| abstract |
An object of the present invention is a crystalline polymorph of rifaximin (INN), referred to as rifaximin α and rifaximin β, and an almost amorphous form, referred to as rifaximin γ, which are used in the preparation of oral and topical rifaximin containing medicaments. Useful, the crystallization process is carried out by hot-dissolving crude rifaximin in ethyl alcohol and adding water at a predetermined temperature and for a predetermined time to induce crystallization of the product, and the specific water content in the final product. It can obtain by drying under the conditions controlled until it is obtained. |