Sodium hyaluronate is a saccharide biopolymer with a key role in maintaining normal joint function. It also has anti-inflammatory properties.

Hyonate is extracted from the capsule of a selected micro-organism and purified to produce an ultra pure form of sodium hyaluronate which is essentially free of protein or nucleic acids. The solution is pyrogen free and sterile. It contains no preservative.

Hyaluronic acid forms the basis of a wide range of saccharide biopolymers (glycosaminoglycans or mucopolysaccharides) consisting of repeating disaccharide units of N-acetyl-D-glucosamine and D-glucuronic acid linked by beta 1-3 and beta 1-4 glycosidic bonds. It is a component of all mammalian connective tissue and therefore widely distributed in body tissues and intercellular fluids. Sodium hyaluronate is the naturally occurring sodium salt of hyaluronic acid. In the normal joint sodium hyaluronate is synthesised by synoviocytes. The resulting long chains form a three dimensionally cross linked network and are the crucial determinant of the properties of the synovial fluid.

The high affinity of sodium hyaluronate for water, which is enclosed rather than bound within the three dimensional structure, is responsible, in particular, for the known high viscosity of the synovial fluid. Recent studies have shown that sodium hyaluronate exerts its lubricant effect primarily on the membrane separating the synovial fluid from the soft tissue (capsule) of the joint which has more powerful retarding action than the joint surfaces. This is explained by the fact that the viscous sodium hyaluronate molecules pass directly from the intercellular space of the synovial membrane into the synovial fluid, thus forming an elastic, fluid transition from capsule to join cavity.

Sodium hyaluronate therefore has various properties:

* it improves the viscosity of the synovial fluid through its 3-dimensional structure (lubrication)

* it assists the filtering function of the synovial membrane (regulation of composition of synovial fluid)

* it is a constituent of hyaline cartilage

* it plays a role in the supply of nutrients to the cartilage.

Sodium hyaluronate also exerts an anti-inflammatory action.