Abstract: The present invention relates to Rifaximin polymorphic forms ?, ? and ?, to their use in medicinal preparations for the oral or topical route and to therapeutic methods using them.

Abstract: The present invention relates to Rifaximin polymorphic forms ?, ? and ?, to their use in medicinal preparations for the oral or topical route and to therapeutic methods using them.

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: The present invention relates to Rifaximin polymorphic forms ?, ? and ?, to their use in medicinal preparations for the oral or topical route and to therapeutic methods using them.

Abstract: Crystalline polymorphous forms of the rifaximin (INN) antibiotic named rifaximin ? and rifaximin ?, and a poorly crystalline form named rifaximin ? have been discovered. These forms are useful in the production of medicinal preparations for oral and topical use and can be 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 the addition of water at a determinate temperature and for a determinate period of time. The crystallization is followed by drying carried out under controlled conditions until a specific water content is reached in the end product.

Abstract: A process is described for the purification of recombinant human beta interferon which comprises the use of three chromatographic stages carried out in series, utilizing as stationary phases: glass particles of controlled porosity, cation exchange polymer resins and polymer resins able to complex heavy metals.

Abstract: This invention firstly provides a method for purifying particular compounds of peptide or pseudo-peptide structure in which the number of protonable basic functions is greater than the number of acid functions and which have a molecular weight of less than 1000 daltons, by ion exchange displacement chromatography. In the method of the present invention the stationary phase used is a cationic exchange resin or a cross-linked polymer matrix activated with acid groups; the transporter solvent used is water if the compound to be purified already possesses at least one net positive charge, or aqueous dilute solutions of inorganic or strong organic acids which protonate the basic groups of the peptide or pseudo-peptide to be separated without modifying the structure of the peptide compound, such as acetic acid, trifluoroacetic acid, formic acid, hydrochloric acid or sulphuric acid; the displacer compound used is a triethylenetetraammonium salt.

Abstract: A new mono-silylating agent of general formula (I)(R.sub.1,R.sub.2,R.sub.3)Si--NH--CO--O--Si(R.sub.1,R.sub.2,R.sub.3) (I)is described as well as its use in the preparation of chromatographic supports based on silica with functional groups covalently bonded thereto, the so-called "bonded stationary phases".The new compounds are easy and safe to prepare from the coresponding mono-halosilanes with ammonium carbamate, and their use as silylating agents leads to stationary phases with a higher degree of surface coating than that attainable with the corresponding chlorosilanes.

Abstract: New retro-inverso peptides and peptide derivatives in the form of analogues of C-terminal hexapeptide fragments of Substance P, which are pharmacologically active, possess prolonged action with time, and are of general formula (I): ##STR1## they being useful as vasedilators.

Abstract: This invention relates to new retro-inverso peptides and peptide derivatives in the form of analogues and the C-terminal penta and hexapeptide fragments of Substance P, which are pharmacologically active, possess prolonged action with time and are useful as vasodilators, their general formula being: ##STR1##