic
Applications (R,R)-Ethambutol-d4 Dihydrochloride is the isotope labelled analog of (R,R)-Ethambutol Dihydrochloride (E889805); a compound that shows antitumor properties when complexed with platinum. Also an isomer of Ethambutol (E889800) which is an antibacterial (tuberculostatic).
References Coluccia, M. et al.: Anticanc. Res., 11, 281 (1991); Wilkinson, et al.: J. Med. Chem., 5, 835 (1962); Kulig, et al.: Diss. Pharm. Pharmacol., 23, 463 (1971); Lee, C.S., et al.: Anal. Profiles Drug Subs., 7, 231 (1978)

Impurity Clarithromycin EP Impurity J
Applications Erythromycin A Oxime (Roxithromycin Impurity C) (Clarithromycin EP Impurity J) is the major metabolite of Roxithromycin and an intermediate of Azithromycin. Antibacterial agent. Roxithromycin impurity C.
References Ferrero, J., et al.: Drug Metab. Dispos., 18, 441 (1990), Gase, C., et al.: J. Antibiot., 44, 313 (1991), Markham, A., et al.: Drugs, 48, 297 (1994), Jarukamjorn, K., et al.: J. Pharm. Pharmacol., 50, 515 (1998),

Applications An impurity of Rifampamycin (R508000).

Stability Store in freezer
Applications A caffeine metabolite.
References Regal, K.A., et al.: J. of Chromatography B, 708, 75 (1998)

Applications Tirofiban intermediate.

Applications It is a potent and selective human CYP2C19 inhibitor.
Not a dangerous good if item is equal to or less than 1g/ml and there is less than 100g/ml in the package
References Suzuki, H., et al.: Drug Metab. Dispos., 30, 235 (2002), Robert, L., et al.: Drug Metab. Dispos., 31, 343 (2003),

Applications A labelled metabolite of Theophylline.
References ottrup, A., et al.: Pharmacol. Toxicol., 67, 340 (1990), El-Kadi, A., et al.: Drug Metab. Dispos., 28, 1112 (2000), Kim, S., et al.: J. Med. Chem., 45, 2131 ( 2002), Hansel, T., et al.: Drugs Today, 40, 55 (2004),

Stability Hygroscopic, Moisture Sensitive
Applications Phoxim-d5 (Phenyl-d5) (Mixture of Isomers) is a useful isotopically labeled compound of Phoxim (P380000(P)), which is an organophosphate insecticide. Phoxim is also an analogous dimethyl ester and an organothiophosphate acaricide.
References Lu, Y., et al.: Nature, 487, 362 (2012); Jokanovic, M., et al.: Arch. Toxicol., 70, 119 (1995); Wang, W., et al.: Pest. Biochem. Physiol., 84, 180 (2006)

Applications Anastrozole Acid Amide is a derivative of Anastrozole (A637425), an aromatase inhibitor. Used as an antineoplastic.
References Plourde, P.V., et al.: Breast Cancer Res. Treat., 30, 103 (1994), Buzdar, A.U., et al.: Cancer, 79, 730 (1997)

Applications Labelled Talinolol. Selective β1-adrenergic blocker structurally related to Practolol. Antihypertensive; antiarrhythmic.
References Assmann, I., et al.: Curr. Med. Res. Opin., 13, 325 (1995), Trausch, B., et al.: Biopharm. Drug Dispos., 16, 403 (1995),

Applications An antimalarial.
References Natarajan, L., et al.: Arzneim.-Forsch., 22, 1230 (1972), Kracmer, J., et al.: Pharmazie, 29, 773 (1974), Ahmad, I., et al.: Anal. Profiles Drug Subs., 21, 43 (1992),

Applications Mono N-Desmethyl Disperse Polyester Dark Blue is a disperse dye for synthetic polyester fibers. It has good heat and light resistance and is used for thermal transfer recording.
References Peters A. T., et al.: J. Soc. Dyers Colour, 108(7-8), 344-8 (1992)

Applications Perindoprilat-d4 is the isotope labelled analog of Perindoprilat (P287531); an angiotensin-converting enzyme (ACE) inhibitor and antihypertensive.
References Pascard, C., et al.: J. Med. Chem., 34, 663 (1991)

