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 delta and rifaximin epsilon 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.