Quality of different chondroitin sulfate preparations in relation to their therapeutic activity

Chondroitin sulfate (CS) is currently recommended by EULAR as a SYSADOA (Symptomatic Slow Acting Drug for OA) drug in Europe in the treatment of knee and hand osteoarthritis (OA) based on research evidence and meta-analysis of numerous clinical studies. Furthermore, recent clinical trials demonstrated its possible structure-modifying effects. CS alone or in combination with glucosamine and/or other ingredients, is also utilized as a nutraceutical in dietary supplements in Europe and the United States. However, CS is derived from animal sources by extraction and purification processes. As a consequence, source material, manufacturing processes, the presence of contaminants, and many other factors contribute to the overall biological and pharmacological actions of these agents. Pharmaceutical grade CS formulations are of high and standardized quality, purity and properties, due to the stricter regulations to which this drug is subjected by local National Institutes of Health as regards production and characteristics. On the contrary, as several published studies available in literature indicate, the CS quality of several nutraceuticals is poor. As a consequence, stricter regulations regarding quality control should be introduced to guarantee the manufacture of high quality products for nutraceutical utilization and to protect customers from low-quality, ineffective and potentially dangerous products. Furthermore, specific and accurate analytical procedures should be enforced for the control of high-quality products and applied by quality control laboratories to confirm the purity and label claims of CS in raw materials and nutraceuticals. Additionally, there are no definite regulations governing the origin of the ingredients in these nutraceuticals and the origin of the ingredients in natural products is the most important factor ensuring quality, and thus safety and efficacy, in particular for CS, due to its extraction from different sources.