Date published: 2026-4-30

1-800-457-3801

SCBT Portrait Logo
Seach Input

Rifaximin (CAS 80621-81-4)

5.0(1)
Write a reviewAsk a question

See product citations (2)

Alternate Names:
Rifaximin is also known as Rifacol.
Application:
Rifaximin is a Pregnane X receptor agonist and antibiotic that inhibits RNA synthesis and activates PXR.
CAS Number:
80621-81-4
Purity:
≥99%
Molecular Weight:
785.88
Molecular Formula:
C43H51N3O11
For Research Use Only. Not Intended for Diagnostic or Therapeutic Use.
* Refer to Certificate of Analysis for lot specific data.

QUICK LINKS

Rifaximin is an antibiotic that inhibits RNA synthesis and acts as a PXR (pregnane-X-receptor) activator. Rifaximin is a derivative of rifamycin that may act to act strongly against Enterococcus, Streptococcus and Staphylococcus, with less activity against Enterobacteriaceae. Rifaximin has been in a variety of gastrointestinal and intestinal epithelial cell studies. Rifaximin reduced the number of colon tumors and suppressed expression of TNFα and Il-1β induced in a colon cancer.


Rifaximin (CAS 80621-81-4) References

  1. In vitro activity and fecal concentration of rifaximin after oral administration.  |  Jiang, ZD., et al. 2000. Antimicrob Agents Chemother. 44: 2205-6. PMID: 10898704
  2. Experimental and clinical pharmacology of rifaximin, a gastrointestinal selective antibiotic.  |  Scarpignato, C. and Pelosini, I. 2006. Digestion. 73 Suppl 1: 13-27. PMID: 16498249
  3. Pretreatment of epithelial cells with rifaximin alters bacterial attachment and internalization profiles.  |  Brown, EL., et al. 2010. Antimicrob Agents Chemother. 54: 388-96. PMID: 19858255
  4. Bile acids improve the antimicrobial effect of rifaximin.  |  Darkoh, C., et al. 2010. Antimicrob Agents Chemother. 54: 3618-24. PMID: 20547807
  5. Rifaximin: a nonsystemic rifamycin antibiotic for gastrointestinal infections.  |  Cottreau, J., et al. 2010. Expert Rev Anti Infect Ther. 8: 747-60. PMID: 20586560
  6. Therapeutic role of rifaximin in inflammatory bowel disease: clinical implication of human pregnane X receptor activation.  |  Cheng, J., et al. 2010. J Pharmacol Exp Ther. 335: 32-41. PMID: 20627999
  7. Pregnane-X-receptor mediates the anti-inflammatory activities of rifaximin on detoxification pathways in intestinal epithelial cells.  |  Mencarelli, A., et al. 2010. Biochem Pharmacol. 80: 1700-7. PMID: 20816942
  8. Clinical trial: the combination of rifaximin with partially hydrolysed guar gum is more effective than rifaximin alone in eradicating small intestinal bacterial overgrowth.  |  Furnari, M., et al. 2010. Aliment Pharmacol Ther. 32: 1000-6. PMID: 20937045
  9. Inhibition of NF-κB by a PXR-dependent pathway mediates counter-regulatory activities of rifaximin on innate immunity in intestinal epithelial cells.  |  Mencarelli, A., et al. 2011. Eur J Pharmacol. 668: 317-24. PMID: 21806984
  10. Rifaximin alters intestinal bacteria and prevents stress-induced gut inflammation and visceral hyperalgesia in rats.  |  Xu, D., et al. 2014. Gastroenterology. 146: 484-96.e4. PMID: 24161699
  11. Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth.  |  Chedid, V., et al. 2014. Glob Adv Health Med. 3: 16-24. PMID: 24891990
  12. Beneficial effects of Rifaximin in post-infectious irritable bowel syndrome mouse model beyond gut microbiota.  |  Jin, Y., et al. 2018. J Gastroenterol Hepatol. 33: 443-452. PMID: 28573746
  13. Rifaximin Alters Intestinal Microbiota and Prevents Progression of Ankylosing Spondylitis in Mice.  |  Yang, L., et al. 2019. Front Cell Infect Microbiol. 9: 44. PMID: 30886835
  14. Rifaximin. A review of its antibacterial activity, pharmacokinetic properties and therapeutic potential in conditions mediated by gastrointestinal bacteria.  |  Gillis, JC. and Brogden, RN. 1995. Drugs. 49: 467-84. PMID: 7774516

Ordering Information

Product NameCatalog #UNITPriceQtyFAVORITES

Rifaximin, 100 mg

sc-205841B
100 mg
$28.00

Rifaximin, 250 mg

sc-205841C
250 mg
$42.00

Rifaximin, 500 mg

sc-205841
500 mg
$79.00

Rifaximin, 1 g

sc-205841A
1 g
$105.00

Rifaximin, 5 g

sc-205841D
5 g
$406.00

Hi, we bought the batch F1715 of sc-205841B. I'd like to know if the purity was measured on dried basis. Morover I noticed that the result of loss on dry is pretty low (<0.15%) we found only rifaximin with water content above 3%, how do you keep it low?

Asked by: A Perandini
Thank you for your question. It would be helpful if you could call us, allowing for a more interactive discussion of this and other related questions.
Answered by: Technical Support
Date published: 2021-07-23
  • y_2026, m_4, d_29, h_11CST
  • bvseo_bulk, prod_bvqa, vn_bulk_3.0.43
  • cp_1, bvpage1
  • co_hasquestionsanswers, tq_1
  • loc_en_US, sid_205841, prod, sort_[SortEntry(order=LAST_APPROVED_ANSWER_SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_scbt
  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • CLOUD, getContent, 114ms
  • QUESTIONS, PRODUCT
Rated 5 out of 5 by from Cheng et alCheng et al. (PubMed ID 20627999) found that rifaximin showed a therapeutic effect against inflammatory bowel disease via human PXR-mediated inhibition of the NF- B signaling cascade. -SCBT Publication Review
Date published: 2015-03-09
  • y_2026, m_4, d_29, h_11
  • bvseo_bulk, prod_bvrr, vn_bulk_3.0.43
  • cp_1, bvpage1
  • co_hasreviews, tv_0, tr_1
  • loc_en_US, sid_205841, prod, sort_[SortEntry(order=SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_scbt
  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • CLOUD, getReviews, 9ms
  • REVIEWS, PRODUCT
Rifaximin is rated 5.0 out of 5 by 1.
  • y_2026, m_4, d_29, h_11
  • bvseo_bulk, prod_bvrr, vn_bulk_3.0.43
  • cp_1, bvpage1
  • co_hasreviews, tv_0, tr_1
  • loc_en_US, sid_205841, prod, sort_[SortEntry(order=SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_scbt
  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • CLOUD, getAggregateRating, 105ms
  • REVIEWS, PRODUCT