Rifaximin

Infectious diarrhea, hepatic encephalopathy and other diseases related to intestinal microecological disorder have long plagued clinical practice. As a representative of non-absorbable broad-spectrum intestinal antibiotics, rifaximin provides a treatment option with low systemic exposure risk for such diseases. Its mechanism of action is to specifically inhibit bacterial DNA-dependent RNA polymerase and block bacterial protein synthesis. After oral administration, only 0.4% is absorbed into the blood, and the vast majority exerts effects locally in the intestinal tract, covering Gram-positive and Gram-negative aerobes and anaerobes. Its clinical indications include acute infectious diarrhea, traveler's diarrhea, and diarrhea related to intestinal flora imbalance. It can also be used to reduce the recurrence risk of overt hepatic encephalopathy. The applicable population covers adults and children over 6 months old, and its long-term use safety is better than that of antibacterial drugs with systemic effects.

As a commonly used and mature variety in the field of clinical intestinal infection, the global market size of rifaximin was approximately USD 890 million in 2023, and it is expected to expand steadily at a compound annual growth rate of 3.2% from 2024 to 2030. The growth rate of the Chinese market is higher than the global average. In 2023, its hospital sales exceeded RMB 1.2 billion, of which oral dosage forms accounted for more than 98%. At present, domestic generic drug enterprises dominate the market. A total of 27 enterprises hold preparation approvals, and 5 varieties have passed the consistency evaluation. In 2022, the average price reduction of rifaximin oral conventional-release dosage forms in inter-provincial centralized procurement in multiple regions reached 61%, further improving clinical accessibility.

The original research enterprise of rifaximin is Alfasigma S.p.A., and the original brand name is "Normix". Its core compound patent expires in 2029 in the United States, while the core patent in China expired in 2017. The main dosage form of the original research drug approved in China is oral tablet, with specifications of 200mg and 400mg, which has been included in the *Catalogue of Chemical Reference Preparations (10th Batch)* issued by the National Medical Products Administration. As of now, the China API Registration Platform has included 31 rifaximin API registration entries, of which 17 have been activated with A status and can be legally supplied for preparation production. 24 oral rifaximin preparation varieties have been approved for marketing in China. (Data as of April 2025, please refer to the official website of CDE for the latest information.)

CATO provides a full set of rifaximin impurity reference standards. Most products are in stock. For in-stock products, orders placed before 16:00 will be shipped on the same day. They fully comply with the regulatory requirements of the Chinese Pharmacopoeia and FDA, and can provide reliable reference standard support for API and preparation enterprises in the whole process of quality research, stability study, registration and declaration, etc.