Applications Flurbiprofen (1S,2R,5S)-(+)-Menthyl Ester is an isomer version of Flurbiprofen rac-Menthyl Ester (M221723), a Flurbiprofen (F598700) derivative. Flurbiprofen is an anti-inflammatory used as an analgesic
References Chalmers, et al.: Ann. Rheum. Dis., 31, 319 (1972), Nishizawa, et al.: Thromb. Res., 3, 577 (1973)

Applications 1,2,4,5-Tetrahydrotestolactone is a steroid with estrogenic properties. A steroid lactone.
References Pollard, I., et al.: Steroids, 11, 897 (1968), Volovel'skii, L. N., et al.: Zh. Obshch. Khim., 43, 1414 (1973)

Impurity Fluocinolone Acetonide EP Impurity I
Applications 14,15-Dehydro Fluocinolone Acetonide is an impurity of Fluocinolone Acetonide (F455800); a glucocorticoid and anti-inflammatory agent.
References Sammul, et al.: J. Assoc. Off. Agric. Chem., 47, 952 (1964); Emerson, M.V., et al.: BioDrugs, 21, 245 (2007)

Applications A metabolite of Quinidine.
References Small, D.L., et al.: J. Chem. Med., 22, 1014 (1979), Guentert, T.W., et al.: Eur. J. Drug Metab. Pharmacokinet., 7, 31 (1982), Rakhir, A., et al.: J. Pharmacokinet. Biopharm., 12, 1 (1984), Christie, D.J., et al.: J. Lab. Clin. Med., 112, 92 (1988),

Applications 3-Methyl Adenine-d3 is labelled 3-Methyl Adenine (M275904). 3-Methyl Adenine is a selective autophagy and phosphoinositide 3-kinase (PI3K) inhibitor (1,2,3). 3-MA inhibits autophagy by blocking autophagosome formation via the inhibition of type III Phosphatidylinositol 3-kinases (PI-3K).
References (1) Munafo, D., et al.: J. Cell Sci., 114, 3619 (2001) (2) Aggarwal, B., et al.: Biochem. Pharmacol., 71, 1397 (2006) (3) Hayat, M., et al.: Oncologist, 12, 20 (2007)

Applications Deuterated Ketoconazole, an inhibitor of cytochrome P-450 dependent steps in the biosynthesis of steroid hormones in vivo. Antimetastatic and antineoplastic activity. Orally active 5-lipoxygenase and thromboxane synthase inhibitor.
Not a dangerous good if item is equal to or less than 1g/ml and there is less than 100g/ml in the package
References Lambert, A., et al.: Biochem. Pharmacol., 35, 3999 (1986), Van Wauwe, J.P. and Janssen, P.A.J., J. Med. Chem., 32, 2231 (1989), Nardone, P.A., et al.: . Surg. Res., 44, 425 (1988), Tucker, W.F.G., et al.: Br. Med. J., 293, 882 (1986)

Applications The major product of the stereoselective human metabolism of Chloroquine, used for the therapy and prevention of malaria. It is a COVID19-related research product.
References Essien, E., et al.: J. Pharm. Pharmacol., 38, 543 (1986), Akintonwa, A., et al.: Ther. Drug Monit., 10, 147 (1988), Boelaert, J., et al.: AIDS, 15, 2205 (2001), Basco, L., et al.: Antimicrob. Agents Chemother., 47, 1391 (2003),

Applications Lisdexamphetamine Dimesylate is used as a treatment for adults with attention-deficit/hyperactivity disorder (ADHD). Lisdexamphetamine Dimesylate has been shown to improve executive dysfunction and depressive symptoms in people with mild major depressive disorder (MDD).
References Martin, P.T., et al.: Clin. Drug Invest., 34, 147 (2014); Madhoo, M., et. al.: Neuropsychopharmacol., 39, 1388 (2014);

Applications A labelled version of Losartan, a nonpeptide angiotensin II AT1-receptor antagonist. Antihypertensive.
References Chiu, T.A., et al.: J. Pharmacol. Exp. Ther., 252, 711 (1990), McIntyre, M., et al.: Pharmacol. Ther., 74, 181 (1997), Pitt, B., et al.: Lancet, 355, 1582 (2000)

