Evaluation of chondroitin sulfate in Czech Republic dietary supplements

Chondroitin sulfate (CS) is recommended by EULAR as a SYSADOA (Symptomatic Slow Acting Drug for OA) drug in Europe in the treatment of knee, hip and hand osteoarthritis based on meta-analysis of numerous clinical studies. However, clinical studies and CS efficacy have been evaluated by using a very pure product having specific properties and physico-chemical characteristics as approved by the various National Institutes of Health.The amount and quality of CS from several food supplement preparations in tablet or capsule form were determined. In order to quantify CS, two different analytical approaches were applied after their validation: specific and sensitive agarose-gel electrophoresis and SAX-HPLC determination of the constituent disaccharides after treatment with specific chondroitin lyases. The quantitative determinations were performed using a very high pure European Pharmacopeia CS reference standard having substantially the same properties as the food supplement CS samples.The CS content in finished products evaluated using the two above-mentioned specific validated methods were found to conform to the label specifications only in four of the ten analyzed samples. Four of the food supplement preparations were found to contain approx. 0-1% CS in comparison with 47, 17, 12 and 6% declared on the label. Two products were found to have approx. 30-45% of the declared CS, and one preparation was found to contain approx. 2% hyaluronic acid. SAX-HPLC separation of unsaturated disaccharides for the nutraceutical CS was also used to evaluate its quality and the possible origin. The CS contained in eight supplements was evaluated to be of bovine or porcine origin, one from cartilagineous fishes and one not determined owing to the very low CS content.In conclusion, a multi-analytical approach was used in the direct quantitation and evaluation of the quality and the possible origin of CS contained in food supplement formulations. On the basis of these analytical results, the quality of several dietary supplements is poor and strict regulations for quality control should be mandatory in order to guarantee the manufacture of high quality 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 claim of CS in raw materials and nutraceuticals.