Polymorphous forms of rifaximin, processes for their production and use thereof in the medicinal preparations

摘要

Crystalline polymorphous forms of the rifaximin (INN) antibiotic named rifaximin δ and rifaximin ε useful in the production of medicinal preparations containing rifaximin for oral and topical use and obtained by means of a crystallization process carried out by hot-dissolving the raw rifaximin in ethyl alcohol and by causing the crystallization of the product by addition of water at a determinate temperature and for a determinate period of time, followed by a drying carried out under controlled conditions until reaching a settled water content in the end product, are the object of the invention.

主权项

1. Rifaximin in polymorphic form δ, wherein the rifaximin polymorphic form δ has x-ray powder diffraction pattern peaks at about 5.7°±0.2, 12.1°±0.2, and 17.0°±0.2 2-θ.