Abstract: The present invention relates to a process for the preparation of pharmaceutical, injectable or ophthalmic grade hyaluronic acid, or a salt thereof, for use in the dermocosmetic or pharmaceutical field or in medical devices, which comprises dissolution of hyaluronic acid or a salt thereof in organic solvent, a heat cycle, and recovery of the product by precipitation and successive washes in organic solvents.

Abstract: The present invention relates to a process for the preparation of crosslinked hyaluronic acid butyrate or crosslinked hyaluronic acid butyrate-formate or an acceptable salt thereof, wherein the process comprises the crosslinking reaction of hyaluronic acid butyrate or hyaluronic acid butyrate-formate or a pharmaceutically acceptable salt thereof in an organic solvent with a carboxyl activating reagent, characterized in that the hyaluronic acid butyrate or hyaluronic acid butyrate-formate or pharmaceutically acceptable salt thereof is a mixture of a high-molecular-weight polysaccharide and a low-molecular-weight polysaccharide.

Abstract: The present invention relates to a process for the preparation of pharmaceutical, injectable or ophthalmic grade hyaluronic acid, or a salt thereof, for use in the dermocosmetic or pharmaceutical field or in medical devices, which comprises dissolution of hyaluronic acid or a salt thereof in organic solvent, a heat cycle, and recovery of the product by precipitation and successive washes in organic solvents.

Abstract: Disclosed is a hydrogel containing hyaluronic acid esterified on its free hydroxyls with lipoic acid or with lipoic acid and formic acid, or a pharmaceutically acceptable salt thereof, and zinc gluconate. Also disclosed is a process for the preparation of the hydrogel, compositions containing it, and the use of the hydrogel and the compositions thereof in the pharmaceutical and cosmetic fields or as topical or injectable medical devices.

Abstract: The present invention relates to a process for the preparation of hyaluronic acid butyrate, or a salt thereof, acceptable for pharmaceutical or cosmetic use or as a medical device, comprising reacting hyaluronic acid, salified with sodium or another alkali metal, in aqueous solution with butyryl-imidazolide in the presence of sodium carbonate. The present invention also relates to pharmaceutical formulations, cosmetic formulations or medical devices containing the hyaluronic acid sodium salt (HA) butyric esters produced by said process.

Abstract: The present invention relates to a process for the preparation of hyaluronic acid butyrate, or a salt thereof, acceptable for pharmaceutical or cosmetic use or as a medical device, comprising reacting hyaluronic acid, salified with sodium or another alkali metal, in aqueous solution with butyryl-imidazolide in the presence of sodium carbonate. The present invention also relates to pharmaceutical formulations, cosmetic formulations or medical devices containing the hyaluronic acid sodium salt (HA) butyric esters produced by said process.

Abstract: Non-crosslinked derivatives of oligo/polysaccharides of formula wherein: X is OH, O?M, NH—R1, O—R1; M is an alkaline or alkaline-earth metal, transition metal, or cation containing a quaternary nitrogen atom; Y is H or R2; R1: the residue of an oligo/polysaccharide; R2: the residue of a C1-C4 linear chain aliphatic carboxylic acid or citric acid; provided that at least one X is NH—R1 or O—R1, while the other two X are present in acid (OH) or salified form (OM).

Abstract: Disclosed are acid polysaccharides characterized by the concomitant presence of alcohol groups esterified with butyric and formic acids.

Abstract: Acid polysaccharides characterized by the concomitant presence of partial esters with non-polysaccharide carboxylic acids and esters between the acid groups of the initial polysaccharide and the alcohol groups of the repetitive units, with the formation of crosslinking among the polysaccharide chains.

Abstract: Non-crosslinked derivatives of oligo/polysaccharides of formula I, wherein: X is OH, OM, NH—R1, O—R1; M is an alkaline or alkaline-earth metal, transition metal, or cation containing a quaternary nitrogen atom; Y is H or R2; R1: the residue of an oligo/polysaccharide; R2: the residue of a C1-C4 linear chain aliphatic carboxylic acid or citric acid; provided that at least one X is NH—R1 or O—R1, while the other two X are present in acid (OH) or salified form (OM).

Abstract: Disclosed are acid polysaccharides characterised by the concomitant presence of alcohol groups esterified with butyric and formic acids.

Abstract: Acid polysaccharides characterised by the concomitant presence of partial esters with non-polysaccharide carboxylic acids and esters between the acid groups of the initial polysaccharide and the alcohol groups of the repetitive units, with the formation of crosslinking among the polysaccharide chains. Process for the preparation of these derivatives comprising the reaction, in homogenous phase in the protic, polar solvent formamide, of the salt of a monovalent inorganic cation of the selected carboxylated polysaccharide with an anhydride of an alkylcarboxylic acid in the presence of a basic catalyst containing an atom of trisubstituted nitrogen. The formamide hydrolysis leads to the formation of a formate ester.