Sodium hyaluronate Hyaluronan

Four intraarticular hyaluronic acid preparations are available for treating pain associated with OA of the knee sodium hyaluronate (Hyalgan 20 mg/2 ml Supartz 25 mg/2.5 mL), hylan polymers (Synvisc 16 mg/2 mL), and hyaluronan (Orthovisc 30 mg/2 mL). Hyalgan and Supartz are administered once weekly for five injections, whereas Synvisc and Orthovisc are administered once weekly for three injections. 

Sodium hyaluronate is the predominant form of hyaluronic acid at physiological pH. The name hyaluronan is used when the polysaccharide is mentioned in general terms, and in the literature the terms hyaluronic acid and sodium hyaluronate are used interchangeably. 

Many drugs that have an anti-inflammatory action may also have other mechanisms of action. Corticosteroids are one of the most commonly administered classes of intraarticular medication in equine medicine. Hyaluronan (sodium hyaluronate, HA) is a natural component of the joint and its intraarticular use has anti-inflammatory actions and may have lubricating effects. Similarly dimethyl sulfoxide is used for both its anti-inflammatory and its antimicrobial actions. 

The term hyaluronan was introduced in 1986 to conform to the international nomenclature of polysaccharides and is attributed to Endre Balazs (Balazs E. A, et al., 1986), who coined it to encompass the different forms of the molecule can take, e.g., the acid form, hyaluronic acid, and the salts, such as sodium hyaluronate, which forms at physiological pH [10], HA was subsequently isolated from many other sources and the physicochemical stracture properties, and biological role of this polysaccharide were studied in numerous laboratories [11]. This work has been summarized in a Ciba Foundation Symposium [12] and a recent review [13]. 

Then a solution of papain (200ml of 0.1% solution of papain per 1kg of material) is added. Enzymatic hydrolysis of proteins is carried out for 20-40h. Every 6-8 h the pH must be adjusted to 6-7 (to optimize enzyme activity). The HA mixture is purified by ultrafiltration and precipitation with 96% ethanol. The final product, sodium hyaluronate, is dried by lyophilization and the precipitate is then dissolved in a water-alcohol mixture containing 40% ethanol. The final purification of hyaluronan is performed by membrane filtration of a solution containing 30-50% ethanol. 

From aU studies of biologically active compounds, hyaluronan reveals the lowest level of antioxidative properties. This correlates with the fact that rate constant of the reaction of OH with sodium hyaluronate is approximately three times lower than values of the rate constants of glutathione, sodium ascorbate and cysteine [18], Based on the data mentioned previously, we try to evaluate the maximum antioxidative effect from the introduction of the studied compounds into derma. 

HA was first isolated from bovine vitreous humor in acid form by Karl Meyer and John Pahner of Columbia University in 1934. They named the new pwlysaccharide hyaluronic acid, meaning uronic acid from hyaloid (vitreous). The term hyaluronan was introduced by Endre Balazs in 1986 to encompass the different forms the molecule can take—for example, the add form, hyaluronic acid, and the salts, such as sodium hyaluronate, which form at physiological pH [17]. Endre Balazs pioneered the medical use of HA. He derived the main concepts for many applications and... 

Human milk octasaccharide, H-126 Humatin, P-13 Humaycin, P-13 Hyalbiuronic acid, H-127 Hyalgan, H-128 Hyalobiuronic acid, H-127 Hyaluronan, H-128 Hyaluronate sodium, H-128... 

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