Applications Testosterone 17-Phenylpropionate, is one of the 17β-fatty acid esters of testosterone, that is increasingly misused by athletes in an attempt to improve sports performance, and thus can be used in doping control. It can also be used as a therapy in glucocorticoid-treated patients to increase the circulating testosterone concentration.
References Shackleton, C. H. L., et al.: Steroids, 62 (7), 523 (1997); Reid, I. R., et al.: Archives Internal Med., 156 (11), 1173 (1996);

Applications Uric Acid-1,3-15N2 is the labeled analogue of Uric Acid (U829200), a heterocyclcic compound that is created when purine nucleotides are broken down of by the human body. High blood concetration of Uric Acid is known as hyperuricemia and is often associated with a wide range of disorders and medical conditions such as gout, diabetes and metabolic syndrome. Uric acid may be a marker of oxidative stress and may have a potential therapeutic role as an antioxidant.
References Heinig, M. et al.: Cle. Clin. J. Med., 73, 1059 (2006); Glantzounis, G.K. et al.: Curr. Pharmac. Des., 11, 4145 (2005); Dehghan, A. et al.: Diab. Care, 31, 361 (2008); Nakagawa, T. et al.: Am. J. Physiol. Renal Physiol., 290, F625 (2006)

Applications Diagnostic aid (radiopaque medium).
References Bourrinet, P., et al.: Invest. Radiol., 29, 1057 (1994), Donadieu, A.-M., et al.: Acta Radiol., 37, 400 (1996),

Applications A potent phosphodiesterase III A (PDE3A) inhibitor (IC50=0.2uM) and inhibitor of adenosine uptake. Has antimitogeni, antithrombotic, vasodilatory and cardiotonic properties in vivo. Also affects lipid levels in vivo.
References Suri, A., et al.: J. Clin. Pharmacol., 38, 144 (1998), Park, S.-W., et al.: Am. J. Cardiol., 84, 511 (1999), Tsuchikane, E., et al.: Circulation, 100, 21 (1999),

Applications A tobacco smoke-derived nitrosamine which is activated by multiple human cytochrome P 450s including the polymorphic human cytochrome P 4502D6.
Not a dangerous good if item is equal to or less than 1g/ml and there is less than 100g/ml in the package
References Castonguay, A., et al.: Cancer Lett., 46, 93 (1989), Crespi, C.L., et al.: Carcinogenesis, 12, 1197 (1991),

Applications (R,R)-Ethambutol Dihydrochloride shows antitumor properties when complexed with platinum. Also an isomer of Ethambutol (E889800), an antibacterial (tuberculostatic).
References Coluccia, M. et al.: Anticanc. Res., 11, 281 (1991); Wilkinson, et al.: J. Med. Chem., 5, 835 (1962), Kulig, et al.: Diss. Pharm. Pharmacol., 23, 463 (1971), Lee, C.S., et al.: Anal. Profiles Drug Subs., 7, 231 (1978)

Applications Oseltamivir citric acid is an impurity of Oseltamivir (O701005), an antiviral drug that is an orally active inhibitor of influenza virus neuraminidase; converted in vivo to the active acid metabolite. It is a COVID19-related research product.
References Oliyai, R., et al.: Pharm. Res., 15, 1300 (1998); Kim, C.U., et al.: Med. Chem. Res., 8, 392 (1998); Hayden, F.G., et al.: N. Engl. J. Med., 341, 1336 (1999); Treanor, J.J., et al.: J. Am. Med. Assoc., 283, 1016 (2000);

Applications S-Ramelteon Metabolite M-II is a metabolite of Ramelteon in serum (M-II).
References Karim, A., et al.: J. Clin. Pharmacol., 44, 1210 (2004); Prescott, E., et al.: Drug Metab. Rev., 36, 203 (2004); Kato, K., et al.: Neuropharmacology, 48, 301 (2005); Karim, A., et al.: J. Clin. Pharmacol., 46, 140 (2006)

Stability Hygroscopic
Applications Itraconazole N,N-Dioxide is a derivative of Itraconazole (I937500). Itraconazole is an orally active antimycotic structurally related to Ketoconazole. Antifungal. It is a COVID19-related research product.
References Espinel-Ingroff, A., et al.: Antimicrob. Agents Chemother., 26, 5 (1984), Heykants, J., et al.: Mycoses, 32, Suppl 1, 67 (1989), Sugar, A.M.,et al.: Curr. Clin. Top. Infect. Dis., 13, 74 (1993),

Applications Ciprofloxacin (C482500).

