Abstract: Crystalline polymorphous forms of rifaximin (INN), referred to as rifaximin ? and rifaximin ?, and a poorly crystalline form referred to as rifaximin ?, useful in the production of medicaments 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 fixed temperature and for a fixed period of time, followed by a drying under controlled conditions until reaching a precise water content in the end product, are the object of the invention.

Abstract: Disclosed are rifamycin derivatives having antibacterial activities, wherein the compounds have the following general formula: wherein: R is hydrogen or acetyl; R1 and R2 are independently selected from the group consisting of hydrogen, (C1-4) alkyl, benzyloxy, mono- and di-(C1-3) alkylamino-(C1-4)alkyl, (C1-3)alkoxy, (C1-4) alkyl, hydroxy-methyl, hydroxy-(C2-4)-alkyl, and nitro or R1 and R2 taken together with two consecutive carbon atoms of the pyridine nucleus form a benzene ring optionally substituted by one or two methyl or ethyl groups and R3 is hydroxyalkyl (C1-4). In addition, processes to obtain these compounds are described.

Abstract: Object of the invention are mucoadhesive and controlled release formulations consisting of aqueous solutions containing 0.05% to 5% by weight of a natural purified polymer having xyloglucan structure and 10% to 70% by weight of glycerol. These formulations are suitable for the application on human mucous membranes, such as nasal, oral and vaginal mucous membranes, as moisturizing and softening agents or as pharmaceutical release system. Further objects of the invention are pharmaceutical formulations and medical devices suitable for the application to human mucous membranes, containing the mucoadhesive and controlled release formulations together with active ingredients and excipients.