Friulchem S.p.A., a Vivaro, Italy-based contract development and manufacturing organization for innovator and generic pharmaceutical products for human and veterinary use, reports on manufacturing developments for rifaximin, an active pharmaceutical ingredient (API) used to treat travelers’ diarrhea in adults and children 12-years of age and older. Rifaximin has also been evaluated for treating hepatic encephalopathy, infectious diarrhea, diverticular disease, and as an antibacterial prophylactic before colon surgery.

Rifaximin is a semi-synthetic product derived from fermentation and that shows many polymorphs, most of them are covered by patent (alpha-, beta-, gamma-, and delta-forms). The alpha-polymorph is the most active. It cannot be absorbed, so its intestinal action is local, according to information from Friulchem.

Friulchem has patented another polymorph, a pseudo-crystalline solid form, FC rifaximin, derived from rifamycin O. The FC patent was filed in 2011 in Europe, Mexico, and the US (PCT/EP2011/058171), and the patent has been granted in Europe and the US. 

FC rifaximin is stable at different contents of water (% KF 2.00 – 4.45) and is distinct from the other patented forms (alpha, beta, and gamma), according to the company. It will be available in 200-mg and 550-mg film-coated tablets for human use.

FC-rifaximin can also be used in veterinary applications. Friulchem has identified a different manufacturing method for a chewable matrix without the limitation related to production by extrusion.

The company reports due to the high palatability showed in preliminary tests, FC-cubes may be used to prepare formulations that can include different APIs, including rifaximin. The matrix composition is 100% palatable and is able to mask also active components that are disliked by animals, according to the company.

Source: Friulchem