Applications Cholinesterase inhibitor. Use as systemic insecticide, acaricide, nematocide. Used in Pesticide detection.
Not a dangerous good if item is equal to or less than 1g/ml and there is less than 100g/ml in the package
References Dorough, W.H., et al.: J. Agric. Food Chem., 16, 319 (1968),

Impurity Ampicillin EP Impurity A ; Amoxicillin USP Related Compound A
Applications (+)-6-Aminopenicillanic Acid (Amoxicillin EP Impurity A) is the core structure in penicillins, obtained from the fermentation brew of the Penicillium mold. (+)-6-Aminopenicillanic Acid is used as the main starting block for the preparation of numerous semisynthetic penicillins.
References Zel'tser, I.Z. et al.: Gig. Truda Prof. Zabol., 5, 59 (1983); Hamilton-Miller, J.M.T.: Int. J. Antimicrob. Agents, 31, 189 (2008); Novikova, N.D. et al.: Mikol. Fitopatol., 7, 101 (1973);

Impurity Fluconazole EP Impurity H
Applications 2-(2,4-Difluorophenyl)-1-(1H-1,2,4-triazol-1-yl)-3-bromopropan-2-ol (Fluconazole EP Impurity H) is an impurity of the antifungal agent Fluconazole (F421000).
References Bourichi, H., et al.: STP Pharma Pratiques, 18, 285 (2008); Richard, K. et al.: Antimicrob. Ag. Chemother., 27, 832 (1985)

Applications Intermediate in the preparation of imidazole antifungal agents.
References Albet, C. et al.; J. Pharmaceut. Biomed. 10, 205 (1992); Raga, M. et al.; Eur. J. Med. Chem. 21, 329 (1986)

Applications Acyclic phosphonate nucleotide analogue; reverse transcriptase inhibitor. Used as an anti-HIV agent. Antiviral.
References Shaw, J.-P., et al.: Pharm. Res., 14, 1824 (1997), Wyles, D., et al.: Clin Infect. Dis., 40, 174 (2005), Peng, J., et al.: J. Clin. Pharmacol., 46, 265 (2006), Seminari, E., et al.: J. Antimicrob. Chemother., 60, 831 (2007),

Impurity Abacavir EP Impurity A
Applications ent-Abacavir (Abacavir EP Impurity A) is an enatiomer of Abacavir (A105000). Abacavir is a carbocyclic 2'-deoxyguanosine nucleoside reverse transcriptase inhibitor and an anti-HIV drug used to treat HIV infection (1). Intracellular enzymes convert Abacavir to its active form, carbovir-triphosphate (CBV-TP), which then selectively inhibits HIV reverse transcriptase by incorporating into viral DNA (2). Abacavir is metabolized in the liver by uridine diphosphate glucuronyltransferase and alcohol dehydrogenase resulting in inactive glucuronide and carboxylate metabolites, respectively.
References (1) Jackson, A., et al.: Antivir Ther. 17, 19 (2012) (2) Yuen, G. J., et al.: Clin Pharmacokinet. 47, 351 (2008)

Impurity Levofloxacin USP Related Compound C
Applications Levofloxacin Ethyl Ester (Levofloxacin USP Related Compound C) is an impurity of Levofloxacin (L360000).
References Lalitha Devi, M. et al.: J. Pharrm. Biomed. ANal., 50, 710 (2009); Mehta, J. et al.: Int. J. PharmTech Res., 2, 1932 (2010);

Applications Ledipasvir is most commonly used in combination with sofosbuvir for treatment in chronic hepatitis C genotype 1 patients. It inhibits an important viral phosphoprotein, NS5A, which is involved in viral replication, assembly, and secretion.
References Lawitz, E., et al.: J. Hepatol., 57, 24 (2012); Afdhal, N., et al.: New England J. Med., 370, 1889 (2014)