Abstract: A process for purifying high molecular weight hyaluronic acid from a biological source, including the steps of adjusting the pH of an aqueous solution containing high molecular weight hyaluronic acid from a biological source to a pH in the range from 1.7 to 3.3 and then diafiltering said aqueous solution at the same pH using a filter having a pore size in the range from 100,000 Daltons nominal molecular cut-off to 0.45 m, and of removing cells from the aqueous solution containing high molecular weight hyaluronic acid from biological source.

Abstract: Described herein is the use of hyaluronic acid for intra-articular irrigation, in the form of an aqueous solution, comprising hyaluronic acid having molecular weight of between 1.8 and 2.2 million daltons, or one of its pharmaceutically acceptable salts, in a concentration of between approximately 0.1% and approximately 0.9% weight/volume, and one or more cationic species chosen from among sodium, potassium, calcium and magnesium, and one or more anionic species chosen from among chloride ions, phosphate ions and citrate ions.

Abstract: The present invention relates to an ophthalmic formulation, for use in eye surgery, comprising sodium hyaluronate, citrate, at least one antioxidant tolerated by the intraocular tissues and a phosphate buffer.

Abstract: Sodium hyaluronate viscous aqueous solutions of molecular weight from 1,200,000 to 2,200,000 Daltons at concentrations from 0.10% to 0.40% by weight are proposed for use as masking fluid in therapeutic photokeratectomy by means of excimer laser (PTK), which realizes the ablation of superficial layers of corneal tissue for the elimination of unevenness and macula derived from different traumatic or pathological conditions. Preferably, the proposed solutions also contain one or more cationic species selected from the group consisting of sodium, potassium, calcium and magnesium ion and one or more anionic species selected from the group consisting of chloride, phosphate and citrate ion and, preferably, glucose. The solutions according to the invention wet the cornea and protect its areas which remain distressed after surgery, enabling the obtainment of uniform and smooth ablated surfaces. Further, they enable the execution of intraoperative corneal topographic tests.